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Rev | Author | Line No. | Line |
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4358 | Serge | 1 | /* |
2 | * Mesa 3-D graphics library |
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3 | * |
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4 | * Copyright (C) 1999-2007 Brian Paul All Rights Reserved. |
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5 | * |
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6 | * Permission is hereby granted, free of charge, to any person obtaining a |
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7 | * copy of this software and associated documentation files (the "Software"), |
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8 | * to deal in the Software without restriction, including without limitation |
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9 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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10 | * and/or sell copies of the Software, and to permit persons to whom the |
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11 | * Software is furnished to do so, subject to the following conditions: |
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12 | * |
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13 | * The above copyright notice and this permission notice shall be included |
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14 | * in all copies or substantial portions of the Software. |
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15 | * |
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16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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17 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR |
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20 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
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21 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
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22 | * OTHER DEALINGS IN THE SOFTWARE. |
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23 | */ |
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24 | |||
25 | |||
26 | #include "main/glheader.h" |
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27 | #include "main/imports.h" |
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28 | #include "main/macros.h" |
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29 | #include "main/mtypes.h" |
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30 | #include "swrast/s_aaline.h" |
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31 | #include "swrast/s_context.h" |
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32 | #include "swrast/s_span.h" |
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33 | #include "swrast/swrast.h" |
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34 | |||
35 | |||
36 | #define SUB_PIXEL 4 |
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37 | |||
38 | |||
39 | /* |
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40 | * Info about the AA line we're rendering |
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41 | */ |
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42 | struct LineInfo |
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43 | { |
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44 | GLfloat x0, y0; /* start */ |
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45 | GLfloat x1, y1; /* end */ |
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46 | GLfloat dx, dy; /* direction vector */ |
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47 | GLfloat len; /* length */ |
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48 | GLfloat halfWidth; /* half of line width */ |
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49 | GLfloat xAdj, yAdj; /* X and Y adjustment for quad corners around line */ |
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50 | /* for coverage computation */ |
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51 | GLfloat qx0, qy0; /* quad vertices */ |
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52 | GLfloat qx1, qy1; |
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53 | GLfloat qx2, qy2; |
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54 | GLfloat qx3, qy3; |
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55 | GLfloat ex0, ey0; /* quad edge vectors */ |
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56 | GLfloat ex1, ey1; |
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57 | GLfloat ex2, ey2; |
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58 | GLfloat ex3, ey3; |
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59 | |||
60 | /* DO_Z */ |
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61 | GLfloat zPlane[4]; |
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62 | /* DO_RGBA - always enabled */ |
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63 | GLfloat rPlane[4], gPlane[4], bPlane[4], aPlane[4]; |
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64 | /* DO_ATTRIBS */ |
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65 | GLfloat wPlane[4]; |
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66 | GLfloat attrPlane[VARYING_SLOT_MAX][4][4]; |
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67 | GLfloat lambda[VARYING_SLOT_MAX]; |
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68 | GLfloat texWidth[VARYING_SLOT_MAX]; |
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69 | GLfloat texHeight[VARYING_SLOT_MAX]; |
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70 | |||
71 | SWspan span; |
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72 | }; |
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73 | |||
74 | |||
75 | |||
76 | /* |
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77 | * Compute the equation of a plane used to interpolate line fragment data |
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78 | * such as color, Z, texture coords, etc. |
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79 | * Input: (x0, y0) and (x1,y1) are the endpoints of the line. |
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80 | * z0, and z1 are the end point values to interpolate. |
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81 | * Output: plane - the plane equation. |
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82 | * |
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83 | * Note: we don't really have enough parameters to specify a plane. |
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84 | * We take the endpoints of the line and compute a plane such that |
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85 | * the cross product of the line vector and the plane normal is |
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86 | * parallel to the projection plane. |
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87 | */ |
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88 | static void |
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89 | compute_plane(GLfloat x0, GLfloat y0, GLfloat x1, GLfloat y1, |
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90 | GLfloat z0, GLfloat z1, GLfloat plane[4]) |
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91 | { |
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92 | #if 0 |
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93 | /* original */ |
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94 | const GLfloat px = x1 - x0; |
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95 | const GLfloat py = y1 - y0; |
