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comparison: gfx/cairo/libpixman/src/pixman-gradient-walker.c
gfx/cairo/libpixman/src/pixman-gradient-walker.c
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| -1:000000000000 | 0:98c75f62b4d3 |
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| 1 /* | |
| 2 * | |
| 3 * Copyright © 2000 Keith Packard, member of The XFree86 Project, Inc. | |
| 4 * 2005 Lars Knoll & Zack Rusin, Trolltech | |
| 5 * | |
| 6 * Permission to use, copy, modify, distribute, and sell this software and its | |
| 7 * documentation for any purpose is hereby granted without fee, provided that | |
| 8 * the above copyright notice appear in all copies and that both that | |
| 9 * copyright notice and this permission notice appear in supporting | |
| 10 * documentation, and that the name of Keith Packard not be used in | |
| 11 * advertising or publicity pertaining to distribution of the software without | |
| 12 * specific, written prior permission. Keith Packard makes no | |
| 13 * representations about the suitability of this software for any purpose. It | |
| 14 * is provided "as is" without express or implied warranty. | |
| 15 * | |
| 16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS | |
| 17 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND | |
| 18 * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY | |
| 19 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
| 20 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN | |
| 21 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING | |
| 22 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
| 23 * SOFTWARE. | |
| 24 */ | |
| 25 | |
| 26 #ifdef HAVE_CONFIG_H | |
| 27 #include <config.h> | |
| 28 #endif | |
| 29 #include "pixman-private.h" | |
| 30 | |
| 31 void | |
| 32 _pixman_gradient_walker_init (pixman_gradient_walker_t *walker, | |
| 33 gradient_t * gradient, | |
| 34 pixman_repeat_t repeat) | |
| 35 { | |
| 36 walker->num_stops = gradient->n_stops; | |
| 37 walker->stops = gradient->stops; | |
| 38 walker->left_x = 0; | |
| 39 walker->right_x = 0x10000; | |
| 40 walker->stepper = 0; | |
| 41 walker->left_ag = 0; | |
| 42 walker->left_rb = 0; | |
| 43 walker->right_ag = 0; | |
| 44 walker->right_rb = 0; | |
| 45 walker->repeat = repeat; | |
| 46 | |
| 47 walker->need_reset = TRUE; | |
| 48 } | |
| 49 | |
| 50 static void | |
| 51 gradient_walker_reset (pixman_gradient_walker_t *walker, | |
| 52 pixman_fixed_48_16_t pos) | |
| 53 { | |
| 54 int32_t x, left_x, right_x; | |
| 55 pixman_color_t *left_c, *right_c; | |
| 56 int n, count = walker->num_stops; | |
| 57 pixman_gradient_stop_t *stops = walker->stops; | |
| 58 | |
| 59 if (walker->repeat == PIXMAN_REPEAT_NORMAL) | |
| 60 { | |
| 61 x = (int32_t)pos & 0xffff; | |
| 62 } | |
| 63 else if (walker->repeat == PIXMAN_REPEAT_REFLECT) | |
| 64 { | |
| 65 x = (int32_t)pos & 0xffff; | |
| 66 if ((int32_t)pos & 0x10000) | |
| 67 x = 0x10000 - x; | |
| 68 } | |
| 69 else | |
| 70 { | |
| 71 x = pos; | |
