Fix regression with hardware layers.

The renderer was checking whether the layer's region is a rect to
draw it with a simple quad. This test was done against the layer's
region structure, which was cleared after generating the mesh.
Unfortunately Region::isRect() returns true when the region is
empty, which was causing the renderer to always use a quad to
draw a mesh on screen.

Change-Id: If4b874579ee0cedcb67367c9efa5c0c98ca55231

2 files changed, 29 insertions, 26 deletions

diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index a167429..1c89577 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -29,6 +29,10 @@ namespace uirenderer {
 void LayerRenderer::prepare(bool opaque) {
     LAYER_RENDERER_LOGD("Rendering into layer, fbo = %d", mLayer->fbo);
 
+#if RENDER_LAYERS_AS_REGIONS
+    mLayer->region.clear();
+#endif
+
     glBindFramebuffer(GL_FRAMEBUFFER, mLayer->fbo);
 
     OpenGLRenderer::prepare(opaque);
@@ -79,7 +83,6 @@ void LayerRenderer::generateMesh() {
             mLayer->meshIndices = NULL;
             mLayer->meshElementCount = 0;
         }
-        mLayer->region.clear();
         return;
     }
 
@@ -131,8 +134,6 @@ void LayerRenderer::generateMesh() {
         indices[index + 4] = quad + 1;   // top-right
         indices[index + 5] = quad + 3;   // bottom-right
     }
-
-    mLayer->region.clear();
 #endif
 }
 
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index b06bbd0..92aa4bd 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -1568,29 +1568,31 @@ void OpenGLRenderer::drawLayer(Layer* layer, float x, float y, SkPaint* paint) {
 
 
 #if RENDER_LAYERS_AS_REGIONS
-    if (layer->region.isRect()) {
-        const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
-        composeLayerRect(layer, r);
-    } else if (!layer->region.isEmpty() && layer->mesh) {
-        const Rect& rect = layer->layer;
-
-        setupDraw();
-        setupDrawWithTexture();
-        setupDrawColor(alpha, alpha, alpha, alpha);
-        setupDrawColorFilter();
-        setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
-        setupDrawProgram();
-        setupDrawDirtyRegionsDisabled();
-        setupDrawPureColorUniforms();
-        setupDrawColorFilterUniforms();
-        setupDrawTexture(layer->texture);
-        setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
-        setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
-
-        glDrawElements(GL_TRIANGLES, layer->meshElementCount,
-                GL_UNSIGNED_SHORT, layer->meshIndices);
-
-        finishDrawTexture();
+    if (!layer->region.isEmpty()) {
+        if (layer->region.isRect()) {
+            const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());
+            composeLayerRect(layer, r);
+        } else if (layer->mesh) {
+            const Rect& rect = layer->layer;
+
+            setupDraw();
+            setupDrawWithTexture();
+            setupDrawColor(alpha, alpha, alpha, alpha);
+            setupDrawColorFilter();
+            setupDrawBlending(layer->blend || layer->alpha < 255, layer->mode, false);
+            setupDrawProgram();
+            setupDrawDirtyRegionsDisabled();
+            setupDrawPureColorUniforms();
+            setupDrawColorFilterUniforms();
+            setupDrawTexture(layer->texture);
+            setupDrawModelViewTranslate(rect.left, rect.top, rect.right, rect.bottom);
+            setupDrawMesh(&layer->mesh[0].position[0], &layer->mesh[0].texture[0]);
+
+            glDrawElements(GL_TRIANGLES, layer->meshElementCount,
+                    GL_UNSIGNED_SHORT, layer->meshIndices);
+
+            finishDrawTexture();
+        }
     }
 #else
     const Rect r(x, y, x + layer->layer.getWidth(), y + layer->layer.getHeight());