Reland "WIP: Optimize default framebuffer's drawable obtaining step"

Defer the actual obtaining until first framebuffer's drawing/reading.

Change-Id: I1bd658cc5350cf52d6462016399455de57702ccf

Author: kakashidinho

src/libANGLE/renderer/metal/ContextMtl.h

@@ -27,6 +27,7 @@ class DisplayMtl;
 class FramebufferMtl;
 class VertexArrayMtl;
 class ProgramMtl;
+class RenderTargetMtl;
 
 class ContextMtl : public ContextImpl, public mtl::Context
 {
@@ -231,25 +232,20 @@ class ContextMtl : public ContextImpl, public mtl::Context
 
     // Check whether compatible render pass has been started.
     bool hasStartedRenderPass(const mtl::RenderPassDesc &desc);
-    bool hasStartedRenderPass(FramebufferMtl *framebuffer);
 
     // Get current render encoder. May be nullptr if no render pass has been started.
     mtl::RenderCommandEncoder *getRenderCommandEncoder();
 
-    mtl::RenderCommandEncoder *getCurrentFramebufferRenderCommandEncoder();
-
     // Will end current command encoder if it is valid, then start new encoder.
     // Unless hasStartedRenderPass(desc) returns true.
     mtl::RenderCommandEncoder *getRenderCommandEncoder(const mtl::RenderPassDesc &desc);
 
-    // Utilities to quickly create render command enconder to a specific texture:
+    // Utilities to quickly create render command encoder to a specific texture:
     // The previous content of texture will be loaded if clearColor is not provided
-    mtl::RenderCommandEncoder *getRenderCommandEncoder(const mtl::TextureRef &textureTarget,
-                                                       const gl::ImageIndex &index,
+    mtl::RenderCommandEncoder *getRenderCommandEncoder(const RenderTargetMtl &renderTarget,
                                                        const Optional<MTLClearColor> &clearColor);
     // The previous content of texture will be loaded
-    mtl::RenderCommandEncoder *getRenderCommandEncoder(const mtl::TextureRef &textureTarget,
-                                                       const gl::ImageIndex &index);
+    mtl::RenderCommandEncoder *getRenderCommandEncoder(const RenderTargetMtl &renderTarget);
 
     // Will end current command encoder and start new blit command encoder. Unless a blit comamnd
     // encoder is already started.

src/libANGLE/renderer/metal/ContextMtl.mm

@@ -728,7 +728,7 @@
 // Framebuffer creation
 FramebufferImpl *ContextMtl::createFramebuffer(const gl::FramebufferState &state)
 {
-    return new FramebufferMtl(state, false);
+    return new FramebufferMtl(state, false, nullptr);
 }
 
 // Texture creation
@@ -1003,7 +1003,7 @@
     ensureCommandBufferValid();
 
     // Always discard default FBO's depth stencil buffers at the end of the frame:
-    if (mDrawFramebufferIsDefault && hasStartedRenderPass(mDrawFramebuffer))
+    if (mDrawFramebufferIsDefault && mDrawFramebuffer->renderPassHasStarted(this))
     {
         constexpr GLenum dsAttachments[] = {GL_DEPTH, GL_STENCIL};
         (void)mDrawFramebuffer->invalidate(context, 2, dsAttachments);
@@ -1037,11 +1037,6 @@
            mRenderEncoder.renderPassDesc().equalIgnoreLoadStoreOptions(desc);
 }
 
-bool ContextMtl::hasStartedRenderPass(FramebufferMtl *framebuffer)
-{
-    return framebuffer && hasStartedRenderPass(framebuffer->getRenderPassDesc(this));
-}
-
 // Get current render encoder
 mtl::RenderCommandEncoder *ContextMtl::getRenderCommandEncoder()
 {
@@ -1053,16 +1048,6 @@
     return &mRenderEncoder;
 }
 
