Add an on-screen overdraw counter

The counter can be enabled by setting the system property called
debug.hwui.overdraw to the string "count". If the string is set
to "show", overdraw will be highlighted on screen instead of
printing out a simple counter.

Change-Id: I9a9c970d54bffab43138bbb7682f6c04bc2c40bd

1 files changed, 14 insertions, 1 deletions

diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index 8eb85e5547eb..367294cb677d 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -342,6 +342,12 @@ const char* gFS_Main_ApplyColorOp[4] = {
 };
 const char* gFS_Main_DebugHighlight =
         "    gl_FragColor.rgb = vec3(0.0, gl_FragColor.a, 0.0);\n";
+const char* gFS_Main_EmulateStencil =
+        "    gl_FragColor.rgba = vec4(1.0 / 255.0, 1.0 / 255.0, 1.0 / 255.0, 1.0);\n"
+        "    return;\n"
+        "    /*\n";
+const char* gFS_Footer_EmulateStencil =
+        "    */\n";
 const char* gFS_Footer =
         "}\n\n";
 
@@ -603,7 +609,8 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
     // Optimization for common cases
     if (!description.isAA && !blendFramebuffer && !description.hasColors &&
             description.colorOp == ProgramDescription::kColorNone &&
-            !description.isPoint && !description.hasDebugHighlight) {
+            !description.isPoint && !description.hasDebugHighlight &&
+            !description.emulateStencil) {
         bool fast = false;
 
         const bool noShader = !description.hasGradient && !description.hasBitmap;
@@ -683,6 +690,9 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
 
     // Begin the shader
     shader.append(gFS_Main); {
+        if (description.emulateStencil) {
+            shader.append(gFS_Main_EmulateStencil);
+        }
         // Stores the result in fragColor directly
         if (description.hasTexture || description.hasExternalTexture) {
             if (description.hasAlpha8Texture) {
@@ -757,6 +767,9 @@ String8 ProgramCache::generateFragmentShader(const ProgramDescription& descripti
             shader.append(gFS_Main_DebugHighlight);
         }
     }
+    if (description.emulateStencil) {
+        shader.append(gFS_Footer_EmulateStencil);
+    }
     // End the shader
     shader.append(gFS_Footer);