Merge "Use float textures to render gradients when possible" into jb-mr2-dev

6 files changed, 192 insertions, 122 deletions

diff --git a/libs/hwui/Dither.cpp b/libs/hwui/Dither.cpp
index e80b325..9bc5c14 100644
--- a/libs/hwui/Dither.cpp
+++ b/libs/hwui/Dither.cpp
@@ -21,38 +21,46 @@ namespace android {
 namespace uirenderer {
 
 ///////////////////////////////////////////////////////////////////////////////
-// Defines
-///////////////////////////////////////////////////////////////////////////////
-
-// Must be a power of two
-#define DITHER_KERNEL_SIZE 4
-
-///////////////////////////////////////////////////////////////////////////////
 // Lifecycle
 ///////////////////////////////////////////////////////////////////////////////
 
 void Dither::bindDitherTexture() {
     if (!mInitialized) {
-        const uint8_t pattern[] = {
-             0,  8,  2, 10,
-            12,  4, 14,  6,
-             3, 11,  1,  9,
-            15,  7, 13,  5
-        };
+        bool useFloatTexture = Extensions::getInstance().getMajorGlVersion() >= 3;
 
         glGenTextures(1, &mDitherTexture);
         glBindTexture(GL_TEXTURE_2D, mDitherTexture);
 
-        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, DITHER_KERNEL_SIZE, DITHER_KERNEL_SIZE, 0,
-                GL_ALPHA, GL_UNSIGNED_BYTE, &pattern);
+        if (useFloatTexture) {
+            float dither = 1.0f / (255.0f * DITHER_KERNEL_SIZE * DITHER_KERNEL_SIZE);
+            const GLfloat pattern[] = {
+                 0 * dither,  8 * dither,  2 * dither, 10 * dither,
+                12 * dither,  4 * dither, 14 * dither,  6 * dither,
+                 3 * dither, 11 * dither,  1 * dither,  9 * dither,
+                15 * dither,  7 * dither, 13 * dither,  5 * dither
+            };
+
+            glPixelStorei(GL_UNPACK_ALIGNMENT, sizeof(GLfloat));
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_R16F, DITHER_KERNEL_SIZE, DITHER_KERNEL_SIZE, 0,
+                    GL_RED, GL_FLOAT, &pattern);
+        } else {
+            const uint8_t pattern[] = {
+                 0,  8,  2, 10,
+                12,  4, 14,  6,
+                 3, 11,  1,  9,
+                15,  7, 13,  5
+            };
+
+            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, DITHER_KERNEL_SIZE, DITHER_KERNEL_SIZE, 0,
+                    GL_ALPHA, GL_UNSIGNED_BYTE, &pattern);
+        }
 
         mInitialized = true;
     } else {
@@ -76,10 +84,7 @@ void Dither::setupProgram(Program* program, GLuint* textureUnit) {
 
     bindDitherTexture();
 
-    float ditherSize = 1.0f / DITHER_KERNEL_SIZE;
     glUniform1i(program->getUniform("ditherSampler"), textureSlot);
-    glUniform1f(program->getUniform("ditherSize"), ditherSize);
-    glUniform1f(program->getUniform("ditherSizeSquared"), ditherSize * ditherSize);
 }
 
 }; // namespace uirenderer
diff --git a/libs/hwui/Dither.h b/libs/hwui/Dither.h
index 34cf9bf..4d1f921 100644
--- a/libs/hwui/Dither.h
+++ b/libs/hwui/Dither.h
@@ -17,13 +17,23 @@
 #ifndef ANDROID_HWUI_DITHER_H
 #define ANDROID_HWUI_DITHER_H
 
