internal/shaderir: cache offset calculations for HLSL

internal/graphicsdriver/directx/graphics11_windows.go

@@ -24,7 +24,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
-	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/hlsl"
 )
 
 var inputElementDescsForDX11 []_D3D11_INPUT_ELEMENT_DESC
@@ -513,7 +512,7 @@ func (g *graphics11) NewShader(program *shaderir.Program) (graphicsdriver.Shader
 		graphics:         g,
 		id:               g.genNextShaderID(),
 		uniformTypes:     program.Uniforms,
-		uniformOffsets:   hlsl.CalcUniformMemoryOffsetsInDWords(program),
+		uniformOffsets:   program.UniformOffsetsInDWords(),
 		vertexShaderBlob: vsh,
 		pixelShaderBlob:  psh,
 	}

internal/graphicsdriver/directx/graphics12_windows.go

@@ -25,7 +25,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/microsoftgdk"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
-	"github.com/hajimehoshi/ebiten/v2/internal/shaderir/hlsl"
 )
 
 type resourceWithSize struct {
@@ -1073,7 +1072,7 @@ func (g *graphics12) NewShader(program *shaderir.Program) (graphicsdriver.Shader
 		graphics:       g,
 		id:             g.genNextShaderID(),
 		uniformTypes:   program.Uniforms,
-		uniformOffsets: hlsl.CalcUniformMemoryOffsetsInDWords(program),
+		uniformOffsets: program.UniformOffsetsInDWords(),
 		vertexShader:   vsh,
 		pixelShader:    psh,
 	}

internal/shaderir/hlsl/hlsl.go

@@ -81,7 +81,7 @@ float4x4 float4x4FromScalar(float x) {
 }`
 
 func Compile(p *shaderir.Program) (vertexShader, pixelShader, prelude string) {
-	offsets := CalcUniformMemoryOffsetsInDWords(p)
+	offsets := p.UniformOffsetsInDWords()
 
 	c := &compileContext{
 		unit: p.Unit,
@@ -119,8 +119,8 @@ func Compile(p *shaderir.Program) (vertexShader, pixelShader, prelude string) {
 		lines = append(lines, "cbuffer Uniforms : register(b0) {")
 		for i, t := range p.Uniforms {
 			// packingoffset is not mandatory, but this is useful to ensure the correct offset is used.
-			offset := fmt.Sprintf("c%d", offsets[i]/boundaryInDWords)
-			switch offsets[i] % boundaryInDWords {
+			offset := fmt.Sprintf("c%d", offsets[i]/shaderir.UniformVariableBoundaryInDWords)
+			switch offsets[i] % shaderir.UniformVariableBoundaryInDWords {
 			case 1:
 				offset += ".y"
 			case 2:

internal/shaderir/program.go

@@ -59,7 +59,8 @@ type Program struct {
 
 	SourceHash SourceHash
 
-	uniformFactors []uint32
+	uniformFactors  []uint32
+	offsetsInDWords []int
 }
 
 type Func struct {

internal/shaderir/hlsl/packing.go → internal/shaderir/uniform.go

@@ -12,95 +12,99 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package hlsl
+package shaderir
 
 import (
 	"fmt"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
-const boundaryInDWords = 4
+const UniformVariableBoundaryInDWords = 4
+
+// UniformOffsetsInDWords returns the offsets of the uniform variables in DWROD units in the HLSL layout.
+func (p *Program) UniformOffsetsInDWords() []int {
+	if len(p.offsetsInDWords) > 0 {
+		return p.offsetsInDWords
+	}
 
-func CalcUniformMemoryOffsetsInDWords(program *shaderir.Program) []int {
 	// https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-packing-rules
 	// https://github.com/microsoft/DirectXShaderCompiler/wiki/Buffer-Packing
 
-	var offsetsInDWords []int
-	var headInDWords int
-
 	align := func(x int) int {
 		if x == 0 {
 			return 0
 		}
-		return ((x-1)/boundaryInDWords + 1) * boundaryInDWords
+		return ((x-1)/UniformVariableBoundaryInDWords + 1) * UniformVariableBoundaryInDWords
 	}
 
+	var offsetsInDWords []int
+	var headInDWords int
+
 	// TODO: Reorder the variables with packoffset.
 	// See https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-variable-packoffset
-	for _, u := range program.Uniforms {
+	for _, u := range p.Uniforms {
 		switch u.Main {
-		case shaderir.Float:
+		case Float:
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 1
-		case shaderir.Int:
+		case Int:
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 1
-		case shaderir.Vec2, shaderir.IVec2:
-			if headInDWords%boundaryInDWords >= 3 {
+		case Vec2, IVec2:
+			if headInDWords%UniformVariableBoundaryInDWords >= 3 {
 				headInDWords = align(headInDWords)
 			}
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 2
-		case shaderir.Vec3, shaderir.IVec3:
-			if headInDWords%boundaryInDWords >= 2 {
+		case Vec3, IVec3:
+			if headInDWords%UniformVariableBoundaryInDWords >= 2 {
 				headInDWords = align(headInDWords)
 			}
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 3
-		case shaderir.Vec4, shaderir.IVec4:
-			if headInDWords%boundaryInDWords >= 1 {
+		case Vec4, IVec4:
+			if headInDWords%UniformVariableBoundaryInDWords >= 1 {
 				headInDWords = align(headInDWords)
 			}
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 4
-		case shaderir.Mat2:
+		case Mat2:
 			// For matrices, each column is aligned to the boundary.
 			headInDWords = align(headInDWords)
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 6
-		case shaderir.Mat3:
+		case Mat3:
 			headInDWords = align(headInDWords)
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 11
-		case shaderir.Mat4:
+		case Mat4:
 			headInDWords = align(headInDWords)
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			headInDWords += 16
-		case shaderir.Array:
+		case Array:
 			// Each array is 16-byte aligned.
 			// TODO: What if the array has 2 or more dimensions?
 			headInDWords = align(headInDWords)
 			offsetsInDWords = append(offsetsInDWords, headInDWords)
 			n := u.Sub[0].Uint32Count()
 			switch u.Sub[0].Main {
-			case shaderir.Mat2:
+			case Mat2:
 				n = 6
-			case shaderir.Mat3:
+			case Mat3:
 				n = 11
-			case shaderir.Mat4:
+			case Mat4:
 				n = 16
 			}
 			headInDWords += (u.Length - 1) * align(n)
 			// The last element is not with a padding.
 			headInDWords += n
-		case shaderir.Struct:
+		case Struct:
 			// TODO: Implement this
 			panic("hlsl: offset for a struct is not implemented yet")
 		default:
 			panic(fmt.Sprintf("hlsl: unexpected type: %s", u.String()))
 		}
 	}
 
-	return offsetsInDWords
+	p.offsetsInDWords = offsetsInDWords
+	return p.offsetsInDWords
 }