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Rev | Author | Line No. | Line |
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1892 | serge | 1 | /* |
2 | * Copyright © 2004 Carl Worth |
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3 | * Copyright © 2006 Red Hat, Inc. |
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4 | * Copyright © 2007 David Turner |
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5 | * Copyright © 2008 M Joonas Pihlaja |
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6 | * Copyright © 2008 Chris Wilson |
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7 | * Copyright © 2009 Intel Corporation |
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8 | * |
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9 | * This library is free software; you can redistribute it and/or |
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10 | * modify it either under the terms of the GNU Lesser General Public |
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11 | * License version 2.1 as published by the Free Software Foundation |
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12 | * (the "LGPL") or, at your option, under the terms of the Mozilla |
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13 | * Public License Version 1.1 (the "MPL"). If you do not alter this |
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14 | * notice, a recipient may use your version of this file under either |
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15 | * the MPL or the LGPL. |
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16 | * |
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17 | * You should have received a copy of the LGPL along with this library |
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18 | * in the file COPYING-LGPL-2.1; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA |
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20 | * You should have received a copy of the MPL along with this library |
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21 | * in the file COPYING-MPL-1.1 |
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22 | * |
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23 | * The contents of this file are subject to the Mozilla Public License |
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24 | * Version 1.1 (the "License"); you may not use this file except in |
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25 | * compliance with the License. You may obtain a copy of the License at |
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26 | * http://www.mozilla.org/MPL/ |
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27 | * |
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28 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY |
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29 | * OF ANY KIND, either express or implied. See the LGPL or the MPL for |
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30 | * the specific language governing rights and limitations. |
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31 | * |
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32 | * The Original Code is the cairo graphics library. |
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33 | * |
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34 | * The Initial Developer of the Original Code is Carl Worth |
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35 | * |
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36 | * Contributor(s): |
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37 | * Carl D. Worth |
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38 | * M Joonas Pihlaja |
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39 | * Chris Wilson |
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40 | */ |
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41 | |||
42 | /* Provide definitions for standalone compilation */ |
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43 | #include "cairoint.h" |
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44 | |||
45 | #include "cairo-error-private.h" |
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3959 | Serge | 46 | #include "cairo-list-inline.h" |
1892 | serge | 47 | #include "cairo-freelist-private.h" |
3959 | Serge | 48 | #include "cairo-combsort-inline.h" |
1892 | serge | 49 | |
50 | #include |
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51 | |||
52 | #define STEP_X CAIRO_FIXED_ONE |
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53 | #define STEP_Y CAIRO_FIXED_ONE |
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54 | #define UNROLL3(x) x x x |
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55 | |||
56 | #define STEP_XY (2*STEP_X*STEP_Y) /* Unit area in the step. */ |
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57 | #define AREA_TO_ALPHA(c) (((c)*255 + STEP_XY/2) / STEP_XY) |
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58 | |||
59 | typedef struct _cairo_bo_intersect_ordinate { |
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60 | int32_t ordinate; |
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61 | enum { EXACT, INEXACT } exactness; |
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62 | } cairo_bo_intersect_ordinate_t; |
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63 | |||
64 | typedef struct _cairo_bo_intersect_point { |
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65 | cairo_bo_intersect_ordinate_t x; |
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66 | cairo_bo_intersect_ordinate_t y; |
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67 | } cairo_bo_intersect_point_t; |
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68 | |||
69 | struct quorem { |
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70 | cairo_fixed_t quo; |
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71 | cairo_fixed_t rem; |
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72 | }; |
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73 | |||
74 | struct run { |
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75 | struct run *next; |
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76 | int sign; |
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77 | cairo_fixed_t y; |
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78 | }; |
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79 | |||
80 | typedef struct edge { |
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81 | cairo_list_t link; |
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82 | |||
83 | cairo_edge_t edge; |
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84 | |||
85 | /* Current x coordinate and advancement. |
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86 | * Initialised to the x coordinate of the top of the |
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87 | * edge. The quotient is in cairo_fixed_t units and the |
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88 | * remainder is mod dy in cairo_fixed_t units. |
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89 | */ |
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90 | cairo_fixed_t dy; |
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91 | struct quorem x; |
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92 | struct quorem dxdy; |
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93 | struct quorem dxdy_full; |
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94 | |||
95 | cairo_bool_t vertical; |
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96 | unsigned int flags; |
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97 | |||
98 | int current_sign; |
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99 | struct run *runs; |
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100 | } edge_t; |
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101 | |||
102 | enum { |
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103 | START = 0x1, |
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104 | STOP = 0x2, |
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105 | }; |
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106 | |||
107 | /* the parent is always given by index/2 */ |
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108 | #define PQ_PARENT_INDEX(i) ((i) >> 1) |
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109 | #define PQ_FIRST_ENTRY 1 |
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110 | |||
111 | /* left and right children are index * 2 and (index * 2) +1 respectively */ |
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112 | #define PQ_LEFT_CHILD_INDEX(i) ((i) << 1) |
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113 | |||
114 | typedef enum { |
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115 | EVENT_TYPE_STOP, |
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116 | EVENT_TYPE_INTERSECTION, |
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117 | EVENT_TYPE_START |
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118 | } event_type_t; |
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119 | |||
120 | typedef struct _event { |
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121 | cairo_fixed_t y; |
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122 | event_type_t type; |
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123 | } event_t; |
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124 | |||
125 | typedef struct _start_event { |
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126 | cairo_fixed_t y; |
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127 | event_type_t type; |
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128 | edge_t *edge; |
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129 | } start_event_t; |
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130 | |||
131 | typedef struct _queue_event { |
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132 | cairo_fixed_t y; |
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133 | event_type_t type; |
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134 | edge_t *e1; |
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135 | edge_t *e2; |
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136 | } queue_event_t; |
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137 | |||
138 | typedef struct _pqueue { |
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139 | int size, max_size; |
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140 | |||
141 | event_t **elements; |
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142 | event_t *elements_embedded[1024]; |
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143 | } pqueue_t; |
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144 | |||
145 | struct cell { |
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146 | struct cell *prev; |
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147 | struct cell *next; |
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148 | int x; |
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149 | int uncovered_area; |
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150 | int covered_height; |
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151 | }; |
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152 | |||
153 | typedef struct _sweep_line { |
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154 | cairo_list_t active; |
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155 | cairo_list_t stopped; |
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156 | cairo_list_t *insert_cursor; |
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157 | cairo_bool_t is_vertical; |
