Fix SkGLContext FBO setup for ES2

Review URL: http://codereview.appspot.com/5452058/


git-svn-id: http://skia.googlecode.com/svn/trunk@2812 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/SkGLContext.cpp b/src/gpu/SkGLContext.cpp
index c50ee6e..f6b7db8 100644
--- a/src/gpu/SkGLContext.cpp
+++ b/src/gpu/SkGLContext.cpp
@@ -24,28 +24,45 @@
 
     fGL = this->createGLContext();
     if (fGL) {
+        // clear any existing GL erorrs
+        GrGLenum error;
+        do {
+            error = SK_GL(*this, GetError());
+        } while (GR_GL_NO_ERROR != error);
         GrGLuint cbID;
         GrGLuint dsID;
         SK_GL(*this, GenFramebuffers(1, &fFBO));
         SK_GL(*this, BindFramebuffer(GR_GL_FRAMEBUFFER, fFBO));
         SK_GL(*this, GenRenderbuffers(1, &cbID));
         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, cbID));
-        SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
-                                         GR_GL_RGBA,
-                                         width, height));
+        if (fGL->supportsES2()) {
+            SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
+                                             GR_GL_RGBA8,
+                                             width, height));
+        } else {
+            SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
+                                             GR_GL_RGBA,
+                                             width, height));
+        }
         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                              GR_GL_COLOR_ATTACHMENT0,
                                              GR_GL_RENDERBUFFER, 
                                              cbID));
         SK_GL(*this, GenRenderbuffers(1, &dsID));
         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, dsID));
-        SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
-                                         GR_GL_DEPTH_STENCIL,
-                                         width, height));
-        SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
-                                             GR_GL_DEPTH_ATTACHMENT,
-                                             GR_GL_RENDERBUFFER,
-                                             dsID));
+        if (fGL->supportsES2()) {
+            SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
+                                             GR_GL_STENCIL_INDEX8,
+                                             width, height));
+        } else {
+            SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
+                                             GR_GL_DEPTH_STENCIL,
+                                             width, height));
+            SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
+                                                 GR_GL_DEPTH_ATTACHMENT,
+                                                 GR_GL_RENDERBUFFER,
+                                                 dsID));
+        }
         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                              GR_GL_STENCIL_ATTACHMENT,
                                              GR_GL_RENDERBUFFER,
@@ -53,10 +70,13 @@
         SK_GL(*this, Viewport(0, 0, width, height));
         SK_GL(*this, ClearStencil(0));
         SK_GL(*this, Clear(GR_GL_STENCIL_BUFFER_BIT));
-
+        
+        error = SK_GL(*this, GetError());
         GrGLenum status =
             SK_GL(*this, CheckFramebufferStatus(GR_GL_FRAMEBUFFER));
-        if (GR_GL_FRAMEBUFFER_COMPLETE != status) {
+
+        if (GR_GL_FRAMEBUFFER_COMPLETE != status ||
+            GR_GL_NO_ERROR != error) {
             fFBO = 0;
             fGL->unref();
             fGL = NULL;