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4680 | right-hear | 1 | #include "fitz.h" |
2 | #include "muxps.h" |
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3 | |||
4 | #define MAX_STOPS 256 |
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5 | |||
6 | enum { SPREAD_PAD, SPREAD_REPEAT, SPREAD_REFLECT }; |
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7 | |||
8 | /* |
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9 | * Parse a list of GradientStop elements. |
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10 | * Fill the offset and color arrays, and |
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11 | * return the number of stops parsed. |
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12 | */ |
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13 | |||
14 | struct stop |
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15 | { |
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16 | float offset; |
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17 | float r, g, b, a; |
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18 | }; |
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19 | |||
20 | static int cmp_stop(const void *a, const void *b) |
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21 | { |
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22 | const struct stop *astop = a; |
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23 | const struct stop *bstop = b; |
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24 | float diff = astop->offset - bstop->offset; |
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25 | if (diff < 0) |
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26 | return -1; |
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27 | if (diff > 0) |
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28 | return 1; |
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29 | return 0; |
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30 | } |
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31 | |||
32 | static inline float lerp(float a, float b, float x) |
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33 | { |
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34 | return a + (b - a) * x; |
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35 | } |
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36 | |||
37 | static int |
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38 | xps_parse_gradient_stops(xps_context *ctx, char *base_uri, xml_element *node, |
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39 | struct stop *stops, int maxcount) |
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40 | { |
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41 | fz_colorspace *colorspace; |
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42 | float sample[8]; |
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43 | float rgb[3]; |
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44 | int before, after; |
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45 | int count; |
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46 | int i; |
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47 | |||
48 | /* We may have to insert 2 extra stops when postprocessing */ |
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49 | maxcount -= 2; |
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50 | |||
51 | count = 0; |
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52 | while (node && count < maxcount) |
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53 | { |
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54 | if (!strcmp(xml_tag(node), "GradientStop")) |
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55 | { |
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56 | char *offset = xml_att(node, "Offset"); |
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57 | char *color = xml_att(node, "Color"); |
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58 | if (offset && color) |
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59 | { |
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60 | stops[count].offset = fz_atof(offset); |
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61 | |||
62 | xps_parse_color(ctx, base_uri, color, &colorspace, sample); |
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63 | |||
64 | fz_convert_color(colorspace, sample + 1, fz_device_rgb, rgb); |
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65 | |||
66 | stops[count].r = rgb[0]; |
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67 | stops[count].g = rgb[1]; |
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68 | stops[count].b = rgb[2]; |
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69 | stops[count].a = sample[0]; |
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70 | |||
71 | count ++; |
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72 | } |
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73 | } |
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74 | node = xml_next(node); |
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75 | } |
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76 | |||
77 | if (count == 0) |
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78 | { |
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79 | fz_warn("gradient brush has no gradient stops"); |
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80 | stops[0].offset = 0; |
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81 | stops[0].r = 0; |
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82 | stops[0].g = 0; |
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83 | stops[0].b = 0; |
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84 | stops[0].a = 1; |
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85 | stops[1].offset = 1; |
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86 | stops[1].r = 1; |
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87 | stops[1].g = 1; |
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88 | stops[1].b = 1; |
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89 | stops[1].a = 1; |
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90 | return 2; |
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91 | } |
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92 | |||
93 | if (count == maxcount) |
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94 | fz_warn("gradient brush exceeded maximum number of gradient stops"); |
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95 | |||
96 | /* Postprocess to make sure the range of offsets is 0.0 to 1.0 */ |
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97 | |||
98 | qsort(stops, count, sizeof(struct stop), cmp_stop); |
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99 | |||
100 | before = -1; |
