1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/cairo/pixman-dither.patch Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,310 @@
1.4 +diff --git a/gfx/cairo/libpixman/src/pixman-dither.h b/gfx/cairo/libpixman/src/pixman-dither.h
1.5 +new file mode 100644
1.6 +--- /dev/null
1.7 ++++ b/gfx/cairo/libpixman/src/pixman-dither.h
1.8 +@@ -0,0 +1,51 @@
1.9 ++#define R16_BITS 5
1.10 ++#define G16_BITS 6
1.11 ++#define B16_BITS 5
1.12 ++
1.13 ++#define R16_SHIFT (B16_BITS + G16_BITS)
1.14 ++#define G16_SHIFT (B16_BITS)
1.15 ++#define B16_SHIFT 0
1.16 ++
1.17 ++#define MASK 0xff
1.18 ++#define ONE_HALF 0x80
1.19 ++
1.20 ++#define A_SHIFT 8 * 3
1.21 ++#define R_SHIFT 8 * 2
1.22 ++#define G_SHIFT 8
1.23 ++#define A_MASK 0xff000000
1.24 ++#define R_MASK 0xff0000
1.25 ++#define G_MASK 0xff00
1.26 ++
1.27 ++#define RB_MASK 0xff00ff
1.28 ++#define AG_MASK 0xff00ff00
1.29 ++#define RB_ONE_HALF 0x800080
1.30 ++#define RB_MASK_PLUS_ONE 0x10000100
1.31 ++
1.32 ++#define ALPHA_8(x) ((x) >> A_SHIFT)
1.33 ++#define RED_8(x) (((x) >> R_SHIFT) & MASK)
1.34 ++#define GREEN_8(x) (((x) >> G_SHIFT) & MASK)
1.35 ++#define BLUE_8(x) ((x) & MASK)
1.36 ++
1.37 ++// This uses the same dithering technique that Skia does.
1.38 ++// It is essentially preturbing the lower bit based on the
1.39 ++// high bit
1.40 ++static inline uint16_t dither_32_to_16(uint32_t c)
1.41 ++{
1.42 ++ uint8_t b = BLUE_8(c);
1.43 ++ uint8_t g = GREEN_8(c);
1.44 ++ uint8_t r = RED_8(c);
1.45 ++ r = ((r << 1) - ((r >> (8 - R16_BITS) << (8 - R16_BITS)) | (r >> R16_BITS))) >> (8 - R16_BITS);
1.46 ++ g = ((g << 1) - ((g >> (8 - G16_BITS) << (8 - G16_BITS)) | (g >> G16_BITS))) >> (8 - G16_BITS);
1.47 ++ b = ((b << 1) - ((b >> (8 - B16_BITS) << (8 - B16_BITS)) | (b >> B16_BITS))) >> (8 - B16_BITS);
1.48 ++ return ((r << R16_SHIFT) | (g << G16_SHIFT) | (b << B16_SHIFT));
1.49 ++}
1.50 ++
1.51 ++static inline uint16_t dither_8888_to_0565(uint32_t color, pixman_bool_t toggle)
1.52 ++{
1.53 ++ // alternate between a preturbed truncation and a regular truncation
1.54 ++ if (toggle) {
1.55 ++ return dither_32_to_16(color);
1.56 ++ } else {
1.57 ++ return CONVERT_8888_TO_0565(color);
1.58 ++ }
1.59 ++}
1.60 +diff --git a/gfx/cairo/libpixman/src/pixman-linear-gradient.c b/gfx/cairo/libpixman/src/pixman-linear-gradient.c
1.61 +--- a/gfx/cairo/libpixman/src/pixman-linear-gradient.c
1.62 ++++ b/gfx/cairo/libpixman/src/pixman-linear-gradient.c
1.63 +@@ -26,16 +26,18 @@
1.64 + */
1.65 +
1.66 + #ifdef HAVE_CONFIG_H
1.67 + #include <config.h>
1.68 + #endif
1.69 + #include <stdlib.h>
1.70 + #include "pixman-private.h"
1.71 +
1.72 ++#include "pixman-dither.h"
1.73 ++
1.74 + static pixman_bool_t
1.75 + linear_gradient_is_horizontal (pixman_image_t *image,
1.76 + int x,
1.77 + int y,
1.78 + int width,
1.79 + int height)
1.80 + {
1.81 + linear_gradient_t *linear = (linear_gradient_t *)image;
1.82 +@@ -222,25 +224,28 @@ linear_get_scanline_narrow (pixman_iter_
1.83 + return iter->buffer;
1.84 + }
1.85 +
1.86 + static uint16_t convert_8888_to_0565(uint32_t color)
1.87 + {
1.88 + return CONVERT_8888_TO_0565(color);
1.89 + }
1.90 +
1.91 ++
1.92 ++
1.93 + static uint32_t *
1.94 + linear_get_scanline_16 (pixman_iter_t *iter,
1.95 + const uint32_t *mask)
1.96 + {
1.97 + pixman_image_t *image = iter->image;
1.98 + int x = iter->x;
1.99 + int y = iter->y;
1.100 + int width = iter->width;
