internal/graphicsdriver: introduce the DirectX driver

Closes #1007

.github/workflows/test.yml

@@ -92,15 +92,10 @@ jobs:
 
       - name: go test
         # TODO: Add more test environments (#1305)
-        if: ${{ startsWith(matrix.os, 'ubuntu-') }}
+        if: ${{ startsWith(matrix.os, 'ubuntu-') || startsWith(matrix.os, 'windows-') }}
         run: |
           go test -tags=example ${{ !startsWith(matrix.go, '1.15.') && !startsWith(matrix.go, '1.16.') && '-shuffle=on' || '' }} -v ./...
 
-      - name: go test (Windows)
-        if: ${{ startsWith(matrix.os, 'windows-') }}
-        run: |
-          go test -tags=example ${{ !startsWith(matrix.go, '1.15.') && !startsWith(matrix.go, '1.16.') && '-shuffle=on' || '' }} -v ./internal/shader
-
       - name: go test (Wasm)
         # TODO: Investigate times out on Windows. (#1313)
         if: ${{ !startsWith(matrix.os, 'windows-') && !startsWith(matrix.go, '1.15.') && !startsWith(matrix.go, '1.16.') }}

doc.go

@@ -71,8 +71,15 @@
 //
 //     "auto":    Ebiten chooses the graphics library automatically. This is the default value.
 //     "opengl":  OpenGL, OpenGL ES, or WebGL.
+//     "directx": DirectX. This works only on Windows.
 //     "metal":   Metal. This works only on macOS or iOS.
 //
+// `EBITEN_DIRECTX` environment variable specifies various parameters for DirectX.
+// You can specify multiple values separated by a comma. The default value is empty (i.e. no parameters).
+//
+//     "warp":  Use WARP (i.e. software rendering).
+//     "debug": Use a debug layer.
+//
 // Build tags
 //
 // `ebitendebug` outputs a log of graphics commands. This is useful to know what happens in Ebiten. In general, the