-#include <GLES2/gl2.h>
+#include <GLES3/gl3.h>
 
 #include "Program.h"
 
 namespace android {
 namespace uirenderer {
 
+///////////////////////////////////////////////////////////////////////////////
+// Defines
+///////////////////////////////////////////////////////////////////////////////
+
+// Must be a power of two
+#define DITHER_KERNEL_SIZE 4
+// These must not use the .0f notation as they are used from GLSL
+#define DITHER_KERNEL_SIZE_INV (1.0 / 4.0)
+#define DITHER_KERNEL_SIZE_INV_SQUARE (1.0 / 16.0)
+
 /**
  * Handles dithering for programs.
  */
diff --git a/libs/hwui/GradientCache.cpp b/libs/hwui/GradientCache.cpp
index d681609..eef366c 100644
--- a/libs/hwui/GradientCache.cpp
+++ b/libs/hwui/GradientCache.cpp
@@ -27,13 +27,6 @@ namespace android {
 namespace uirenderer {
 
 ///////////////////////////////////////////////////////////////////////////////
-// Defines
-///////////////////////////////////////////////////////////////////////////////
-
-#define GRADIENT_TEXTURE_HEIGHT 2
-#define GRADIENT_BYTES_PER_PIXEL 4
-
-///////////////////////////////////////////////////////////////////////////////
 // Functions
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -83,6 +76,10 @@ GradientCache::GradientCache():
     glGetIntegerv(GL_MAX_TEXTURE_SIZE, &mMaxTextureSize);
 
     mCache.setOnEntryRemovedListener(this);
+
+    const Extensions& extensions = Extensions::getInstance();
+    mUseFloatTexture = extensions.getMajorGlVersion() >= 3;
+    mHasNpot = extensions.hasNPot();
 }
 
 GradientCache::GradientCache(uint32_t maxByteSize):
@@ -120,7 +117,7 @@ void GradientCache::setMaxSize(uint32_t maxSize) {
 
 void GradientCache::operator()(GradientCacheEntry& shader, Texture*& texture) {
     if (texture) {
-        const uint32_t size = texture->width * texture->height * GRADIENT_BYTES_PER_PIXEL;
+        const uint32_t size = texture->width * texture->height * bytesPerPixel();
         mSize -= size;
 
         glDeleteTextures(1, &texture->id);
@@ -151,7 +148,7 @@ void GradientCache::getGradientInfo(const uint32_t* colors, const int count,
         GradientInfo& info) {
     uint32_t width = 256 * (count - 1);
 
-    if (!Extensions::getInstance().hasNPot()) {
+    if (!mHasNpot) {
         width = 1 << (31 - __builtin_clz(width));
     }
 
@@ -175,12 +172,12 @@ Texture* GradientCache::addLinearGradient(GradientCacheEntry& gradient,
 
     Texture* texture = new Texture;
     texture->width = info.width;
-    texture->height = GRADIENT_TEXTURE_HEIGHT;
+    texture->height = 2;
     texture->blend = info.hasAlpha;
     texture->generation = 1;
 
     // Asume the cache is always big enough
-    const uint32_t size = texture->width * texture->height * GRADIENT_BYTES_PER_PIXEL;
+    const uint32_t size = texture->width * texture->height * bytesPerPixel();
     while (getSize() + size > mMaxSize) {
         mCache.removeOldest();
     }
@@ -193,69 +190,110 @@ Texture* GradientCache::addLinearGradient(GradientCacheEntry& gradient,
     return texture;
 }
 