-mtl::RenderCommandEncoder *ContextMtl::getCurrentFramebufferRenderCommandEncoder()
-{
-    if (!mDrawFramebuffer)
-    {
-        return nullptr;
-    }
-
-    return getRenderCommandEncoder(mDrawFramebuffer->getRenderPassDesc(this));
-}
-
 mtl::RenderCommandEncoder *ContextMtl::getRenderCommandEncoder(const mtl::RenderPassDesc &desc)
 {
     if (hasStartedRenderPass(desc))
@@ -1080,36 +1065,31 @@
     return &mRenderEncoder.restart(desc);
 }
 
-// Utilities to quickly create render command enconder to a specific texture:
+// Utilities to quickly create render command encoder to a specific texture:
 // The previous content of texture will be loaded if clearColor is not provided
 mtl::RenderCommandEncoder *ContextMtl::getRenderCommandEncoder(
-    const mtl::TextureRef &textureTarget,
-    const gl::ImageIndex &index,
+    const RenderTargetMtl &renderTarget,
     const Optional<MTLClearColor> &clearColor)
 {
-    ASSERT(textureTarget && textureTarget->valid());
+    ASSERT(renderTarget.getTexture());
 
     mtl::RenderPassDesc rpDesc;
-
-    rpDesc.colorAttachments[0].texture = textureTarget;
-    rpDesc.colorAttachments[0].level   = index.getLevelIndex();
-    rpDesc.colorAttachments[0].slice   = index.hasLayer() ? index.getLayerIndex() : 0;
-    rpDesc.numColorAttachments         = 1;
+    renderTarget.toRenderPassAttachmentDesc(&rpDesc.colorAttachments[0]);
+    rpDesc.numColorAttachments = 1;
 
     if (clearColor.valid())
     {
         rpDesc.colorAttachments[0].loadAction = MTLLoadActionClear;
-        rpDesc.colorAttachments[0].clearColor =
-            mtl::EmulatedAlphaClearColor(clearColor.value(), textureTarget->getColorWritableMask());
+        rpDesc.colorAttachments[0].clearColor = mtl::EmulatedAlphaClearColor(
+            clearColor.value(), renderTarget.getTexture()->getColorWritableMask());
     }
 
     return getRenderCommandEncoder(rpDesc);
 }
 // The previous content of texture will be loaded
-mtl::RenderCommandEncoder *ContextMtl::getRenderCommandEncoder(const mtl::TextureRef &textureTarget,
-                                                               const gl::ImageIndex &index)
+mtl::RenderCommandEncoder *ContextMtl::getRenderCommandEncoder(const RenderTargetMtl &renderTarget)
 {
-    return getRenderCommandEncoder(textureTarget, index, Optional<MTLClearColor>());
+    return getRenderCommandEncoder(renderTarget, Optional<MTLClearColor>());
 }
 
 mtl::BlitCommandEncoder *ContextMtl::getBlitCommandEncoder()
@@ -1354,8 +1334,7 @@
     if (mDirtyBits.test(DIRTY_BIT_DRAW_FRAMEBUFFER))
     {
         // Start new render command encoder
-        const mtl::RenderPassDesc &rpDesc = mDrawFramebuffer->getRenderPassDesc(this);
-        ANGLE_MTL_TRY(this, getRenderCommandEncoder(rpDesc));
+        ANGLE_MTL_TRY(this, mDrawFramebuffer->ensureRenderPassStarted(context));
 
         // re-apply everything
         invalidateState(context);
@@ -1552,15 +1531,15 @@
 
     // Need to handle the case when render pass doesn't have depth/stencil attachment.
     mtl::DepthStencilDesc dsDesc              = mDepthStencilDesc;
-    const mtl::RenderPassDesc &renderPassDesc = mDrawFramebuffer->getRenderPassDesc(this);
+    const mtl::RenderPassDesc &renderPassDesc = mRenderEncoder.renderPassDesc();
 