internal/graphicsdriver/directx/pipeline_windows.go

@@ -0,0 +1,686 @@
+// Copyright 2022 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package directx
+
+import (
+	"fmt"
+	"math"
+	"unsafe"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
+)
+
+const numDescriptorsPerFrame = 256
+
+func operationToBlend(c graphicsdriver.Operation, alpha bool) _D3D12_BLEND {
+	switch c {
+	case graphicsdriver.Zero:
+		return _D3D12_BLEND_ZERO
+	case graphicsdriver.One:
+		return _D3D12_BLEND_ONE
+	case graphicsdriver.SrcAlpha:
+		return _D3D12_BLEND_SRC_ALPHA
+	case graphicsdriver.DstAlpha:
+		return _D3D12_BLEND_DEST_ALPHA
+	case graphicsdriver.OneMinusSrcAlpha:
+		return _D3D12_BLEND_INV_SRC_ALPHA
+	case graphicsdriver.OneMinusDstAlpha:
+		return _D3D12_BLEND_INV_DEST_ALPHA
+	case graphicsdriver.DstColor:
+		if alpha {
+			return _D3D12_BLEND_DEST_ALPHA
+		}
+		return _D3D12_BLEND_DEST_COLOR
+	default:
+		panic(fmt.Sprintf("directx: invalid operation: %d", c))
+	}
+}
+
+type builtinPipelineStatesKey struct {
+	useColorM     bool
+	compositeMode graphicsdriver.CompositeMode
+	filter        graphicsdriver.Filter
+	address       graphicsdriver.Address
+	stencilMode   stencilMode
+	screen        bool
+}
+
+func (k *builtinPipelineStatesKey) defs() ([]_D3D_SHADER_MACRO, error) {
+	var defs []_D3D_SHADER_MACRO
+	defval := []byte("1\x00")
+	if k.useColorM {
+		name := []byte("USE_COLOR_MATRIX\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	}
+
+	switch k.filter {
+	case graphicsdriver.FilterNearest:
+		name := []byte("FILTER_NEAREST\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	case graphicsdriver.FilterLinear:
+		name := []byte("FILTER_LINEAR\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	case graphicsdriver.FilterScreen:
+		name := []byte("FILTER_SCREEN\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	default:
+		return nil, fmt.Errorf("directx: invalid filter: %d", k.filter)
+	}
+
+	switch k.address {
+	case graphicsdriver.AddressUnsafe:
+		name := []byte("ADDRESS_UNSAFE\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	case graphicsdriver.AddressClampToZero:
+		name := []byte("ADDRESS_CLAMP_TO_ZERO\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	case graphicsdriver.AddressRepeat:
+		name := []byte("ADDRESS_REPEAT\x00")
+		defs = append(defs, _D3D_SHADER_MACRO{&name[0], &defval[0]})
+	default:
+		return nil, fmt.Errorf("directx: invalid address: %d", k.address)
+	}
+
+	// Termination
+	defs = append(defs, _D3D_SHADER_MACRO{})
+
+	return defs, nil
+}
+
+func (k *builtinPipelineStatesKey) source() []byte {
+	return []byte(`struct PSInput {
+  float4 position : SV_POSITION;
+  float2 texcoord : TEXCOORD0;
+  float4 color : COLOR;
+};
+
+cbuffer ShaderParameter : register(b0) {
+  float2 viewport_size;
+  float2 source_size;
+  float4x4 color_matrix_body;
+  float4 color_matrix_translation;
+  float4 source_region;
+
+  // This member should be the last not to create a new sector.
+  // https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-packing-rules
+  float scale;
+}
+
+PSInput VSMain(float2 position : POSITION, float2 tex : TEXCOORD, float4 color : COLOR) {
+  // In DirectX, the NDC's Y direction (upward) and the framebuffer's Y direction (downward) don't
+  // match. Then, the Y direction must be inverted.
+  float4x4 projectionMatrix = {
+    2.0 / viewport_size.x, 0, 0, -1,
+    0, -2.0 / viewport_size.y, 0, 1,
+    0, 0, 1, 0,
+    0, 0, 0, 1,
+  };
+
+  PSInput result;
+  result.position = mul(projectionMatrix, float4(position, 0, 1));
+  result.texcoord = tex;
+  result.color = float4(color.rgb, 1) * color.a;
+  return result;
+}
+
+Texture2D tex : register(t0);
+SamplerState samp : register(s0);
+
+float euclideanMod(float x, float y) {
+  // Assume that y is always positive.
+  return x - y * floor(x/y);
+}
+
+float2 adjustTexelByAddress(float2 p, float4 source_region) {
+#if defined(ADDRESS_CLAMP_TO_ZERO)
+  return p;
+#endif
+
+#if defined(ADDRESS_REPEAT)
+  float2 o = float2(source_region[0], source_region[1]);
+  float2 size = float2(source_region[2] - source_region[0], source_region[3] - source_region[1]);
+  return float2(euclideanMod((p.x - o.x), size.x) + o.x, euclideanMod((p.y - o.y), size.y) + o.y);
+#endif
+
+#if defined(ADDRESS_UNSAFE)