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158 | |||
159 | cairo_fixed_t current_row; |
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160 | cairo_fixed_t current_subrow; |
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161 | |||
162 | struct coverage { |
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163 | struct cell head; |
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164 | struct cell tail; |
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165 | |||
166 | struct cell *cursor; |
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167 | int count; |
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168 | |||
169 | cairo_freepool_t pool; |
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170 | } coverage; |
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171 | |||
172 | struct event_queue { |
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173 | pqueue_t pq; |
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174 | event_t **start_events; |
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175 | |||
176 | cairo_freepool_t pool; |
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177 | } queue; |
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178 | |||
179 | cairo_freepool_t runs; |
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180 | |||
181 | jmp_buf unwind; |
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182 | } sweep_line_t; |
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183 | |||
184 | cairo_always_inline static struct quorem |
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185 | floored_divrem (int a, int b) |
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186 | { |
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187 | struct quorem qr; |
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188 | qr.quo = a/b; |
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189 | qr.rem = a%b; |
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190 | if ((a^b)<0 && qr.rem) { |
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191 | qr.quo--; |
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192 | qr.rem += b; |
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193 | } |
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194 | return qr; |
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195 | } |
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196 | |||
197 | static struct quorem |
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198 | floored_muldivrem(int x, int a, int b) |
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199 | { |
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200 | struct quorem qr; |
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201 | long long xa = (long long)x*a; |
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202 | qr.quo = xa/b; |
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203 | qr.rem = xa%b; |
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204 | if ((xa>=0) != (b>=0) && qr.rem) { |
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205 | qr.quo--; |
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206 | qr.rem += b; |
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207 | } |
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208 | return qr; |
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209 | } |
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210 | |||
211 | static cairo_fixed_t |
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212 | line_compute_intersection_x_for_y (const cairo_line_t *line, |
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213 | cairo_fixed_t y) |
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214 | { |
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215 | cairo_fixed_t x, dy; |
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216 | |||
217 | if (y == line->p1.y) |
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218 | return line->p1.x; |
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219 | if (y == line->p2.y) |
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220 | return line->p2.x; |
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221 | |||
222 | x = line->p1.x; |
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223 | dy = line->p2.y - line->p1.y; |
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224 | if (dy != 0) { |
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225 | x += _cairo_fixed_mul_div_floor (y - line->p1.y, |
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226 | line->p2.x - line->p1.x, |
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227 | dy); |
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228 | } |
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229 | |||
230 | return x; |
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231 | } |
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232 | |||
233 | /* |
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234 | * We need to compare the x-coordinates of a pair of lines for a particular y, |
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235 | * without loss of precision. |
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236 | * |
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237 | * The x-coordinate along an edge for a given y is: |
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238 | * X = A_x + (Y - A_y) * A_dx / A_dy |
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239 | * |
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240 | * So the inequality we wish to test is: |
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241 | * A_x + (Y - A_y) * A_dx / A_dy ∘ B_x + (Y - B_y) * B_dx / B_dy, |
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242 | * where ∘ is our inequality operator. |
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243 | * |
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244 | * By construction, we know that A_dy and B_dy (and (Y - A_y), (Y - B_y)) are |
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245 | * all positive, so we can rearrange it thus without causing a sign change: |
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246 | * A_dy * B_dy * (A_x - B_x) ∘ (Y - B_y) * B_dx * A_dy |
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247 | * - (Y - A_y) * A_dx * B_dy |
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248 | * |
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249 | * Given the assumption that all the deltas fit within 32 bits, we can compute |
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250 | * this comparison directly using 128 bit arithmetic. For certain, but common, |
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251 | * input we can reduce this down to a single 32 bit compare by inspecting the |
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252 | * deltas. |
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253 | * |
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254 | * (And put the burden of the work on developing fast 128 bit ops, which are |
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255 | * required throughout the tessellator.) |
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256 | * |
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257 | * See the similar discussion for _slope_compare(). |
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258 | */ |
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259 | static int |
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260 | edges_compare_x_for_y_general (const cairo_edge_t *a, |
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261 | const cairo_edge_t *b, |
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262 | int32_t y) |
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263 | { |
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264 | /* XXX: We're assuming here that dx and dy will still fit in 32 |
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265 | * bits. That's not true in general as there could be overflow. We |
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266 | * should prevent that before the tessellation algorithm |
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267 | * begins. |
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268 | */ |
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269 | int32_t dx; |
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270 | int32_t adx, ady; |
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271 | int32_t bdx, bdy; |
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272 | enum { |
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273 | HAVE_NONE = 0x0, |
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274 | HAVE_DX = 0x1, |
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275 | HAVE_ADX = 0x2, |
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276 | HAVE_DX_ADX = HAVE_DX | HAVE_ADX, |
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277 | HAVE_BDX = 0x4, |
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278 | HAVE_DX_BDX = HAVE_DX | HAVE_BDX, |
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279 | HAVE_ADX_BDX = HAVE_ADX | HAVE_BDX, |
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280 | HAVE_ALL = HAVE_DX | HAVE_ADX | HAVE_BDX |
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281 | } have_dx_adx_bdx = HAVE_ALL; |
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282 | |||
283 | /* don't bother solving for abscissa if the edges' bounding boxes |
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284 | * can be used to order them. */ |
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285 | { |
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286 | int32_t amin, amax; |
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287 | int32_t bmin, bmax; |
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288 | if (a->line.p1.x < a->line.p2.x) { |
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289 | amin = a->line.p1.x; |
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290 | amax = a->line.p2.x; |
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291 | } else { |
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292 | amin = a->line.p2.x; |
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293 | amax = a->line.p1.x; |
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294 | } |
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295 | if (b->line.p1.x < b->line.p2.x) { |
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296 | bmin = b->line.p1.x; |
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297 | bmax = b->line.p2.x; |
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298 | } else { |
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299 | bmin = b->line.p2.x; |
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300 | bmax = b->line.p1.x; |
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301 | } |
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302 | if (amax < bmin) return -1; |
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303 | if (amin > bmax) return +1; |
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304 | } |
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305 | |||
306 | ady = a->line.p2.y - a->line.p1.y; |
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307 | adx = a->line.p2.x - a->line.p1.x; |
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308 | if (adx == 0) |
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309 | have_dx_adx_bdx &= ~HAVE_ADX; |
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310 | |||
311 | bdy = b->line.p2.y - b->line.p1.y; |
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312 | bdx = b->line.p2.x - b->line.p1.x; |
