1 #include "../test/utils.h" 2 #include "gtk-utils.h" 3 4 #define NUM_GRADIENTS 9 5 #define NUM_STOPS 3 6 #define NUM_REPEAT 4 7 #define SIZE 128 8 #define WIDTH (SIZE * NUM_GRADIENTS) 9 #define HEIGHT (SIZE * NUM_REPEAT) 10 11 /* 12 * We want to test all the possible relative positions of the start 13 * and end circle: 14 * 15 * - The start circle can be smaller/equal/bigger than the end 16 * circle. A radial gradient can be classified in one of these 17 * three cases depending on the sign of dr. 18 * 19 * - The smaller circle can be completely inside/internally 20 * tangent/outside (at least in part) of the bigger circle. This 21 * classification is the same as the one which can be computed by 22 * examining the sign of a = (dx^2 + dy^2 - dr^2). 23 * 24 * - If the two circles have the same size, neither can be inside or 25 * internally tangent 26 * 27 * This test draws radial gradients whose circles always have the same 28 * centers (0, 0) and (1, 0), but with different radiuses. From left 29 * to right: 30 * 31 * - Degenerate start circle completely inside the end circle 32 * 0.00 -> 1.75; dr = 1.75 > 0; a = 1 - 1.75^2 < 0 33 * 34 * - Small start circle completely inside the end circle 35 * 0.25 -> 1.75; dr = 1.5 > 0; a = 1 - 1.50^2 < 0 36 * 37 * - Small start circle internally tangent to the end circle 38 * 0.50 -> 1.50; dr = 1.0 > 0; a = 1 - 1.00^2 = 0 39 * 40 * - Small start circle outside of the end circle 41 * 0.50 -> 1.00; dr = 0.5 > 0; a = 1 - 0.50^2 > 0 42 * 43 * - Start circle with the same size as the end circle 44 * 1.00 -> 1.00; dr = 0.0 = 0; a = 1 - 0.00^2 > 0 45 * 46 * - Small end circle outside of the start circle 47 * 1.00 -> 0.50; dr = -0.5 > 0; a = 1 - 0.50^2 > 0 48 * 49 * - Small end circle internally tangent to the start circle 50 * 1.50 -> 0.50; dr = -1.0 > 0; a = 1 - 1.00^2 = 0 51 * 52 * - Small end circle completely inside the start circle 53 * 1.75 -> 0.25; dr = -1.5 > 0; a = 1 - 1.50^2 < 0 54 * 55 * - Degenerate end circle completely inside the start circle 56 * 0.00 -> 1.75; dr = 1.75 > 0; a = 1 - 1.75^2 < 0 57 * 58 */ 59 60 const static double radiuses[NUM_GRADIENTS] = { 61 0.00, 62 0.25, 63 0.50, 64 0.50, 65 1.00, 66 1.00, 67 1.50, 68 1.75, 69 1.75 70 }; 71 72 #define double_to_color(x) \ 73 (((uint32_t) ((x)*65536)) - (((uint32_t) ((x)*65536)) >> 16)) 74 75 #define PIXMAN_STOP(offset,r,g,b,a) \ 76 { pixman_double_to_fixed (offset), \ 77 { \ 78 double_to_color (r), \ 79 double_to_color (g), \ 80 double_to_color (b), \ 81 double_to_color (a) \ 82 } \ 83 } 84 85 static const pixman_gradient_stop_t stops[NUM_STOPS] = { 86 PIXMAN_STOP (0.0, 1, 0, 0, 0.75), 87 PIXMAN_STOP (0.70710678, 0, 1, 0, 0), 88 PIXMAN_STOP (1.0, 0, 0, 1, 1) 89 }; 90 91 static pixman_image_t * 92 create_radial (int index) 93 { 94 pixman_point_fixed_t p0, p1; 95 pixman_fixed_t r0, r1; 96 double x0, x1, radius0, radius1, left, right, center; 97 98 x0 = 0; 99 x1 = 1; 100 radius0 = radiuses[index]; 101 radius1 = radiuses[NUM_GRADIENTS - index - 1]; 102 103 /* center the gradient */ 104 left = MIN (x0 - radius0, x1 - radius1); 105 right = MAX (x0 + radius0, x1 + radius1); 106 center = (left + right) * 0.5; 107 x0 -= center; 108 x1 -= center; 109 110 /* scale to make it fit within a 1x1 rect centered in (0,0) */ 111 x0 *= 0.25; 112 x1 *= 0.25; 113 radius0 *= 0.25; 114 radius1 *= 0.25; 115 116 p0.x = pixman_double_to_fixed (x0); 117 p0.y = pixman_double_to_fixed (0); 118 119 p1.x = pixman_double_to_fixed (x1); 120 p1.y = pixman_double_to_fixed (0); 121 122 r0 = pixman_double_to_fixed (radius0); 123 r1 = pixman_double_to_fixed (radius1); 124 125 return pixman_image_create_radial_gradient (&p0, &p1, 126 r0, r1, 127 stops, NUM_STOPS); 128 } 129 130 static const pixman_repeat_t repeat[NUM_REPEAT] = { 131 PIXMAN_REPEAT_NONE, 132 PIXMAN_REPEAT_NORMAL, 133 PIXMAN_REPEAT_REFLECT, 134 PIXMAN_REPEAT_PAD 135 }; 136 137 int 138 main (int argc, char **argv) 139 { 140 pixman_transform_t transform; 141 pixman_image_t *src_img, *dest_img; 142 int i, j; 143 144 enable_divbyzero_exceptions (); 145 146 dest_img = pixman_image_create_bits (PIXMAN_a8r8g8b8, 147 WIDTH, HEIGHT, 148 NULL, 0); 149 150 draw_checkerboard (dest_img, 25, 0xffaaaaaa, 0xffbbbbbb); 151 152 pixman_transform_init_identity (&transform); 153 154 /* 155 * The create_radial() function returns gradients centered in the 156 * origin and whose interesting part fits a 1x1 square. We want to 157 * paint these gradients on a SIZExSIZE square and to make things 158 * easier we want the origin in the top-left corner of the square 159 * we want to see. 160 */ 161 pixman_transform_translate (NULL, &transform, 162 pixman_double_to_fixed (0.5), 163 pixman_double_to_fixed (0.5)); 164 165 pixman_transform_scale (NULL, &transform, 166 pixman_double_to_fixed (SIZE), 167 pixman_double_to_fixed (SIZE)); 168 169 /* 170 * Gradients are evaluated at the center of each pixel, so we need 171 * to translate by half a pixel to trigger some interesting 172 * cornercases. In particular, the original implementation of PDF 173 * radial gradients tried to divide by 0 when using this transform 174 * on the "tangent circles" cases. 175 */ 176 pixman_transform_translate (NULL, &transform, 177 pixman_double_to_fixed (0.5), 178 pixman_double_to_fixed (0.5)); 179 180 for (i = 0; i < NUM_GRADIENTS; i++) 181 { 182 src_img = create_radial (i); 183 pixman_image_set_transform (src_img, &transform); 184 185 for (j = 0; j < NUM_REPEAT; j++) 186 { 187 pixman_image_set_repeat (src_img, repeat[j]); 188 189 pixman_image_composite32 (PIXMAN_OP_OVER, 190 src_img, 191 NULL, 192 dest_img, 193 0, 0, 194 0, 0, 195 i * SIZE, j * SIZE, 196 SIZE, SIZE); 197 198 } 199 200 pixman_image_unref (src_img); 201 } 202 203 show_image (dest_img); 204 205 pixman_image_unref (dest_img); 206 207 return 0; 208 } 209
