Skip copytexsubimage2D code path when src is multisampled.

src/gpu/gl/GrGpuGL.cpp

Index: src/gpu/gl/GrGpuGL.cpp
===================================================================
--- src/gpu/gl/GrGpuGL.cpp	(revision 8719)
+++ src/gpu/gl/GrGpuGL.cpp	(working copy)
@@ -2262,6 +2262,12 @@
     if (NULL != dstRT && dstRT->renderFBOID() != dstRT->textureFBOID()) {
         return false;
     }

[robertphillips, 2013/04/17 14:22:26]

Does it make any sense to make this a test on GrSurface (e.g., isCopyable)?

[bsalomon, 2013/04/18 18:09:33]

Hmm... it's really a GL-specific thing.

+    const GrGLRenderTarget* srcRT = static_cast<const GrGLRenderTarget*>(src->asRenderTarget());
+    // If the src is multisampled (and uses an extension where there is a separate MSAA
+    // renderbuffer) then it is an invalid operation to call CopyTexSubImage
+    if (NULL != srcRT && srcRT->renderFBOID() != srcRT->textureFBOID()) {
+        return false;
+    }
     if (gpu->isConfigRenderable(src->config()) && NULL != dst->asTexture() &&
         dst->origin() == src->origin() && kIndex_8_GrPixelConfig != src->config()) {
         if (NULL != wouldNeedTempFBO) {
@@ -2312,10 +2318,18 @@
         // glCopyTexSubImage2D doesn't work with this config. We'll want to make it a render target
         // in order to call glBlitFramebuffer or to copy to it by rendering.
         INHERITED::initCopySurfaceDstDesc(src, desc);
+        return;
     } else if (NULL == src->asRenderTarget()) {
         // We don't want to have to create an FBO just to use glCopyTexSubImage2D. Let the base
         // class handle it by rendering.
         INHERITED::initCopySurfaceDstDesc(src, desc);
+        return;
+    }
+
+    const GrGLRenderTarget* srcRT = static_cast<const GrGLRenderTarget*>(src->asRenderTarget());
+    if (NULL != srcRT && srcRT->renderFBOID() != srcRT->textureFBOID()) {
+        // It's illegal to call CopyTexSubImage2D on a MSAA renderbuffer.
+        INHERITED::initCopySurfaceDstDesc(src, desc);
     } else {
         desc->fConfig = src->config();
         desc->fOrigin = src->origin();