-    if (!renderPassDesc.depthAttachment.texture)
+    if (!renderPassDesc.depthAttachment.texture())
     {
         dsDesc.depthWriteEnabled    = false;
         dsDesc.depthCompareFunction = MTLCompareFunctionAlways;
     }
 
-    if (!renderPassDesc.stencilAttachment.texture)
+    if (!renderPassDesc.stencilAttachment.texture())
     {
         dsDesc.frontFaceStencil.reset();
         dsDesc.backFaceStencil.reset();
@@ -1606,7 +1585,7 @@
 
     if (rppChange)
     {
-        const mtl::RenderPassDesc &renderPassDesc = mDrawFramebuffer->getRenderPassDesc(this);
+        const mtl::RenderPassDesc &renderPassDesc = mRenderEncoder.renderPassDesc();
         // Obtain RenderPipelineDesc's output descriptor.
         renderPassDesc.populateRenderPipelineOutputDesc(mBlendDesc,
                                                         &mRenderPipelineDesc.outputDescriptor);

src/libANGLE/renderer/metal/FrameBufferMtl.h

@@ -18,13 +18,17 @@
 
 namespace rx
 {
+namespace mtl
+{
+class RenderCommandEncoder;
+}
 class ContextMtl;
 class SurfaceMtl;
 
 class FramebufferMtl : public FramebufferImpl
 {
   public:
-    explicit FramebufferMtl(const gl::FramebufferState &state, bool flipY);
+    explicit FramebufferMtl(const gl::FramebufferState &state, bool flipY, SurfaceMtl *backbuffer);
     ~FramebufferMtl() override;
     void destroy(const gl::Context *context) override;
 
@@ -81,19 +85,20 @@ class FramebufferMtl : public FramebufferImpl
                                     size_t index,
                                     GLfloat *xy) const override;
 
-    RenderTargetMtl *getColorReadRenderTarget() const;
+    RenderTargetMtl *getColorReadRenderTarget(const gl::Context *context) const;
 
     bool flipY() const { return mFlipY; }
 
     gl::Rectangle getCompleteRenderArea() const;
 
-    const mtl::RenderPassDesc &getRenderPassDesc(ContextMtl *context);
+    bool renderPassHasStarted(ContextMtl *contextMtl) const;
+    mtl::RenderCommandEncoder *ensureRenderPassStarted(const gl::Context *context);
 
     // Call this to notify FramebufferMtl whenever its render pass has started.
     void onStartedDrawingToFrameBuffer(const gl::Context *context);
 
     // The actual area will be adjusted based on framebuffer flipping property.
-    gl::Rectangle getReadPixelArea(const gl::Rectangle &glArea);
+    gl::Rectangle getReadPixelArea(const gl::Context *context, const gl::Rectangle &glArea);
 
     // NOTE: this method doesn't do the flipping of area. Caller must do it if needed before
     // callling this. See getReadPixelsArea().
@@ -122,6 +127,9 @@ class FramebufferMtl : public FramebufferImpl
                                     gl::DrawBufferMask drawColorBuffers,
                                     mtl::RenderPassDesc *descOut);
 
+    mtl::RenderCommandEncoder *ensureRenderPassStarted(const gl::Context *context,
+                                                       const mtl::RenderPassDesc &desc);
+
     void overrideClearColor(const mtl::TextureRef &texture,
                             MTLClearColor clearColor,
                             MTLClearColor *colorOut);
@@ -140,7 +148,9 @@ class FramebufferMtl : public FramebufferImpl
     RenderTargetMtl *mDepthRenderTarget   = nullptr;
     RenderTargetMtl *mStencilRenderTarget = nullptr;
     mtl::RenderPassDesc mRenderPassDesc;
-    const bool mFlipY = false;
+
+    SurfaceMtl *mBackbuffer = nullptr;
+    const bool mFlipY       = false;
 };
 }  // namespace rx