mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-27 04:08:53 +01:00
104 lines
2.7 KiB
Go
104 lines
2.7 KiB
Go
// 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 hlsl
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
|
|
)
|
|
|
|
const boundaryInBytes = 16
|
|
|
|
func calculateMemoryOffsets(uniforms []shaderir.Type) []int {
|
|
// https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-packing-rules
|
|
// https://github.com/microsoft/DirectXShaderCompiler/wiki/Buffer-Packing
|
|
|
|
var offsets []int
|
|
var head int
|
|
|
|
align := func(x int) int {
|
|
if x == 0 {
|
|
return 0
|
|
}
|
|
return ((x-1)/boundaryInBytes + 1) * boundaryInBytes
|
|
}
|
|
|
|
// TODO: Reorder the variables with packoffset.
|
|
// See https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-variable-packoffset
|
|
for _, u := range uniforms {
|
|
switch u.Main {
|
|
case shaderir.Float:
|
|
offsets = append(offsets, head)
|
|
head += 4
|
|
case shaderir.Vec2:
|
|
if head%boundaryInBytes >= 4*3 {
|
|
head = align(head)
|
|
}
|
|
offsets = append(offsets, head)
|
|
head += 4 * 2
|
|
case shaderir.Vec3:
|
|
if head%boundaryInBytes >= 4*2 {
|
|
head = align(head)
|
|
}
|
|
offsets = append(offsets, head)
|
|
head += 4 * 3
|
|
case shaderir.Vec4:
|
|
if head%boundaryInBytes >= 4*1 {
|
|
head = align(head)
|
|
}
|
|
offsets = append(offsets, head)
|
|
head += 4 * 4
|
|
case shaderir.Mat2:
|
|
// For matrices, each column is aligned to the boundary.
|
|
head = align(head)
|
|
offsets = append(offsets, head)
|
|
head += 4 * 6
|
|
case shaderir.Mat3:
|
|
head = align(head)
|
|
offsets = append(offsets, head)
|
|
head += 4 * 11
|
|
case shaderir.Mat4:
|
|
head = align(head)
|
|
offsets = append(offsets, head)
|
|
head += 4 * 16
|
|
case shaderir.Array:
|
|
// Each array is 16-byte aligned.
|
|
// TODO: What if the array has 2 or more dimensions?
|
|
head = align(head)
|
|
offsets = append(offsets, head)
|
|
n := u.Sub[0].FloatNum()
|
|
switch u.Sub[0].Main {
|
|
case shaderir.Mat2:
|
|
n = 6
|
|
case shaderir.Mat3:
|
|
n = 11
|
|
case shaderir.Mat4:
|
|
n = 16
|
|
}
|
|
head += (u.Length - 1) * align(4*n)
|
|
// The last element is not with a padding.
|
|
head += 4 * n
|
|
case shaderir.Struct:
|
|
// TODO: Implement this
|
|
panic("hlsl: offset for a struct is not implemented yet")
|
|
default:
|
|
panic(fmt.Sprintf("hlsl: unexpected type: %d", u.Main))
|
|
}
|
|
}
|
|
|
|
return offsets
|
|
}
|