Don't blend transparent pixels when rendering layers.
With this change, the rendere keeps track of what regions are rendered into
and generates a mesh that matches these regions exactly. The mesh is used
to composite the layer on screen.
Change-Id: I1f342576b9134fb29caff7fb8f4c1da179fe956d
diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index a25c95e..cd2554e 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -29,6 +29,10 @@
void LayerRenderer::prepare(bool opaque) {
LAYER_RENDERER_LOGD("Rendering into layer, fbo = %d", mLayer->fbo);
+#if RENDER_LAYERS_AS_REGIONS
+ mLayer->region.clear();
+#endif
+
glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint*) &mPreviousFbo);
glBindFramebuffer(GL_FRAMEBUFFER, mLayer->fbo);
@@ -39,11 +43,97 @@
OpenGLRenderer::finish();
glBindFramebuffer(GL_FRAMEBUFFER, mPreviousFbo);
+ generateMesh();
+
LAYER_RENDERER_LOGD("Finished rendering into layer, fbo = %d", mLayer->mFbo);
}
///////////////////////////////////////////////////////////////////////////////
-// Static functions
+// Dirty region tracking
+///////////////////////////////////////////////////////////////////////////////
+
+bool LayerRenderer::hasLayer() {
+ return true;
+}
+
+Region* LayerRenderer::getRegion() {
+#if RENDER_LAYERS_AS_REGIONS
+ if (getSnapshot()->flags & Snapshot::kFlagFboTarget) {
+ return OpenGLRenderer::getRegion();
+ }
+ return &mLayer->region;
+#else
+ return OpenGLRenderer::getRegion();
+#endif
+}
+
+void LayerRenderer::generateMesh() {
+#if RENDER_LAYERS_AS_REGIONS
+ if (mLayer->region.isRect() || mLayer->region.isEmpty()) {
+ if (mLayer->mesh) {
+ delete mLayer->mesh;
+ delete mLayer->meshIndices;
+
+ mLayer->mesh = NULL;
+ mLayer->meshIndices = NULL;
+ mLayer->meshElementCount = 0;
+ }
+ return;
+ }
+
+ size_t count;
+ const android::Rect* rects = mLayer->region.getArray(&count);
+
+ GLsizei elementCount = count * 6;
+
+ if (mLayer->mesh && mLayer->meshElementCount < elementCount) {
+ delete mLayer->mesh;
+ delete mLayer->meshIndices;
+
+ mLayer->mesh = NULL;
+ mLayer->meshIndices = NULL;
+ }
+
+ if (!mLayer->mesh) {
+ mLayer->mesh = new TextureVertex[count * 4];
+ mLayer->meshIndices = new uint16_t[elementCount];
+ mLayer->meshElementCount = elementCount;
+ }
+
+ const float texX = 1.0f / float(mLayer->width);
+ const float texY = 1.0f / float(mLayer->height);
+ const float height = mLayer->layer.getHeight();
+
+ TextureVertex* mesh = mLayer->mesh;
+ uint16_t* indices = mLayer->meshIndices;
+
+ for (size_t i = 0; i < count; i++) {
+ const android::Rect* r = &rects[i];
+
+ const float u1 = r->left * texX;
+ const float v1 = (height - r->top) * texY;
+ const float u2 = r->right * texX;
+ const float v2 = (height - r->bottom) * texY;
+
+ TextureVertex::set(mesh++, r->left, r->top, u1, v1);
+ TextureVertex::set(mesh++, r->right, r->top, u2, v1);
+ TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
+ TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
+
+ uint16_t quad = i * 4;
+ int index = i * 6;
+ indices[index ] = quad; // top-left
+ indices[index + 1] = quad + 1; // top-right
+ indices[index + 2] = quad + 2; // bottom-left
+ indices[index + 3] = quad + 2; // bottom-left
+ indices[index + 4] = quad + 1; // top-right
+ indices[index + 5] = quad + 3; // bottom-right
+ }
+#endif
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Layers management
///////////////////////////////////////////////////////////////////////////////
Layer* LayerRenderer::createLayer(uint32_t width, uint32_t height, bool isOpaque) {