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313 | if (bdx == 0) |
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314 | have_dx_adx_bdx &= ~HAVE_BDX; |
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315 | |||
316 | dx = a->line.p1.x - b->line.p1.x; |
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317 | if (dx == 0) |
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318 | have_dx_adx_bdx &= ~HAVE_DX; |
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319 | |||
320 | #define L _cairo_int64x32_128_mul (_cairo_int32x32_64_mul (ady, bdy), dx) |
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321 | #define A _cairo_int64x32_128_mul (_cairo_int32x32_64_mul (adx, bdy), y - a->line.p1.y) |
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322 | #define B _cairo_int64x32_128_mul (_cairo_int32x32_64_mul (bdx, ady), y - b->line.p1.y) |
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323 | switch (have_dx_adx_bdx) { |
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324 | default: |
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325 | case HAVE_NONE: |
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326 | return 0; |
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327 | case HAVE_DX: |
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328 | /* A_dy * B_dy * (A_x - B_x) ∘ 0 */ |
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329 | return dx; /* ady * bdy is positive definite */ |
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330 | case HAVE_ADX: |
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331 | /* 0 ∘ - (Y - A_y) * A_dx * B_dy */ |
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332 | return adx; /* bdy * (y - a->top.y) is positive definite */ |
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333 | case HAVE_BDX: |
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334 | /* 0 ∘ (Y - B_y) * B_dx * A_dy */ |
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335 | return -bdx; /* ady * (y - b->top.y) is positive definite */ |
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336 | case HAVE_ADX_BDX: |
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337 | /* 0 ∘ (Y - B_y) * B_dx * A_dy - (Y - A_y) * A_dx * B_dy */ |
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338 | if ((adx ^ bdx) < 0) { |
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339 | return adx; |
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340 | } else if (a->line.p1.y == b->line.p1.y) { /* common origin */ |
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341 | cairo_int64_t adx_bdy, bdx_ady; |
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342 | |||
343 | /* ∴ A_dx * B_dy ∘ B_dx * A_dy */ |
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344 | |||
345 | adx_bdy = _cairo_int32x32_64_mul (adx, bdy); |
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346 | bdx_ady = _cairo_int32x32_64_mul (bdx, ady); |
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347 | |||
348 | return _cairo_int64_cmp (adx_bdy, bdx_ady); |
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349 | } else |
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350 | return _cairo_int128_cmp (A, B); |
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351 | case HAVE_DX_ADX: |
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352 | /* A_dy * (A_x - B_x) ∘ - (Y - A_y) * A_dx */ |
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353 | if ((-adx ^ dx) < 0) { |
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354 | return dx; |
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355 | } else { |
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356 | cairo_int64_t ady_dx, dy_adx; |
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357 | |||
358 | ady_dx = _cairo_int32x32_64_mul (ady, dx); |
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359 | dy_adx = _cairo_int32x32_64_mul (a->line.p1.y - y, adx); |
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360 | |||
361 | return _cairo_int64_cmp (ady_dx, dy_adx); |
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362 | } |
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363 | case HAVE_DX_BDX: |
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364 | /* B_dy * (A_x - B_x) ∘ (Y - B_y) * B_dx */ |
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365 | if ((bdx ^ dx) < 0) { |
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366 | return dx; |
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367 | } else { |
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368 | cairo_int64_t bdy_dx, dy_bdx; |
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369 | |||
370 | bdy_dx = _cairo_int32x32_64_mul (bdy, dx); |
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371 | dy_bdx = _cairo_int32x32_64_mul (y - b->line.p1.y, bdx); |
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372 | |||
373 | return _cairo_int64_cmp (bdy_dx, dy_bdx); |
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374 | } |
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375 | case HAVE_ALL: |
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376 | /* XXX try comparing (a->line.p2.x - b->line.p2.x) et al */ |
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377 | return _cairo_int128_cmp (L, _cairo_int128_sub (B, A)); |
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378 | } |
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379 | #undef B |
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380 | #undef A |
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381 | #undef L |
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382 | } |
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383 | |||
384 | /* |
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385 | * We need to compare the x-coordinate of a line for a particular y wrt to a |
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386 | * given x, without loss of precision. |
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387 | * |
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388 | * The x-coordinate along an edge for a given y is: |
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389 | * X = A_x + (Y - A_y) * A_dx / A_dy |
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390 | * |
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391 | * So the inequality we wish to test is: |
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392 | * A_x + (Y - A_y) * A_dx / A_dy ∘ X |
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393 | * where ∘ is our inequality operator. |
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394 | * |
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395 | * By construction, we know that A_dy (and (Y - A_y)) are |
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396 | * all positive, so we can rearrange it thus without causing a sign change: |
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397 | * (Y - A_y) * A_dx ∘ (X - A_x) * A_dy |
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398 | * |
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399 | * Given the assumption that all the deltas fit within 32 bits, we can compute |
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400 | * this comparison directly using 64 bit arithmetic. |
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401 | * |
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402 | * See the similar discussion for _slope_compare() and |
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403 | * edges_compare_x_for_y_general(). |
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404 | */ |
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405 | static int |
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406 | edge_compare_for_y_against_x (const cairo_edge_t *a, |
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407 | int32_t y, |
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408 | int32_t x) |
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409 | { |
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410 | int32_t adx, ady; |
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411 | int32_t dx, dy; |
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412 | cairo_int64_t L, R; |
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413 | |||
414 | if (a->line.p1.x <= a->line.p2.x) { |
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415 | if (x < a->line.p1.x) |
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416 | return 1; |
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417 | if (x > a->line.p2.x) |
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418 | return -1; |
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419 | } else { |
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420 | if (x < a->line.p2.x) |
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421 | return 1; |
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422 | if (x > a->line.p1.x) |
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423 | return -1; |
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424 | } |
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425 | |||
426 | adx = a->line.p2.x - a->line.p1.x; |
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427 | dx = x - a->line.p1.x; |
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428 | |||
429 | if (adx == 0) |
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430 | return -dx; |
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431 | if (dx == 0 || (adx ^ dx) < 0) |
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432 | return adx; |
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433 | |||
434 | dy = y - a->line.p1.y; |
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435 | ady = a->line.p2.y - a->line.p1.y; |
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436 | |||
437 | L = _cairo_int32x32_64_mul (dy, adx); |
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438 | R = _cairo_int32x32_64_mul (dx, ady); |
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439 | |||
440 | return _cairo_int64_cmp (L, R); |
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441 | } |
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442 | |||
443 | static int |
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444 | edges_compare_x_for_y (const cairo_edge_t *a, |
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445 | const cairo_edge_t *b, |
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446 | int32_t y) |
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447 | { |
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448 | /* If the sweep-line is currently on an end-point of a line, |
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449 | * then we know its precise x value (and considering that we often need to |
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450 | * compare events at end-points, this happens frequently enough to warrant |
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451 | * special casing). |
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452 | */ |
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453 | enum { |
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454 | HAVE_NEITHER = 0x0, |
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455 | HAVE_AX = 0x1, |
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456 | HAVE_BX = 0x2, |
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457 | HAVE_BOTH = HAVE_AX | HAVE_BX |
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458 | } have_ax_bx = HAVE_BOTH; |
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459 | int32_t ax, bx; |