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96 | const GLfloat pz = z1 - z0; |
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97 | const GLfloat qx = -py; |
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98 | const GLfloat qy = px; |
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99 | const GLfloat qz = 0; |
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100 | const GLfloat a = py * qz - pz * qy; |
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101 | const GLfloat b = pz * qx - px * qz; |
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102 | const GLfloat c = px * qy - py * qx; |
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103 | const GLfloat d = -(a * x0 + b * y0 + c * z0); |
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104 | plane[0] = a; |
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105 | plane[1] = b; |
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106 | plane[2] = c; |
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107 | plane[3] = d; |
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108 | #else |
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109 | /* simplified */ |
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110 | const GLfloat px = x1 - x0; |
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111 | const GLfloat py = y1 - y0; |
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112 | const GLfloat pz = z0 - z1; |
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113 | const GLfloat a = pz * px; |
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114 | const GLfloat b = pz * py; |
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115 | const GLfloat c = px * px + py * py; |
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116 | const GLfloat d = -(a * x0 + b * y0 + c * z0); |
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117 | if (a == 0.0 && b == 0.0 && c == 0.0 && d == 0.0) { |
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118 | plane[0] = 0.0; |
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119 | plane[1] = 0.0; |
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120 | plane[2] = 1.0; |
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121 | plane[3] = 0.0; |
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122 | } |
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123 | else { |
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124 | plane[0] = a; |
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125 | plane[1] = b; |
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126 | plane[2] = c; |
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127 | plane[3] = d; |
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128 | } |
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129 | #endif |
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130 | } |
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131 | |||
132 | |||
133 | static inline void |
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134 | constant_plane(GLfloat value, GLfloat plane[4]) |
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135 | { |
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136 | plane[0] = 0.0; |
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137 | plane[1] = 0.0; |
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138 | plane[2] = -1.0; |
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139 | plane[3] = value; |
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140 | } |
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141 | |||
142 | |||
143 | static inline GLfloat |
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144 | solve_plane(GLfloat x, GLfloat y, const GLfloat plane[4]) |
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145 | { |
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146 | const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2]; |
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147 | return z; |
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148 | } |
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149 | |||
150 | #define SOLVE_PLANE(X, Y, PLANE) \ |
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151 | ((PLANE[3] + PLANE[0] * (X) + PLANE[1] * (Y)) / -PLANE[2]) |
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152 | |||
153 | |||
154 | /* |
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155 | * Return 1 / solve_plane(). |
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156 | */ |
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157 | static inline GLfloat |
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158 | solve_plane_recip(GLfloat x, GLfloat y, const GLfloat plane[4]) |
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159 | { |
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160 | const GLfloat denom = plane[3] + plane[0] * x + plane[1] * y; |
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161 | if (denom == 0.0) |
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162 | return 0.0; |
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163 | else |
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164 | return -plane[2] / denom; |
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165 | } |
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166 | |||
167 | |||
168 | /* |
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169 | * Solve plane and return clamped GLchan value. |
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170 | */ |
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171 | static inline GLchan |
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172 | solve_plane_chan(GLfloat x, GLfloat y, const GLfloat plane[4]) |
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173 | { |
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174 | const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2]; |
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175 | #if CHAN_TYPE == GL_FLOAT |
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176 | return CLAMP(z, 0.0F, CHAN_MAXF); |
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177 | #else |
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178 | if (z < 0) |
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179 | return 0; |
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180 | else if (z > CHAN_MAX) |
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181 | return CHAN_MAX; |
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182 | return (GLchan) IROUND_POS(z); |
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183 | #endif |
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184 | } |
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185 | |||
186 | |||
187 | /* |
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188 | * Compute mipmap level of detail. |
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189 | */ |
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190 | static inline GLfloat |
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191 | compute_lambda(const GLfloat sPlane[4], const GLfloat tPlane[4], |
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192 | GLfloat invQ, GLfloat width, GLfloat height) |
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193 | { |
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194 | GLfloat dudx = sPlane[0] / sPlane[2] * invQ * width; |
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195 | GLfloat dudy = sPlane[1] / sPlane[2] * invQ * width; |
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196 | GLfloat dvdx = tPlane[0] / tPlane[2] * invQ * height; |
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197 | GLfloat dvdy = tPlane[1] / tPlane[2] * invQ * height; |