+  return p;
+#endif
+}
+
+float4 PSMain(PSInput input) : SV_TARGET {
+#if defined(FILTER_NEAREST)
+# if defined(ADDRESS_UNSAFE)
+  float4 color = tex.Sample(samp, input.texcoord);
+# else
+  float4 color;
+  float2 pos = adjustTexelByAddress(input.texcoord, source_region);
+  if (source_region[0] <= pos.x &&
+      source_region[1] <= pos.y &&
+      pos.x < source_region[2] &&
+      pos.y < source_region[3]) {
+    color = tex.Sample(samp, pos);
+  } else {
+    color = float4(0, 0, 0, 0);
+  }
+# endif // defined(ADDRESS_UNSAFE)
+#endif // defined(FILTER_NEAREST)
+
+#if defined(FILTER_LINEAR)
+  float2 pos = input.texcoord;
+  float2 texel_size = 1.0 / source_size;
+
+  // Shift 1/512 [texel] to avoid the tie-breaking issue.
+  // As all the vertex positions are aligned to 1/16 [pixel], this shiting should work in most cases.
+  float2 p0 = pos - (texel_size) / 2.0 + (texel_size / 512.0);
+  float2 p1 = pos + (texel_size) / 2.0 + (texel_size / 512.0);
+
+# if !defined(ADDRESS_UNSAFE)
+  p0 = adjustTexelByAddress(p0, source_region);
+  p1 = adjustTexelByAddress(p1, source_region);
+# endif  // !defined(ADDRESS_UNSAFE)
+
+  float4 c0 = tex.Sample(samp, p0);
+  float4 c1 = tex.Sample(samp, float2(p1.x, p0.y));
+  float4 c2 = tex.Sample(samp, float2(p0.x, p1.y));
+  float4 c3 = tex.Sample(samp, p1);
+
+# if !defined(ADDRESS_UNSAFE)
+  if (p0.x < source_region[0]) {
+    c0 = float4(0, 0, 0, 0);
+    c2 = float4(0, 0, 0, 0);
+  }
+  if (p0.y < source_region[1]) {
+    c0 = float4(0, 0, 0, 0);
+    c1 = float4(0, 0, 0, 0);
+  }
+  if (source_region[2] <= p1.x) {
+    c1 = float4(0, 0, 0, 0);
+    c3 = float4(0, 0, 0, 0);
+  }
+  if (source_region[3] <= p1.y) {
+    c2 = float4(0, 0, 0, 0);
+    c3 = float4(0, 0, 0, 0);
+  }
+# endif  // !defined(ADDRESS_UNSAFE)
+
+  float2 rate = frac(p0 * source_size);
+  float4 color = lerp(lerp(c0, c1, rate.x), lerp(c2, c3, rate.x), rate.y);
+#endif // defined(FILTER_LINEAR)
+
+#if defined(FILTER_SCREEN)
+  float2 pos = input.texcoord;
+  float2 texel_size = 1.0 / source_size;
+  float2 half_scaled_texel_size = texel_size / 2.0 / scale;
+
+  float2 p0 = pos - half_scaled_texel_size + (texel_size / 512.0);
+  float2 p1 = pos + half_scaled_texel_size + (texel_size / 512.0);
+
+  float4 c0 = tex.Sample(samp, p0);
+  float4 c1 = tex.Sample(samp, float2(p1.x, p0.y));
+  float4 c2 = tex.Sample(samp, float2(p0.x, p1.y));
+  float4 c3 = tex.Sample(samp, p1);
+  // Texels must be in the source rect, so it is not necessary to check that like linear filter.
+
+  float2 rate_center = float2(1.0, 1.0) - half_scaled_texel_size;
+  float2 rate = clamp(((frac(p0 * source_size) - rate_center) * scale) + rate_center, 0.0, 1.0);
+  float4 color = lerp(lerp(c0, c1, rate.x), lerp(c2, c3, rate.x), rate.y);
+#endif // defined(FILTER_SCREEN)
+
+#if defined(USE_COLOR_MATRIX)
+  // Un-premultiply alpha.
+  // When the alpha is 0, 1.0 - sign(alpha) is 1.0, which means division does nothing.
+  color.rgb /= color.a + (1.0 - sign(color.a));
+  // Apply the color matrix or scale.
+  color = mul(color_matrix_body, color) + color_matrix_translation;
+  // Premultiply alpha
+  color.rgb *= color.a;
+  // Apply color scale.
+  color *= input.color;
+  // Clamp the output.
+  color.rgb = min(color.rgb, color.a);
+  return color;
+#elif defined(FILTER_SCREEN)
+  return color;
+#else
+  return input.color * color;
+#endif // defined(USE_COLOR_MATRIX)
+
+}`)
+}
+
+type pipelineStates struct {
+	rootSignature *iD3D12RootSignature
+
+	cache map[builtinPipelineStatesKey]*iD3D12PipelineState
+
+	// builtinShaders is a set of the built-in vertex/pixel shaders that are never released.
+	builtinShaders []*iD3DBlob
+
+	shaderDescriptorHeap *iD3D12DescriptorHeap
+	shaderDescriptorSize uint32
+
+	samplerDescriptorHeap *iD3D12DescriptorHeap
+
+	constantBuffers [frameCount][]*iD3D12Resource1
+}
+
+const numConstantBufferAndSourceTextures = 1 + graphics.ShaderImageNum
+
+func (p *pipelineStates) initialize(device *iD3D12Device) (ferr error) {
+	// Create a CBV/SRV/UAV descriptor heap.
+	//   5n+0:        constants
+	//   5n+m (1<=4): textures
+	shaderH, err := device.CreateDescriptorHeap(&_D3D12_DESCRIPTOR_HEAP_DESC{
+		Type:           _D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV,
