Add dithering to gradients
Change-Id: Ic1208855bde3a254eca2fd7cef43e0f1318ce419
diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index d601f01..0e77cb2 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -75,9 +75,11 @@
// Linear
"varying highp vec2 linear;\n",
"varying highp float linear;\n",
+
// Circular
"varying highp vec2 circular;\n",
"varying highp vec2 circular;\n",
+
// Sweep
"varying highp vec2 sweep;\n",
"varying highp vec2 sweep;\n",
@@ -92,9 +94,11 @@
// Linear
" linear = vec2((screenSpace * position).x, 0.5);\n",
" linear = (screenSpace * position).x;\n",
+
// Circular
" circular = (screenSpace * position).xy;\n",
" circular = (screenSpace * position).xy;\n",
+
// Sweep
" sweep = (screenSpace * position).xy;\n",
" sweep = (screenSpace * position).xy;\n",
@@ -137,19 +141,24 @@
"uniform sampler2D sampler;\n";
const char* gFS_Uniforms_ExternalTextureSampler =
"uniform samplerExternalOES sampler;\n";
+#define FS_UNIFORMS_DITHER \
+ "uniform float ditherSize;\n" \
+ "uniform sampler2D ditherSampler;\n"
+#define FS_UNIFORMS_GRADIENT \
+ "uniform vec4 startColor;\n" \
+ "uniform vec4 endColor;\n"
const char* gFS_Uniforms_GradientSampler[6] = {
// Linear
- "uniform sampler2D gradientSampler;\n",
- "uniform vec4 startColor;\n"
- "uniform vec4 endColor;\n",
+ FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
+ FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT,
+
// Circular
- "uniform sampler2D gradientSampler;\n",
- "uniform vec4 startColor;\n"
- "uniform vec4 endColor;\n",
+ FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
+ FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT,
+
// Sweep
- "uniform sampler2D gradientSampler;\n",
- "uniform vec4 startColor;\n"
- "uniform vec4 endColor;\n",
+ FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
+ FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT
};
const char* gFS_Uniforms_BitmapSampler =
"uniform sampler2D bitmapSampler;\n";
@@ -176,6 +185,11 @@
" highp vec2 outBitmapTexCoords = outPointBitmapTexCoords + "
"((gl_PointCoord - vec2(0.5, 0.5)) * textureDimension * vec2(pointSize, pointSize));\n";
+#define FS_MAIN_DITHER \
+ "texture2D(ditherSampler, gl_FragCoord.xy * ditherSize).a * ditherSize * ditherSize"
+const char* gFS_Main_AddDitherToGradient =
+ " gradientColor += " FS_MAIN_DITHER ";\n";
+
// Fast cases
const char* gFS_Fast_SingleColor =
"\nvoid main(void) {\n"
@@ -207,18 +221,18 @@
"}\n\n";
const char* gFS_Fast_SingleGradient[2] = {
"\nvoid main(void) {\n"
- " gl_FragColor = texture2D(gradientSampler, linear);\n"
+ " gl_FragColor = " FS_MAIN_DITHER " + texture2D(gradientSampler, linear);\n"
"}\n\n",
"\nvoid main(void) {\n"
- " gl_FragColor = mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
+ " gl_FragColor = " FS_MAIN_DITHER " + mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
"}\n\n"
};
const char* gFS_Fast_SingleModulateGradient[2] = {
"\nvoid main(void) {\n"
- " gl_FragColor = color.a * texture2D(gradientSampler, linear);\n"
+ " gl_FragColor " FS_MAIN_DITHER " + color.a * texture2D(gradientSampler, linear);\n"
"}\n\n",
"\nvoid main(void) {\n"
- " gl_FragColor = color.a * mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
+ " gl_FragColor " FS_MAIN_DITHER " + color.a * mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
"}\n\n"
};
@@ -254,16 +268,21 @@
};
const char* gFS_Main_FetchGradient[6] = {
// Linear
- " vec4 gradientColor = texture2D(gradientSampler, linear);\n",
- " vec4 gradientColor = mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n",
+ " highp vec4 gradientColor = texture2D(gradientSampler, linear);\n",
+
+ " highp vec4 gradientColor = mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n",
+
// Circular
- " vec4 gradientColor = texture2D(gradientSampler, vec2(length(circular), 0.5));\n",
- " vec4 gradientColor = mix(startColor, endColor, clamp(length(circular), 0.0, 1.0));\n",
+ " highp vec4 gradientColor = texture2D(gradientSampler, vec2(length(circular), 0.5));\n",
+
+ " highp vec4 gradientColor = mix(startColor, endColor, clamp(length(circular), 0.0, 1.0));\n",
+
// Sweep
" highp float index = atan(sweep.y, sweep.x) * 0.15915494309; // inv(2 * PI)\n"
- " vec4 gradientColor = texture2D(gradientSampler, vec2(index - floor(index), 0.5));\n",
+ " highp vec4 gradientColor = texture2D(gradientSampler, vec2(index - floor(index), 0.5));\n",
+
" highp float index = atan(sweep.y, sweep.x) * 0.15915494309; // inv(2 * PI)\n"
- " vec4 gradientColor = mix(startColor, endColor, clamp(index - floor(index), 0.0, 1.0));\n"
+ " highp vec4 gradientColor = mix(startColor, endColor, clamp(index - floor(index), 0.0, 1.0));\n"
};
const char* gFS_Main_FetchBitmap =
" vec4 bitmapColor = texture2D(bitmapSampler, outBitmapTexCoords);\n";
@@ -651,6 +670,7 @@
}
if (description.hasGradient) {
shader.append(gFS_Main_FetchGradient[gradientIndex(description)]);
+ shader.append(gFS_Main_AddDitherToGradient);
}
if (description.hasBitmap) {
if (description.isPoint) {