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460 | |||
461 | /* XXX given we have x and dx? */ |
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462 | |||
463 | if (y == a->line.p1.y) |
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464 | ax = a->line.p1.x; |
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465 | else if (y == a->line.p2.y) |
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466 | ax = a->line.p2.x; |
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467 | else |
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468 | have_ax_bx &= ~HAVE_AX; |
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469 | |||
470 | if (y == b->line.p1.y) |
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471 | bx = b->line.p1.x; |
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472 | else if (y == b->line.p2.y) |
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473 | bx = b->line.p2.x; |
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474 | else |
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475 | have_ax_bx &= ~HAVE_BX; |
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476 | |||
477 | switch (have_ax_bx) { |
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478 | default: |
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479 | case HAVE_NEITHER: |
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480 | return edges_compare_x_for_y_general (a, b, y); |
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481 | case HAVE_AX: |
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482 | return -edge_compare_for_y_against_x (b, y, ax); |
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483 | case HAVE_BX: |
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484 | return edge_compare_for_y_against_x (a, y, bx); |
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485 | case HAVE_BOTH: |
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486 | return ax - bx; |
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487 | } |
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488 | } |
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489 | |||
490 | static inline int |
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491 | slope_compare (const edge_t *a, |
||
492 | const edge_t *b) |
||
493 | { |
||
494 | cairo_int64_t L, R; |
||
495 | int cmp; |
||
496 | |||
497 | cmp = a->dxdy.quo - b->dxdy.quo; |
||
498 | if (cmp) |
||
499 | return cmp; |
||
500 | |||
501 | if (a->dxdy.rem == 0) |
||
502 | return -b->dxdy.rem; |
||
503 | if (b->dxdy.rem == 0) |
||
504 | return a->dxdy.rem; |
||
505 | |||
506 | L = _cairo_int32x32_64_mul (b->dy, a->dxdy.rem); |
||
507 | R = _cairo_int32x32_64_mul (a->dy, b->dxdy.rem); |
||
508 | return _cairo_int64_cmp (L, R); |
||
509 | } |
||
510 | |||
511 | static inline int |
||
512 | line_equal (const cairo_line_t *a, const cairo_line_t *b) |
||
513 | { |
||
514 | return a->p1.x == b->p1.x && a->p1.y == b->p1.y && |
||
515 | a->p2.x == b->p2.x && a->p2.y == b->p2.y; |
||
516 | } |
||
517 | |||
518 | static inline int |
||
519 | sweep_line_compare_edges (const edge_t *a, |
||
520 | const edge_t *b, |
||
521 | cairo_fixed_t y) |
||
522 | { |
||
523 | int cmp; |
||
524 | |||
525 | if (line_equal (&a->edge.line, &b->edge.line)) |
||
526 | return 0; |
||
527 | |||
528 | cmp = edges_compare_x_for_y (&a->edge, &b->edge, y); |
||
529 | if (cmp) |
||
530 | return cmp; |
||
531 | |||
532 | return slope_compare (a, b); |
||
533 | } |
||
534 | |||
535 | static inline cairo_int64_t |
||
536 | det32_64 (int32_t a, int32_t b, |
||
537 | int32_t c, int32_t d) |
||
538 | { |
||
539 | /* det = a * d - b * c */ |
||
540 | return _cairo_int64_sub (_cairo_int32x32_64_mul (a, d), |
||
541 | _cairo_int32x32_64_mul (b, c)); |
||
542 | } |
||
543 | |||
544 | static inline cairo_int128_t |
||
545 | det64x32_128 (cairo_int64_t a, int32_t b, |
||
546 | cairo_int64_t c, int32_t d) |
||
547 | { |
||
548 | /* det = a * d - b * c */ |
||
549 | return _cairo_int128_sub (_cairo_int64x32_128_mul (a, d), |
||
550 | _cairo_int64x32_128_mul (c, b)); |
||
551 | } |
||
552 | |||
553 | /* Compute the intersection of two lines as defined by two edges. The |
||
554 | * result is provided as a coordinate pair of 128-bit integers. |
||
555 | * |
||
556 | * Returns %CAIRO_BO_STATUS_INTERSECTION if there is an intersection or |
||
557 | * %CAIRO_BO_STATUS_PARALLEL if the two lines are exactly parallel. |
||
558 | */ |
||
559 | static cairo_bool_t |
||
560 | intersect_lines (const edge_t *a, const edge_t *b, |
||
561 | cairo_bo_intersect_point_t *intersection) |
||
562 | { |
||
563 | cairo_int64_t a_det, b_det; |
||
564 | |||
565 | /* XXX: We're assuming here that dx and dy will still fit in 32 |
||
566 | * bits. That's not true in general as there could be overflow. We |
||
567 | * should prevent that before the tessellation algorithm begins. |
||
568 | * What we're doing to mitigate this is to perform clamping in |
||
569 | * cairo_bo_tessellate_polygon(). |
||
570 | */ |
||
571 | int32_t dx1 = a->edge.line.p1.x - a->edge.line.p2.x; |
||
572 | int32_t dy1 = a->edge.line.p1.y - a->edge.line.p2.y; |
||
573 | |||
574 | int32_t dx2 = b->edge.line.p1.x - b->edge.line.p2.x; |
||
575 | int32_t dy2 = b->edge.line.p1.y - b->edge.line.p2.y; |
||
576 | |||
577 | cairo_int64_t den_det; |
||
578 | cairo_int64_t R; |
||
579 | cairo_quorem64_t qr; |
||
580 | |||
581 | den_det = det32_64 (dx1, dy1, dx2, dy2); |
||
582 | |||
583 | /* Q: Can we determine that the lines do not intersect (within range) |
||
584 | * much more cheaply than computing the intersection point i.e. by |
||
585 | * avoiding the division? |
||
586 | * |
||
587 | * X = ax + t * adx = bx + s * bdx; |
||
588 | * Y = ay + t * ady = by + s * bdy; |
||
589 | * ∴ t * (ady*bdx - bdy*adx) = bdx * (by - ay) + bdy * (ax - bx) |
||
590 | * => t * L = R |
||
591 | * |
||
592 | * Therefore we can reject any intersection (under the criteria for |
||
593 | * valid intersection events) if: |
||
594 | * L^R < 0 => t < 0, or |
||
595 | * L |
||
596 | * |
||
597 | * (where top/bottom must at least extend to the line endpoints). |
||
598 | * |
||
599 | * A similar substitution can be performed for s, yielding: |
||
600 | * s * (ady*bdx - bdy*adx) = ady * (ax - bx) - adx * (ay - by) |
||
601 | */ |
||
602 | R = det32_64 (dx2, dy2, |
||
603 | b->edge.line.p1.x - a->edge.line.p1.x, |
||
604 | b->edge.line.p1.y - a->edge.line.p1.y); |
||
605 | if (_cairo_int64_negative (den_det)) { |
||
606 | if (_cairo_int64_ge (den_det, R)) |
||
607 | return FALSE; |
||
608 | } else { |
||
609 | if (_cairo_int64_le (den_det, R)) |
||
610 | return FALSE; |
||
611 | } |
||
612 | |||
613 | R = det32_64 (dy1, dx1, |
||
614 | a->edge.line.p1.y - b->edge.line.p1.y, |
||
615 | a->edge.line.p1.x - b->edge.line.p1.x); |
||
616 | if (_cairo_int64_negative (den_det)) { |
||
617 | if (_cairo_int64_ge (den_det, R)) |
||
618 | return FALSE; |
||
619 | } else { |
||
620 | if (_cairo_int64_le (den_det, R)) |
||
621 | return FALSE; |
||
622 | } |
||
623 | |||
624 | /* We now know that the two lines should intersect within range. */ |
||
625 | |||
626 | a_det = det32_64 (a->edge.line.p1.x, a->edge.line.p1.y, |
||
627 | a->edge.line.p2.x, a->edge.line.p2.y); |
||
628 | b_det = det32_64 (b->edge.line.p1.x, b->edge.line.p1.y, |
||
629 | b->edge.line.p2.x, b->edge.line.p2.y); |
||
630 | |||
631 | /* x = det (a_det, dx1, b_det, dx2) / den_det */ |
||
632 | qr = _cairo_int_96by64_32x64_divrem (det64x32_128 (a_det, dx1, |
||
633 | b_det, dx2), |
||
634 | den_det); |
||
635 | if (_cairo_int64_eq (qr.rem, den_det)) |
||
636 | return FALSE; |
||
637 | #if 0 |
||
638 | intersection->x.exactness = _cairo_int64_is_zero (qr.rem) ? EXACT : INEXACT; |
||
639 | #else |
||
640 | intersection->x.exactness = EXACT; |
||
641 | if (! _cairo_int64_is_zero (qr.rem)) { |
||
642 | if (_cairo_int64_negative (den_det) ^ _cairo_int64_negative (qr.rem)) |
||
643 | qr.rem = _cairo_int64_negate (qr.rem); |
||
644 | qr.rem = _cairo_int64_mul (qr.rem, _cairo_int32_to_int64 (2)); |
||
645 | if (_cairo_int64_ge (qr.rem, den_det)) { |
||
646 | qr.quo = _cairo_int64_add (qr.quo, |
||
647 | _cairo_int32_to_int64 (_cairo_int64_negative (qr.quo) ? -1 : 1)); |
||
648 | } else |
||
649 | intersection->x.exactness = INEXACT; |
||
650 | } |
||
651 | #endif |
||
652 | intersection->x.ordinate = _cairo_int64_to_int32 (qr.quo); |
||
653 | |||
654 | /* y = det (a_det, dy1, b_det, dy2) / den_det */ |
||
655 | qr = _cairo_int_96by64_32x64_divrem (det64x32_128 (a_det, dy1, |
||
656 | b_det, dy2), |
||
657 | den_det); |
||
658 | if (_cairo_int64_eq (qr.rem, den_det)) |
||
659 | return FALSE; |
||
660 | #if 0 |
||
661 | intersection->y.exactness = _cairo_int64_is_zero (qr.rem) ? EXACT : INEXACT; |
||
662 | #else |
||
663 | intersection->y.exactness = EXACT; |
||
664 | if (! _cairo_int64_is_zero (qr.rem)) { |
||
665 | /* compute ceiling away from zero */ |
||
666 | qr.quo = _cairo_int64_add (qr.quo, |
||
667 | _cairo_int32_to_int64 (_cairo_int64_negative (qr.quo) ? -1 : 1)); |
||
668 | intersection->y.exactness = INEXACT; |
||
669 | } |
||
670 | #endif |
||
671 | intersection->y.ordinate = _cairo_int64_to_int32 (qr.quo); |
||
672 | |||
673 | return TRUE; |
||
674 | } |
||
675 | |||
676 | static int |
||
677 | bo_intersect_ordinate_32_compare (int32_t a, int32_t b, int exactness) |
||
678 | { |
||
679 | int cmp; |
||
680 | |||
681 | /* First compare the quotient */ |
||
682 | cmp = a - b; |
||
683 | if (cmp) |
||
684 | return cmp; |
||
685 | |||
686 | /* With quotient identical, if remainder is 0 then compare equal */ |
||
687 | /* Otherwise, the non-zero remainder makes a > b */ |
||
688 | return -(INEXACT == exactness); |
||
689 | } |
||
690 | |||
691 | /* Does the given edge contain the given point. The point must already |
||
692 | * be known to be contained within the line determined by the edge, |
||
693 | * (most likely the point results from an intersection of this edge |
||
694 | * with another). |
||
695 | * |
||
696 | * If we had exact arithmetic, then this function would simply be a |
||
697 | * matter of examining whether the y value of the point lies within |
||
698 | * the range of y values of the edge. But since intersection points |
||
699 | * are not exact due to being rounded to the nearest integer within |
||
700 | * the available precision, we must also examine the x value of the |
||
701 | * point. |
||
702 | * |
||
703 | * The definition of "contains" here is that the given intersection |
||
704 | * point will be seen by the sweep line after the start event for the |
||
705 | * given edge and before the stop event for the edge. See the comments |
||
706 | * in the implementation for more details. |
||
707 | */ |
||
708 | static cairo_bool_t |
||
709 | bo_edge_contains_intersect_point (const edge_t *edge, |
||
710 | cairo_bo_intersect_point_t *point) |
||
711 | { |
||
712 | int cmp_top, cmp_bottom; |
||
713 | |||
714 | /* XXX: When running the actual algorithm, we don't actually need to |
||
715 | * compare against edge->top at all here, since any intersection above |
||
716 | * top is eliminated early via a slope comparison. We're leaving these |
||
717 | * here for now only for the sake of the quadratic-time intersection |
||
718 | * finder which needs them. |
||
719 | */ |
||
720 | |||
721 | cmp_top = bo_intersect_ordinate_32_compare (point->y.ordinate, |
||
722 | edge->edge.top, |
||
723 | point->y.exactness); |
||
724 | if (cmp_top < 0) |
||
725 | return FALSE; |
||
726 | |||
727 | cmp_bottom = bo_intersect_ordinate_32_compare (point->y.ordinate, |
||
728 | edge->edge.bottom, |
||
729 | point->y.exactness); |
||
730 | if (cmp_bottom > 0) |
||
731 | return FALSE; |
||
732 | |||
733 | if (cmp_top > 0 && cmp_bottom < 0) |
||
734 | return TRUE; |