+		NumDescriptors: frameCount * numDescriptorsPerFrame * numConstantBufferAndSourceTextures,
+		Flags:          _D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE,
+		NodeMask:       0,
+	})
+	if err != nil {
+		return err
+	}
+	p.shaderDescriptorHeap = shaderH
+	defer func() {
+		if ferr != nil {
+			p.shaderDescriptorHeap.Release()
+			p.shaderDescriptorHeap = nil
+		}
+	}()
+	p.shaderDescriptorSize = device.GetDescriptorHandleIncrementSize(_D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV)
+
+	samplerH, err := device.CreateDescriptorHeap(&_D3D12_DESCRIPTOR_HEAP_DESC{
+		Type:           _D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER,
+		NumDescriptors: 1,
+		Flags:          _D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE,
+		NodeMask:       0,
+	})
+	if err != nil {
+		return err
+	}
+	p.samplerDescriptorHeap = samplerH
+
+	device.CreateSampler(&_D3D12_SAMPLER_DESC{
+		Filter:         _D3D12_FILTER_MIN_MAG_MIP_POINT,
+		AddressU:       _D3D12_TEXTURE_ADDRESS_MODE_WRAP,
+		AddressV:       _D3D12_TEXTURE_ADDRESS_MODE_WRAP,
+		AddressW:       _D3D12_TEXTURE_ADDRESS_MODE_WRAP,
+		ComparisonFunc: _D3D12_COMPARISON_FUNC_NEVER,
+		MinLOD:         -math.MaxFloat32,
+		MaxLOD:         math.MaxFloat32,
+	}, p.samplerDescriptorHeap.GetCPUDescriptorHandleForHeapStart())
+
+	return nil
+}
+
+func (p *pipelineStates) builtinGraphicsPipelineState(device *iD3D12Device, key builtinPipelineStatesKey) (*iD3D12PipelineState, error) {
+	state, ok := p.cache[key]
+	if ok {
+		return state, nil
+	}
+
+	defs, err := key.defs()
+	if err != nil {
+		return nil, err
+	}
+
+	vsh, psh, err := newShader(key.source(), defs)
+	if err != nil {
+		return nil, err
+	}
+	// Keep the shaders. These are never released.
+	p.builtinShaders = append(p.builtinShaders, vsh, psh)
+
+	s, err := p.newPipelineState(device, vsh, psh, key.compositeMode, key.stencilMode, key.screen)
+	if err != nil {
+		return nil, err
+	}
+	if p.cache == nil {
+		p.cache = map[builtinPipelineStatesKey]*iD3D12PipelineState{}
+	}
+	p.cache[key] = s
+	return s, nil
+}
+
+func (p *pipelineStates) useGraphicsPipelineState(device *iD3D12Device, commandList *iD3D12GraphicsCommandList, frameIndex int, pipelineState *iD3D12PipelineState, srcs [graphics.ShaderImageNum]*Image, uniforms []float32) error {
+	idx := len(p.constantBuffers[frameIndex])
+	if idx >= numDescriptorsPerFrame*2 {
+		return fmt.Errorf("directx: too many constant buffers")
+	}
+
+	if cap(p.constantBuffers[frameIndex]) > idx {
+		p.constantBuffers[frameIndex] = p.constantBuffers[frameIndex][:idx+1]
+	} else {
+		p.constantBuffers[frameIndex] = append(p.constantBuffers[frameIndex], nil)
+	}
+
+	const bufferSizeAlignement = 256
+	bufferSize := uint32(unsafe.Sizeof(float32(0))) * uint32(len(uniforms))
+	if bufferSize > 0 {
+		bufferSize = ((bufferSize-1)/bufferSizeAlignement + 1) * bufferSizeAlignement
+	}
+
+	cb := p.constantBuffers[frameIndex][idx]
+	if cb != nil {
+		if uint32(cb.GetDesc().Width) < bufferSize {
+			p.constantBuffers[frameIndex][idx].Release()
+			p.constantBuffers[frameIndex][idx] = nil
+			cb = nil
+		}
+	}
+	if cb == nil {
+		var err error
+		cb, err = createBuffer(device, uint64(bufferSize), _D3D12_HEAP_TYPE_UPLOAD)
+		if err != nil {
+			return err
+		}
+		p.constantBuffers[frameIndex][idx] = cb
+
+		h := p.shaderDescriptorHeap.GetCPUDescriptorHandleForHeapStart()
+		h.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+		device.CreateConstantBufferView(&_D3D12_CONSTANT_BUFFER_VIEW_DESC{
+			BufferLocation: cb.GetGPUVirtualAddress(),
+			SizeInBytes:    bufferSize,
+		}, h)
+	}
+
+	h := p.shaderDescriptorHeap.GetCPUDescriptorHandleForHeapStart()
+	h.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+	for _, src := range srcs {
+		h.Offset(1, p.shaderDescriptorSize)
+		if src == nil {
+			continue
+		}
+		device.CreateShaderResourceView(src.resource(), &_D3D12_SHADER_RESOURCE_VIEW_DESC{
+			Format:                  _DXGI_FORMAT_R8G8B8A8_UNORM,
+			ViewDimension:           _D3D12_SRV_DIMENSION_TEXTURE2D,
+			Shader4ComponentMapping: _D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING,
+			Texture2D: _D3D12_TEX2D_SRV{
+				MipLevels: 1,
+			},
+		}, h)
+	}
+
+	// Update the constant buffer.
+	m, err := cb.Map(0, &_D3D12_RANGE{0, 0})