+size_t GradientCache::bytesPerPixel() const {
+    // We use 4 channels (RGBA)
+    return 4 * (mUseFloatTexture ? sizeof(float) : sizeof(uint8_t));
+}
+
+void GradientCache::splitToBytes(uint32_t inColor, GradientColor& outColor) const {
+    outColor.r = (inColor >> 16) & 0xff;
+    outColor.g = (inColor >>  8) & 0xff;
+    outColor.b = (inColor >>  0) & 0xff;
+    outColor.a = (inColor >> 24) & 0xff;
+}
+
+void GradientCache::splitToFloats(uint32_t inColor, GradientColor& outColor) const {
+    outColor.r = ((inColor >> 16) & 0xff) / 255.0f;
+    outColor.g = ((inColor >>  8) & 0xff) / 255.0f;
+    outColor.b = ((inColor >>  0) & 0xff) / 255.0f;
+    outColor.a = ((inColor >> 24) & 0xff) / 255.0f;
+}
+
+void GradientCache::mixBytes(GradientColor& start, GradientColor& end, float amount,
+        uint8_t*& dst) const {
+    float oppAmount = 1.0f - amount;
+    const float alpha = start.a * oppAmount + end.a * amount;
+    const float a = alpha / 255.0f;
+
+    *dst++ = uint8_t(a * (start.r * oppAmount + end.r * amount));
+    *dst++ = uint8_t(a * (start.g * oppAmount + end.g * amount));
+    *dst++ = uint8_t(a * (start.b * oppAmount + end.b * amount));
+    *dst++ = uint8_t(alpha);
+}
+
+void GradientCache::mixFloats(GradientColor& start, GradientColor& end, float amount,
+        uint8_t*& dst) const {
+    float oppAmount = 1.0f - amount;
+    const float a = start.a * oppAmount + end.a * amount;
+
+    float* d = (float*) dst;
+    *d++ = a * (start.r * oppAmount + end.r * amount);
+    *d++ = a * (start.g * oppAmount + end.g * amount);
+    *d++ = a * (start.b * oppAmount + end.b * amount);
+    *d++ = a;
+
+    dst += 4 * sizeof(float);
+}
+
 void GradientCache::generateTexture(uint32_t* colors, float* positions,
         int count, Texture* texture) {
-
     const uint32_t width = texture->width;
-    const GLsizei rowBytes = width * GRADIENT_BYTES_PER_PIXEL;
-    uint32_t pixels[width * texture->height];
+    const GLsizei rowBytes = width * bytesPerPixel();
+    uint8_t pixels[rowBytes * texture->height];
 
-    int currentPos = 1;
+    static ChannelSplitter gSplitters[] = {
+            &android::uirenderer::GradientCache::splitToBytes,
+            &android::uirenderer::GradientCache::splitToFloats,
+    };
+    ChannelSplitter split = gSplitters[mUseFloatTexture];
 
-    float startA = (colors[0] >> 24) & 0xff;
-    float startR = (colors[0] >> 16) & 0xff;
-    float startG = (colors[0] >>  8) & 0xff;
-    float startB = (colors[0] >>  0) & 0xff;
+    static ChannelMixer gMixers[] = {
+            &android::uirenderer::GradientCache::mixBytes,
+            &android::uirenderer::GradientCache::mixFloats,
+    };
+    ChannelMixer mix = gMixers[mUseFloatTexture];
 
-    float endA = (colors[1] >> 24) & 0xff;
-    float endR = (colors[1] >> 16) & 0xff;
-    float endG = (colors[1] >>  8) & 0xff;
-    float endB = (colors[1] >>  0) & 0xff;
+    GradientColor start;
+    (this->*split)(colors[0], start);
 
-    float start = positions[0];
-    float distance = positions[1] - start;
+    GradientColor end;
+    (this->*split)(colors[1], end);
 
-    uint8_t* p = (uint8_t*) pixels;
+    int currentPos = 1;
+    float startPos = positions[0];
+    float distance = positions[1] - startPos;
+
+    uint8_t* dst = pixels;
     for (uint32_t x = 0; x < width; x++) {
         float pos = x / float(width - 1);
         if (pos > positions[currentPos]) {
-            startA = endA;
-            startR = endR;
-            startG = endG;
-            startB = endB;
-            start = positions[currentPos];
+            start = end;
+            startPos = positions[currentPos];
 
             currentPos++;
 
-            endA = (colors[currentPos] >> 24) & 0xff;
-            endR = (colors[currentPos] >> 16) & 0xff;
-            endG = (colors[currentPos] >>  8) & 0xff;
-            endB = (colors[currentPos] >>  0) & 0xff;
-            distance = positions[currentPos] - start;
+            (this->*split)(colors[currentPos], end);
+            distance = positions[currentPos] - startPos;
         }
 