||
735 | |||
736 | /* At this stage, the point lies on the same y value as either |
||
737 | * edge->top or edge->bottom, so we have to examine the x value in |
||
738 | * order to properly determine containment. */ |
||
739 | |||
740 | /* If the y value of the point is the same as the y value of the |
||
741 | * top of the edge, then the x value of the point must be greater |
||
742 | * to be considered as inside the edge. Similarly, if the y value |
||
743 | * of the point is the same as the y value of the bottom of the |
||
744 | * edge, then the x value of the point must be less to be |
||
745 | * considered as inside. */ |
||
746 | |||
747 | if (cmp_top == 0) { |
||
748 | cairo_fixed_t top_x; |
||
749 | |||
750 | top_x = line_compute_intersection_x_for_y (&edge->edge.line, |
||
751 | edge->edge.top); |
||
752 | return bo_intersect_ordinate_32_compare (top_x, point->x.ordinate, point->x.exactness) < 0; |
||
753 | } else { /* cmp_bottom == 0 */ |
||
754 | cairo_fixed_t bot_x; |
||
755 | |||
756 | bot_x = line_compute_intersection_x_for_y (&edge->edge.line, |
||
757 | edge->edge.bottom); |
||
758 | return bo_intersect_ordinate_32_compare (point->x.ordinate, bot_x, point->x.exactness) < 0; |
||
759 | } |
||
760 | } |
||
761 | |||
762 | static cairo_bool_t |
||
763 | edge_intersect (const edge_t *a, |
||
764 | const edge_t *b, |
||
765 | cairo_point_t *intersection) |
||
766 | { |
||
767 | cairo_bo_intersect_point_t quorem; |
||
768 | |||
769 | if (! intersect_lines (a, b, &quorem)) |
||
770 | return FALSE; |
||
771 | |||
772 | if (a->edge.top != a->edge.line.p1.y || a->edge.bottom != a->edge.line.p2.y) { |
||
773 | if (! bo_edge_contains_intersect_point (a, &quorem)) |
||
774 | return FALSE; |
||
775 | } |
||
776 | |||
777 | if (b->edge.top != b->edge.line.p1.y || b->edge.bottom != b->edge.line.p2.y) { |
||
778 | if (! bo_edge_contains_intersect_point (b, &quorem)) |
||
779 | return FALSE; |
||
780 | } |
||
781 | |||
782 | /* Now that we've correctly compared the intersection point and |
||
783 | * determined that it lies within the edge, then we know that we |
||
784 | * no longer need any more bits of storage for the intersection |
||
785 | * than we do for our edge coordinates. We also no longer need the |
||
786 | * remainder from the division. */ |
||
787 | intersection->x = quorem.x.ordinate; |
||
788 | intersection->y = quorem.y.ordinate; |
||
789 | |||
790 | return TRUE; |
||
791 | } |
||
792 | |||
793 | static inline int |
||
794 | event_compare (const event_t *a, const event_t *b) |
||
795 | { |
||
796 | return a->y - b->y; |
||
797 | } |
||
798 | |||
799 | static void |
||
800 | pqueue_init (pqueue_t *pq) |
||
801 | { |
||
802 | pq->max_size = ARRAY_LENGTH (pq->elements_embedded); |
||
803 | pq->size = 0; |
||
804 | |||
805 | pq->elements = pq->elements_embedded; |
||
806 | } |
||
807 | |||
808 | static void |
||
809 | pqueue_fini (pqueue_t *pq) |
||
810 | { |
||
811 | if (pq->elements != pq->elements_embedded) |
||
812 | free (pq->elements); |
||
813 | } |
||
814 | |||
815 | static cairo_bool_t |
||
816 | pqueue_grow (pqueue_t *pq) |
||
817 | { |
||
818 | event_t **new_elements; |
||
819 | pq->max_size *= 2; |
||
820 | |||
821 | if (pq->elements == pq->elements_embedded) { |
||
822 | new_elements = _cairo_malloc_ab (pq->max_size, |
||
823 | sizeof (event_t *)); |
||
824 | if (unlikely (new_elements == NULL)) |
||
825 | return FALSE; |
||
826 | |||
827 | memcpy (new_elements, pq->elements_embedded, |
||
828 | sizeof (pq->elements_embedded)); |
||
829 | } else { |
||
830 | new_elements = _cairo_realloc_ab (pq->elements, |
||
831 | pq->max_size, |
||
832 | sizeof (event_t *)); |
||
833 | if (unlikely (new_elements == NULL)) |
||
834 | return FALSE; |
||
835 | } |
||
836 | |||
837 | pq->elements = new_elements; |
||
838 | return TRUE; |
||
839 | } |
||
840 | |||
841 | static inline void |
||
842 | pqueue_push (sweep_line_t *sweep_line, event_t *event) |
||
843 | { |
||
844 | event_t **elements; |
||
845 | int i, parent; |
||
846 | |||
847 | if (unlikely (sweep_line->queue.pq.size + 1 == sweep_line->queue.pq.max_size)) { |
||
848 | if (unlikely (! pqueue_grow (&sweep_line->queue.pq))) { |
||
849 | longjmp (sweep_line->unwind, |
||
850 | _cairo_error (CAIRO_STATUS_NO_MEMORY)); |
||
851 | } |
||
852 | } |
||
853 | |||
854 | elements = sweep_line->queue.pq.elements; |
||
855 | for (i = ++sweep_line->queue.pq.size; |
||
856 | i != PQ_FIRST_ENTRY && |
||
857 | event_compare (event, |
||
858 | elements[parent = PQ_PARENT_INDEX (i)]) < 0; |
||
859 | i = parent) |
||
860 | { |
||
861 | elements[i] = elements[parent]; |
||
862 | } |
||
863 | |||
864 | elements[i] = event; |
||
865 | } |
||
866 | |||
867 | static inline void |
||
868 | pqueue_pop (pqueue_t *pq) |
||
869 | { |
||
870 | event_t **elements = pq->elements; |
||
871 | event_t *tail; |
||
872 | int child, i; |
||
873 | |||
874 | tail = elements[pq->size--]; |
||
875 | if (pq->size == 0) { |
||
876 | elements[PQ_FIRST_ENTRY] = NULL; |
||
877 | return; |
||
878 | } |
||
879 | |||
880 | for (i = PQ_FIRST_ENTRY; |
||
881 | (child = PQ_LEFT_CHILD_INDEX (i)) <= pq->size; |
||
882 | i = child) |
||
883 | { |
||
884 | if (child != pq->size && |
||
885 | event_compare (elements[child+1], |
||
886 | elements[child]) < 0) |
||
887 | { |
||
888 | child++; |
||
889 | } |
||
890 | |||
891 | if (event_compare (elements[child], tail) >= 0) |
||
892 | break; |
||
893 | |||
894 | elements[i] = elements[child]; |
||
895 | } |
||
896 | elements[i] = tail; |
||
897 | } |
||
898 | |||
899 | static inline void |
||
900 | event_insert (sweep_line_t *sweep_line, |
||
901 | event_type_t type, |
||
902 | edge_t *e1, |
||
903 | edge_t *e2, |
||
904 | cairo_fixed_t y) |
||
905 | { |
||
906 | queue_event_t *event; |
||
907 | |||
908 | event = _cairo_freepool_alloc (&sweep_line->queue.pool); |
||
909 | if (unlikely (event == NULL)) { |
||
910 | longjmp (sweep_line->unwind, |
||
911 | _cairo_error (CAIRO_STATUS_NO_MEMORY)); |
||
912 | } |
||
913 | |||
914 | event->y = y; |
||
915 | event->type = type; |
||
916 | event->e1 = e1; |
||
917 | event->e2 = e2; |
||
918 | |||
919 | pqueue_push (sweep_line, (event_t *) event); |
||
920 | } |
||
921 | |||
922 | static void |
||
923 | event_delete (sweep_line_t *sweep_line, |
||
924 | event_t *event) |
||
925 | { |
||
926 | _cairo_freepool_free (&sweep_line->queue.pool, event); |
||
927 | } |
||
928 | |||
929 | static inline event_t * |
||
930 | event_next (sweep_line_t *sweep_line) |
||
931 | { |
||
932 | event_t *event, *cmp; |
||
933 | |||
934 | event = sweep_line->queue.pq.elements[PQ_FIRST_ENTRY]; |
||
935 | cmp = *sweep_line->queue.start_events; |
||
936 | if (event == NULL || |
||
937 | (cmp != NULL && event_compare (cmp, event) < 0)) |
||
938 | { |
||
939 | event = cmp; |
||
940 | sweep_line->queue.start_events++; |
||
941 | } |
||
942 | else |
||
943 | { |
||
944 | pqueue_pop (&sweep_line->queue.pq); |
||
945 | } |
||
946 | |||
947 | return event; |
||
948 | } |
||
949 | |||
950 | CAIRO_COMBSORT_DECLARE (start_event_sort, event_t *, event_compare) |
||
951 | |||
952 | static inline void |
||
953 | event_insert_stop (sweep_line_t *sweep_line, |
||
954 | edge_t *edge) |
||
955 | { |
||
956 | event_insert (sweep_line, |
||
957 | EVENT_TYPE_STOP, |
||
958 | edge, NULL, |
||
959 | edge->edge.bottom); |
||
960 | } |
||
961 | |||
962 | static inline void |
||
963 | event_insert_if_intersect_below_current_y (sweep_line_t *sweep_line, |
||
964 | edge_t *left, |
||
965 | edge_t *right) |
||
966 | { |
||
967 | cairo_point_t intersection; |
||
968 | |||
969 | /* start points intersect */ |
||
970 | if (left->edge.line.p1.x == right->edge.line.p1.x && |
||
971 | left->edge.line.p1.y == right->edge.line.p1.y) |
||
972 | { |
||
973 | return; |
||
974 | } |
||
975 | |||
976 | /* end points intersect, process DELETE events first */ |
||
977 | if (left->edge.line.p2.x == right->edge.line.p2.x && |
||
978 | left->edge.line.p2.y == right->edge.line.p2.y) |
||
979 | { |
||
980 | return; |
||
981 | } |
||
982 | |||
983 | if (slope_compare (left, right) <= 0) |
||
984 | return; |
||
985 | |||
986 | if (! edge_intersect (left, right, &intersection)) |
||
987 | return; |
||
988 | |||
989 | event_insert (sweep_line, |
||
990 | EVENT_TYPE_INTERSECTION, |
||
991 | left, right, |
||
992 | intersection.y); |
||
993 | } |
||
994 | |||
995 | static inline edge_t * |
||
996 | link_to_edge (cairo_list_t *link) |
||
997 | { |
||
998 | return (edge_t *) link; |
||
999 | } |
||
1000 | |||
1001 | static void |
||
1002 | sweep_line_insert (sweep_line_t *sweep_line, |
||
1003 | edge_t *edge) |
||
1004 | { |
||
1005 | cairo_list_t *pos; |
||
1006 | cairo_fixed_t y = sweep_line->current_subrow; |
||
1007 | |||
1008 | pos = sweep_line->insert_cursor; |
||
1009 | if (pos == &sweep_line->active) |
||
1010 | pos = sweep_line->active.next; |
||
1011 | if (pos != &sweep_line->active) { |
||
1012 | int cmp; |
||
1013 | |||
1014 | cmp = sweep_line_compare_edges (link_to_edge (pos), |
||
1015 | edge, |
||
1016 | y); |
||
1017 | if (cmp < 0) { |
||
1018 | while (pos->next != &sweep_line->active && |
||
1019 | sweep_line_compare_edges (link_to_edge (pos->next), |
||
1020 | edge, |
||
1021 | y) < 0) |
||
1022 | { |
||
1023 | pos = pos->next; |
||
1024 | } |
||
1025 | } else if (cmp > 0) { |
||
1026 | do { |
||
1027 | pos = pos->prev; |
||
1028 | } while (pos != &sweep_line->active && |
||
1029 | sweep_line_compare_edges (link_to_edge (pos), |
||
1030 | edge, |
||
1031 | y) > 0); |
||
1032 | } |
||
1033 | } |
||
1034 | cairo_list_add (&edge->link, pos); |
||
1035 | sweep_line->insert_cursor = &edge->link; |
||
1036 | } |
||
1037 | |||
1038 | inline static void |
||
1039 | coverage_rewind (struct coverage *cells) |
||
1040 | { |
||
1041 | cells->cursor = &cells->head; |
||
1042 | } |
||
1043 | |||
1044 | static void |
||
1045 | coverage_init (struct coverage *cells) |
||
1046 | { |
||
1047 | _cairo_freepool_init (&cells->pool, |
||
1048 | sizeof (struct cell)); |
||
1049 | cells->head.prev = NULL; |
||
1050 | cells->head.next = &cells->tail; |
||
1051 | cells->head.x = INT_MIN; |
||
1052 | cells->tail.prev = &cells->head; |
||
1053 | cells->tail.next = NULL; |
||
1054 | cells->tail.x = INT_MAX; |
||
1055 | cells->count = 0; |
||
1056 | coverage_rewind (cells); |
||
1057 | } |
||
1058 | |||
1059 | static void |
||
1060 | coverage_fini (struct coverage *cells) |
||
1061 | { |
||
1062 | _cairo_freepool_fini (&cells->pool); |
||
1063 | } |
||
1064 | |||
1065 | inline static void |
||
1066 | coverage_reset (struct coverage *cells) |
||
1067 | { |
||
1068 | cells->head.next = &cells->tail; |
||
1069 | cells->tail.prev = &cells->head; |
||
1070 | cells->count = 0; |
||
1071 | _cairo_freepool_reset (&cells->pool); |
||
1072 | coverage_rewind (cells); |
||
1073 | } |
||
1074 | |||
3959 | Serge | 1075 | static struct cell * |
1892 | serge | 1076 | coverage_alloc (sweep_line_t *sweep_line, |
1077 | struct cell *tail, |
||
1078 | int x) |
||
1079 | { |
||
1080 | struct cell *cell; |
||
1081 | |||
1082 | cell = _cairo_freepool_alloc (&sweep_line->coverage.pool); |
||
1083 | if (unlikely (NULL == cell)) { |
||
1084 | longjmp (sweep_line->unwind, |
||
1085 | _cairo_error (CAIRO_STATUS_NO_MEMORY)); |
||
1086 | } |
||
1087 | |||
1088 | tail->prev->next = cell; |
||
1089 | cell->prev = tail->prev; |
||
1090 | cell->next = tail; |
||
1091 | tail->prev = cell; |
||
1092 | cell->x = x; |
||
1093 | cell->uncovered_area = 0; |
||
1094 | cell->covered_height = 0; |
||
1095 | sweep_line->coverage.count++; |
||
1096 | return cell; |
||
1097 | } |
||
1098 | |||
1099 | inline static struct cell * |
||
1100 | coverage_find (sweep_line_t *sweep_line, int x) |
||
1101 | { |
||
1102 | struct cell *cell; |
||
1103 | |||
1104 | cell = sweep_line->coverage.cursor; |
||