+	if err != nil {
+		return err
+	}
+	copyFloat32s(m, uniforms)
+
+	if err := cb.Unmap(0, nil); err != nil {
+		return err
+	}
+
+	commandList.SetPipelineState(pipelineState)
+
+	rs, err := p.ensureRootSignature(device)
+	if err != nil {
+		return err
+	}
+	commandList.SetGraphicsRootSignature(rs)
+
+	commandList.SetDescriptorHeaps([]*iD3D12DescriptorHeap{
+		p.shaderDescriptorHeap,
+		p.samplerDescriptorHeap,
+	})
+
+	// Match the indices with rootParams in graphicsPipelineState.
+	gh := p.shaderDescriptorHeap.GetGPUDescriptorHandleForHeapStart()
+	gh.Offset(int32(frameIndex*numDescriptorsPerFrame+numConstantBufferAndSourceTextures*idx), p.shaderDescriptorSize)
+	commandList.SetGraphicsRootDescriptorTable(0, gh)
+	gh.Offset(1, p.shaderDescriptorSize)
+	commandList.SetGraphicsRootDescriptorTable(1, gh)
+	commandList.SetGraphicsRootDescriptorTable(2, p.samplerDescriptorHeap.GetGPUDescriptorHandleForHeapStart())
+
+	return nil
+}
+
+func (p *pipelineStates) ensureRootSignature(device *iD3D12Device) (rootSignature *iD3D12RootSignature, ferr error) {
+	if p.rootSignature != nil {
+		return p.rootSignature, nil
+	}
+
+	cbv := _D3D12_DESCRIPTOR_RANGE{
+		RangeType:                         _D3D12_DESCRIPTOR_RANGE_TYPE_CBV, // b0
+		NumDescriptors:                    1,
+		BaseShaderRegister:                0,
+		RegisterSpace:                     0,
+		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+	}
+	srv := _D3D12_DESCRIPTOR_RANGE{
+		RangeType:                         _D3D12_DESCRIPTOR_RANGE_TYPE_SRV, // t0
+		NumDescriptors:                    graphics.ShaderImageNum,
+		BaseShaderRegister:                0,
+		RegisterSpace:                     0,
+		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+	}
+	sampler := _D3D12_DESCRIPTOR_RANGE{
+		RangeType:                         _D3D12_DESCRIPTOR_RANGE_TYPE_SAMPLER, // s0
+		NumDescriptors:                    1,
+		BaseShaderRegister:                0,
+		RegisterSpace:                     0,
+		OffsetInDescriptorsFromTableStart: _D3D12_DESCRIPTOR_RANGE_OFFSET_APPEND,
+	}
+
+	rootParams := [...]_D3D12_ROOT_PARAMETER{
+		{
+			ParameterType: _D3D12_ROOT_PARAMETER_TYPE_DESCRIPTOR_TABLE,
+			DescriptorTable: _D3D12_ROOT_DESCRIPTOR_TABLE{
+				NumDescriptorRanges: 1,
+				pDescriptorRanges:   &cbv,
+			},
+			ShaderVisibility: _D3D12_SHADER_VISIBILITY_ALL,
+		},
+		{
+			ParameterType: _D3D12_ROOT_PARAMETER_TYPE_DESCRIPTOR_TABLE,
+			DescriptorTable: _D3D12_ROOT_DESCRIPTOR_TABLE{
+				NumDescriptorRanges: 1,
+				pDescriptorRanges:   &srv,
+			},
+			ShaderVisibility: _D3D12_SHADER_VISIBILITY_PIXEL,
+		},
+		{
+			ParameterType: _D3D12_ROOT_PARAMETER_TYPE_DESCRIPTOR_TABLE,
+			DescriptorTable: _D3D12_ROOT_DESCRIPTOR_TABLE{
+				NumDescriptorRanges: 1,
+				pDescriptorRanges:   &sampler,
+			},
+			ShaderVisibility: _D3D12_SHADER_VISIBILITY_PIXEL,
+		},
+	}
+
+	// Create a root signature.
+	sig, err := d3D12SerializeRootSignature(&_D3D12_ROOT_SIGNATURE_DESC{
+		NumParameters:     uint32(len(rootParams)),
+		pParameters:       &rootParams[0],
+		NumStaticSamplers: 0,
+		pStaticSamplers:   nil,
+		Flags:             _D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT,
+	}, _D3D_ROOT_SIGNATURE_VERSION_1_0)
+	if err != nil {
+		return nil, err
+	}
+	defer sig.Release()
+
+	rs, err := device.CreateRootSignature(0, sig.GetBufferPointer(), sig.GetBufferSize())
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if ferr != nil {
+			rootSignature.Release()
+		}
+	}()
+
+	p.rootSignature = rs
+
+	return p.rootSignature, nil
+}
+
+func newShader(source []byte, defs []_D3D_SHADER_MACRO) (vsh, psh *iD3DBlob, ferr error) {
+	// Create a shader
+	v, err := d3DCompile(source, "shader", defs, nil, "VSMain", "vs_5_0", 0, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer func() {
+		if ferr != nil {
+			v.Release()
+		}
+	}()
+
+	p, err := d3DCompile(source, "shader", defs, nil, "PSMain", "ps_5_0", 0, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer func() {
+		if ferr != nil {
+			p.Release()
+		}
+	}()
+
+	return v, p, nil
+}
+
+func (p *pipelineStates) newPipelineState(device *iD3D12Device, vsh, psh *iD3DBlob, compositeMode graphicsdriver.CompositeMode, stencilMode stencilMode, screen bool) (state *iD3D12PipelineState, ferr error) {
