ebiten/internal/testing/shader.go
Hajime Hoshi 49582519c1 all: add a compiler directive kage:unit
This change adds a new compiler directive 'kage:unit' to Kage. This
takes one of these two values: 'pixel' and 'texel'. The default value
is 'texel'.

With the pixel-unit mode, all the built-in functions treats pixels
instead of texels, and the texCoord argument of Fragment is in pixels.
This simplifies shader programs as programs no longer have the notion
of texels.

With the texel-unit mode, the behavior is the same as the current
behavior.

Closes #1431
2023-04-23 22:11:57 +09:00

65 lines
1.7 KiB
Go

// Copyright 2020 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 testing
import (
"fmt"
"strings"
"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
)
// ShaderProgramFill returns a shader source to fill the frambuffer.
func ShaderProgramFill(r, g, b, a byte) *shaderir.Program {
ir, err := graphics.CompileShader([]byte(fmt.Sprintf(`//kage:unit pixel
package main
func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
return vec4(%0.9f, %0.9f, %0.9f, %0.9f)
}
`, float64(r)/0xff, float64(g)/0xff, float64(b)/0xff, float64(a)/0xff)))
if err != nil {
panic(err)
}
return ir
}
// ShaderProgramImages returns a shader source to render the frambuffer with the given images.
func ShaderProgramImages(numImages int) *shaderir.Program {
if numImages <= 0 {
panic("testing: numImages must be >= 1")
}
var exprs []string
for i := 0; i < numImages; i++ {
exprs = append(exprs, fmt.Sprintf("imageSrc%dUnsafeAt(texCoord)", i))
}
ir, err := graphics.CompileShader([]byte(fmt.Sprintf(`//kage:unit pixel
package main
func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
return %s
}
`, strings.Join(exprs, " + "))))
if err != nil {
panic(err)
}
return ir
}