Add support for advanced blend modes with the framebuffer.
This adds the ability to blend with the framebuffer using Darken,
Lighten, Add, Multiply, Overlay and Screen.
Change-Id: Iae01a53797d4ad39c373cba6ff2a42293129da1a
diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index 39fe85a..ff65c1b 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -66,6 +66,8 @@
// Fragment shaders snippets
///////////////////////////////////////////////////////////////////////////////
+const char* gFS_Header_Extension_FramebufferFetch =
+ "#extension GL_NV_shader_framebuffer_fetch : enable\n\n";
const char* gFS_Header =
"precision mediump float;\n\n";
const char* gFS_Uniforms_Color =
@@ -115,6 +117,8 @@
" fragColor = bitmapColor * fragColor.a;\n";
const char* gFS_Main_FragColor =
" gl_FragColor = fragColor;\n";
+const char* gFS_Main_FragColor_Blend =
+ " gl_FragColor = blendFramebuffer(fragColor, gl_LastFragColor);\n";
const char* gFS_Main_ApplyColorOp[4] = {
// None
"",
@@ -281,7 +285,14 @@
String8 ProgramCache::generateFragmentShader(const ProgramDescription& description) {
// Set the default precision
- String8 shader(gFS_Header);
+ String8 shader;
+
+ bool blendFramebuffer = description.framebufferMode >= SkXfermode::kPlus_Mode;
+ if (blendFramebuffer) {
+ shader.append(gFS_Header_Extension_FramebufferFetch);
+ }
+
+ shader.append(gFS_Header);
// Varyings
if (description.hasTexture) {
@@ -315,6 +326,9 @@
if (description.colorOp == ProgramDescription::kColorBlend) {
generateBlend(shader, "blendColors", description.colorMode);
}
+ if (blendFramebuffer) {
+ generateBlend(shader, "blendFramebuffer", description.framebufferMode);
+ }
if (description.isBitmapNpot) {
generateTextureWrap(shader, description.bitmapWrapS, description.bitmapWrapT);
}
@@ -359,7 +373,11 @@
// Apply the color op if needed
shader.append(gFS_Main_ApplyColorOp[description.colorOp]);
// Output the fragment
- shader.append(gFS_Main_FragColor);
+ if (!blendFramebuffer) {
+ shader.append(gFS_Main_FragColor);
+ } else {
+ shader.append(gFS_Main_FragColor_Blend);
+ }
}
// End the shader
shader.append(gFS_Footer);