+	rootSignature, err := p.ensureRootSignature(device)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if ferr != nil {
+			rootSignature.Release()
+		}
+	}()
+
+	depthStencilDesc := _D3D12_DEPTH_STENCIL_DESC{
+		DepthEnable:      0,
+		DepthWriteMask:   _D3D12_DEPTH_WRITE_MASK_ALL,
+		DepthFunc:        _D3D12_COMPARISON_FUNC_LESS,
+		StencilEnable:    0,
+		StencilReadMask:  _D3D12_DEFAULT_STENCIL_READ_MASK,
+		StencilWriteMask: _D3D12_DEFAULT_STENCIL_WRITE_MASK,
+		FrontFace: _D3D12_DEPTH_STENCILOP_DESC{
+			StencilFailOp:      _D3D12_STENCIL_OP_KEEP,
+			StencilDepthFailOp: _D3D12_STENCIL_OP_KEEP,
+			StencilPassOp:      _D3D12_STENCIL_OP_KEEP,
+			StencilFunc:        _D3D12_COMPARISON_FUNC_ALWAYS,
+		},
+		BackFace: _D3D12_DEPTH_STENCILOP_DESC{
+			StencilFailOp:      _D3D12_STENCIL_OP_KEEP,
+			StencilDepthFailOp: _D3D12_STENCIL_OP_KEEP,
+			StencilPassOp:      _D3D12_STENCIL_OP_KEEP,
+			StencilFunc:        _D3D12_COMPARISON_FUNC_ALWAYS,
+		},
+	}
+	writeMask := uint8(_D3D12_COLOR_WRITE_ENABLE_ALL)
+
+	switch stencilMode {
+	case prepareStencil:
+		depthStencilDesc.StencilEnable = 1
+		depthStencilDesc.FrontFace.StencilPassOp = _D3D12_STENCIL_OP_INVERT
+		depthStencilDesc.BackFace.StencilPassOp = _D3D12_STENCIL_OP_INVERT
+		writeMask = 0
+	case drawWithStencil:
+		depthStencilDesc.StencilEnable = 1
+		depthStencilDesc.FrontFace.StencilFunc = _D3D12_COMPARISON_FUNC_NOT_EQUAL
+		depthStencilDesc.BackFace.StencilFunc = _D3D12_COMPARISON_FUNC_NOT_EQUAL
+	}
+
+	rtvFormat := _DXGI_FORMAT_R8G8B8A8_UNORM
+	if screen {
+		rtvFormat = _DXGI_FORMAT_B8G8R8A8_UNORM
+	}
+
+	// Create a pipeline state.
+	srcOp, dstOp := compositeMode.Operations()
+	psoDesc := _D3D12_GRAPHICS_PIPELINE_STATE_DESC{
+		pRootSignature: rootSignature,
+		VS: _D3D12_SHADER_BYTECODE{
+			pShaderBytecode: vsh.GetBufferPointer(),
+			BytecodeLength:  vsh.GetBufferSize(),
+		},
+		PS: _D3D12_SHADER_BYTECODE{
+			pShaderBytecode: psh.GetBufferPointer(),
+			BytecodeLength:  psh.GetBufferSize(),
+		},
+		BlendState: _D3D12_BLEND_DESC{
+			AlphaToCoverageEnable:  0,
+			IndependentBlendEnable: 0,
+			RenderTarget: [8]_D3D12_RENDER_TARGET_BLEND_DESC{
+				{
+					BlendEnable:           1,
+					LogicOpEnable:         0,
+					SrcBlend:              operationToBlend(srcOp, false),
+					DestBlend:             operationToBlend(dstOp, false),
+					BlendOp:               _D3D12_BLEND_OP_ADD,
+					SrcBlendAlpha:         operationToBlend(srcOp, true),
+					DestBlendAlpha:        operationToBlend(dstOp, true),
+					BlendOpAlpha:          _D3D12_BLEND_OP_ADD,
+					LogicOp:               _D3D12_LOGIC_OP_NOOP,
+					RenderTargetWriteMask: writeMask,
+				},
+			},
+		},
+		SampleMask: math.MaxUint32,
+		RasterizerState: _D3D12_RASTERIZER_DESC{
+			FillMode:              _D3D12_FILL_MODE_SOLID,
+			CullMode:              _D3D12_CULL_MODE_NONE,
+			FrontCounterClockwise: 0,
+			DepthBias:             _D3D12_DEFAULT_DEPTH_BIAS,
+			DepthBiasClamp:        _D3D12_DEFAULT_DEPTH_BIAS_CLAMP,
+			SlopeScaledDepthBias:  _D3D12_DEFAULT_SLOPE_SCALED_DEPTH_BIAS,
+			DepthClipEnable:       0,
+			MultisampleEnable:     0,
+			AntialiasedLineEnable: 0,
+			ForcedSampleCount:     0,
+			ConservativeRaster:    _D3D12_CONSERVATIVE_RASTERIZATION_MODE_OFF,
+		},
+		DepthStencilState: depthStencilDesc,
+		InputLayout: _D3D12_INPUT_LAYOUT_DESC{
+			pInputElementDescs: &inputElementDescs[0],
+			NumElements:        uint32(len(inputElementDescs)),
+		},
+		PrimitiveTopologyType: _D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE,
+		NumRenderTargets:      1,
+		RTVFormats: [8]_DXGI_FORMAT{
+			rtvFormat,
+		},
+		DSVFormat: _DXGI_FORMAT_D24_UNORM_S8_UINT,
+		SampleDesc: _DXGI_SAMPLE_DESC{
+			Count:   1,
+			Quality: 0,
+		},
+	}
+
+	s, err := device.CreateGraphicsPipelineState(&psoDesc)
+	if err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (p *pipelineStates) releaseConstantBuffers(frameIndex int) {
+	for i := range p.constantBuffers[frameIndex] {
+		p.constantBuffers[frameIndex][i].Release()
+		p.constantBuffers[frameIndex][i] = nil
+	}
+	p.constantBuffers[frameIndex] = p.constantBuffers[frameIndex][:0]
+}
+
+func (p *pipelineStates) resetConstantBuffers(frameIndex int) {
+	p.constantBuffers[frameIndex] = p.constantBuffers[frameIndex][:0]
+}

