Be more explicit checking for render targets with MSAA render buffers

Previously, wrapping a non-0 FBO would always cause us to think it
was MSAA, causing it to be un-copyable.

Fixes https://github.com/flutter/flutter/issues/10284

Bug: skia:7412
Change-Id: If9c0f306ad8c0c3e23dee793a541a6852737f7d9
Reviewed-on: https://skia-review.googlesource.com/97100
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index fb82a54448..179391f3d9 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -3367,6 +3367,14 @@ static inline bool can_blit_framebuffer_for_copy_surface(
     return true;
 }
 
+static bool rt_has_msaa_render_buffer(const GrGLRenderTarget* rt, const GrGLCaps& glCaps) {
+    // A RT has a separate MSAA renderbuffer if:
+    // 1) It's multisampled
+    // 2) We're using an extension with separate MSAA renderbuffers
+    // 3) It's not FBO 0, which is special and always auto-resolves
+    return rt->numColorSamples() > 0 && glCaps.usesMSAARenderBuffers() && rt->renderFBOID() != 0;
+}
+
 static inline bool can_copy_texsubimage(const GrSurface* dst, GrSurfaceOrigin dstOrigin,
                                         const GrSurface* src, GrSurfaceOrigin srcOrigin,
                                         const GrGLGpu* gpu) {
@@ -3380,13 +3388,13 @@ static inline bool can_copy_texsubimage(const GrSurface* dst, GrSurfaceOrigin ds
     const GrGLRenderTarget* dstRT = static_cast<const GrGLRenderTarget*>(dst->asRenderTarget());
     // If dst is multisampled (and uses an extension where there is a separate MSAA renderbuffer)
     // then we don't want to copy to the texture but to the MSAA buffer.
-    if (dstRT && dstRT->renderFBOID() != dstRT->textureFBOID()) {
+    if (dstRT && rt_has_msaa_render_buffer(dstRT, gpu->glCaps())) {
         return false;
     }
     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 (srcRT && srcRT->renderFBOID() != srcRT->textureFBOID()) {
+    if (srcRT && rt_has_msaa_render_buffer(srcRT, gpu->glCaps())) {
         return false;
     }