-        float amount = (pos - start) / distance;
-        float oppAmount = 1.0f - amount;
-
-        const float alpha = startA * oppAmount + endA * amount;
-        const float a = alpha / 255.0f;
-        *p++ = uint8_t(a * (startR * oppAmount + endR * amount));
-        *p++ = uint8_t(a * (startG * oppAmount + endG * amount));
-        *p++ = uint8_t(a * (startB * oppAmount + endB * amount));
-        *p++ = uint8_t(alpha);
+        float amount = (pos - startPos) / distance;
+        (this->*mix)(start, end, amount, dst);
     }
 
-    for (int i = 1; i < GRADIENT_TEXTURE_HEIGHT; i++) {
-        memcpy(pixels + width * i, pixels, rowBytes);
-    }
+    memcpy(pixels + rowBytes, pixels, rowBytes);
 
     glGenTextures(1, &texture->id);
-
     glBindTexture(GL_TEXTURE_2D, texture->id);
-    glPixelStorei(GL_UNPACK_ALIGNMENT, GRADIENT_BYTES_PER_PIXEL);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
 
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, texture->height, 0,
-            GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+    if (mUseFloatTexture) {
+        // We have to use GL_RGBA16F because GL_RGBA32F does not support filtering
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, texture->height, 0,
+                GL_RGBA, GL_FLOAT, pixels);
+    } else {
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, texture->height, 0,
+                GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+    }
 
     texture->setFilter(GL_LINEAR);
     texture->setWrap(GL_CLAMP_TO_EDGE);
diff --git a/libs/hwui/GradientCache.h b/libs/hwui/GradientCache.h
index 7dc5b8a..43934d9 100644
--- a/libs/hwui/GradientCache.h
+++ b/libs/hwui/GradientCache.h
@@ -17,7 +17,7 @@
 #ifndef ANDROID_HWUI_GRADIENT_CACHE_H
 #define ANDROID_HWUI_GRADIENT_CACHE_H
 
-#include <GLES2/gl2.h>
+#include <GLES3/gl3.h>
 
 #include <SkShader.h>
 
@@ -160,12 +160,35 @@ private:
 
     void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
 
+    size_t bytesPerPixel() const;
+
+    struct GradientColor {
+        float r;
+        float g;
+        float b;
+        float a;
+    };
+
+    typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
+            GradientColor& outColor) const;
+
+    void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
+    void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
+
+    typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
+            float amount, uint8_t*& dst) const;
+
+    void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
+    void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
+
     LruCache<GradientCacheEntry, Texture*> mCache;
 
     uint32_t mSize;
     uint32_t mMaxSize;
 
     GLint mMaxTextureSize;
+    bool mUseFloatTexture;
+    bool mHasNpot;
 
     Vector<SkShader*> mGarbage;
     mutable Mutex mLock;
diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index f78fb2d..2479630 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -19,6 +19,7 @@
 #include <utils/String8.h>
 
 #include "Caches.h"
+#include "Dither.h"
 #include "ProgramCache.h"
 
 namespace android {
@@ -32,6 +33,9 @@ namespace uirenderer {
 #define MODULATE_OP_MODULATE 1
 #define MODULATE_OP_MODULATE_A8 2
 
+#define STR(x) STR1(x)
+#define STR1(x) #x
+
 ///////////////////////////////////////////////////////////////////////////////
 // Vertex shaders snippets
 ///////////////////////////////////////////////////////////////////////////////
@@ -51,17 +55,8 @@ const char* gVS_Header_Uniforms =
         "uniform mat4 transform;\n";
 const char* gVS_Header_Uniforms_IsPoint =
         "uniform mediump float pointSize;\n";
-const char* gVS_Header_Uniforms_HasGradient[3] = {
-        // Linear
-        "uniform mat4 screenSpace;\n"
-        "uniform float ditherSize;\n",
-        // Circular
-        "uniform mat4 screenSpace;\n"
-        "uniform float ditherSize;\n",
-        // Sweep
-        "uniform mat4 screenSpace;\n"
-        "uniform float ditherSize;\n"
-};
+const char* gVS_Header_Uniforms_HasGradient =
+        "uniform mat4 screenSpace;\n";
 const char* gVS_Header_Uniforms_HasBitmap =
         "uniform mat4 textureTransform;\n"
         "uniform mediump vec2 textureDimension;\n";
@@ -105,21 +100,21 @@ const char* gVS_Main_OutTransformedTexCoords =
 const char* gVS_Main_OutGradient[6] = {
         // Linear
         "    linear = vec2((screenSpace * position).x, 0.5);\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
         "    linear = (screenSpace * position).x;\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
 