1.101 + uint16_t * buffer = (uint16_t*)iter->buffer;
1.102 ++ pixman_bool_t toggle = ((x ^ y) & 1);
1.103 +
1.104 + pixman_vector_t v, unit;
1.105 + pixman_fixed_32_32_t l;
1.106 + pixman_fixed_48_16_t dx, dy;
1.107 + gradient_t *gradient = (gradient_t *)image;
1.108 + linear_gradient_t *linear = (linear_gradient_t *)image;
1.109 + uint16_t *end = buffer + width;
1.110 + pixman_gradient_walker_t walker;
1.111 +@@ -294,34 +299,47 @@ linear_get_scanline_16 (pixman_iter_t *
1.112 + t = ((dx * v.vector[0] + dy * v.vector[1]) -
1.113 + (dx * linear->p1.x + dy * linear->p1.y) * v2) * invden;
1.114 + inc = (dx * unit.vector[0] + dy * unit.vector[1]) * invden;
1.115 + }
1.116 + next_inc = 0;
1.117 +
1.118 + if (((pixman_fixed_32_32_t )(inc * width)) == 0)
1.119 + {
1.120 +- register uint16_t color;
1.121 ++ register uint32_t color;
1.122 ++ uint16_t dither_diff;
1.123 ++ uint16_t color16;
1.124 ++ uint16_t color16b;
1.125 +
1.126 +- color = convert_8888_to_0565(_pixman_gradient_walker_pixel (&walker, t));
1.127 +- while (buffer < end)
1.128 +- *buffer++ = color;
1.129 ++ color = _pixman_gradient_walker_pixel (&walker, t);
1.130 ++ color16 = dither_8888_to_0565(color, toggle);
1.131 ++ color16b = dither_8888_to_0565(color, toggle^1);
1.132 ++ // compute the difference
1.133 ++ dither_diff = color16 ^ color16b;
1.134 ++ while (buffer < end) {
1.135 ++ *buffer++ = color16;
1.136 ++ // use dither_diff to toggle between color16 and color16b
1.137 ++ color16 ^= dither_diff;
1.138 ++ toggle ^= 1;
1.139 ++ }
1.140 + }
1.141 + else
1.142 + {
1.143 + int i;
1.144 +
1.145 + i = 0;
1.146 + while (buffer < end)
1.147 + {
1.148 + if (!mask || *mask++)
1.149 + {
1.150 +- *buffer = convert_8888_to_0565(_pixman_gradient_walker_pixel (&walker,
1.151 +- t + next_inc));
1.152 ++ *buffer = dither_8888_to_0565(_pixman_gradient_walker_pixel (&walker,
1.153 ++ t + next_inc),
1.154 ++ toggle);
1.155 + }
1.156 ++ toggle ^= 1;
1.157 + i++;
1.158 + next_inc = inc * i;
1.159 + buffer++;
1.160 + }
1.161 + }
1.162 + }
1.163 + else
1.164 + {
1.165 +@@ -340,18 +358,20 @@ linear_get_scanline_16 (pixman_iter_t *
1.166 +
1.167 + invden = pixman_fixed_1 * (double) pixman_fixed_1 /
1.168 + (l * (double) v.vector[2]);
1.169 + v2 = v.vector[2] * (1. / pixman_fixed_1);
1.170 + t = ((dx * v.vector[0] + dy * v.vector[1]) -
1.171 + (dx * linear->p1.x + dy * linear->p1.y) * v2) * invden;
1.172 + }
1.173 +
1.174 +- *buffer = convert_8888_to_0565(_pixman_gradient_walker_pixel (&walker, t));
1.175 ++ *buffer = dither_8888_to_0565(_pixman_gradient_walker_pixel (&walker, t),
1.176 ++ toggle);
1.177 + }
1.178 ++ toggle ^= 1;
1.179 +
1.180 + ++buffer;
1.181 +
1.182 + v.vector[0] += unit.vector[0];
1.183 + v.vector[1] += unit.vector[1];
1.184 + v.vector[2] += unit.vector[2];
1.185 + }
1.186 + }
1.187 +@@ -369,17 +389,18 @@ linear_get_scanline_wide (pixman_iter_t
1.188 + pixman_expand ((uint64_t *)buffer, buffer, PIXMAN_a8r8g8b8, iter->width);
1.189 +
1.190 + return buffer;
1.191 + }
1.192 +
1.193 + void
1.194 + _pixman_linear_gradient_iter_init (pixman_image_t *image, pixman_iter_t *iter)
1.195 + {
1.196 +- if (linear_gradient_is_horizontal (
1.197 ++ // XXX: we can't use this optimization when dithering
1.198 ++ if (0 && linear_gradient_is_horizontal (
1.199 + iter->image, iter->x, iter->y, iter->width, iter->height))
1.200 + {
1.201 + if (iter->flags & ITER_16)