internal/graphicsdriver/graphics.go

@@ -54,6 +54,7 @@ type Graphics interface {
 	NeedsRestoring() bool
 	NeedsClearingScreen() bool
 	IsGL() bool
+	IsDirectX() bool
 	HasHighPrecisionFloat() bool
 	MaxImageSize() int
 

internal/graphicsdriver/metal/graphics_darwin.go

@@ -1046,6 +1046,10 @@ func (g *Graphics) IsGL() bool {
 	return false
 }
 
+func (g *Graphics) IsDirectX() bool {
+	return false
+}
+
 func (g *Graphics) HasHighPrecisionFloat() bool {
 	return true
 }

internal/graphicsdriver/opengl/graphics.go

@@ -392,6 +392,10 @@ func (g *Graphics) IsGL() bool {
 	return true
 }
 
+func (g *Graphics) IsDirectX() bool {
+	return false
+}
+
 func (g *Graphics) HasHighPrecisionFloat() bool {
 	return g.context.hasHighPrecisionFloat()
 }

internal/ui/context.go

@@ -61,7 +61,18 @@ func (c *contextImpl) updateFrame(graphicsDriver graphicsdriver.Graphics, outsid
 }
 
 func (c *contextImpl) forceUpdateFrame(graphicsDriver graphicsdriver.Graphics, outsideWidth, outsideHeight float64, deviceScaleFactor float64) error {
-	return c.updateFrameImpl(graphicsDriver, 1, outsideWidth, outsideHeight, deviceScaleFactor)
+	n := 1
+	if graphicsDriver.IsDirectX() {
+		// On DirectX, both framebuffers in the swap chain should be updated.
+		// Or, the rendering result becomes unexpected when the window is resized.
+		n = 2
+	}
+	for i := 0; i < n; i++ {
+		if err := c.updateFrameImpl(graphicsDriver, 1, outsideWidth, outsideHeight, deviceScaleFactor); err != nil {
+			return err
+		}
+	}
+	return nil
 }
 
 func (c *contextImpl) updateFrameImpl(graphicsDriver graphicsdriver.Graphics, updateCount int, outsideWidth, outsideHeight float64, deviceScaleFactor float64) error {

internal/ui/ui_glfw.go

@@ -811,19 +811,6 @@ event:
 }
 
 func (u *userInterfaceImpl) init() error {
-	g, err := chooseGraphicsDriver(&graphicsDriverGetterImpl{})
-	if err != nil {
-		return err
-	}
-	u.graphicsDriver = g
-	if u.graphicsDriver.IsGL() {
-		glfw.WindowHint(glfw.ClientAPI, glfw.OpenGLAPI)
-		glfw.WindowHint(glfw.ContextVersionMajor, 2)
-		glfw.WindowHint(glfw.ContextVersionMinor, 1)
-	} else {
-		glfw.WindowHint(glfw.ClientAPI, glfw.NoAPI)
-	}
-
 	glfw.WindowHint(glfw.AutoIconify, glfw.False)
 
 	decorated := glfw.False
@@ -832,13 +819,30 @@ func (u *userInterfaceImpl) init() error {
 	}
 	glfw.WindowHint(glfw.Decorated, decorated)
 
-	transparent := glfw.False
-	if u.isInitScreenTransparent() {
-		transparent = glfw.True
+	transparent := u.isInitScreenTransparent()
+	glfwTransparent := glfw.False
+	if transparent {
+		glfwTransparent = glfw.True
 	}
-	glfw.WindowHint(glfw.TransparentFramebuffer, transparent)
+	glfw.WindowHint(glfw.TransparentFramebuffer, glfwTransparent)
+
+	g, err := chooseGraphicsDriver(&graphicsDriverGetterImpl{
+		transparent: transparent,
+	})
+	if err != nil {
+		return err
+	}
+	u.graphicsDriver = g
 	u.graphicsDriver.SetTransparent(u.isInitScreenTransparent())
 
