Fix behavior of stencil clipping within clearLayerRegions

bug:16376960

The draw within clearLayerRegions should never be affected by the
current stencil clip, since it's just ensuring that the content of the
layer is cleared, and not doing real content drawing.

Also, add optional verbose GL event logging

Change-Id: I538b1bc631fc091340b76e12db6af0c219851b57

1 files changed, 46 insertions, 8 deletions

diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 41f89c254c14..de777f0f538d 100755
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -45,6 +45,12 @@
 #include "Vector.h"
 #include "VertexBuffer.h"
 
+#if DEBUG_DETAILED_EVENTS
+    #define EVENT_LOGD(...) eventMarkDEBUG(__VA_ARGS__)
+#else
+    #define EVENT_LOGD(...)
+#endif
+
 namespace android {
 namespace uirenderer {
 
@@ -389,6 +395,21 @@ status_t OpenGLRenderer::callDrawGLFunction(Functor* functor, Rect& dirty) {
 // Debug
 ///////////////////////////////////////////////////////////////////////////////
 
+void OpenGLRenderer::eventMarkDEBUG(const char* fmt, ...) const {
+#if DEBUG_DETAILED_EVENTS
+    const int BUFFER_SIZE = 256;
+    va_list ap;
+    char buf[BUFFER_SIZE];
+
+    va_start(ap, fmt);
+    vsnprintf(buf, BUFFER_SIZE, fmt, ap);
+    va_end(ap);
+
+    eventMark(buf);
+#endif
+}
+
+
 void OpenGLRenderer::eventMark(const char* name) const {
     mCaches.eventMark(0, name);
 }
@@ -977,7 +998,13 @@ void OpenGLRenderer::drawTextureLayer(Layer* layer, const Rect& rect) {
 }
 
 void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap) {
-    if (!layer->isTextureLayer()) {
+    if (layer->isTextureLayer()) {
+        EVENT_LOGD("composeTextureLayerRect");
+        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
+        drawTextureLayer(layer, rect);
+        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
+    } else {
+        EVENT_LOGD("composeHardwareLayerRect");
         const Rect& texCoords = layer->texCoords;
         resetDrawTextureTexCoords(texCoords.left, texCoords.top,
                 texCoords.right, texCoords.bottom);
@@ -1012,10 +1039,6 @@ void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap)
                 GL_TRIANGLE_STRIP, gMeshCount, swap, swap || simpleTransform);
 
         resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
-    } else {
-        resetDrawTextureTexCoords(0.0f, 1.0f, 1.0f, 0.0f);
-        drawTextureLayer(layer, rect);
-        resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
     }
 }
 
@@ -1115,6 +1138,7 @@ void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
         return;
     }
 
+    EVENT_LOGD("composeLayerRegion");
     // standard Region based draw
     size_t count;
     const android::Rect* rects;
@@ -1288,6 +1312,7 @@ void OpenGLRenderer::clearLayerRegions() {
     if (count == 0) return;
 
     if (!currentSnapshot()->isIgnored()) {
+        EVENT_LOGD("clearLayerRegions");
         // Doing several glScissor/glClear here can negatively impact
         // GPUs with a tiler architecture, instead we draw quads with
         // the Clear blending mode
@@ -1465,6 +1490,8 @@ void OpenGLRenderer::attachStencilBufferToLayer(Layer* layer) {
 void OpenGLRenderer::setStencilFromClip() {
     if (!mCaches.debugOverdraw) {
         if (!currentSnapshot()->clipRegion->isEmpty()) {
+            EVENT_LOGD("setStencilFromClip - enabling");
+
             // NOTE: The order here is important, we must set dirtyClip to false
             //       before any draw call to avoid calling back into this method
             mDirtyClip = false;
@@ -1510,6 +1537,7 @@ void OpenGLRenderer::setStencilFromClip() {
                 drawRegionRects(*(currentSnapshot()->clipRegion), paint);
             }
         } else {
+            EVENT_LOGD("setStencilFromClip - disabling");
             mCaches.stencil.disable();
         }
     }
@@ -1561,17 +1589,24 @@ void OpenGLRenderer::debugClip() {
 // Drawing commands
 ///////////////////////////////////////////////////////////////////////////////
 
-void OpenGLRenderer::setupDraw(bool clear) {
+void OpenGLRenderer::setupDraw(bool clearLayer) {
     // TODO: It would be best if we could do this before quickRejectSetupScissor()
     //       changes the scissor test state
-    if (clear) clearLayerRegions();
+    if (clearLayer) clearLayerRegions();
     // Make sure setScissor & setStencil happen at the beginning of
     // this method
     if (mDirtyClip) {
         if (mCaches.scissorEnabled) {
             setScissorFromClip();
         }
-        setStencilFromClip();
+
+        if (clearLayer) {
+            setStencilFromClip();
+        } else {
+            // While clearing layer, force disable stencil buffer, since
+            // it's invalid to stencil-clip *during* the layer clear
+            mCaches.stencil.disable();
+        }
     }
 
     mDescription.reset();
@@ -2964,6 +2999,9 @@ status_t OpenGLRenderer::drawLayer(Layer* layer, float x, float y) {
         return DrawGlInfo::kStatusDone;
     }
 
+    EVENT_LOGD("drawLayer," RECT_STRING ", clipRequired %d", x, y,
+            x + layer->layer.getWidth(), y + layer->layer.getHeight(), clipRequired);
+
     updateLayer(layer, true);
 
     mCaches.setScissorEnabled(mScissorOptimizationDisabled || clipRequired);