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198 | GLfloat r1 = dudx * dudx + dudy * dudy; |
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199 | GLfloat r2 = dvdx * dvdx + dvdy * dvdy; |
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200 | GLfloat rho2 = r1 + r2; |
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201 | /* return log base 2 of rho */ |
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202 | if (rho2 == 0.0F) |
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203 | return 0.0; |
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204 | else |
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205 | return (GLfloat) (LOGF(rho2) * 1.442695 * 0.5);/* 1.442695 = 1/log(2) */ |
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206 | } |
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207 | |||
208 | |||
209 | |||
210 | |||
211 | /* |
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212 | * Fill in the samples[] array with the (x,y) subpixel positions of |
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213 | * xSamples * ySamples sample positions. |
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214 | * Note that the four corner samples are put into the first four |
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215 | * positions of the array. This allows us to optimize for the common |
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216 | * case of all samples being inside the polygon. |
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217 | */ |
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218 | static void |
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219 | make_sample_table(GLint xSamples, GLint ySamples, GLfloat samples[][2]) |
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220 | { |
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221 | const GLfloat dx = 1.0F / (GLfloat) xSamples; |
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222 | const GLfloat dy = 1.0F / (GLfloat) ySamples; |
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223 | GLint x, y; |
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224 | GLint i; |
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225 | |||
226 | i = 4; |
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227 | for (x = 0; x < xSamples; x++) { |
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228 | for (y = 0; y < ySamples; y++) { |
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229 | GLint j; |
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230 | if (x == 0 && y == 0) { |
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231 | /* lower left */ |
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232 | j = 0; |
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233 | } |
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234 | else if (x == xSamples - 1 && y == 0) { |
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235 | /* lower right */ |
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236 | j = 1; |
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237 | } |
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238 | else if (x == 0 && y == ySamples - 1) { |
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239 | /* upper left */ |
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240 | j = 2; |
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241 | } |
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242 | else if (x == xSamples - 1 && y == ySamples - 1) { |
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243 | /* upper right */ |
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244 | j = 3; |
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245 | } |
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246 | else { |
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247 | j = i++; |
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248 | } |
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249 | samples[j][0] = x * dx + 0.5F * dx; |
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250 | samples[j][1] = y * dy + 0.5F * dy; |
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251 | } |
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252 | } |
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253 | } |
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254 | |||
255 | |||
256 | |||
257 | /* |
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258 | * Compute how much of the given pixel's area is inside the rectangle |
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259 | * defined by vertices v0, v1, v2, v3. |
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260 | * Vertices MUST be specified in counter-clockwise order. |
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261 | * Return: coverage in [0, 1]. |
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262 | */ |
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263 | static GLfloat |
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264 | compute_coveragef(const struct LineInfo *info, |
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265 | GLint winx, GLint winy) |
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266 | { |
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267 | static GLfloat samples[SUB_PIXEL * SUB_PIXEL][2]; |
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268 | static GLboolean haveSamples = GL_FALSE; |
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269 | const GLfloat x = (GLfloat) winx; |
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270 | const GLfloat y = (GLfloat) winy; |
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271 | GLint stop = 4, i; |
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272 | GLfloat insideCount = SUB_PIXEL * SUB_PIXEL; |
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273 | |||
274 | if (!haveSamples) { |
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275 | make_sample_table(SUB_PIXEL, SUB_PIXEL, samples); |
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276 | haveSamples = GL_TRUE; |
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277 | } |
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278 | |||
279 | #if 0 /*DEBUG*/ |
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280 | { |
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281 | const GLfloat area = dx0 * dy1 - dx1 * dy0; |
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282 | assert(area >= 0.0); |
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283 | } |
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284 | #endif |
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285 | |||
286 | for (i = 0; i < stop; i++) { |
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287 | const GLfloat sx = x + samples[i][0]; |
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288 | const GLfloat sy = y + samples[i][1]; |
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289 | const GLfloat fx0 = sx - info->qx0; |
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290 | const GLfloat fy0 = sy - info->qy0; |
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291 | const GLfloat fx1 = sx - info->qx1; |
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292 | const GLfloat fy1 = sy - info->qy1; |
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293 | const GLfloat fx2 = sx - info->qx2; |
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294 | const GLfloat fy2 = sy - info->qy2; |
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295 | const GLfloat fx3 = sx - info->qx3; |
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296 | const GLfloat fy3 = sy - info->qy3; |