         // Circular
         "    circular = (screenSpace * position).xy;\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
         "    circular = (screenSpace * position).xy;\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
 
         // Sweep
         "    sweep = (screenSpace * position).xy;\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
         "    sweep = (screenSpace * position).xy;\n"
-        "    ditherTexCoords = (transform * position).xy * ditherSize;\n",
+        "    ditherTexCoords = (transform * position).xy * " STR(DITHER_KERNEL_SIZE_INV) ";\n",
 };
 const char* gVS_Main_OutBitmapTexCoords =
         "    outBitmapTexCoords = (textureTransform * position).xy * textureDimension;\n";
@@ -153,24 +148,14 @@ const char* gFS_Uniforms_TextureSampler =
         "uniform sampler2D baseSampler;\n";
 const char* gFS_Uniforms_ExternalTextureSampler =
         "uniform samplerExternalOES baseSampler;\n";
-#define FS_UNIFORMS_DITHER \
-        "uniform float ditherSizeSquared;\n" \
-        "uniform sampler2D ditherSampler;\n"
-#define FS_UNIFORMS_GRADIENT \
-        "uniform vec4 startColor;\n" \
+const char* gFS_Uniforms_Dither =
+        "uniform sampler2D ditherSampler;";
+const char* gFS_Uniforms_GradientSampler[2] = {
+        "%s\n"
+        "uniform sampler2D gradientSampler;\n",
+        "%s\n"
+        "uniform vec4 startColor;\n"
         "uniform vec4 endColor;\n"
-const char* gFS_Uniforms_GradientSampler[6] = {
-        // Linear
-        FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
-        FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT,
-
-        // Circular
-        FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
-        FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT,
-
-        // Sweep
-        FS_UNIFORMS_DITHER "uniform sampler2D gradientSampler;\n",
-        FS_UNIFORMS_DITHER FS_UNIFORMS_GRADIENT
 };
 const char* gFS_Uniforms_BitmapSampler =
         "uniform sampler2D bitmapSampler;\n";
@@ -197,10 +182,14 @@ const char* gFS_Main_PointBitmapTexCoords =
         "    highp vec2 outBitmapTexCoords = outPointBitmapTexCoords + "
         "((gl_PointCoord - vec2(0.5, 0.5)) * textureDimension * vec2(pointSize, pointSize));\n";
 
-#define FS_MAIN_DITHER \
-        "texture2D(ditherSampler, ditherTexCoords).a * ditherSizeSquared"
+const char* gFS_Main_Dither[2] = {
+        // ES 2.0
+        "texture2D(ditherSampler, ditherTexCoords).a * " STR(DITHER_KERNEL_SIZE_INV_SQUARE),
+        // ES 3.0
+        "texture2D(ditherSampler, ditherTexCoords).r"
+};
 const char* gFS_Main_AddDitherToGradient =
-        "    gradientColor += " FS_MAIN_DITHER ";\n";
+        "    gradientColor += %s;\n";
 