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101 | after = -1; |
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102 | |||
103 | for (i = 0; i < count; i++) |
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104 | { |
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105 | if (stops[i].offset < 0) |
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106 | before = i; |
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107 | if (stops[i].offset > 1) |
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108 | { |
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109 | after = i; |
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110 | break; |
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111 | } |
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112 | } |
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113 | |||
114 | /* Remove all stops < 0 except the largest one */ |
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115 | if (before > 0) |
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116 | { |
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117 | memmove(stops, stops + before, (count - before) * sizeof(struct stop)); |
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118 | count -= before; |
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119 | } |
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120 | |||
121 | /* Remove all stops > 1 except the smallest one */ |
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122 | if (after >= 0) |
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123 | count = after + 1; |
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124 | |||
125 | /* Expand single stop to 0 .. 1 */ |
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126 | if (count == 1) |
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127 | { |
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128 | stops[1] = stops[0]; |
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129 | stops[0].offset = 0; |
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130 | stops[1].offset = 1; |
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131 | return 2; |
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132 | } |
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133 | |||
134 | /* First stop < 0 -- interpolate value to 0 */ |
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135 | if (stops[0].offset < 0) |
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136 | { |
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137 | float d = -stops[0].offset / (stops[1].offset - stops[0].offset); |
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138 | stops[0].offset = 0; |
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139 | stops[0].r = lerp(stops[0].r, stops[1].r, d); |
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140 | stops[0].g = lerp(stops[0].g, stops[1].g, d); |
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141 | stops[0].b = lerp(stops[0].b, stops[1].b, d); |
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142 | stops[0].a = lerp(stops[0].a, stops[1].a, d); |
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143 | } |
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144 | |||
145 | /* Last stop > 1 -- interpolate value to 1 */ |
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146 | if (stops[count-1].offset > 1) |
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147 | { |
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148 | float d = (1 - stops[count-2].offset) / (stops[count-1].offset - stops[count-2].offset); |
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149 | stops[count-1].offset = 1; |
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150 | stops[0].r = lerp(stops[count-2].r, stops[count-1].r, d); |
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151 | stops[0].g = lerp(stops[count-2].g, stops[count-1].g, d); |
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152 | stops[0].b = lerp(stops[count-2].b, stops[count-1].b, d); |
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153 | stops[0].a = lerp(stops[count-2].a, stops[count-1].a, d); |
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154 | } |
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155 | |||
156 | /* First stop > 0 -- insert a duplicate at 0 */ |
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157 | if (stops[0].offset > 0) |
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158 | { |
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159 | memmove(stops + 1, stops, count * sizeof(struct stop)); |
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160 | stops[0] = stops[1]; |
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161 | stops[0].offset = 0; |
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162 | count++; |
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163 | } |
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164 | |||
165 | /* Last stop < 1 -- insert a duplicate at 1 */ |
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166 | if (stops[count-1].offset < 1) |
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167 | { |
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168 | stops[count] = stops[count-1]; |
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169 | stops[count].offset = 1; |
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170 | count++; |
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171 | } |
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172 | |||
173 | return count; |
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174 | } |
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175 | |||
176 | static void |
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177 | xps_sample_gradient_stops(fz_shade *shade, struct stop *stops, int count) |
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178 | { |
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179 | float offset, d; |
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180 | int i, k; |
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181 | |||
182 | k = 0; |
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183 | for (i = 0; i < 256; i++) |
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184 | { |
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185 | offset = i / 255.0f; |
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186 | while (k + 1 < count && offset > stops[k+1].offset) |
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187 | k++; |
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188 | |||
189 | d = (offset - stops[k].offset) / (stops[k+1].offset - stops[k].offset); |
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190 | |||
191 | shade->function[i][0] = lerp(stops[k].r, stops[k+1].r, d); |
