Avoid EGLImage target texture reuse on PowerVR

gpu/command_buffer/service/texture_definition.cc

Index: gpu/command_buffer/service/texture_definition.cc
diff --git a/gpu/command_buffer/service/texture_definition.cc b/gpu/command_buffer/service/texture_definition.cc
index bb3c49de4e7a6c221c3df8b98795977f760a65d5..a5fe1d388deee2fef9c3095ca42371eee0fef590 100644
--- a/gpu/command_buffer/service/texture_definition.cc
+++ b/gpu/command_buffer/service/texture_definition.cc
@@ -243,6 +243,8 @@ class NativeImageBufferStub : public NativeImageBuffer {
   DISALLOW_COPY_AND_ASSIGN(NativeImageBufferStub);
 };
 
+bool g_avoid_egl_target_texture_reuse = false;
+
 }  // anonymous namespace
 
 // static
@@ -260,6 +262,11 @@ scoped_refptr<NativeImageBuffer> NativeImageBuffer::Create(GLuint texture_id) {
   }
 }
 
+// static
+void TextureDefinition::AvoidEGLTargetTextureReuse() {
+  g_avoid_egl_target_texture_reuse = true;
+}
+
 TextureDefinition::LevelInfo::LevelInfo()
     : target(0),
       internal_format(0),
@@ -347,12 +354,12 @@ Texture* TextureDefinition::CreateTexture() const {
   glGenTextures(1, &texture_id);
 
   Texture* texture(new Texture(texture_id));
-  UpdateTexture(texture);
+  UpdateTextureInternal(texture);
 
   return texture;
 }
 
-void TextureDefinition::UpdateTexture(Texture* texture) const {
+void TextureDefinition::UpdateTextureInternal(Texture* texture) const {
   gfx::ScopedTextureBinder texture_binder(target_, texture->service_id());
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filter_);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mag_filter_);
@@ -397,6 +404,22 @@ void TextureDefinition::UpdateTexture(Texture* texture) const {
   texture->usage_ = usage_;
 }
 
+void TextureDefinition::UpdateTexture(Texture* texture) const {
+  GLuint old_service_id = 0u;
+  if (image_buffer_.get() && g_avoid_egl_target_texture_reuse) {
+    GLuint service_id = 0u;
+    glGenTextures(1, &service_id);
+    old_service_id = texture->service_id();
+    texture->SetServiceId(service_id);
+  }
+

[no sievers, 2015/04/29 17:21:30]

Sorry I missed this though we talked about it - but we have to fix it:
Need to handle the case where old_service_id is currently bound. I think it's
simple, we just bind the new texture if that is the case.

I'm also not fully sure about what if the texture is bound to an FBO.
On the one hand it's the same buffer (egl image), so in that regard it doesn't
really matter. But maybe I'm missing something that can go wrong, because the
old and not the new texture really remains the attachment.

[boliu, 2015/04/29 18:22:36]

SG, I'll make the patch.
So... do nothing for now?

+  UpdateTextureInternal(texture);
+
+  if (old_service_id) {
+    glDeleteTextures(1, &old_service_id);
+  }
+}
+
 bool TextureDefinition::Matches(const Texture* texture) const {
   DCHECK(target_ == texture->target());
   if (texture->min_filter_ != min_filter_ ||