 // Fast cases
 const char* gFS_Fast_SingleColor =
@@ -233,18 +222,18 @@ const char* gFS_Fast_SingleModulateA8Texture_ApplyGamma =
         "}\n\n";
 const char* gFS_Fast_SingleGradient[2] = {
         "\nvoid main(void) {\n"
-        "    gl_FragColor = " FS_MAIN_DITHER " + texture2D(gradientSampler, linear);\n"
+        "    gl_FragColor = %s + texture2D(gradientSampler, linear);\n"
         "}\n\n",
         "\nvoid main(void) {\n"
-        "    gl_FragColor = " FS_MAIN_DITHER " + mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
-        "}\n\n"
+        "    gl_FragColor = %s + mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
+        "}\n\n",
 };
 const char* gFS_Fast_SingleModulateGradient[2] = {
         "\nvoid main(void) {\n"
-        "    gl_FragColor = " FS_MAIN_DITHER " + color.a * texture2D(gradientSampler, linear);\n"
+        "    gl_FragColor = %s + color.a * texture2D(gradientSampler, linear);\n"
         "}\n\n",
         "\nvoid main(void) {\n"
-        "    gl_FragColor = " FS_MAIN_DITHER " + color.a * mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
+        "    gl_FragColor = %s + color.a * mix(startColor, endColor, clamp(linear, 0.0, 1.0));\n"
         "}\n\n"
 };
 
@@ -410,7 +399,7 @@ const char* gBlendOps[18] = {
 // Constructors/destructors
 ///////////////////////////////////////////////////////////////////////////////
 
-ProgramCache::ProgramCache() {
+ProgramCache::ProgramCache(): mHasES3(Extensions::getInstance().getMajorGlVersion() >= 3) {
 }
 
 ProgramCache::~ProgramCache() {
@@ -484,7 +473,7 @@ String8 ProgramCache::generateVertexShader(const ProgramDescription& description
         shader.append(gVS_Header_Uniforms_TextureTransform);
     }
     if (description.hasGradient) {
-        shader.append(gVS_Header_Uniforms_HasGradient[description.gradientType]);
+        shader.append(gVS_Header_Uniforms_HasGradient);
     }
     if (description.hasBitmap) {
         shader.append(gVS_Header_Uniforms_HasBitmap);
@@ -601,7 +590,8 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
         shader.append(gFS_Uniforms_ExternalTextureSampler);
     }
     if (description.hasGradient) {
-        shader.append(gFS_Uniforms_GradientSampler[gradientIndex(description)]);
+        shader.appendFormat(gFS_Uniforms_GradientSampler[description.isSimpleGradient],
+                gFS_Uniforms_Dither);
     }
     if (description.hasBitmap && description.isPoint) {
         shader.append(gFS_Header_Uniforms_PointHasBitmap);
@@ -652,9 +642,11 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
             fast = true;
         } else if (singleGradient) {
             if (!description.modulate) {
-                shader.append(gFS_Fast_SingleGradient[description.isSimpleGradient]);
+                shader.appendFormat(gFS_Fast_SingleGradient[description.isSimpleGradient],
+                        gFS_Main_Dither[mHasES3]);
             } else {
-                shader.append(gFS_Fast_SingleModulateGradient[description.isSimpleGradient]);
+                shader.appendFormat(gFS_Fast_SingleModulateGradient[description.isSimpleGradient],
+                        gFS_Main_Dither[mHasES3]);
             }
             fast = true;
         }
@@ -708,7 +700,7 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
         }
         if (description.hasGradient) {
             shader.append(gFS_Main_FetchGradient[gradientIndex(description)]);
-            shader.append(gFS_Main_AddDitherToGradient);
+            shader.appendFormat(gFS_Main_AddDitherToGradient, gFS_Main_Dither[mHasES3]);
         }
         if (description.hasBitmap) {
             if (description.isPoint) {
diff --git a/libs/hwui/ProgramCache.h b/libs/hwui/ProgramCache.h
index 1ca148d..38f6f99 100644
--- a/libs/hwui/ProgramCache.h
+++ b/libs/hwui/ProgramCache.h
@@ -57,6 +57,8 @@ private:
     void printLongString(const String8& shader) const;
 
     KeyedVector<programid, Program*> mCache;
+
+    const bool mHasES3;
 }; // class ProgramCache
 
 }; // namespace uirenderer