1.202 + linear_get_scanline_16 (iter, NULL);
1.203 + else if (iter->flags & ITER_NARROW)
1.204 + linear_get_scanline_narrow (iter, NULL);
1.205 + else
1.206 + linear_get_scanline_wide (iter, NULL);
1.207 +diff --git a/gfx/cairo/libpixman/src/pixman-radial-gradient.c b/gfx/cairo/libpixman/src/pixman-radial-gradient.c
1.208 +--- a/gfx/cairo/libpixman/src/pixman-radial-gradient.c
1.209 ++++ b/gfx/cairo/libpixman/src/pixman-radial-gradient.c
1.210 +@@ -29,16 +29,18 @@
1.211 +
1.212 + #ifdef HAVE_CONFIG_H
1.213 + #include <config.h>
1.214 + #endif
1.215 + #include <stdlib.h>
1.216 + #include <math.h>
1.217 + #include "pixman-private.h"
1.218 +
1.219 ++#include "pixman-dither.h"
1.220 ++
1.221 + static inline pixman_fixed_32_32_t
1.222 + dot (pixman_fixed_48_16_t x1,
1.223 + pixman_fixed_48_16_t y1,
1.224 + pixman_fixed_48_16_t z1,
1.225 + pixman_fixed_48_16_t x2,
1.226 + pixman_fixed_48_16_t y2,
1.227 + pixman_fixed_48_16_t z2)
1.228 + {
1.229 +@@ -489,16 +491,17 @@ radial_get_scanline_16 (pixman_iter_t *i
1.230 + * <=> for every p, the radiuses associated with the two t solutions
1.231 + * have opposite sign
1.232 + */
1.233 + pixman_image_t *image = iter->image;
1.234 + int x = iter->x;
1.235 + int y = iter->y;
1.236 + int width = iter->width;
1.237 + uint16_t *buffer = iter->buffer;
1.238 ++ pixman_bool_t toggle = ((x ^ y) & 1);
1.239 +
1.240 + gradient_t *gradient = (gradient_t *)image;
1.241 + radial_gradient_t *radial = (radial_gradient_t *)image;
1.242 + uint16_t *end = buffer + width;
1.243 + pixman_gradient_walker_t walker;
1.244 + pixman_vector_t v, unit;
1.245 +
1.246 + /* reference point is the center of the pixel */
1.247 +@@ -575,25 +578,27 @@ radial_get_scanline_16 (pixman_iter_t *i
1.248 + unit.vector[0], unit.vector[1], 0);
1.249 + ddc = 2 * dot (unit.vector[0], unit.vector[1], 0,
1.250 + unit.vector[0], unit.vector[1], 0);
1.251 +
1.252 + while (buffer < end)
1.253 + {
1.254 + if (!mask || *mask++)
1.255 + {
1.256 +- *buffer = convert_8888_to_0565(
1.257 ++ *buffer = dither_8888_to_0565(
1.258 + radial_compute_color (radial->a, b, c,
1.259 + radial->inva,
1.260 + radial->delta.radius,
1.261 + radial->mindr,
1.262 + &walker,
1.263 +- image->common.repeat));
1.264 ++ image->common.repeat),
1.265 ++ toggle);
1.266 + }
1.267 +
1.268 ++ toggle ^= 1;
1.269 + b += db;
1.270 + c += dc;
1.271 + dc += ddc;
1.272 + ++buffer;
1.273 + }
1.274 + }
1.275 + else
1.276 + {
1.277 +@@ -621,31 +626,33 @@ radial_get_scanline_16 (pixman_iter_t *i
1.278 + radial->delta.x, radial->delta.y,
1.279 + radial->delta.radius);
1.280 + /* / pixman_fixed_1 / pixman_fixed_1 */
1.281 +
1.282 + c = fdot (pdx, pdy, -radial->c1.radius,
1.283 + pdx, pdy, radial->c1.radius);
1.284 + /* / pixman_fixed_1 / pixman_fixed_1 */
1.285 +
1.286 +- *buffer = convert_8888_to_0565 (
1.287 ++ *buffer = dither_8888_to_0565 (
1.288 + radial_compute_color (radial->a, b, c,
1.289 + radial->inva,
1.290 + radial->delta.radius,
1.291 + radial->mindr,
1.292 + &walker,
1.293 +- image->common.repeat));
1.294 ++ image->common.repeat),
1.295 ++ toggle);
1.296 + }
1.297 + else
1.298 + {
1.299 + *buffer = 0;
1.300 + }
1.301 + }
1.302 +
1.303 + ++buffer;
1.304 ++ toggle ^= 1;
1.305 +
1.306 + v.vector[0] += unit.vector[0];
1.307 + v.vector[1] += unit.vector[1];
1.308 + v.vector[2] += unit.vector[2];
1.309 + }
1.310 + }
1.311 +
1.312 + iter->y++;
1.313 +
