commit 87e2f757be9b24d369bab354e37c276e851b1fc7
author Romain Guy <romainguy@google.com> Mon Sep 24 11:37:12 2012 -0700
committer Romain Guy <romainguy@google.com> Mon Sep 24 11:47:52 2012 -0700
tree dd8a123cd63666a7f767cb0c38afcc9726d007db
parent 97dc9172b0e58979c63de0dedbab656399a62281

Add a property to disable libhwui's scissor optimization
Bug #7158326

When scissor optimization is enabled, OpenGLRenderer will attempt to
minimize the use of scissor by selectively enabling and disabling the
GL scissor test.
When the optimization is disabled, OpenGLRenderer will keep the GL
scissor test enabled and change the scissor rect as needed.
Some GPUs (for instance the SGX 540) perform better when changing
the scissor rect often than when enabling/disabling the scissor test
often.

Change-Id: Idb68862e287a23358f9188d577ae0f86161902fd

libs/hwui/OpenGLRenderer.cpp

diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index a4403c8..35cc716 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -34,6 +34,7 @@
 #include "OpenGLRenderer.h"
 #include "DisplayListRenderer.h"
 #include "PathRenderer.h"
+#include "Properties.h"
 #include "Vector.h"
 
 namespace android {
@@ -117,6 +118,8 @@
     memcpy(mMeshVertices, gMeshVertices, sizeof(gMeshVertices));
 
     mFirstSnapshot = new Snapshot;
+
+    mScissorOptimizationDisabled = false;
 }
 
 OpenGLRenderer::~OpenGLRenderer() {
@@ -124,16 +127,15 @@
     // GL APIs. All GL state should be kept in Caches.h
 }
 
-///////////////////////////////////////////////////////////////////////////////
-// Debug
-///////////////////////////////////////////////////////////////////////////////
-
-void OpenGLRenderer::startMark(const char* name) const {
-    mCaches.startMark(0, name);
-}
-
-void OpenGLRenderer::endMark() const {
-    mCaches.endMark();
+void OpenGLRenderer::initProperties() {
+    char property[PROPERTY_VALUE_MAX];
+    if (property_get(PROPERTY_DISABLE_SCISSOR_OPTIMIZATION, property, "false")) {
+        mScissorOptimizationDisabled = !strcasecmp(property, "true");
+        INIT_LOGD("  Scissor optimization %s",
+                mScissorOptimizationDisabled ? "disabled" : "enabled");
+    } else {
+        INIT_LOGD("  Scissor optimization enabled");
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -268,40 +270,6 @@
     }
 }
 
-void OpenGLRenderer::debugOverdraw(bool enable, bool clear) {
-    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
-        if (clear) {
-            mCaches.disableScissor();
-            mCaches.stencil.clear();
-        }
-        if (enable) {
-            mCaches.stencil.enableDebugWrite();
-        } else {
-            mCaches.stencil.disable();
-        }
-    }
-}
-
-void OpenGLRenderer::renderOverdraw() {
-    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
-        const Rect* clip = mTilingSnapshot->clipRect;
-
-        mCaches.enableScissor();
-        mCaches.setScissor(clip->left, mTilingSnapshot->height - clip->bottom,
-                clip->right - clip->left, clip->bottom - clip->top);
-
-        mCaches.stencil.enableDebugTest(2);
-        drawColor(0x2f0000ff, SkXfermode::kSrcOver_Mode);
-        mCaches.stencil.enableDebugTest(3);
-        drawColor(0x2f00ff00, SkXfermode::kSrcOver_Mode);
-        mCaches.stencil.enableDebugTest(4);
-        drawColor(0x3fff0000, SkXfermode::kSrcOver_Mode);
-        mCaches.stencil.enableDebugTest(4, true);
-        drawColor(0x7fff0000, SkXfermode::kSrcOver_Mode);
-        mCaches.stencil.disable();
-    }
-}
-
 void OpenGLRenderer::interrupt() {
     if (mCaches.currentProgram) {
         if (mCaches.currentProgram->isInUse()) {
@@ -439,6 +407,52 @@
 }
 
 ///////////////////////////////////////////////////////////////////////////////
+// Debug
+///////////////////////////////////////////////////////////////////////////////
+
+void OpenGLRenderer::startMark(const char* name) const {
+    mCaches.startMark(0, name);
+}
+
+void OpenGLRenderer::endMark() const {
+    mCaches.endMark();
+}
+
+void OpenGLRenderer::debugOverdraw(bool enable, bool clear) {
+    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
+        if (clear) {
+            mCaches.disableScissor();
+            mCaches.stencil.clear();
+        }
+        if (enable) {
+            mCaches.stencil.enableDebugWrite();
+        } else {
+            mCaches.stencil.disable();
+        }
+    }
+}
+
+void OpenGLRenderer::renderOverdraw() {
+    if (mCaches.debugOverdraw && getTargetFbo() == 0) {
+        const Rect* clip = mTilingSnapshot->clipRect;
+
+        mCaches.enableScissor();
+        mCaches.setScissor(clip->left, mTilingSnapshot->height - clip->bottom,
+                clip->right - clip->left, clip->bottom - clip->top);
+
+        mCaches.stencil.enableDebugTest(2);
+        drawColor(0x2f0000ff, SkXfermode::kSrcOver_Mode);
+        mCaches.stencil.enableDebugTest(3);
+        drawColor(0x2f00ff00, SkXfermode::kSrcOver_Mode);
+        mCaches.stencil.enableDebugTest(4);
+        drawColor(0x3fff0000, SkXfermode::kSrcOver_Mode);
+        mCaches.stencil.enableDebugTest(4, true);
+        drawColor(0x7fff0000, SkXfermode::kSrcOver_Mode);
+        mCaches.stencil.disable();
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
 // Layers
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -1248,7 +1262,7 @@
 
     bool rejected = !clipRect.intersects(r);
     if (!isDeferred() && !rejected) {
-        mCaches.setScissorEnabled(!clipRect.contains(r));
+        mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clipRect.contains(r));
     }
 
     return rejected;
@@ -2711,7 +2725,7 @@
         debugLayerUpdate = mCaches.debugLayersUpdates;
     }
 
-    mCaches.setScissorEnabled(!clip.contains(transformed));
+    mCaches.setScissorEnabled(mScissorOptimizationDisabled || !clip.contains(transformed));
     mCaches.activeTexture(0);
 
     if (CC_LIKELY(!layer->region.isEmpty())) {