Optimize shaders for dithered gradients
It's faster to compute a dither calculation in the vertex shader and use
a varying (letting the GPU interpolate the fragment values) than to perform
that calculation in the fragment shader as part of a texture lookup.
Issue #7207600 Prime mr1 shader performance issues
Issue #7158326 Bad framerates on MR1 (Mako, Manta, Prime)
Change-Id: I15789582a6e9e2d8b9dd22aa5b0f72f0ba1cce7f
diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index 6baf448..8c81ce2 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -53,11 +53,14 @@
"uniform mediump float pointSize;\n";
const char* gVS_Header_Uniforms_HasGradient[3] = {
// Linear
- "uniform mat4 screenSpace;\n",
+ "uniform mat4 screenSpace;\n"
+ "uniform float ditherSize;\n",
// Circular
- "uniform mat4 screenSpace;\n",
+ "uniform mat4 screenSpace;\n"
+ "uniform float ditherSize;\n",
// Sweep
"uniform mat4 screenSpace;\n"
+ "uniform float ditherSize;\n"
};
const char* gVS_Header_Uniforms_HasBitmap =
"uniform mat4 textureTransform;\n"
@@ -75,16 +78,22 @@
"varying highp vec2 outPointBitmapTexCoords;\n";
const char* gVS_Header_Varyings_HasGradient[6] = {
// Linear
- "varying highp vec2 linear;\n",
- "varying float linear;\n",
+ "varying highp vec2 linear;\n"
+ "varying vec2 ditherTexCoords;\n",
+ "varying float linear;\n"
+ "varying vec2 ditherTexCoords;\n",
// Circular
- "varying highp vec2 circular;\n",
- "varying highp vec2 circular;\n",
+ "varying highp vec2 circular;\n"
+ "varying vec2 ditherTexCoords;\n",
+ "varying highp vec2 circular;\n"
+ "varying vec2 ditherTexCoords;\n",
// Sweep
- "varying highp vec2 sweep;\n",
- "varying highp vec2 sweep;\n",
+ "varying highp vec2 sweep;\n"
+ "varying vec2 ditherTexCoords;\n",
+ "varying highp vec2 sweep;\n"
+ "varying vec2 ditherTexCoords;\n",
};
const char* gVS_Main =
"\nvoid main(void) {\n";
@@ -94,16 +103,22 @@
" outTexCoords = (mainTextureTransform * vec4(texCoords, 0.0, 1.0)).xy;\n";
const char* gVS_Main_OutGradient[6] = {
// Linear
- " linear = vec2((screenSpace * position).x, 0.5);\n",
- " linear = (screenSpace * position).x;\n",
+ " linear = vec2((screenSpace * position).x, 0.5);\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
+ " linear = (screenSpace * position).x;\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
// Circular
- " circular = (screenSpace * position).xy;\n",
- " circular = (screenSpace * position).xy;\n",
+ " circular = (screenSpace * position).xy;\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
+ " circular = (screenSpace * position).xy;\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
// Sweep
- " sweep = (screenSpace * position).xy;\n",
- " sweep = (screenSpace * position).xy;\n",
+ " sweep = (screenSpace * position).xy;\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
+ " sweep = (screenSpace * position).xy;\n"
+ " ditherTexCoords = (gl_Position * ditherSize).xy;\n",
};
const char* gVS_Main_OutBitmapTexCoords =
" outBitmapTexCoords = (textureTransform * position).xy * textureDimension;\n";
@@ -144,7 +159,7 @@
const char* gFS_Uniforms_ExternalTextureSampler =
"uniform samplerExternalOES baseSampler;\n";
#define FS_UNIFORMS_DITHER \
- "uniform float ditherSize;\n" \
+ "uniform float ditherSizeSquared;\n" \
"uniform sampler2D ditherSampler;\n"
#define FS_UNIFORMS_GRADIENT \
"uniform vec4 startColor;\n" \
@@ -188,7 +203,7 @@
"((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"
+ "texture2D(ditherSampler, ditherTexCoords).a * ditherSizeSquared"
const char* gFS_Main_AddDitherToGradient =
" gradientColor += " FS_MAIN_DITHER ";\n";
@@ -505,9 +520,6 @@
} else if (description.isAA) {
shader.append(gVS_Main_AA);
}
- if (description.hasGradient) {
- shader.append(gVS_Main_OutGradient[gradientIndex(description)]);
- }
if (description.hasBitmap) {
shader.append(description.isPoint ?
gVS_Main_OutPointBitmapTexCoords :
@@ -518,6 +530,9 @@
}
// Output transformed position
shader.append(gVS_Main_Position);
+ if (description.hasGradient) {
+ shader.append(gVS_Main_OutGradient[gradientIndex(description)]);
+ }
}
// End the shader
shader.append(gVS_Footer);