diff --git a/internal/graphicsdriver/directx/graphics11_windows.go b/internal/graphicsdriver/directx/graphics11_windows.go
index 6a111edbf..4d91d703f 100644
--- a/internal/graphicsdriver/directx/graphics11_windows.go
+++ b/internal/graphicsdriver/directx/graphics11_windows.go
@@ -27,34 +27,56 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/hlsl"
 )
 
-var inputElementDescsForDX11 = []_D3D11_INPUT_ELEMENT_DESC{
-	{
-		SemanticName:         &([]byte("POSITION\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
-	{
-		SemanticName:         &([]byte("TEXCOORD\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
-	{
-		SemanticName:         &([]byte("COLOR\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
+var inputElementDescsForDX11 []_D3D11_INPUT_ELEMENT_DESC
+
+func init() {
+	inputElementDescsForDX11 = []_D3D11_INPUT_ELEMENT_DESC{
+		{
+			SemanticName:         &([]byte("POSITION\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+		{
+			SemanticName:         &([]byte("TEXCOORD\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+		{
+			SemanticName:         &([]byte("COLOR\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+	}
+	diff := graphics.VertexFloatCount - 8
+	if diff == 0 {
+		return
+	}
+	if diff%4 != 0 {
+		panic("directx: unexpected attribute layout")
+	}
+	for i := 0; i < diff/4; i++ {
+		inputElementDescsForDX11 = append(inputElementDescsForDX11, _D3D11_INPUT_ELEMENT_DESC{
+			SemanticName:         &([]byte("COLOR\000"))[0],
+			SemanticIndex:        uint32(i) + 1,
+			Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D11_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D11_INPUT_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		})
+	}
 }
 
 func blendFactorToBlend11(f graphicsdriver.BlendFactor, alpha bool) _D3D11_BLEND {
diff --git a/internal/graphicsdriver/directx/pipeline12_windows.go b/internal/graphicsdriver/directx/pipeline12_windows.go
index 819454786..ce666ee42 100644
--- a/internal/graphicsdriver/directx/pipeline12_windows.go
+++ b/internal/graphicsdriver/directx/pipeline12_windows.go
@@ -23,34 +23,56 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 )
 
-var inputElementDescsForDX12 = []_D3D12_INPUT_ELEMENT_DESC{
-	{
-		SemanticName:         &([]byte("POSITION\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
-	{
-		SemanticName:         &([]byte("TEXCOORD\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
-	{
-		SemanticName:         &([]byte("COLOR\000"))[0],
-		SemanticIndex:        0,
-		Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
-		InputSlot:            0,
-		AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
-		InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
-		InstanceDataStepRate: 0,
-	},
+var inputElementDescsForDX12 []_D3D12_INPUT_ELEMENT_DESC
+
+func init() {
+	inputElementDescsForDX12 = []_D3D12_INPUT_ELEMENT_DESC{
+		{
+			SemanticName:         &([]byte("POSITION\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+		{
+			SemanticName:         &([]byte("TEXCOORD\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+		{
+			SemanticName:         &([]byte("COLOR\000"))[0],
+			SemanticIndex:        0,
+			Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		},
+	}
+	diff := graphics.VertexFloatCount - 8
+	if diff == 0 {
+		return
+	}
+	if diff%4 != 0 {
+		panic("directx: unexpected attribute layout")
+	}
+	for i := 0; i < diff/4; i++ {
+		inputElementDescsForDX12 = append(inputElementDescsForDX12, _D3D12_INPUT_ELEMENT_DESC{
+			SemanticName:         &([]byte("COLOR\000"))[0],
+			SemanticIndex:        uint32(i) + 1,
+			Format:               _DXGI_FORMAT_R32G32B32A32_FLOAT,
+			InputSlot:            0,
+			AlignedByteOffset:    _D3D12_APPEND_ALIGNED_ELEMENT,
+			InputSlotClass:       _D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
+			InstanceDataStepRate: 0,
+		})
+	}
 }
 
 const numDescriptorsPerFrame = 32
diff --git a/internal/shaderir/hlsl/hlsl.go b/internal/shaderir/hlsl/hlsl.go
index 22a05e635..d1e558407 100644
--- a/internal/shaderir/hlsl/hlsl.go
+++ b/internal/shaderir/hlsl/hlsl.go
@@ -52,13 +52,7 @@ func (c *compileContext) structName(p *shaderir.Program, t *shaderir.Type) strin
 	return n
 }
 
-const Prelude = `struct Varyings {
-	float4 Position : SV_POSITION;
-	float2 M0 : TEXCOORD0;
-	float4 M1 : COLOR;
-};
-
-float mod(float x, float y) {
+const Prelude = `float mod(float x, float y) {
 	return x - y * floor(x/y);
 }
 
@@ -95,6 +89,27 @@ func Compile(p *shaderir.Program) (vertexShader, pixelShader string) {
 
 	var lines []string
 	lines = append(lines, strings.Split(Prelude, "\n")...)
+
+	lines = append(lines, "", "struct Varyings {")
+	lines = append(lines, "\tfloat4 Position : SV_POSITION;")
+	if len(p.Varyings) > 0 {
+		for i, v := range p.Varyings {
+			switch i {
+			case 0:
+				lines = append(lines, fmt.Sprintf("\tfloat2 M%d : TEXCOORD0;", i))
+			case 1:
+				lines = append(lines, fmt.Sprintf("\tfloat4 M%d : COLOR0;", i))
+			default:
+				// Use COLOR[n] as a general purpose varying.
+				if v.Main != shaderir.Vec4 {
+					lines = append(lines, fmt.Sprintf("\t?(unexpected type: %s) M%d : COLOR%d;", v, i, i-1))
+				} else {
+					lines = append(lines, fmt.Sprintf("\tfloat4 M%d : COLOR%d;", i, i-1))
+				}
+			}
+		}
+	}
+	lines = append(lines, "};")
 	lines = append(lines, "", "{{.Structs}}")
 
 	if len(p.Uniforms) > 0 {
@@ -156,7 +171,25 @@ func Compile(p *shaderir.Program) (vertexShader, pixelShader string) {
 	}
 	if p.VertexFunc.Block != nil && len(p.VertexFunc.Block.Stmts) > 0 {
 		vslines = append(vslines, "")
-		vslines = append(vslines, "Varyings VSMain(float2 A0 : POSITION, float2 A1 : TEXCOORD, float4 A2 : COLOR) {")
+		var args []string
+		for i, a := range p.Attributes {
+			switch i {
+			case 0:
+				args = append(args, fmt.Sprintf("float2 A%d : POSITION", i))
+			case 1:
+				args = append(args, fmt.Sprintf("float2 A%d : TEXCOORD0", i))
+			case 2:
+				args = append(args, fmt.Sprintf("float4 A%d : COLOR0", i))
+			default:
+				// Use COLOR[n] as a general purpose varying.
+				if a.Main != shaderir.Vec4 {
+					args = append(args, fmt.Sprintf("?(unexpected type: %s) A%d : COLOR%d", a, i, i-2))
+				} else {
+					args = append(args, fmt.Sprintf("float4 A%d : COLOR%d", i, i-2))
+				}
+			}
+		}
+		vslines = append(vslines, "Varyings VSMain("+strings.Join(args, ", ")+") {")
 		vslines = append(vslines, fmt.Sprintf("\tVaryings %s;", vsOut))
 		vslines = append(vslines, c.block(p, p.VertexFunc.Block, p.VertexFunc.Block, 0)...)
 		if last := fmt.Sprintf("\treturn %s;", vsOut); vslines[len(vslines)-1] != last {