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192 | shade->function[i][1] = lerp(stops[k].g, stops[k+1].g, d); |
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193 | shade->function[i][2] = lerp(stops[k].b, stops[k+1].b, d); |
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194 | shade->function[i][3] = lerp(stops[k].a, stops[k+1].a, d); |
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195 | } |
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196 | } |
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197 | |||
198 | /* |
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199 | * Radial gradients map more or less to Radial shadings. |
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200 | * The inner circle is always a point. |
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201 | * The outer circle is actually an ellipse, |
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202 | * mess with the transform to squash the circle into the right aspect. |
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203 | */ |
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204 | |||
205 | static void |
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206 | xps_draw_one_radial_gradient(xps_context *ctx, fz_matrix ctm, |
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207 | struct stop *stops, int count, |
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208 | int extend, |
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209 | float x0, float y0, float r0, |
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210 | float x1, float y1, float r1) |
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211 | { |
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212 | fz_shade *shade; |
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213 | |||
214 | /* TODO: this (and the stuff in pdf_shade) should move to res_shade.c */ |
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215 | shade = fz_malloc(sizeof(fz_shade)); |
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216 | shade->refs = 1; |
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217 | shade->colorspace = fz_device_rgb; |
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218 | shade->bbox = fz_infinite_rect; |
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219 | shade->matrix = fz_identity; |
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220 | shade->use_background = 0; |
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221 | shade->use_function = 1; |
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222 | shade->type = FZ_RADIAL; |
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223 | shade->extend[0] = extend; |
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224 | shade->extend[1] = extend; |
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225 | |||
226 | xps_sample_gradient_stops(shade, stops, count); |
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227 | |||
228 | shade->mesh_len = 6; |
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229 | shade->mesh_cap = 6; |
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230 | shade->mesh = fz_calloc(shade->mesh_cap, sizeof(float)); |
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231 | shade->mesh[0] = x0; |
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232 | shade->mesh[1] = y0; |
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233 | shade->mesh[2] = r0; |
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234 | shade->mesh[3] = x1; |
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235 | shade->mesh[4] = y1; |
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236 | shade->mesh[5] = r1; |
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237 | |||
238 | fz_fill_shade(ctx->dev, shade, ctm, 1); |
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239 | |||
240 | fz_drop_shade(shade); |
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241 | } |
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242 | |||
243 | /* |
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244 | * Linear gradients map to Axial shadings. |
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245 | */ |
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246 | |||
247 | static void |
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248 | xps_draw_one_linear_gradient(xps_context *ctx, fz_matrix ctm, |
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249 | struct stop *stops, int count, |
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250 | int extend, |
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251 | float x0, float y0, float x1, float y1) |
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252 | { |
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253 | fz_shade *shade; |
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254 | |||
255 | /* TODO: this (and the stuff in pdf_shade) should move to res_shade.c */ |
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256 | shade = fz_malloc(sizeof(fz_shade)); |
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257 | shade->refs = 1; |
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258 | shade->colorspace = fz_device_rgb; |
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259 | shade->bbox = fz_infinite_rect; |
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260 | shade->matrix = fz_identity; |
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261 | shade->use_background = 0; |
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262 | shade->use_function = 1; |
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263 | shade->type = FZ_LINEAR; |
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264 | shade->extend[0] = extend; |
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265 | shade->extend[1] = extend; |
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266 | |||
267 | xps_sample_gradient_stops(shade, stops, count); |
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268 | |||
269 | shade->mesh_len = 6; |
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270 | shade->mesh_cap = 6; |
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271 | shade->mesh = fz_calloc(shade->mesh_cap, sizeof(float)); |
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272 | shade->mesh[0] = x0; |
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273 | shade->mesh[1] = y0; |
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274 | shade->mesh[2] = 0; |
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275 | shade->mesh[3] = x1; |
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276 | shade->mesh[4] = y1; |
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277 | shade->mesh[5] = 0; |
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278 | |||
279 | fz_fill_shade(ctx->dev, shade, ctm, 1); |
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280 | |||
