From 1ce29e2afa44266593014ba1a6b665386cddae85 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Fri, 4 Nov 2022 17:20:33 +0900
Subject: [PATCH] internal/graphicsdriver/directx: reduce rendering paths for
 even-odd rendering

---
 .../directx/graphics_windows.go               | 34 +------------------
 .../directx/pipeline_windows.go               | 27 +++++++++++++--
 2 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/internal/graphicsdriver/directx/graphics_windows.go b/internal/graphicsdriver/directx/graphics_windows.go
index bdefaa365..900ff7be5 100644
--- a/internal/graphicsdriver/directx/graphics_windows.go
+++ b/internal/graphicsdriver/directx/graphics_windows.go
@@ -1262,42 +1262,10 @@ func (g *Graphics) DrawTriangles(dstID graphicsdriver.ImageID, srcs [graphics.Sh
 		Format:         _DXGI_FORMAT_R16_UINT,
 	})
 
-	if evenOdd {
-		s, err := shader.pipelineState(blend, prepareStencil, dst.screen)
-		if err != nil {
-			return err
-		}
-		if err := g.drawTriangles(s, srcImages, flattenUniforms, indexLen, indexOffset); err != nil {
-			return err
-		}
-
-		s, err = shader.pipelineState(blend, drawWithStencil, dst.screen)
-		if err != nil {
-			return err
-		}
-		if err := g.drawTriangles(s, srcImages, flattenUniforms, indexLen, indexOffset); err != nil {
-			return err
-		}
-	} else {
-		s, err := shader.pipelineState(blend, noStencil, dst.screen)
-		if err != nil {
-			return err
-		}
-		if err := g.drawTriangles(s, srcImages, flattenUniforms, indexLen, indexOffset); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (g *Graphics) drawTriangles(pipelineState *_ID3D12PipelineState, srcs [graphics.ShaderImageCount]*Image, flattenUniforms []float32, indexLen int, indexOffset int) error {
-	if err := g.pipelineStates.useGraphicsPipelineState(g.device, g.drawCommandList, g.frameIndex, pipelineState, srcs, flattenUniforms); err != nil {
+	if err := g.pipelineStates.drawTriangles(g.device, g.drawCommandList, g.frameIndex, dst.screen, srcImages, shader, flattenUniforms, blend, indexLen, indexOffset, evenOdd); err != nil {
 		return err
 	}
 
-	g.drawCommandList.DrawIndexedInstanced(uint32(indexLen), 1, uint32(indexOffset), 0, 0)
-
 	return nil
 }
 
diff --git a/internal/graphicsdriver/directx/pipeline_windows.go b/internal/graphicsdriver/directx/pipeline_windows.go
index 28c882dd6..849449ef9 100644
--- a/internal/graphicsdriver/directx/pipeline_windows.go
+++ b/internal/graphicsdriver/directx/pipeline_windows.go
@@ -146,7 +146,7 @@ func (p *pipelineStates) initialize(device *_ID3D12Device) (ferr error) {
 	return nil
 }
 
-func (p *pipelineStates) useGraphicsPipelineState(device *_ID3D12Device, commandList *_ID3D12GraphicsCommandList, frameIndex int, pipelineState *_ID3D12PipelineState, srcs [graphics.ShaderImageCount]*Image, uniforms []float32) error {
+func (p *pipelineStates) drawTriangles(device *_ID3D12Device, commandList *_ID3D12GraphicsCommandList, frameIndex int, screen bool, srcs [graphics.ShaderImageCount]*Image, shader *Shader, uniforms []float32, blend graphicsdriver.Blend, indexLen int, indexOffset int, evenOdd bool) error {
 	idx := len(p.constantBuffers[frameIndex])
 	if idx >= numDescriptorsPerFrame {
 		return fmt.Errorf("directx: too many constant buffers")
@@ -230,8 +230,6 @@ func (p *pipelineStates) useGraphicsPipelineState(device *_ID3D12Device, command
 	// Update the constant buffer.
 	copy(unsafe.Slice((*float32)(unsafe.Pointer(m)), len(uniforms)), uniforms)
 
-	commandList.SetPipelineState(pipelineState)
-
 	rs, err := p.ensureRootSignature(device)
 	if err != nil {
 		return err
@@ -257,6 +255,29 @@ func (p *pipelineStates) useGraphicsPipelineState(device *_ID3D12Device, command
 	}
 	commandList.SetGraphicsRootDescriptorTable(2, sh)
 
+	if evenOdd {
+		s, err := shader.pipelineState(blend, prepareStencil, screen)
+		if err != nil {
+			return err
+		}
+		commandList.SetPipelineState(s)
+		commandList.DrawIndexedInstanced(uint32(indexLen), 1, uint32(indexOffset), 0, 0)
+
+		s, err = shader.pipelineState(blend, drawWithStencil, screen)
+		if err != nil {
+			return err
+		}
+		commandList.SetPipelineState(s)
+		commandList.DrawIndexedInstanced(uint32(indexLen), 1, uint32(indexOffset), 0, 0)
+	} else {
+		s, err := shader.pipelineState(blend, noStencil, screen)
+		if err != nil {
+			return err
+		}
+		commandList.SetPipelineState(s)
+		commandList.DrawIndexedInstanced(uint32(indexLen), 1, uint32(indexOffset), 0, 0)
+	}
+
 	return nil
 }