1105 | if (unlikely (cell->x > x)) { |
||
1106 | do { |
||
1107 | if (cell->prev->x < x) |
||
1108 | break; |
||
1109 | cell = cell->prev; |
||
1110 | } while (TRUE); |
||
1111 | } else { |
||
1112 | if (cell->x == x) |
||
1113 | return cell; |
||
1114 | |||
1115 | do { |
||
1116 | UNROLL3({ |
||
1117 | cell = cell->next; |
||
1118 | if (cell->x >= x) |
||
1119 | break; |
||
1120 | }); |
||
1121 | } while (TRUE); |
||
1122 | } |
||
1123 | |||
1124 | if (cell->x != x) |
||
1125 | cell = coverage_alloc (sweep_line, cell, x); |
||
1126 | |||
1127 | return sweep_line->coverage.cursor = cell; |
||
1128 | } |
||
1129 | |||
1130 | static void |
||
1131 | coverage_render_cells (sweep_line_t *sweep_line, |
||
1132 | cairo_fixed_t left, cairo_fixed_t right, |
||
1133 | cairo_fixed_t y1, cairo_fixed_t y2, |
||
1134 | int sign) |
||
1135 | { |
||
1136 | int fx1, fx2; |
||
1137 | int ix1, ix2; |
||
1138 | int dx, dy; |
||
1139 | |||
1140 | /* Orient the edge left-to-right. */ |
||
1141 | dx = right - left; |
||
1142 | if (dx >= 0) { |
||
1143 | ix1 = _cairo_fixed_integer_part (left); |
||
1144 | fx1 = _cairo_fixed_fractional_part (left); |
||
1145 | |||
1146 | ix2 = _cairo_fixed_integer_part (right); |
||
1147 | fx2 = _cairo_fixed_fractional_part (right); |
||
1148 | |||
1149 | dy = y2 - y1; |
||
1150 | } else { |
||
1151 | ix1 = _cairo_fixed_integer_part (right); |
||
1152 | fx1 = _cairo_fixed_fractional_part (right); |
||
1153 | |||
1154 | ix2 = _cairo_fixed_integer_part (left); |
||
1155 | fx2 = _cairo_fixed_fractional_part (left); |
||
1156 | |||
1157 | dx = -dx; |
||
1158 | sign = -sign; |
||
1159 | dy = y1 - y2; |
||
1160 | y1 = y2 - dy; |
||
1161 | y2 = y1 + dy; |
||
1162 | } |
||
1163 | |||
1164 | /* Add coverage for all pixels [ix1,ix2] on this row crossed |
||
1165 | * by the edge. */ |
||
1166 | { |
||
1167 | struct quorem y = floored_divrem ((STEP_X - fx1)*dy, dx); |
||
1168 | struct cell *cell; |
||
1169 | |||
1170 | cell = sweep_line->coverage.cursor; |
||
1171 | if (cell->x != ix1) { |
||
1172 | if (unlikely (cell->x > ix1)) { |
||
1173 | do { |
||
1174 | if (cell->prev->x < ix1) |
||
1175 | break; |
||
1176 | cell = cell->prev; |
||
1177 | } while (TRUE); |
||
1178 | } else do { |
||
1179 | UNROLL3({ |
||
1180 | if (cell->x >= ix1) |
||
1181 | break; |
||
1182 | cell = cell->next; |
||
1183 | }); |
||
1184 | } while (TRUE); |
||
1185 | |||
1186 | if (cell->x != ix1) |
||
1187 | cell = coverage_alloc (sweep_line, cell, ix1); |
||
1188 | } |
||
1189 | |||
1190 | cell->uncovered_area += sign * y.quo * (STEP_X + fx1); |
||
1191 | cell->covered_height += sign * y.quo; |
||
1192 | y.quo += y1; |
||
1193 | |||
1194 | cell = cell->next; |
||
1195 | if (cell->x != ++ix1) |
||
1196 | cell = coverage_alloc (sweep_line, cell, ix1); |
||
1197 | if (ix1 < ix2) { |
||
1198 | struct quorem dydx_full = floored_divrem (STEP_X*dy, dx); |
||
1199 | |||
1200 | do { |
||
1201 | cairo_fixed_t y_skip = dydx_full.quo; |
||
1202 | y.rem += dydx_full.rem; |
||
1203 | if (y.rem >= dx) { |
||
1204 | ++y_skip; |
||
1205 | y.rem -= dx; |
||
1206 | } |
||
1207 | |||
1208 | y.quo += y_skip; |
||
1209 | |||
1210 | y_skip *= sign; |
||
1211 | cell->covered_height += y_skip; |
||
1212 | cell->uncovered_area += y_skip*STEP_X; |
||
1213 | |||
1214 | cell = cell->next; |
||
1215 | if (cell->x != ++ix1) |
||
1216 | cell = coverage_alloc (sweep_line, cell, ix1); |
||
1217 | } while (ix1 != ix2); |
||
1218 | } |
||
1219 | cell->uncovered_area += sign*(y2 - y.quo)*fx2; |
||
1220 | cell->covered_height += sign*(y2 - y.quo); |
||
1221 | sweep_line->coverage.cursor = cell; |
||
1222 | } |
||
1223 | } |
||
1224 | |||
1225 | inline static void |
||
1226 | full_inc_edge (edge_t *edge) |
||
1227 | { |
||
1228 | edge->x.quo += edge->dxdy_full.quo; |
||
1229 | edge->x.rem += edge->dxdy_full.rem; |
||
1230 | if (edge->x.rem >= 0) { |
||
1231 | ++edge->x.quo; |
||
1232 | edge->x.rem -= edge->dy; |
||
1233 | } |
||
1234 | } |
||
1235 | |||
1236 | static void |
||
1237 | full_add_edge (sweep_line_t *sweep_line, edge_t *edge, int sign) |
||
1238 | { |
||
1239 | struct cell *cell; |
||
1240 | cairo_fixed_t x1, x2; |
||
1241 | int ix1, ix2; |
||
1242 | int frac; |
||
1243 | |||
1244 | edge->current_sign = sign; |
||
1245 | |||
1246 | ix1 = _cairo_fixed_integer_part (edge->x.quo); |
||
1247 | |||
1248 | if (edge->vertical) { |
||
1249 | frac = _cairo_fixed_fractional_part (edge->x.quo); |
||
1250 | cell = coverage_find (sweep_line, ix1); |
||
1251 | cell->covered_height += sign * STEP_Y; |
||
1252 | cell->uncovered_area += sign * 2 * frac * STEP_Y; |
||
1253 | return; |
||
1254 | } |
||
1255 | |||
1256 | x1 = edge->x.quo; |
||
1257 | full_inc_edge (edge); |
||
1258 | x2 = edge->x.quo; |
||
1259 | |||
1260 | ix2 = _cairo_fixed_integer_part (edge->x.quo); |
||
1261 | |||
1262 | /* Edge is entirely within a column? */ |
||
1263 | if (likely (ix1 == ix2)) { |
||
1264 | frac = _cairo_fixed_fractional_part (x1) + |
||
1265 | _cairo_fixed_fractional_part (x2); |
||
1266 | cell = coverage_find (sweep_line, ix1); |
||
1267 | cell->covered_height += sign * STEP_Y; |
||
1268 | cell->uncovered_area += sign * frac * STEP_Y; |
||
1269 | return; |
||
1270 | } |
||
1271 | |||
1272 | coverage_render_cells (sweep_line, x1, x2, 0, STEP_Y, sign); |
||
1273 | } |
||
1274 | |||
1275 | static void |
||
1276 | full_nonzero (sweep_line_t *sweep_line) |
||
1277 | { |
||
1278 | cairo_list_t *pos; |
||
1279 | |||
1280 | sweep_line->is_vertical = TRUE; |
||
1281 | pos = sweep_line->active.next; |
||
1282 | do { |
||
1283 | edge_t *left = link_to_edge (pos), *right; |
||
1284 | int winding = left->edge.dir; |
||
1285 | |||
1286 | sweep_line->is_vertical &= left->vertical; |
||
1287 | |||
1288 | pos = left->link.next; |
||
1289 | do { |
||
1290 | if (unlikely (pos == &sweep_line->active)) { |
||
1291 | full_add_edge (sweep_line, left, +1); |
||
1292 | return; |
||
1293 | } |
||
1294 | |||
1295 | right = link_to_edge (pos); |
||
1296 | pos = pos->next; |
||
1297 | sweep_line->is_vertical &= right->vertical; |
||
1298 | |||
1299 | winding += right->edge.dir; |
||
1300 | if (0 == winding) { |
||
1301 | if (pos == &sweep_line->active || |
||
1302 | link_to_edge (pos)->x.quo != right->x.quo) |
||
1303 | { |
||
1304 | break; |
||
1305 | } |
||
1306 | } |
||
1307 | |||
1308 | if (! right->vertical) |
||
1309 | full_inc_edge (right); |
||
1310 | } while (TRUE); |
||
1311 | |||
1312 | full_add_edge (sweep_line, left, +1); |
||
1313 | full_add_edge (sweep_line, right, -1); |
||
1314 | } while (pos != &sweep_line->active); |
||
1315 | } |
||
1316 | |||
1317 | static void |
||
1318 | full_evenodd (sweep_line_t *sweep_line) |
||
1319 | { |
||
1320 | cairo_list_t *pos; |
||
1321 | |||
1322 | sweep_line->is_vertical = TRUE; |
||
1323 | pos = sweep_line->active.next; |
||
1324 | do { |
||
1325 | edge_t *left = link_to_edge (pos), *right; |
||
1326 | int winding = 0; |
||
1327 | |||
1328 | sweep_line->is_vertical &= left->vertical; |
||
1329 | |||
1330 | pos = left->link.next; |
||
1331 | do { |
||
1332 | if (pos == &sweep_line->active) { |
||
1333 | full_add_edge (sweep_line, left, +1); |
||
1334 | return; |
||
1335 | } |
||
1336 | |||
1337 | right = link_to_edge (pos); |
||
1338 | pos = pos->next; |
||
1339 | sweep_line->is_vertical &= right->vertical; |
||
1340 | |||
1341 | if (++winding & 1) { |
||
1342 | if (pos == &sweep_line->active || |
||
1343 | link_to_edge (pos)->x.quo != right->x.quo) |
||
1344 | { |
||
1345 | break; |
||
1346 | } |
||
1347 | } |
||
1348 | |||
1349 | if (! right->vertical) |
||
1350 | full_inc_edge (right); |
||
1351 | } while (TRUE); |
||
1352 | |||
1353 | full_add_edge (sweep_line, left, +1); |
||
1354 | full_add_edge (sweep_line, right, -1); |
||
1355 | } while (pos != &sweep_line->active); |
||
1356 | } |
||
1357 | |||
1358 | static void |
||
1359 | render_rows (cairo_botor_scan_converter_t *self, |
||
1360 | sweep_line_t *sweep_line, |
||
1361 | int y, int height, |
||
1362 | cairo_span_renderer_t *renderer) |
||
1363 | { |
||
1364 | cairo_half_open_span_t spans_stack[CAIRO_STACK_ARRAY_LENGTH (cairo_half_open_span_t)]; |
||
1365 | cairo_half_open_span_t *spans = spans_stack; |
||
1366 | struct cell *cell; |
||
1367 | int prev_x, cover; |
||
1368 | int num_spans; |
||
1369 | cairo_status_t status; |
||
1370 | |||
1371 | if (unlikely (sweep_line->coverage.count == 0)) { |
||
1372 | status = renderer->render_rows (renderer, y, height, NULL, 0); |
||
1373 | if (unlikely (status)) |
||
1374 | longjmp (sweep_line->unwind, status); |
||
1375 | return; |
||
1376 | } |
||
1377 | |||
1378 | /* Allocate enough spans for the row. */ |
||
1379 | |||
1380 | num_spans = 2*sweep_line->coverage.count+2; |
||
1381 | if (unlikely (num_spans > ARRAY_LENGTH (spans_stack))) { |
||
1382 | spans = _cairo_malloc_ab (num_spans, sizeof (cairo_half_open_span_t)); |
||
1383 | if (unlikely (spans == NULL)) { |
||
1384 | longjmp (sweep_line->unwind, |
||
1385 | _cairo_error (CAIRO_STATUS_NO_MEMORY)); |
||
1386 | } |
||
1387 | } |
||
1388 | |||
1389 | /* Form the spans from the coverage and areas. */ |
||
1390 | num_spans = 0; |
||
1391 | prev_x = self->xmin; |
||
1392 | cover = 0; |
||
1393 | cell = sweep_line->coverage.head.next; |
||
1394 | do { |
||
1395 | int x = cell->x; |
||
1396 | int area; |
||
1397 | |||
1398 | if (x > prev_x) { |
||
1399 | spans[num_spans].x = prev_x; |
||
3959 | Serge | 1400 | spans[num_spans].inverse = 0; |
1892 | serge | 1401 | spans[num_spans].coverage = AREA_TO_ALPHA (cover); |
1402 | ++num_spans; |
||
1403 | } |
||
1404 | |||
1405 | cover += cell->covered_height*STEP_X*2; |
||
1406 | area = cover - cell->uncovered_area; |
||
1407 | |||
1408 | spans[num_spans].x = x; |
||
1409 | spans[num_spans].coverage = AREA_TO_ALPHA (area); |
||
1410 | ++num_spans; |
||
1411 | |||
1412 | prev_x = x + 1; |
||
1413 | } while ((cell = cell->next) != &sweep_line->coverage.tail); |
||
1414 | |||
1415 | if (prev_x <= self->xmax) { |
||
1416 | spans[num_spans].x = prev_x; |
||
3959 | Serge | 1417 | spans[num_spans].inverse = 0; |
1892 | serge | 1418 | spans[num_spans].coverage = AREA_TO_ALPHA (cover); |
1419 | ++num_spans; |
||
1420 | } |
||
1421 | |||
1422 | if (cover && prev_x < self->xmax) { |
||
1423 | spans[num_spans].x = self->xmax; |
||
3959 | Serge | 1424 | spans[num_spans].inverse = 1; |
1892 | serge | 1425 | spans[num_spans].coverage = 0; |
1426 | ++num_spans; |
||
1427 | } |
||
1428 | |||
1429 | status = renderer->render_rows (renderer, y, height, spans, num_spans); |
||
1430 | |||
1431 | if (unlikely (spans != spans_stack)) |
||
1432 | free (spans); |
||
1433 | |||
1434 | coverage_reset (&sweep_line->coverage); |
||
1435 | |||
1436 | if (unlikely (status)) |
||
1437 | longjmp (sweep_line->unwind, status); |
||
1438 | } |
||
1439 | |||
1440 | static void |
||
1441 | full_repeat (sweep_line_t *sweep) |
||
1442 | { |
||
1443 | edge_t *edge; |
||
1444 | |||
1445 | cairo_list_foreach_entry (edge, edge_t, &sweep->active, link) { |
||
1446 | if (edge->current_sign) |
||
1447 | full_add_edge (sweep, edge, edge->current_sign); |
||
1448 | else if (! edge->vertical) |
||
1449 | full_inc_edge (edge); |
||
1450 | } |
||
1451 | } |
||
1452 | |||
1453 | static void |
||
1454 | full_reset (sweep_line_t *sweep) |
||
1455 | { |
||
1456 | edge_t *edge; |
||
1457 | |||
1458 | cairo_list_foreach_entry (edge, edge_t, &sweep->active, link) |
||
1459 | edge->current_sign = 0; |
||
1460 | } |
||
1461 | |||
1462 | static void |
||
1463 | full_step (cairo_botor_scan_converter_t *self, |
||
1464 | sweep_line_t *sweep_line, |
||
1465 | cairo_fixed_t row, |
||
1466 | cairo_span_renderer_t *renderer) |
||
1467 | { |
||
1468 | int top, bottom; |
||
1469 | |||
1470 | top = _cairo_fixed_integer_part (sweep_line->current_row); |
||
1471 | bottom = _cairo_fixed_integer_part (row); |
||
