Use FixedVector for storing textures referenced by a framebuffer.

This improves the performance of Framebuffer::hasTextureAttachment 3X.

BUG=angleproject:2188

Change-Id: I6acc7f4440fe0232438182274d7bba6075530f38
Reviewed-on: https://chromium-review.googlesource.com/1159171
Reviewed-by: Jamie Madill <[email protected]>
Commit-Queue: Jamie Madill <[email protected]>

Author: vonture

src/libANGLE/Framebuffer.cpp

@@ -2344,31 +2344,32 @@ bool Framebuffer::hasTextureAttachment(const Texture *texture) const
 {
     if (!mAttachedTextures.valid())
     {
-        std::set<const FramebufferAttachmentObject *> attachedTextures;
+        FramebufferTextureAttachmentVector attachedTextures;
 
         for (const auto &colorAttachment : mState.mColorAttachments)
         {
             if (colorAttachment.isAttached() && colorAttachment.type() == GL_TEXTURE)
             {
-                attachedTextures.insert(colorAttachment.getResource());
+                attachedTextures.push_back(colorAttachment.getResource());
             }
         }
 
         if (mState.mDepthAttachment.isAttached() && mState.mDepthAttachment.type() == GL_TEXTURE)
         {
-            attachedTextures.insert(mState.mDepthAttachment.getResource());
+            attachedTextures.push_back(mState.mDepthAttachment.getResource());
         }
 
         if (mState.mStencilAttachment.isAttached() &&
             mState.mStencilAttachment.type() == GL_TEXTURE)
         {
-            attachedTextures.insert(mState.mStencilAttachment.getResource());
+            attachedTextures.push_back(mState.mStencilAttachment.getResource());
         }
 
         mAttachedTextures = std::move(attachedTextures);
     }
 
-    return (mAttachedTextures.value().count(texture) > 0);
+    return std::find(mAttachedTextures.value().begin(), mAttachedTextures.value().end(), texture) !=
+           mAttachedTextures.value().end();
 }
 
 }  // namespace gl

src/libANGLE/Framebuffer.h

@@ -12,6 +12,7 @@
 
 #include <vector>
 
+#include "common/FixedVector.h"
 #include "common/Optional.h"
 #include "common/angleutils.h"
 #include "libANGLE/Constants.h"
@@ -422,7 +423,10 @@ class Framebuffer final : public angle::ObserverInterface,
     Optional<DirtyBits> mDirtyBitsGuard;
 
     // A cache of attached textures for quick validation of feedback loops.
-    mutable Optional<std::set<const FramebufferAttachmentObject *>> mAttachedTextures;
+    using FramebufferTextureAttachmentVector =
+        angle::FixedVector<const FramebufferAttachmentObject *,
+                           IMPLEMENTATION_MAX_FRAMEBUFFER_ATTACHMENTS>;
+    mutable Optional<FramebufferTextureAttachmentVector> mAttachedTextures;
 };
 
 }  // namespace gl