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/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index f70bca7..6c90704 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -240,10 +240,14 @@
if (p) {
alpha = p->getAlpha();
- const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
- if (!isMode) {
- // Assume SRC_OVER
- mode = SkXfermode::kSrcOver_Mode;
+ if (!mExtensions.hasFramebufferFetch()) {
+ const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
+ if (!isMode) {
+ // Assume SRC_OVER
+ mode = SkXfermode::kSrcOver_Mode;
+ }
+ } else {
+ mode = getXfermode(p->getXfermode());
}
} else {
mode = SkXfermode::kSrcOver_Mode;
@@ -519,11 +523,14 @@
}
SkXfermode::Mode mode;
-
- const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
- if (!isMode) {
- // Assume SRC_OVER
- mode = SkXfermode::kSrcOver_Mode;
+ if (!mExtensions.hasFramebufferFetch()) {
+ const bool isMode = SkXfermode::IsMode(p->getXfermode(), &mode);
+ if (!isMode) {
+ // Assume SRC_OVER
+ mode = SkXfermode::kSrcOver_Mode;
+ }
+ } else {
+ mode = getXfermode(p->getXfermode());
}
// Skia draws using the color's alpha channel if < 255
@@ -731,11 +738,12 @@
}
}
+ // Setup the blending mode
+ chooseBlending(true, mode, description);
+
// Build and use the appropriate shader
useProgram(mCaches.programCache.get(description));
- // Setup the blending mode
- chooseBlending(true, mode);
bindTexture(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE, textureUnit);
glUniform1i(mCaches.currentProgram->getUniform("sampler"), textureUnit);
@@ -837,9 +845,6 @@
GLuint textureUnit = 0;
- // Setup the blending mode
- chooseBlending(alpha < 255 || (mShader && mShader->blend()), mode);
-
// Describe the required shaders
ProgramDescription description;
if (mShader) {
@@ -849,6 +854,9 @@
mColorFilter->describe(description, mExtensions);
}
+ // Setup the blending mode
+ chooseBlending(alpha < 255 || (mShader && mShader->blend()), mode, description);
+
// Build and use the appropriate shader
useProgram(mCaches.programCache.get(description));
@@ -907,11 +915,11 @@
mModelView.loadTranslate(left, top, 0.0f);
mModelView.scale(right - left, bottom - top, 1.0f);
+ chooseBlending(blend || alpha < 1.0f, mode, description);
+
useProgram(mCaches.programCache.get(description));
mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
- chooseBlending(blend || alpha < 1.0f, mode);
-
// Texture
bindTexture(texture, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE, 0);
glUniform1i(mCaches.currentProgram->getUniform("sampler"), 0);
@@ -939,23 +947,35 @@
glDisableVertexAttribArray(texCoordsSlot);
}
-void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied) {
+void OpenGLRenderer::chooseBlending(bool blend, SkXfermode::Mode mode,
+ ProgramDescription& description) {
blend = blend || mode != SkXfermode::kSrcOver_Mode;
if (blend) {
- if (!mCaches.blend) {
- glEnable(GL_BLEND);
- }
+ if (mode < SkXfermode::kPlus_Mode) {
+ if (!mCaches.blend) {
+ glEnable(GL_BLEND);
+ }
- GLenum sourceMode = gBlends[mode].src;
- GLenum destMode = gBlends[mode].dst;
- if (!isPremultiplied && sourceMode == GL_ONE) {
- sourceMode = GL_SRC_ALPHA;
- }
+ GLenum sourceMode = gBlends[mode].src;
+ GLenum destMode = gBlends[mode].dst;
- if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
- glBlendFunc(sourceMode, destMode);
- mCaches.lastSrcMode = sourceMode;
- mCaches.lastDstMode = destMode;
+ if (sourceMode != mCaches.lastSrcMode || destMode != mCaches.lastDstMode) {
+ glBlendFunc(sourceMode, destMode);
+ mCaches.lastSrcMode = sourceMode;
+ mCaches.lastDstMode = destMode;
+ }
+ } else {
+ // These blend modes are not supported by OpenGL directly and have
+ // to be implemented using shaders. Since the shader will perform
+ // the blending, turn blending off here
+ if (mExtensions.hasFramebufferFetch()) {
+ description.framebufferMode = mode;
+ }
+
+ if (mCaches.blend) {
+ glDisable(GL_BLEND);
+ }
+ blend = false;
}
} else if (mCaches.blend) {
glDisable(GL_BLEND);
@@ -983,10 +1003,14 @@
void OpenGLRenderer::getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
if (paint) {
- const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
- if (!isMode) {
- // Assume SRC_OVER
- *mode = SkXfermode::kSrcOver_Mode;
+ if (!mExtensions.hasFramebufferFetch()) {
+ const bool isMode = SkXfermode::IsMode(paint->getXfermode(), mode);
+ if (!isMode) {
+ // Assume SRC_OVER
+ *mode = SkXfermode::kSrcOver_Mode;
+ }
+ } else {
+ *mode = getXfermode(paint->getXfermode());
}
// Skia draws using the color's alpha channel if < 255
@@ -1002,6 +1026,13 @@
}
}
+SkXfermode::Mode OpenGLRenderer::getXfermode(SkXfermode* mode) {
+ if (mode == NULL) {
+ return SkXfermode::kSrcOver_Mode;
+ }
+ return mode->fMode;
+}
+
void OpenGLRenderer::bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit) {
glActiveTexture(gTextureUnits[textureUnit]);
glBindTexture(GL_TEXTURE_2D, texture);