GL MSAA tweaks

* Invalidate the msaa color buffer after resolving, in hopes that the driver can avoid flushing it out to memory.

* Add a glFinish in the texture_target_gl tests to work around an ANGLE driver bug.

Diffs=
7cc6f5bbe3 GL MSAA tweaks (#8753)

Co-authored-by: Chris Dalton <99840794+csmartdalton@users.noreply.github.com>

.rive_head

@@ -1 +1 @@
-3c322193bf69e92663ae4346cf16396ef1578239
+7cc6f5bbe3c726fc1c94f2075aed7f262240282d

renderer/include/rive/renderer/gl/gles3.hpp

@@ -119,7 +119,7 @@ struct GLCapabilities
     int contextVersionMajor;
     int contextVersionMinor;
     bool isGLES : 1;
-    bool isANGLEOrWebGL : 1;
+    bool isAndroidANGLE : 1;
     bool isPowerVR : 1;
     bool ANGLE_base_vertex_base_instance_shader_builtin : 1;
     bool ANGLE_shader_pixel_local_storage : 1;

renderer/src/gl/render_context_gl_impl.cpp

@@ -1683,26 +1683,32 @@ void RenderContextGLImpl::flush(const FlushDescriptor& desc)
     }
     else
     {
-        // Depth/stencil don't need to be written out.
-        glInvalidateFramebuffer(GL_DRAW_FRAMEBUFFER,
+        // Depth/stencil can be discarded.
+        glInvalidateFramebuffer(GL_FRAMEBUFFER,
                                 2,
                                 msaaDepthStencilColor.data());
-        if ((desc.combinedShaderFeatures &
-             gpu::ShaderFeatures::ENABLE_ADVANCED_BLEND) &&
-            m_capabilities.KHR_blend_equation_advanced_coherent)
-        {
-            glDisable(GL_BLEND_ADVANCED_COHERENT_KHR);
-        }
-        glDisable(GL_DEPTH_TEST);
-        glDisable(GL_STENCIL_TEST);
         if (msaaResolveAction ==
             RenderTargetGL::MSAAResolveAction::framebufferBlit)
         {
             renderTarget->bindDestinationFramebuffer(GL_DRAW_FRAMEBUFFER);
             glutils::BlitFramebuffer(desc.renderTargetUpdateBounds,
                                      renderTarget->height(),
                                      GL_COLOR_BUFFER_BIT);
+            // Now that color is resolved elsewhere we can discard the MSAA
+            // color buffer as well.
+            glInvalidateFramebuffer(GL_READ_FRAMEBUFFER,
+                                    1,
+                                    msaaDepthStencilColor.data() + 2);
         }
+
+        if ((desc.combinedShaderFeatures &
+             gpu::ShaderFeatures::ENABLE_ADVANCED_BLEND) &&
+            m_capabilities.KHR_blend_equation_advanced_coherent)
+        {
+            glDisable(GL_BLEND_ADVANCED_COHERENT_KHR);
+        }
+        glDisable(GL_DEPTH_TEST);
+        glDisable(GL_STENCIL_TEST);
         if (clipPlanesEnabled)
         {
             glDisable(GL_CLIP_DISTANCE0_EXT);
@@ -1779,10 +1785,8 @@ std::unique_ptr<RenderContext> RenderContextGLImpl::MakeContext(
 #endif
     if (capabilities.isGLES)
     {
-#ifdef RIVE_WEBGL
-        capabilities.isANGLEOrWebGL = true;
-#else
-        capabilities.isANGLEOrWebGL = strstr(glVersionStr, "ANGLE") != NULL;
+#ifdef RIVE_ANDROID
+        capabilities.isAndroidANGLE = strstr(glVersionStr, "ANGLE") != NULL;
 #endif
 #ifdef _MSC_VER
         sscanf_s(
@@ -1796,7 +1800,6 @@ std::unique_ptr<RenderContext> RenderContextGLImpl::MakeContext(
     }
     else
     {
-        capabilities.isANGLEOrWebGL = false;
 #ifdef _MSC_VER
         sscanf_s(
 #else
@@ -1924,7 +1927,7 @@ std::unique_ptr<RenderContext> RenderContextGLImpl::MakeContext(
         // this extension but then doesn't support gl_ClipDistance in the
         // shader. Only use clip planes on ANGLE if ANGLE_clip_cull_distance is
         // supported.
-        else if (!capabilities.isANGLEOrWebGL &&
+        else if (!capabilities.isAndroidANGLE &&
                  strcmp(ext, "GL_EXT_clip_cull_distance") == 0)
         {
             capabilities.EXT_clip_cull_distance = true;

tests/gm/texture_target_gl.cpp

@@ -84,6 +84,17 @@ class TextureTargetGL : public GM
             copyFrameDescriptor.clearColor = 0xffff0000;
             renderContext->beginFrame(std::move(copyFrameDescriptor));
             originalRenderTarget->bindDestinationFramebuffer(GL_FRAMEBUFFER);
+            if (plsImplGL->capabilities().isAndroidANGLE)
+            {
+                // Some android devices shipping with ANGLE have a
+                // syncronization issue drawing this texture into the main
+                // framebuffer. glFinish is a very heavy handed workaround, but
+                // it's the only one so far to work.
+                // Sadly, we can't incorporate a workaround this heavy into the
+                // main GL runtime. Apps that run into it will have to come up
+                // with the best workaround for them.
+                glFinish();
+            }
             plsImplGL->blitTextureToFramebufferAsDraw(m_offscreenTex,
                                                       {0, 0, 256, 256},
                                                       256);