Bug 709490 - Part 8: Copy to a temp texture when readback from IOSurface, r=jgilbert

gfx/gl/GLContext.cpp

@@ -2650,6 +2650,7 @@ GLContext::Readback(SharedSurface* src, gfx::DataSourceSurface* dest)
     }
 
     GLuint tempFB = 0;
+    GLuint tempTex = 0;
 
     {
         ScopedBindFramebuffer autoFB(this);
@@ -2681,6 +2682,24 @@ GLContext::Readback(SharedSurface* src, gfx::DataSourceSurface* dest)
             MOZ_ASSERT(status == LOCAL_GL_FRAMEBUFFER_COMPLETE);
         }
 
+        if (src->NeedsIndirectReads()) {
+            fGenTextures(1, &tempTex);
+            {
+                ScopedBindTexture autoTex(this, tempTex);
+
+                GLenum format = src->mHasAlpha ? LOCAL_GL_RGBA
+                                               : LOCAL_GL_RGB;
+                auto width = src->mSize.width;
+                auto height = src->mSize.height;
+                fCopyTexImage2D(LOCAL_GL_TEXTURE_2D, 0, format, 0, 0, width,
+                                height, 0);
+            }
+
+            fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                                  LOCAL_GL_COLOR_ATTACHMENT0,
+                                  LOCAL_GL_TEXTURE_2D, tempTex, 0);
+        }
+
         ReadPixelsIntoDataSurface(this, dest);
 
         src->ProducerReadRelease();
@@ -2689,6 +2708,10 @@ GLContext::Readback(SharedSurface* src, gfx::DataSourceSurface* dest)
     if (tempFB)
         fDeleteFramebuffers(1, &tempFB);
 
+    if (tempTex) {
+        fDeleteTextures(1, &tempTex);
+    }
+
     if (needsSwap) {
         src->UnlockProd();
         if (prev)