| 72 } | |
| 73 | |
| 74 for (n = 0; n < count; n++) | |
| 75 { | |
| 76 if (x < stops[n].x) | |
| 77 break; | |
| 78 } | |
| 79 | |
| 80 left_x = stops[n - 1].x; | |
| 81 left_c = &stops[n - 1].color; | |
| 82 | |
| 83 right_x = stops[n].x; | |
| 84 right_c = &stops[n].color; | |
| 85 | |
| 86 if (walker->repeat == PIXMAN_REPEAT_NORMAL) | |
| 87 { | |
| 88 left_x += (pos - x); | |
| 89 right_x += (pos - x); | |
| 90 } | |
| 91 else if (walker->repeat == PIXMAN_REPEAT_REFLECT) | |
| 92 { | |
| 93 if ((int32_t)pos & 0x10000) | |
| 94 { | |
| 95 pixman_color_t *tmp_c; | |
| 96 int32_t tmp_x; | |
| 97 | |
| 98 tmp_x = 0x10000 - right_x; | |
| 99 right_x = 0x10000 - left_x; | |
| 100 left_x = tmp_x; | |
| 101 | |
| 102 tmp_c = right_c; | |
| 103 right_c = left_c; | |
| 104 left_c = tmp_c; | |
| 105 | |
| 106 x = 0x10000 - x; | |
| 107 } | |
| 108 left_x += (pos - x); | |
| 109 right_x += (pos - x); | |
| 110 } | |
| 111 else if (walker->repeat == PIXMAN_REPEAT_NONE) | |
| 112 { | |
| 113 if (n == 0) | |
| 114 right_c = left_c; | |
| 115 else if (n == count) | |
| 116 left_c = right_c; | |
| 117 } | |
| 118 | |
| 119 walker->left_x = left_x; | |
| 120 walker->right_x = right_x; | |
| 121 walker->left_ag = ((left_c->alpha >> 8) << 16) | (left_c->green >> 8); | |
| 122 walker->left_rb = ((left_c->red & 0xff00) << 8) | (left_c->blue >> 8); | |
| 123 walker->right_ag = ((right_c->alpha >> 8) << 16) | (right_c->green >> 8); | |
| 124 walker->right_rb = ((right_c->red & 0xff00) << 8) | (right_c->blue >> 8); | |
| 125 | |
| 126 if (walker->left_x == walker->right_x || | |
| 127 (walker->left_ag == walker->right_ag && | |
| 128 walker->left_rb == walker->right_rb)) | |
| 129 { | |
| 130 walker->stepper = 0; | |
| 131 } | |
| 132 else | |
| 133 { | |
| 134 int32_t width = right_x - left_x; | |
| 135 walker->stepper = ((1 << 24) + width / 2) / width; | |
| 136 } | |
| 137 | |
| 138 walker->need_reset = FALSE; | |
| 139 } | |
| 140 | |
| 141 uint32_t | |
| 142 _pixman_gradient_walker_pixel (pixman_gradient_walker_t *walker, | |
| 143 pixman_fixed_48_16_t x) | |
| 144 { | |
| 145 int dist, idist; | |
| 146 uint32_t t1, t2, a, color; | |
| 147 | |
| 148 if (walker->need_reset || x < walker->left_x || x >= walker->right_x) | |
| 149 gradient_walker_reset (walker, x); | |
| 150 | |
| 151 dist = ((int)(x - walker->left_x) * walker->stepper) >> 16; | |
| 152 idist = 256 - dist; | |
| 153 | |
| 154 /* combined INTERPOLATE and premultiply */ | |
| 155 t1 = walker->left_rb * idist + walker->right_rb * dist; | |
| 156 t1 = (t1 >> 8) & 0xff00ff; | |
| 157 | |
| 158 t2 = walker->left_ag * idist + walker->right_ag * dist; | |
| 159 t2 &= 0xff00ff00; | |
| 160 | |
| 161 color = t2 & 0xff000000; | |
| 162 a = t2 >> 24; | |
| 163 | |
| 164 t1 = t1 * a + 0x800080; | |
| 165 t1 = (t1 + ((t1 >> 8) & 0xff00ff)) >> 8; | |
| 166 | |
| 167 t2 = (t2 >> 8) * a + 0x800080; | |
| 168 t2 = (t2 + ((t2 >> 8) & 0xff00ff)); | |
| 169 | |
| 170 return (color | (t1 & 0xff00ff) | (t2 & 0xff00)); | |
| 171 } | |
| 172 |