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297 | /* cross product determines if sample is inside or outside each edge */ |
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298 | GLfloat cross0 = (info->ex0 * fy0 - info->ey0 * fx0); |
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299 | GLfloat cross1 = (info->ex1 * fy1 - info->ey1 * fx1); |
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300 | GLfloat cross2 = (info->ex2 * fy2 - info->ey2 * fx2); |
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301 | GLfloat cross3 = (info->ex3 * fy3 - info->ey3 * fx3); |
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302 | /* Check if the sample is exactly on an edge. If so, let cross be a |
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303 | * positive or negative value depending on the direction of the edge. |
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304 | */ |
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305 | if (cross0 == 0.0F) |
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306 | cross0 = info->ex0 + info->ey0; |
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307 | if (cross1 == 0.0F) |
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308 | cross1 = info->ex1 + info->ey1; |
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309 | if (cross2 == 0.0F) |
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310 | cross2 = info->ex2 + info->ey2; |
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311 | if (cross3 == 0.0F) |
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312 | cross3 = info->ex3 + info->ey3; |
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313 | if (cross0 < 0.0F || cross1 < 0.0F || cross2 < 0.0F || cross3 < 0.0F) { |
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314 | /* point is outside quadrilateral */ |
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315 | insideCount -= 1.0F; |
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316 | stop = SUB_PIXEL * SUB_PIXEL; |
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317 | } |
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318 | } |
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319 | if (stop == 4) |
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320 | return 1.0F; |
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321 | else |
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322 | return insideCount * (1.0F / (SUB_PIXEL * SUB_PIXEL)); |
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323 | } |
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324 | |||
325 | |||
326 | typedef void (*plot_func)(struct gl_context *ctx, struct LineInfo *line, |
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327 | int ix, int iy); |
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328 | |||
329 | |||
330 | |||
331 | /* |
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332 | * Draw an AA line segment (called many times per line when stippling) |
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333 | */ |
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334 | static void |
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335 | segment(struct gl_context *ctx, |
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336 | struct LineInfo *line, |
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337 | plot_func plot, |
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338 | GLfloat t0, GLfloat t1) |
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339 | { |
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340 | const GLfloat absDx = (line->dx < 0.0F) ? -line->dx : line->dx; |
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341 | const GLfloat absDy = (line->dy < 0.0F) ? -line->dy : line->dy; |
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342 | /* compute the actual segment's endpoints */ |
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343 | const GLfloat x0 = line->x0 + t0 * line->dx; |
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344 | const GLfloat y0 = line->y0 + t0 * line->dy; |
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345 | const GLfloat x1 = line->x0 + t1 * line->dx; |
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346 | const GLfloat y1 = line->y0 + t1 * line->dy; |
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347 | |||
348 | /* compute vertices of the line-aligned quadrilateral */ |
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349 | line->qx0 = x0 - line->yAdj; |
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350 | line->qy0 = y0 + line->xAdj; |
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351 | line->qx1 = x0 + line->yAdj; |
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352 | line->qy1 = y0 - line->xAdj; |
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353 | line->qx2 = x1 + line->yAdj; |
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354 | line->qy2 = y1 - line->xAdj; |
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355 | line->qx3 = x1 - line->yAdj; |
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356 | line->qy3 = y1 + line->xAdj; |
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357 | /* compute the quad's edge vectors (for coverage calc) */ |
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358 | line->ex0 = line->qx1 - line->qx0; |
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359 | line->ey0 = line->qy1 - line->qy0; |
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360 | line->ex1 = line->qx2 - line->qx1; |
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361 | line->ey1 = line->qy2 - line->qy1; |
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362 | line->ex2 = line->qx3 - line->qx2; |
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363 | line->ey2 = line->qy3 - line->qy2; |
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364 | line->ex3 = line->qx0 - line->qx3; |
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365 | line->ey3 = line->qy0 - line->qy3; |
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366 | |||
367 | if (absDx > absDy) { |
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368 | /* X-major line */ |
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369 | GLfloat dydx = line->dy / line->dx; |
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370 | GLfloat xLeft, xRight, yBot, yTop; |
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371 | GLint ix, ixRight; |
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372 | if (x0 < x1) { |
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373 | xLeft = x0 - line->halfWidth; |
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374 | xRight = x1 + line->halfWidth; |
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375 | if (line->dy >= 0.0) { |
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376 | yBot = y0 - 3.0F * line->halfWidth; |
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377 | yTop = y0 + line->halfWidth; |
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378 | } |
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379 | else { |
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380 | yBot = y0 - line->halfWidth; |
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381 | yTop = y0 + 3.0F * line->halfWidth; |
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382 | } |
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383 | } |
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384 | else { |
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385 | xLeft = x1 - line->halfWidth; |
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386 | xRight = x0 + line->halfWidth; |