1472 | if (cairo_list_is_empty (&sweep_line->active)) { |
||
1473 | cairo_status_t status; |
||
1474 | |||
1475 | status = renderer->render_rows (renderer, top, bottom - top, NULL, 0); |
||
1476 | if (unlikely (status)) |
||
1477 | longjmp (sweep_line->unwind, status); |
||
1478 | |||
1479 | return; |
||
1480 | } |
||
1481 | |||
1482 | if (self->fill_rule == CAIRO_FILL_RULE_WINDING) |
||
1483 | full_nonzero (sweep_line); |
||
1484 | else |
||
1485 | full_evenodd (sweep_line); |
||
1486 | |||
1487 | if (sweep_line->is_vertical || bottom == top + 1) { |
||
1488 | render_rows (self, sweep_line, top, bottom - top, renderer); |
||
1489 | full_reset (sweep_line); |
||
1490 | return; |
||
1491 | } |
||
1492 | |||
1493 | render_rows (self, sweep_line, top++, 1, renderer); |
||
1494 | do { |
||
1495 | full_repeat (sweep_line); |
||
1496 | render_rows (self, sweep_line, top, 1, renderer); |
||
1497 | } while (++top != bottom); |
||
1498 | |||
1499 | full_reset (sweep_line); |
||
1500 | } |
||
1501 | |||
1502 | cairo_always_inline static void |
||
1503 | sub_inc_edge (edge_t *edge, |
||
1504 | cairo_fixed_t height) |
||
1505 | { |
||
1506 | if (height == 1) { |
||
1507 | edge->x.quo += edge->dxdy.quo; |
||
1508 | edge->x.rem += edge->dxdy.rem; |
||
1509 | if (edge->x.rem >= 0) { |
||
1510 | ++edge->x.quo; |
||
1511 | edge->x.rem -= edge->dy; |
||
1512 | } |
||
1513 | } else { |
||
1514 | edge->x.quo += height * edge->dxdy.quo; |
||
1515 | edge->x.rem += height * edge->dxdy.rem; |
||
1516 | if (edge->x.rem >= 0) { |
||
1517 | int carry = edge->x.rem / edge->dy + 1; |
||
1518 | edge->x.quo += carry; |
||
1519 | edge->x.rem -= carry * edge->dy; |
||
1520 | } |
||
1521 | } |
||
1522 | } |
||
1523 | |||
1524 | static void |
||
1525 | sub_add_run (sweep_line_t *sweep_line, edge_t *edge, int y, int sign) |
||
1526 | { |
||
1527 | struct run *run; |
||
1528 | |||
1529 | run = _cairo_freepool_alloc (&sweep_line->runs); |
||
1530 | if (unlikely (run == NULL)) |
||
1531 | longjmp (sweep_line->unwind, _cairo_error (CAIRO_STATUS_NO_MEMORY)); |
||
1532 | |||
1533 | run->y = y; |
||
1534 | run->sign = sign; |
||
1535 | run->next = edge->runs; |
||
1536 | edge->runs = run; |
||
1537 | |||
1538 | edge->current_sign = sign; |
||
1539 | } |
||
1540 | |||
1541 | inline static cairo_bool_t |
||
1542 | edges_coincident (edge_t *left, edge_t *right, cairo_fixed_t y) |
||
1543 | { |
||
1544 | /* XXX is compare_x_for_y() worth executing during sub steps? */ |
||
1545 | return line_equal (&left->edge.line, &right->edge.line); |
||
1546 | //edges_compare_x_for_y (&left->edge, &right->edge, y) >= 0; |
||
1547 | } |
||
1548 | |||
1549 | static void |
||
1550 | sub_nonzero (sweep_line_t *sweep_line) |
||
1551 | { |
||
1552 | cairo_fixed_t y = sweep_line->current_subrow; |
||
1553 | cairo_fixed_t fy = _cairo_fixed_fractional_part (y); |
||
1554 | cairo_list_t *pos; |
||
1555 | |||
1556 | pos = sweep_line->active.next; |
||
1557 | do { |
||
1558 | edge_t *left = link_to_edge (pos), *right; |
||
1559 | int winding = left->edge.dir; |
||
1560 | |||
1561 | pos = left->link.next; |
||
1562 | do { |
||
1563 | if (unlikely (pos == &sweep_line->active)) { |
||
1564 | if (left->current_sign != +1) |
||
1565 | sub_add_run (sweep_line, left, fy, +1); |
||
1566 | return; |
||
1567 | } |
||
1568 | |||
1569 | right = link_to_edge (pos); |
||
1570 | pos = pos->next; |
||
1571 | |||
1572 | winding += right->edge.dir; |
||
1573 | if (0 == winding) { |
||
1574 | if (pos == &sweep_line->active || |
||
1575 | ! edges_coincident (right, link_to_edge (pos), y)) |
||
1576 | { |
||
1577 | break; |
||
1578 | } |
||
1579 | } |
||
1580 | |||
1581 | if (right->current_sign) |
||
1582 | sub_add_run (sweep_line, right, fy, 0); |
||
1583 | } while (TRUE); |
||
1584 | |||
1585 | if (left->current_sign != +1) |
||
1586 | sub_add_run (sweep_line, left, fy, +1); |
||
1587 | if (right->current_sign != -1) |
||
1588 | sub_add_run (sweep_line, right, fy, -1); |
||
1589 | } while (pos != &sweep_line->active); |
||
1590 | } |
||
1591 | |||
1592 | static void |
||
1593 | sub_evenodd (sweep_line_t *sweep_line) |
||
1594 | { |
||
1595 | cairo_fixed_t y = sweep_line->current_subrow; |
||
1596 | cairo_fixed_t fy = _cairo_fixed_fractional_part (y); |
||
1597 | cairo_list_t *pos; |
||
1598 | |||
1599 | pos = sweep_line->active.next; |
||
1600 | do { |
||
1601 | edge_t *left = link_to_edge (pos), *right; |
||
1602 | int winding = 0; |
||
1603 | |||
1604 | pos = left->link.next; |
||
1605 | do { |
||
1606 | if (unlikely (pos == &sweep_line->active)) { |
||
1607 | if (left->current_sign != +1) |
||
1608 | sub_add_run (sweep_line, left, fy, +1); |
||
1609 | return; |
||
1610 | } |
||
1611 | |||
1612 | right = link_to_edge (pos); |
||
1613 | pos = pos->next; |
||
1614 | |||
1615 | if (++winding & 1) { |
||
1616 | if (pos == &sweep_line->active || |
||
1617 | ! edges_coincident (right, link_to_edge (pos), y)) |
||
1618 | { |
||
1619 | break; |
||
1620 | } |
||
1621 | } |
||
1622 | |||
1623 | if (right->current_sign) |
||
1624 | sub_add_run (sweep_line, right, fy, 0); |
||
1625 | } while (TRUE); |
||
1626 | |||
1627 | if (left->current_sign != +1) |
||
1628 | sub_add_run (sweep_line, left, fy, +1); |
||
1629 | if (right->current_sign != -1) |
||
1630 | sub_add_run (sweep_line, right, fy, -1); |
||
1631 | } while (pos != &sweep_line->active); |
||
1632 | } |
||
1633 | |||
1634 | cairo_always_inline static void |
||
1635 | sub_step (cairo_botor_scan_converter_t *self, |
||
1636 | sweep_line_t *sweep_line) |
||
1637 | { |
||
1638 | if (cairo_list_is_empty (&sweep_line->active)) |
||
1639 | return; |
||
1640 | |||
1641 | if (self->fill_rule == CAIRO_FILL_RULE_WINDING) |
||
1642 | sub_nonzero (sweep_line); |
||
1643 | else |
||
1644 | sub_evenodd (sweep_line); |
||
1645 | } |
||
1646 | |||
1647 | static void |
||
1648 | coverage_render_runs (sweep_line_t *sweep, edge_t *edge, |
||
1649 | cairo_fixed_t y1, cairo_fixed_t y2) |
||
1650 | { |
||
1651 | struct run tail; |
||
1652 | struct run *run = &tail; |
||
1653 | |||
1654 | tail.next = NULL; |
||
1655 | tail.y = y2; |
||
1656 | |||
1657 | /* Order the runs top->bottom */ |
||
1658 | while (edge->runs) { |
||
1659 | struct run *r; |
||
1660 | |||
1661 | r = edge->runs; |
||
1662 | edge->runs = r->next; |
||
1663 | r->next = run; |
||
1664 | run = r; |
||
1665 | } |
||
1666 | |||
1667 | if (run->y > y1) |
||
1668 | sub_inc_edge (edge, run->y - y1); |
||
1669 | |||
1670 | do { |
||
1671 | cairo_fixed_t x1, x2; |
||
1672 | |||
1673 | y1 = run->y; |
||
1674 | y2 = run->next->y; |
||
1675 | |||
1676 | x1 = edge->x.quo; |
||
1677 | if (y2 - y1 == STEP_Y) |
||
1678 | full_inc_edge (edge); |
||
1679 | else |
||
1680 | sub_inc_edge (edge, y2 - y1); |
||
1681 | x2 = edge->x.quo; |
||
1682 | |||
1683 | if (run->sign) { |
||
1684 | int ix1, ix2; |
||
1685 | |||
1686 | ix1 = _cairo_fixed_integer_part (x1); |
||
1687 | ix2 = _cairo_fixed_integer_part (x2); |
||
1688 | |||
1689 | /* Edge is entirely within a column? */ |
||
1690 | if (likely (ix1 == ix2)) { |
||
1691 | struct cell *cell; |
||
1692 | int frac; |
||
1693 | |||
1694 | frac = _cairo_fixed_fractional_part (x1) + |
||
1695 | _cairo_fixed_fractional_part (x2); |
||
1696 | cell = coverage_find (sweep, ix1); |
||
1697 | cell->covered_height += run->sign * (y2 - y1); |
||
1698 | cell->uncovered_area += run->sign * (y2 - y1) * frac; |
||
1699 | } else { |
||
1700 | coverage_render_cells (sweep, x1, x2, y1, y2, run->sign); |
||
1701 | } |
||
1702 | } |
||
1703 | |||
1704 | run = run->next; |
||
1705 | } while (run->next != NULL); |
||
1706 | } |
||
1707 | |||
1708 | static void |
||
1709 | coverage_render_vertical_runs (sweep_line_t *sweep, edge_t *edge, cairo_fixed_t y2) |
||
1710 | { |
||
1711 | struct cell *cell; |
||
1712 | struct run *run; |
||
1713 | int height = 0; |
||
1714 | |||
1715 | for (run = edge->runs; run != NULL; run = run->next) { |
||
1716 | if (run->sign) |
||
1717 | height += run->sign * (y2 - run->y); |
||
1718 | y2 = run->y; |
||
1719 | } |
||
1720 | |||
1721 | cell = coverage_find (sweep, _cairo_fixed_integer_part (edge->x.quo)); |
||
1722 | cell->covered_height += height; |
||
1723 | cell->uncovered_area += 2 * _cairo_fixed_fractional_part (edge->x.quo) * height; |
||
1724 | } |
||
1725 | |||
1726 | cairo_always_inline static void |
||
1727 | sub_emit (cairo_botor_scan_converter_t *self, |
||
1728 | sweep_line_t *sweep, |
||
1729 | cairo_span_renderer_t *renderer) |
||
1730 | { |
||
1731 | edge_t *edge; |
||
1732 | |||
1733 | sub_step (self, sweep); |
||
1734 | |||
1735 | /* convert the runs into coverages */ |
||
1736 | |||
1737 | cairo_list_foreach_entry (edge, edge_t, &sweep->active, link) { |
||
1738 | if (edge->runs == NULL) { |
||
1739 | if (! edge->vertical) { |
||
1740 | if (edge->flags & START) { |
||
1741 | sub_inc_edge (edge, |
||
1742 | STEP_Y - _cairo_fixed_fractional_part (edge->edge.top)); |
||
1743 | edge->flags &= ~START; |
||
1744 | } else |
||
1745 | full_inc_edge (edge); |
||
1746 | } |
||
1747 | } else { |
||
1748 | if (edge->vertical) { |
||
1749 | coverage_render_vertical_runs (sweep, edge, STEP_Y); |
||
1750 | } else { |
||
1751 | int y1 = 0; |
||
1752 | if (edge->flags & START) { |
||
1753 | y1 = _cairo_fixed_fractional_part (edge->edge.top); |
||
1754 | edge->flags &= ~START; |
||
1755 | } |
||
1756 | coverage_render_runs (sweep, edge, y1, STEP_Y); |
||
1757 | } |
||
1758 | } |
||
1759 | edge->current_sign = 0; |
||
1760 | edge->runs = NULL; |
||
1761 | } |
||
1762 | |||
1763 | cairo_list_foreach_entry (edge, edge_t, &sweep->stopped, link) { |
||
1764 | int y2 = _cairo_fixed_fractional_part (edge->edge.bottom); |
||
1765 | if (edge->vertical) { |
||
1766 | coverage_render_vertical_runs (sweep, edge, y2); |
||
1767 | } else { |
||
1768 | int y1 = 0; |
||
1769 | if (edge->flags & START) |
||
1770 | y1 = _cairo_fixed_fractional_part (edge->edge.top); |
||
1771 | coverage_render_runs (sweep, edge, y1, y2); |
||
1772 | } |
||
1773 | } |
||
1774 | cairo_list_init (&sweep->stopped); |
||
1775 | |||
1776 | _cairo_freepool_reset (&sweep->runs); |
||
1777 | |||
1778 | render_rows (self, sweep, |
||
1779 | _cairo_fixed_integer_part (sweep->current_row), 1, |
||
1780 | renderer); |
||
1781 | } |
||
1782 | |||
1783 | static void |
||
1784 | sweep_line_init (sweep_line_t *sweep_line, |
||
1785 | event_t **start_events, |
||
1786 | int num_events) |
||
1787 | { |
||
1788 | cairo_list_init (&sweep_line->active); |
||
1789 | cairo_list_init (&sweep_line->stopped); |
||
1790 | sweep_line->insert_cursor = &sweep_line->active; |
||
1791 | |||
1792 | sweep_line->current_row = INT32_MIN; |
||
1793 | sweep_line->current_subrow = INT32_MIN; |
||
1794 | |||
1795 | coverage_init (&sweep_line->coverage); |
||
1796 | _cairo_freepool_init (&sweep_line->runs, sizeof (struct run)); |
||
1797 | |||
1798 | start_event_sort (start_events, num_events); |
||
1799 | start_events[num_events] = NULL; |
||
1800 | |||
1801 | sweep_line->queue.start_events = start_events; |
||
1802 | |||
1803 | _cairo_freepool_init (&sweep_line->queue.pool, |
||
1804 | sizeof (queue_event_t)); |
||
1805 | pqueue_init (&sweep_line->queue.pq); |
||
1806 | sweep_line->queue.pq.elements[PQ_FIRST_ENTRY] = NULL; |
||
1807 | } |
||
1808 | |||
1809 | static void |
||
1810 | sweep_line_delete (sweep_line_t *sweep_line, |
||
1811 | edge_t *edge) |
||
1812 | { |
||
1813 | if (sweep_line->insert_cursor == &edge->link) |
||
1814 | sweep_line->insert_cursor = edge->link.prev; |
||
1815 | |||
1816 | cairo_list_del (&edge->link); |
||
1817 | if (edge->runs) |
||
1818 | cairo_list_add_tail (&edge->link, &sweep_line->stopped); |
||
1819 | edge->flags |= STOP; |
||
1820 | } |
||
1821 | |||
1822 | static void |
||
1823 | sweep_line_swap (sweep_line_t *sweep_line, |
||
1824 | edge_t *left, |
||
1825 | edge_t *right) |
||