281 | fz_drop_shade(shade); |
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282 | } |
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283 | |||
284 | /* |
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285 | * We need to loop and create many shading objects to account |
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286 | * for the Repeat and Reflect SpreadMethods. |
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287 | * I'm not smart enough to calculate this analytically |
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288 | * so we iterate and check each object until we |
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289 | * reach a reasonable limit for infinite cases. |
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290 | */ |
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291 | |||
292 | static inline float point_inside_circle(float px, float py, float x, float y, float r) |
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293 | { |
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294 | float dx = px - x; |
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295 | float dy = py - y; |
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296 | return dx * dx + dy * dy <= r * r; |
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297 | } |
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298 | |||
299 | static void |
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300 | xps_draw_radial_gradient(xps_context *ctx, fz_matrix ctm, |
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301 | struct stop *stops, int count, |
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302 | xml_element *root, int spread) |
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303 | { |
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304 | float x0, y0, r0; |
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305 | float x1, y1, r1; |
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306 | float xrad = 1; |
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307 | float yrad = 1; |
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308 | float invscale; |
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309 | |||
310 | char *center_att = xml_att(root, "Center"); |
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311 | char *origin_att = xml_att(root, "GradientOrigin"); |
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312 | char *radius_x_att = xml_att(root, "RadiusX"); |
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313 | char *radius_y_att = xml_att(root, "RadiusY"); |
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314 | |||
315 | if (origin_att) |
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316 | sscanf(origin_att, "%g,%g", &x0, &y0); |
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317 | if (center_att) |
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318 | sscanf(center_att, "%g,%g", &x1, &y1); |
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319 | if (radius_x_att) |
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320 | xrad = fz_atof(radius_x_att); |
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321 | if (radius_y_att) |
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322 | yrad = fz_atof(radius_y_att); |
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323 | |||
324 | /* scale the ctm to make ellipses */ |
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325 | ctm = fz_concat(fz_scale(1, yrad / xrad), ctm); |
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326 | |||
327 | invscale = xrad / yrad; |
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328 | y0 = y0 * invscale; |
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329 | y1 = y1 * invscale; |
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330 | |||
331 | r0 = 0; |
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332 | r1 = xrad; |
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333 | |||
334 | xps_draw_one_radial_gradient(ctx, ctm, stops, count, 1, x0, y0, r0, x1, y1, r1); |
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335 | } |
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336 | |||
337 | /* |
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338 | * Calculate how many iterations are needed to cover |
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339 | * the bounding box. |
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340 | */ |
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341 | |||
342 | static void |
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343 | xps_draw_linear_gradient(xps_context *ctx, fz_matrix ctm, |
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344 | struct stop *stops, int count, |
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345 | xml_element *root, int spread) |
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346 | { |
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347 | float x0, y0, x1, y1; |
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348 | |||
349 | char *start_point_att = xml_att(root, "StartPoint"); |
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350 | char *end_point_att = xml_att(root, "EndPoint"); |
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351 | |||
352 | x0 = y0 = 0; |
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353 | x1 = y1 = 1; |
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354 | |||
355 | if (start_point_att) |
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356 | sscanf(start_point_att, "%g,%g", &x0, &y0); |
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357 | if (end_point_att) |
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358 | sscanf(end_point_att, "%g,%g", &x1, &y1); |
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359 | |||
360 | xps_draw_one_linear_gradient(ctx, ctm, stops, count, 1, x0, y0, x1, y1); |
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361 | } |
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362 | |||
363 | /* |
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364 | * Parse XML tag and attributes for a gradient brush, create color/opacity |
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365 | * function objects and call gradient drawing primitives. |
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366 | */ |
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367 | |||
368 | static void |
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369 | xps_parse_gradient_brush(xps_context *ctx, fz_matrix ctm, fz_rect area, |
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370 | char *base_uri, xps_resource *dict, xml_element *root, |
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371 | void (*draw)(xps_context *, fz_matrix, struct stop *, int, xml_element *, int)) |