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387 | if (line->dy <= 0.0) { |
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388 | yBot = y1 - 3.0F * line->halfWidth; |
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389 | yTop = y1 + line->halfWidth; |
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390 | } |
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391 | else { |
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392 | yBot = y1 - line->halfWidth; |
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393 | yTop = y1 + 3.0F * line->halfWidth; |
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394 | } |
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395 | } |
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396 | |||
397 | /* scan along the line, left-to-right */ |
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398 | ixRight = (GLint) (xRight + 1.0F); |
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399 | |||
400 | /*printf("avg span height: %g\n", yTop - yBot);*/ |
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401 | for (ix = (GLint) xLeft; ix < ixRight; ix++) { |
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402 | const GLint iyBot = (GLint) yBot; |
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403 | const GLint iyTop = (GLint) (yTop + 1.0F); |
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404 | GLint iy; |
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405 | /* scan across the line, bottom-to-top */ |
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406 | for (iy = iyBot; iy < iyTop; iy++) { |
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407 | (*plot)(ctx, line, ix, iy); |
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408 | } |
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409 | yBot += dydx; |
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410 | yTop += dydx; |
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411 | } |
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412 | } |
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413 | else { |
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414 | /* Y-major line */ |
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415 | GLfloat dxdy = line->dx / line->dy; |
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416 | GLfloat yBot, yTop, xLeft, xRight; |
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417 | GLint iy, iyTop; |
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418 | if (y0 < y1) { |
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419 | yBot = y0 - line->halfWidth; |
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420 | yTop = y1 + line->halfWidth; |
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421 | if (line->dx >= 0.0) { |
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422 | xLeft = x0 - 3.0F * line->halfWidth; |
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423 | xRight = x0 + line->halfWidth; |
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424 | } |
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425 | else { |
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426 | xLeft = x0 - line->halfWidth; |
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427 | xRight = x0 + 3.0F * line->halfWidth; |
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428 | } |
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429 | } |
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430 | else { |
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431 | yBot = y1 - line->halfWidth; |
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432 | yTop = y0 + line->halfWidth; |
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433 | if (line->dx <= 0.0) { |
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434 | xLeft = x1 - 3.0F * line->halfWidth; |
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435 | xRight = x1 + line->halfWidth; |
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436 | } |
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437 | else { |
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438 | xLeft = x1 - line->halfWidth; |
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439 | xRight = x1 + 3.0F * line->halfWidth; |
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440 | } |
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441 | } |
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442 | |||
443 | /* scan along the line, bottom-to-top */ |
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444 | iyTop = (GLint) (yTop + 1.0F); |
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445 | |||
446 | /*printf("avg span width: %g\n", xRight - xLeft);*/ |
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447 | for (iy = (GLint) yBot; iy < iyTop; iy++) { |
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448 | const GLint ixLeft = (GLint) xLeft; |
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449 | const GLint ixRight = (GLint) (xRight + 1.0F); |
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450 | GLint ix; |
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451 | /* scan across the line, left-to-right */ |
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452 | for (ix = ixLeft; ix < ixRight; ix++) { |
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453 | (*plot)(ctx, line, ix, iy); |
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454 | } |
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455 | xLeft += dxdy; |
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456 | xRight += dxdy; |
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457 | } |
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458 | } |
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459 | } |
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460 | |||
461 | |||
462 | #define NAME(x) aa_rgba_##x |
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463 | #define DO_Z |
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464 | #include "s_aalinetemp.h" |
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465 | |||
466 | |||
467 | #define NAME(x) aa_general_rgba_##x |
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468 | #define DO_Z |
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469 | #define DO_ATTRIBS |
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470 | #include "s_aalinetemp.h" |
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471 | |||
472 | |||
473 | |||
474 | void |
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475 | _swrast_choose_aa_line_function(struct gl_context *ctx) |
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476 | { |
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477 | SWcontext *swrast = SWRAST_CONTEXT(ctx); |
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478 | |||
479 | ASSERT(ctx->Line.SmoothFlag); |
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480 | |||
481 | if (ctx->Texture._EnabledCoordUnits != 0 |
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482 | || _swrast_use_fragment_program(ctx) |
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483 | || (ctx->Light.Enabled && |
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484 | ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR) |
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485 | || ctx->Fog.ColorSumEnabled |
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486 | || swrast->_FogEnabled) { |
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487 | swrast->Line = aa_general_rgba_line; |
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488 | } |
||
489 | else { |
||
490 | swrast->Line = aa_rgba_line; |
||
491 | } |
||
492 | }>>=>>>>=>>>>>>>>>>>> |