1826 | { |
||
1827 | right->link.prev = left->link.prev; |
||
1828 | left->link.next = right->link.next; |
||
1829 | right->link.next = &left->link; |
||
1830 | left->link.prev = &right->link; |
||
1831 | left->link.next->prev = &left->link; |
||
1832 | right->link.prev->next = &right->link; |
||
1833 | } |
||
1834 | |||
1835 | static void |
||
1836 | sweep_line_fini (sweep_line_t *sweep_line) |
||
1837 | { |
||
1838 | pqueue_fini (&sweep_line->queue.pq); |
||
1839 | _cairo_freepool_fini (&sweep_line->queue.pool); |
||
1840 | coverage_fini (&sweep_line->coverage); |
||
1841 | _cairo_freepool_fini (&sweep_line->runs); |
||
1842 | } |
||
1843 | |||
1844 | static cairo_status_t |
||
1845 | botor_generate (cairo_botor_scan_converter_t *self, |
||
1846 | event_t **start_events, |
||
1847 | cairo_span_renderer_t *renderer) |
||
1848 | { |
||
1849 | cairo_status_t status; |
||
1850 | sweep_line_t sweep_line; |
||
1851 | cairo_fixed_t ybot; |
||
1852 | event_t *event; |
||
1853 | cairo_list_t *left, *right; |
||
1854 | edge_t *e1, *e2; |
||
1855 | int bottom; |
||
1856 | |||
1857 | sweep_line_init (&sweep_line, start_events, self->num_edges); |
||
1858 | if ((status = setjmp (sweep_line.unwind))) |
||
1859 | goto unwind; |
||
1860 | |||
1861 | ybot = self->extents.p2.y; |
||
1862 | sweep_line.current_subrow = self->extents.p1.y; |
||
1863 | sweep_line.current_row = _cairo_fixed_floor (self->extents.p1.y); |
||
1864 | event = *sweep_line.queue.start_events++; |
||
1865 | do { |
||
1866 | /* Can we process a full step in one go? */ |
||
1867 | if (event->y >= sweep_line.current_row + STEP_Y) { |
||
1868 | bottom = _cairo_fixed_floor (event->y); |
||
1869 | full_step (self, &sweep_line, bottom, renderer); |
||
1870 | sweep_line.current_row = bottom; |
||
1871 | sweep_line.current_subrow = bottom; |
||
1872 | } |
||
1873 | |||
1874 | do { |
||
1875 | if (event->y > sweep_line.current_subrow) { |
||
1876 | sub_step (self, &sweep_line); |
||
1877 | sweep_line.current_subrow = event->y; |
||
1878 | } |
||
1879 | |||
1880 | do { |
||
1881 | /* Update the active list using Bentley-Ottmann */ |
||
1882 | switch (event->type) { |
||
1883 | case EVENT_TYPE_START: |
||
1884 | e1 = ((start_event_t *) event)->edge; |
||
1885 | |||
1886 | sweep_line_insert (&sweep_line, e1); |
||
1887 | event_insert_stop (&sweep_line, e1); |
||
1888 | |||
1889 | left = e1->link.prev; |
||
1890 | right = e1->link.next; |
||
1891 | |||
1892 | if (left != &sweep_line.active) { |
||
1893 | event_insert_if_intersect_below_current_y (&sweep_line, |
||
1894 | link_to_edge (left), e1); |
||
1895 | } |
||
1896 | |||
1897 | if (right != &sweep_line.active) { |
||
1898 | event_insert_if_intersect_below_current_y (&sweep_line, |
||
1899 | e1, link_to_edge (right)); |
||
1900 | } |
||
1901 | |||
1902 | break; |
||
1903 | |||
1904 | case EVENT_TYPE_STOP: |
||
1905 | e1 = ((queue_event_t *) event)->e1; |
||
1906 | event_delete (&sweep_line, event); |
||
1907 | |||
1908 | left = e1->link.prev; |
||
1909 | right = e1->link.next; |
||
1910 | |||
1911 | sweep_line_delete (&sweep_line, e1); |
||
1912 | |||
1913 | if (left != &sweep_line.active && |
||
1914 | right != &sweep_line.active) |
||
1915 | { |
||
1916 | event_insert_if_intersect_below_current_y (&sweep_line, |
||
1917 | link_to_edge (left), |
||
1918 | link_to_edge (right)); |
||
1919 | } |
||
1920 | |||
1921 | break; |
||
1922 | |||
1923 | case EVENT_TYPE_INTERSECTION: |
||
1924 | e1 = ((queue_event_t *) event)->e1; |
||
1925 | e2 = ((queue_event_t *) event)->e2; |
||
1926 | |||
1927 | event_delete (&sweep_line, event); |
||
1928 | if (e1->flags & STOP) |
||
1929 | break; |
||
1930 | if (e2->flags & STOP) |
||
1931 | break; |
||
1932 | |||
1933 | /* skip this intersection if its edges are not adjacent */ |
||
1934 | if (&e2->link != e1->link.next) |
||
1935 | break; |
||
1936 | |||
1937 | left = e1->link.prev; |
||
1938 | right = e2->link.next; |
||
1939 | |||
1940 | sweep_line_swap (&sweep_line, e1, e2); |
||
1941 | |||
1942 | /* after the swap e2 is left of e1 */ |
||
1943 | if (left != &sweep_line.active) { |
||
1944 | event_insert_if_intersect_below_current_y (&sweep_line, |
||
1945 | link_to_edge (left), e2); |
||
1946 | } |
||
1947 | |||
1948 | if (right != &sweep_line.active) { |
||
1949 | event_insert_if_intersect_below_current_y (&sweep_line, |
||
1950 | e1, link_to_edge (right)); |
||
1951 | } |
||
1952 | |||
1953 | break; |
||
1954 | } |
||
1955 | |||
1956 | event = event_next (&sweep_line); |
||
1957 | if (event == NULL) |
||
1958 | goto end; |
||
1959 | } while (event->y == sweep_line.current_subrow); |
||
1960 | } while (event->y < sweep_line.current_row + STEP_Y); |
||
1961 | |||
1962 | bottom = sweep_line.current_row + STEP_Y; |
||
1963 | sub_emit (self, &sweep_line, renderer); |
||
1964 | sweep_line.current_subrow = bottom; |
||
1965 | sweep_line.current_row = sweep_line.current_subrow; |
||
1966 | } while (TRUE); |
||
1967 | |||
1968 | end: |
||
1969 | /* flush any partial spans */ |
||
1970 | if (sweep_line.current_subrow != sweep_line.current_row) { |
||
1971 | sub_emit (self, &sweep_line, renderer); |
||
1972 | sweep_line.current_row += STEP_Y; |
||
1973 | sweep_line.current_subrow = sweep_line.current_row; |
||
1974 | } |
||
1975 | /* clear the rest */ |
||
1976 | if (sweep_line.current_subrow < ybot) { |
||
1977 | bottom = _cairo_fixed_integer_part (sweep_line.current_row); |
||
1978 | status = renderer->render_rows (renderer, |
||
1979 | bottom, _cairo_fixed_integer_ceil (ybot) - bottom, |
||
1980 | NULL, 0); |
||
1981 | } |
||
1982 | |||
1983 | unwind: |
||
1984 | sweep_line_fini (&sweep_line); |
||
1985 | |||
1986 | return status; |
||
1987 | } |
||
1988 | |||
1989 | static cairo_status_t |
||
1990 | _cairo_botor_scan_converter_generate (void *converter, |
||
1991 | cairo_span_renderer_t *renderer) |
||
1992 | { |
||
1993 | cairo_botor_scan_converter_t *self = converter; |
||
1994 | start_event_t stack_events[CAIRO_STACK_ARRAY_LENGTH (start_event_t)]; |
||
1995 | start_event_t *events; |
||
1996 | event_t *stack_event_ptrs[ARRAY_LENGTH (stack_events) + 1]; |
||
1997 | event_t **event_ptrs; |
||
1998 | struct _cairo_botor_scan_converter_chunk *chunk; |
||
1999 | cairo_status_t status; |
||
2000 | int num_events; |
||
2001 | int i, j; |
||
2002 | |||
2003 | num_events = self->num_edges; |
||
2004 | if (unlikely (0 == num_events)) { |
||
2005 | return renderer->render_rows (renderer, |
||
2006 | _cairo_fixed_integer_floor (self->extents.p1.y), |
||
2007 | _cairo_fixed_integer_ceil (self->extents.p2.y) - |
||
2008 | _cairo_fixed_integer_floor (self->extents.p1.y), |
||
2009 | NULL, 0); |
||
2010 | } |
||
2011 | |||
2012 | events = stack_events; |
||
2013 | event_ptrs = stack_event_ptrs; |
||
2014 | if (unlikely (num_events >= ARRAY_LENGTH (stack_events))) { |
||
2015 | events = _cairo_malloc_ab_plus_c (num_events, |
||
2016 | sizeof (start_event_t) + sizeof (event_t *), |
||
2017 | sizeof (event_t *)); |
||
2018 | if (unlikely (events == NULL)) |
||
2019 | return _cairo_error (CAIRO_STATUS_NO_MEMORY); |
||
2020 | |||
2021 | event_ptrs = (event_t **) (events + num_events); |
||
2022 | } |
||
2023 | |||
2024 | j = 0; |
||
2025 | for (chunk = &self->chunks; chunk != NULL; chunk = chunk->next) { |
||
2026 | edge_t *edge; |
||
2027 | |||
2028 | edge = chunk->base; |
||
2029 | for (i = 0; i < chunk->count; i++) { |
||
2030 | event_ptrs[j] = (event_t *) &events[j]; |
||
2031 | |||
2032 | events[j].y = edge->edge.top; |
||
2033 | events[j].type = EVENT_TYPE_START; |
||
2034 | events[j].edge = edge; |
||
2035 | |||
2036 | edge++, j++; |
||
2037 | } |
||
2038 | } |
||
2039 | |||
2040 | status = botor_generate (self, event_ptrs, renderer); |
||
2041 | |||
2042 | if (events != stack_events) |
||
2043 | free (events); |
||
2044 | |||
2045 | return status; |
||
2046 | } |
||
2047 | |||
2048 | static edge_t * |
||
2049 | botor_allocate_edge (cairo_botor_scan_converter_t *self) |
||
2050 | { |
||
2051 | struct _cairo_botor_scan_converter_chunk *chunk; |
||
2052 | |||
2053 | chunk = self->tail; |
||
2054 | if (chunk->count == chunk->size) { |
||
2055 | int size; |
||
2056 | |||
2057 | size = chunk->size * 2; |
||
2058 | chunk->next = _cairo_malloc_ab_plus_c (size, |
||
2059 | sizeof (edge_t), |
||
2060 | sizeof (struct _cairo_botor_scan_converter_chunk)); |
||
2061 | if (unlikely (chunk->next == NULL)) |
||
2062 | return NULL; |
||
2063 | |||
2064 | chunk = chunk->next; |
||
2065 | chunk->next = NULL; |
||
2066 | chunk->count = 0; |
||
2067 | chunk->size = size; |
||
2068 | chunk->base = chunk + 1; |
||
2069 | self->tail = chunk; |
||
2070 | } |
||
2071 | |||
2072 | return (edge_t *) chunk->base + chunk->count++; |
||
2073 | } |
||
2074 | |||
2075 | static cairo_status_t |
||
2076 | botor_add_edge (cairo_botor_scan_converter_t *self, |
||
2077 | const cairo_edge_t *edge) |
||
2078 | { |
||
2079 | edge_t *e; |
||
2080 | cairo_fixed_t dx, dy; |
||
2081 | |||
2082 | e = botor_allocate_edge (self); |
||
2083 | if (unlikely (e == NULL)) |
||
2084 | return _cairo_error (CAIRO_STATUS_NO_MEMORY); |
||
2085 | |||
2086 | cairo_list_init (&e->link); |
||
2087 | e->edge = *edge; |
||
2088 | |||
2089 | dx = edge->line.p2.x - edge->line.p1.x; |
||
2090 | dy = edge->line.p2.y - edge->line.p1.y; |
||
2091 | e->dy = dy; |
||
2092 | |||
2093 | if (dx == 0) { |
||
2094 | e->vertical = TRUE; |
||
2095 | e->x.quo = edge->line.p1.x; |
||
2096 | e->x.rem = 0; |
||
2097 | e->dxdy.quo = 0; |
||
2098 | e->dxdy.rem = 0; |
||
2099 | e->dxdy_full.quo = 0; |
||
2100 | e->dxdy_full.rem = 0; |
||
2101 | } else { |
||
2102 | e->vertical = FALSE; |
||
2103 | e->dxdy = floored_divrem (dx, dy); |
||
2104 | if (edge->top == edge->line.p1.y) { |
||
2105 | e->x.quo = edge->line.p1.x; |
||
2106 | e->x.rem = 0; |
||
2107 | } else { |
||
2108 | e->x = floored_muldivrem (edge->top - edge->line.p1.y, |
||
2109 | dx, dy); |
||
2110 | e->x.quo += edge->line.p1.x; |
||
2111 | } |
||
2112 | |||
2113 | if (_cairo_fixed_integer_part (edge->bottom) - _cairo_fixed_integer_part (edge->top) > 1) { |
||
2114 | e->dxdy_full = floored_muldivrem (STEP_Y, dx, dy); |
||
2115 | } else { |
||
2116 | e->dxdy_full.quo = 0; |
||
2117 | e->dxdy_full.rem = 0; |
||
2118 | } |
||
2119 | } |
||
2120 | |||
2121 | e->x.rem = -e->dy; |
||
2122 | e->current_sign = 0; |
||
2123 | e->runs = NULL; |
||
2124 | e->flags = START; |
||
2125 | |||
2126 | self->num_edges++; |
||
2127 | |||
2128 | return CAIRO_STATUS_SUCCESS; |
||
2129 | } |
||
2130 | |||
2131 | static void |
||
2132 | _cairo_botor_scan_converter_destroy (void *converter) |
||
2133 | { |
||
2134 | cairo_botor_scan_converter_t *self = converter; |
||
2135 | struct _cairo_botor_scan_converter_chunk *chunk, *next; |
||
2136 | |||
2137 | for (chunk = self->chunks.next; chunk != NULL; chunk = next) { |
||
2138 | next = chunk->next; |
||
2139 | free (chunk); |
||
2140 | } |
||
2141 | } |
||
2142 | |||
2143 | void |
||
2144 | _cairo_botor_scan_converter_init (cairo_botor_scan_converter_t *self, |
||
2145 | const cairo_box_t *extents, |
||
2146 | cairo_fill_rule_t fill_rule) |
||
2147 | { |
||
2148 | self->base.destroy = _cairo_botor_scan_converter_destroy; |
||
2149 | self->base.generate = _cairo_botor_scan_converter_generate; |
||
2150 | |||
2151 | self->extents = *extents; |
||
2152 | self->fill_rule = fill_rule; |
||
2153 | |||
2154 | self->xmin = _cairo_fixed_integer_floor (extents->p1.x); |
||
2155 | self->xmax = _cairo_fixed_integer_ceil (extents->p2.x); |
||
2156 | |||
2157 | self->chunks.base = self->buf; |
||
2158 | self->chunks.next = NULL; |
||
2159 | self->chunks.count = 0; |
||
2160 | self->chunks.size = sizeof (self->buf) / sizeof (edge_t); |
||
2161 | self->tail = &self->chunks; |
||
2162 | |||
2163 | self->num_edges = 0; |
||
2164 | }>>>>=>>>>>>=>>>=>>>>>>>>>>>=>>>>>>>0>><> |