Merge "Add stencil buffer to the EGL config"

Author: Romain Guy

core/java/android/view/GLES20Canvas.java

@@ -189,7 +189,7 @@ public int getMaximumBitmapHeight() {
     }
 
     private static native int nGetMaximumTextureWidth();
-    private static native int nGetMaximumTextureHeight();    
+    private static native int nGetMaximumTextureHeight();
 
     ///////////////////////////////////////////////////////////////////////////
     // Setup
@@ -268,14 +268,31 @@ public void onPostDraw() {
 
     private static native void nFinish(int renderer);
 
+    /**
+     * Returns the size of the stencil buffer required by the underlying
+     * implementation.
+     * 
+     * @return The minimum number of bits the stencil buffer must. Always >= 0.
+     * 
+     * @hide
+     */
+    public static int getStencilSize() {
+        return nGetStencilSize();
+    }
+
+    private static native int nGetStencilSize();
+
+    ///////////////////////////////////////////////////////////////////////////
+    // Functor
+    ///////////////////////////////////////////////////////////////////////////
+
     @Override
     public boolean callDrawGLFunction(int drawGLFunction) {
         return nCallDrawGLFunction(mRenderer, drawGLFunction);
     }
 
     private static native boolean nCallDrawGLFunction(int renderer, int drawGLFunction);
 
-
     ///////////////////////////////////////////////////////////////////////////
     // Memory
     ///////////////////////////////////////////////////////////////////////////

core/java/android/view/HardwareRenderer.java

@@ -1047,7 +1047,7 @@ int[] getConfig(boolean dirtyRegions) {
                     EGL_BLUE_SIZE, 8,
                     EGL_ALPHA_SIZE, 8,
                     EGL_DEPTH_SIZE, 0,
-                    EGL_STENCIL_SIZE, 0,
+                    EGL_STENCIL_SIZE, GLES20Canvas.getStencilSize(),
                     EGL_SURFACE_TYPE, EGL_WINDOW_BIT |
                             (dirtyRegions ? EGL_SWAP_BEHAVIOR_PRESERVED_BIT : 0),
                     EGL_NONE

core/jni/android_view_GLES20Canvas.cpp

@@ -188,6 +188,14 @@ static void android_view_GLES20Canvas_finish(JNIEnv* env, jobject clazz,
     renderer->finish();
 }
 
+static jint android_view_GLES20Canvas_getStencilSize(JNIEnv* env, jobject clazz) {
+    return OpenGLRenderer::getStencilSize();
+}
+
+// ----------------------------------------------------------------------------
+// Functor
+// ----------------------------------------------------------------------------
+
 static bool android_view_GLES20Canvas_callDrawGLFunction(JNIEnv* env, jobject clazz,
         OpenGLRenderer* renderer, Functor *functor) {
     android::uirenderer::Rect dirty;
@@ -808,6 +816,8 @@ static JNINativeMethod gMethods[] = {
     { "nPrepareDirty",      "(IIIIIZ)V",       (void*) android_view_GLES20Canvas_prepareDirty },
     { "nFinish",            "(I)V",            (void*) android_view_GLES20Canvas_finish },
 
+    { "nGetStencilSize",    "()I",             (void*) android_view_GLES20Canvas_getStencilSize },
+
     { "nCallDrawGLFunction", "(II)Z",
             (void*) android_view_GLES20Canvas_callDrawGLFunction },
 

docs/html/guide/topics/ui/how-android-draws.jd

@@ -62,7 +62,7 @@ and each View is responsible for drawing itself.
 
    <p>
    The measure pass uses two classes to communicate dimensions. The
-   {@link android.view.View.MeasureSpec} class is used by Views to tell their parents how they
+   {@link android.view.ViewGroup.LayoutParams} class is used by Views to tell their parents how they
    want to be measured and positioned. The base LayoutParams class just
    describes how big the View wants to be for both width and height. For each
    dimension, it can specify one of:</p>

libs/hwui/OpenGLRenderer.cpp

@@ -127,6 +127,10 @@ OpenGLRenderer::~OpenGLRenderer() {
 // Setup
 ///////////////////////////////////////////////////////////////////////////////
 
+uint32_t OpenGLRenderer::getStencilSize() {
+    return STENCIL_BUFFER_SIZE;
+}
+
 void OpenGLRenderer::setViewport(int width, int height) {
     mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
 

libs/hwui/OpenGLRenderer.h

@@ -141,6 +141,8 @@ class OpenGLRenderer {
 
     SkPaint* filterPaint(SkPaint* paint);
 
+    ANDROID_API static uint32_t getStencilSize();
+
 protected:
     /**
      * Compose the layer defined in the current snapshot with the layer

libs/hwui/Properties.h

@@ -37,6 +37,11 @@
 // Textures used by layers must have dimensions multiples of this number
 #define LAYER_SIZE 64
 
+// Defines the size in bits of the stencil buffer
+// Note: We only want 1 bit, but in practice we'll get 8 bits on all GPUs
+//       for the foreseeable future
+#define STENCIL_BUFFER_SIZE 0
+
 /**
  * Debug level for app developers.
  */