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372 | { |
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373 | xml_element *node; |
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374 | |||
375 | char *opacity_att; |
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376 | char *interpolation_att; |
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377 | char *spread_att; |
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378 | char *mapping_att; |
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379 | char *transform_att; |
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380 | |||
381 | xml_element *transform_tag = NULL; |
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382 | xml_element *stop_tag = NULL; |
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383 | |||
384 | struct stop stop_list[MAX_STOPS]; |
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385 | int stop_count; |
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386 | fz_matrix transform; |
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387 | int spread_method; |
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388 | |||
389 | opacity_att = xml_att(root, "Opacity"); |
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390 | interpolation_att = xml_att(root, "ColorInterpolationMode"); |
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391 | spread_att = xml_att(root, "SpreadMethod"); |
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392 | mapping_att = xml_att(root, "MappingMode"); |
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393 | transform_att = xml_att(root, "Transform"); |
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394 | |||
395 | for (node = xml_down(root); node; node = xml_next(node)) |
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396 | { |
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397 | if (!strcmp(xml_tag(node), "LinearGradientBrush.Transform")) |
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398 | transform_tag = xml_down(node); |
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399 | if (!strcmp(xml_tag(node), "RadialGradientBrush.Transform")) |
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400 | transform_tag = xml_down(node); |
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401 | if (!strcmp(xml_tag(node), "LinearGradientBrush.GradientStops")) |
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402 | stop_tag = xml_down(node); |
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403 | if (!strcmp(xml_tag(node), "RadialGradientBrush.GradientStops")) |
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404 | stop_tag = xml_down(node); |
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405 | } |
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406 | |||
407 | xps_resolve_resource_reference(ctx, dict, &transform_att, &transform_tag, NULL); |
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408 | |||
409 | spread_method = SPREAD_PAD; |
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410 | if (spread_att) |
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411 | { |
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412 | if (!strcmp(spread_att, "Pad")) |
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413 | spread_method = SPREAD_PAD; |
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414 | if (!strcmp(spread_att, "Reflect")) |
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415 | spread_method = SPREAD_REFLECT; |
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416 | if (!strcmp(spread_att, "Repeat")) |
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417 | spread_method = SPREAD_REPEAT; |
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418 | } |
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419 | |||
420 | transform = fz_identity; |
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421 | if (transform_att) |
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422 | xps_parse_render_transform(ctx, transform_att, &transform); |
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423 | if (transform_tag) |
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424 | xps_parse_matrix_transform(ctx, transform_tag, &transform); |
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425 | ctm = fz_concat(transform, ctm); |
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426 | |||
427 | if (!stop_tag) { |
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428 | fz_warn("missing gradient stops tag"); |
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429 | return; |
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430 | } |
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431 | |||
432 | stop_count = xps_parse_gradient_stops(ctx, base_uri, stop_tag, stop_list, MAX_STOPS); |
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433 | if (stop_count == 0) |
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434 | { |
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435 | fz_warn("no gradient stops found"); |
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436 | return; |
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437 | } |
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438 | |||
439 | xps_begin_opacity(ctx, ctm, area, base_uri, dict, opacity_att, NULL); |
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440 | |||
441 | draw(ctx, ctm, stop_list, stop_count, root, spread_method); |
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442 | |||
443 | xps_end_opacity(ctx, base_uri, dict, opacity_att, NULL); |
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444 | } |
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445 | |||
446 | void |
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447 | xps_parse_linear_gradient_brush(xps_context *ctx, fz_matrix ctm, fz_rect area, |
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448 | char *base_uri, xps_resource *dict, xml_element *root) |
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449 | { |
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450 | xps_parse_gradient_brush(ctx, ctm, area, base_uri, dict, root, xps_draw_linear_gradient); |
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451 | } |
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452 | |||
453 | void |
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454 | xps_parse_radial_gradient_brush(xps_context *ctx, fz_matrix ctm, fz_rect area, |
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455 | char *base_uri, xps_resource *dict, xml_element *root) |
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456 | { |
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457 | xps_parse_gradient_brush(ctx, ctm, area, base_uri, dict, root, xps_draw_radial_gradient); |
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458 | }=>>>>>>>>>>>> |