+	if u.graphicsDriver.IsGL() {
+		glfw.WindowHint(glfw.ClientAPI, glfw.OpenGLAPI)
+		glfw.WindowHint(glfw.ContextVersionMajor, 2)
+		glfw.WindowHint(glfw.ContextVersionMinor, 1)
+	} else {
+		glfw.WindowHint(glfw.ClientAPI, glfw.NoAPI)
+	}
+
 	// Before creating a window, set it unresizable no matter what u.isInitWindowResizable() is (#1987).
 	// Making the window resizable here doesn't work correctly when switching to enable resizing.
 	resizable := glfw.False

internal/ui/ui_glfw_darwin.go

@@ -232,7 +232,9 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-type graphicsDriverGetterImpl struct{}
+type graphicsDriverGetterImpl struct {
+	transparent bool
+}
 
 func (g *graphicsDriverGetterImpl) getAuto() graphicsdriver.Graphics {
 	if m := g.getMetal(); m != nil {

internal/ui/ui_glfw_unix.go

@@ -31,7 +31,9 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-type graphicsDriverGetterImpl struct{}
+type graphicsDriverGetterImpl struct {
+	transparent bool
+}
 
 func (g *graphicsDriverGetterImpl) getAuto() graphicsdriver.Graphics {
 	return g.getOpenGL()

internal/ui/ui_glfw_windows.go

@@ -26,12 +26,18 @@ import (
 
 	"github.com/hajimehoshi/ebiten/v2/internal/glfw"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/directx"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl"
 )
 
-type graphicsDriverGetterImpl struct{}
+type graphicsDriverGetterImpl struct {
+	transparent bool
+}
 
 func (g *graphicsDriverGetterImpl) getAuto() graphicsdriver.Graphics {
+	if d := g.getDirectX(); d != nil {
+		return d
+	}
 	return g.getOpenGL()
 }
 
@@ -42,7 +48,13 @@ func (*graphicsDriverGetterImpl) getOpenGL() graphicsdriver.Graphics {
 	return nil
 }
 
-func (*graphicsDriverGetterImpl) getDirectX() graphicsdriver.Graphics {
+func (g *graphicsDriverGetterImpl) getDirectX() graphicsdriver.Graphics {
+	if g.transparent {
+		return nil
+	}
+	if d := directx.Get(); d != nil {
+		return d
+	}
 	return nil
 }
 

shader_test.go

@@ -17,6 +17,7 @@ package ebiten_test
 import (
 	"image"
 	"image/color"
+	"math"
 	"testing"
 
 	"github.com/hajimehoshi/ebiten/v2"
@@ -654,3 +655,74 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		}
 	}
 }
+
+func TestShaderTextureAt(t *testing.T) {
+	const w, h = 16, 16
+
+	src := ebiten.NewImage(w, h)
+	src.Fill(color.RGBA{0x10, 0x20, 0x30, 0xff})
+
+	dst := ebiten.NewImage(w, h)
+	s, err := ebiten.NewShader([]byte(`package main
+
+func textureAt(uv vec2) vec4 {
+	return imageSrc0UnsafeAt(uv)
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	return textureAt(texCoord)
+}
+`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	op := &ebiten.DrawRectShaderOptions{}
+	op.Images[0] = src
+	dst.DrawRectShader(w, h, s, op)
+
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			got := dst.At(i, j).(color.RGBA)
+			want := color.RGBA{0x10, 0x20, 0x30, 0xff}
+			if !sameColors(got, want, 2) {
+				t.Errorf("dst.At(%d, %d): got: %v, want: %v", i, j, got, want)
+			}
+		}
+	}
+}
+
+func TestShaderAtan2(t *testing.T) {
+	const w, h = 16, 16
+
+	src := ebiten.NewImage(w, h)
+	src.Fill(color.RGBA{0x10, 0x20, 0x30, 0xff})
+
+	dst := ebiten.NewImage(w, h)
+	s, err := ebiten.NewShader([]byte(`package main
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	y := vec4(1, 1, 1, 1)
+	x := vec4(1, 1, 1, 1)
+	return atan2(y, x)
+}
+`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	op := &ebiten.DrawRectShaderOptions{}
+	op.Images[0] = src
+	dst.DrawRectShader(w, h, s, op)
+
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			got := dst.At(i, j).(color.RGBA)
+			v := byte(math.Floor(0xff * math.Pi / 4))
+			want := color.RGBA{v, v, v, v}
+			if !sameColors(got, want, 2) {
+				t.Errorf("dst.At(%d, %d): got: %v, want: %v", i, j, got, want)
+			}
+		}
+	}
+}