From b48c2aa1038c1592a21e0b711d51911bb6c39066 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Fri, 15 Jul 2022 03:40:22 +0900
Subject: [PATCH] internal/graphicsdriver/directx: bug fix: too many constant
 buffers could be allocated

Closes #2204
---
 image_test.go                                 | 44 +++++++++++++++++++
 .../directx/graphics_windows.go               | 20 +++++----
 2 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/image_test.go b/image_test.go
index 954dccae8..e3b3404ff 100644
--- a/image_test.go
+++ b/image_test.go
@@ -3376,3 +3376,47 @@ func TestImageSetOverSet(t *testing.T) {
 		t.Errorf("got: %v, want: %v", got, want)
 	}
 }
+
+// Issue #2204
+func TestImageTooManyConstantBuffersInDirectX(t *testing.T) {
+	src := ebiten.NewImage(3, 3)
+	src.Fill(color.White)
+	src = src.SubImage(image.Rect(1, 1, 2, 2)).(*ebiten.Image)
+
+	vs := []ebiten.Vertex{
+		{
+			DstX: 0, DstY: 0, SrcX: 1, SrcY: 1,
+			ColorR: 1, ColorG: 1, ColorB: 1, ColorA: 1,
+		},
+		{
+			DstX: 16, DstY: 0, SrcX: 1, SrcY: 1,
+			ColorR: 1, ColorG: 1, ColorB: 1, ColorA: 1,
+		},
+		{
+			DstX: 0, DstY: 16, SrcX: 1, SrcY: 1,
+			ColorR: 1, ColorG: 1, ColorB: 1, ColorA: 1,
+		},
+		{
+			DstX: 16, DstY: 16, SrcX: 1, SrcY: 1,
+			ColorR: 1, ColorG: 1, ColorB: 1, ColorA: 1,
+		},
+	}
+	is := []uint16{0, 1, 2, 1, 2, 3}
+
+	dst0 := ebiten.NewImage(16, 16)
+	dst1 := ebiten.NewImage(16, 16)
+	op := &ebiten.DrawTrianglesOptions{
+		FillRule: ebiten.EvenOdd,
+	}
+	for i := 0; i < 100; i++ {
+		dst0.DrawTriangles(vs, is, src, op)
+		dst1.DrawTriangles(vs, is, src, op)
+	}
+
+	if got, want := dst0.At(0, 0), (color.RGBA{0xff, 0xff, 0xff, 0xff}); got != want {
+		t.Errorf("got: %v, want: %v", got, want)
+	}
+	if got, want := dst1.At(0, 0), (color.RGBA{0xff, 0xff, 0xff, 0xff}); got != want {
+		t.Errorf("got: %v, want: %v", got, want)
+	}
+}
diff --git a/internal/graphicsdriver/directx/graphics_windows.go b/internal/graphicsdriver/directx/graphics_windows.go
index 298cdf418..a7fe0b8ed 100644
--- a/internal/graphicsdriver/directx/graphics_windows.go
+++ b/internal/graphicsdriver/directx/graphics_windows.go
@@ -1160,6 +1160,18 @@ func (g *Graphics) DrawTriangles(dstID graphicsdriver.ImageID, srcs [graphics.Sh
 		return err
 	}
 
+	// Release constant buffers when too many ones were created.
+	numPipelines := 1
+	if evenOdd {
+		numPipelines = 2
+	}
+	if len(g.pipelineStates.constantBuffers[g.frameIndex])+numPipelines > numDescriptorsPerFrame {
+		if err := g.flushCommandList(g.drawCommandList); err != nil {
+			return err
+		}
+		g.pipelineStates.releaseConstantBuffers(g.frameIndex)
+	}
+
 	dst := g.images[dstID]
 	var resourceBarriers []_D3D12_RESOURCE_BARRIER_Transition
 	if rb, ok := dst.transiteState(_D3D12_RESOURCE_STATE_RENDER_TARGET); ok {
@@ -1382,14 +1394,6 @@ func (g *Graphics) DrawTriangles(dstID graphicsdriver.ImageID, srcs [graphics.Sh
 		}
 	}
 
-	// Release constant buffers when too many ones were created.
-	if len(g.pipelineStates.constantBuffers[g.frameIndex]) >= numDescriptorsPerFrame {
-		if err := g.flushCommandList(g.drawCommandList); err != nil {
-			return err
-		}
-		g.pipelineStates.releaseConstantBuffers(g.frameIndex)
-	}
-
 	return nil
 }