Revert "ebiten: use Kage shaders instead of built-in shaders for a color matrix"

This reverts commit 7fc79c50c3.

Reason: a color scale might be used with ColorM (DrawTriangles)

Updates #2364

image.go

@@ -21,7 +21,6 @@ import (
 
 	"github.com/hajimehoshi/ebiten/v2/internal/affine"
 	"github.com/hajimehoshi/ebiten/v2/internal/atlas"
-	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/ui"
@@ -234,22 +233,7 @@ func (i *Image) DrawImage(img *Image, options *DrawImageOptions) {
 
 	srcs := [graphics.ShaderImageCount]*ui.Image{img.image}
 
-	useColorM := !colorm.IsIdentity()
+	i.image.DrawTriangles(srcs, vs, is, colorm, mode, filter, graphicsdriver.AddressUnsafe, i.adjustedRegion(), graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, false, canSkipMipmap(options.GeoM, filter))
-	var shader *ui.Shader
-	var uniforms [][]float32
-	if useColorM {
-		s := builtinShader(graphicsdriver.Filter(filter), graphicsdriver.AddressUnsafe)
-		var body [16]float32
-		var translation [4]float32
-		colorm.Elements(body[:], translation[:])
-		uniforms = s.convertUniforms(map[string]interface{}{
-			builtinshader.UniformColorMBody:        body[:],
-			builtinshader.UniformColorMTranslation: translation[:],
-		})
-		shader = s.shader
-	}
-
-	i.image.DrawTriangles(srcs, vs, is, affine.ColorMIdentity{}, mode, filter, graphicsdriver.AddressUnsafe, i.adjustedRegion(), graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, shader, uniforms, false, canSkipMipmap(options.GeoM, filter))
 }
 
 // Vertex represents a vertex passed to DrawTriangles.
@@ -414,22 +398,7 @@ func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, o
 
 	srcs := [graphics.ShaderImageCount]*ui.Image{img.image}
 
-	useColorM := !colorm.IsIdentity()
+	i.image.DrawTriangles(srcs, vs, is, colorm, mode, filter, address, i.adjustedRegion(), sr, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, options.FillRule == EvenOdd, false)
-	var shader *ui.Shader
-	var uniforms [][]float32
-	if useColorM {
-		s := builtinShader(graphicsdriver.Filter(filter), graphicsdriver.Address(address))
-		var body [16]float32
-		var translation [4]float32
-		colorm.Elements(body[:], translation[:])
-		uniforms = s.convertUniforms(map[string]interface{}{
-			builtinshader.UniformColorMBody:        body[:],
-			builtinshader.UniformColorMTranslation: translation[:],
-		})
-		shader = s.shader
-	}
-
-	i.image.DrawTriangles(srcs, vs, is, affine.ColorMIdentity{}, mode, filter, address, i.adjustedRegion(), sr, [graphics.ShaderImageCount - 1][2]float32{}, shader, uniforms, options.FillRule == EvenOdd, false)
 }
 
 // DrawTrianglesShaderOptions represents options for DrawTrianglesShader.

internal/builtinshader/shader.go

@@ -1,155 +0,0 @@
-// Copyright 2022 The Ebitengine 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 builtinshader
-
-import (
-	"bytes"
-	"fmt"
-	"sync"
-	"text/template"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-)
-
-const (
-	UniformColorMBody        = "ColorMBody"
-	UniformColorMTranslation = "ColorMTranslation"
-)
-
-type key struct {
-	Filter    graphicsdriver.Filter
-	Address   graphicsdriver.Address
-	UseColorM bool
-}
-
-var (
-	shaders  = map[key][]byte{}
-	shadersM sync.Mutex
-)
-
-var tmpl = template.Must(template.New("tmpl").Parse(`package main
-
-{{if .UseColorM}}
-var ColorMBody mat4
-var ColorMTranslation vec4
-{{end}}
-
-{{if eq .Address .AddressRepeat}}
-func adjustTexelForAddressRepeat(p vec2) vec2 {
-	origin, size := imageSrcRegionOnTexture()
-	return mod(p - origin, size) + origin
-}
-{{end}}
-
-func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
-{{if eq .Filter .FilterNearest}}
-{{if eq .Address .AddressUnsafe}}
-	clr := imageSrc0UnsafeAt(texCoord)
-{{else if eq .Address .AddressClampToZero}}
-	clr := imageSrc0At(texCoord)
-{{else if eq .Address .AddressRepeat}}
-	clr := imageSrc0At(adjustTexelForAddressRepeat(texCoord))
-{{end}}
-{{else if eq .Filter .FilterLinear}}
-	sourceSize := imageSrcTextureSize()
-	texelSize := 1 / sourceSize
-
-	// Shift 1/512 [texel] to avoid the tie-breaking issue (#1212).
-	// As all the vertex positions are aligned to 1/16 [pixel], this shiting should work in most cases.
-	p0 := texCoord - texelSize/2 + texelSize/512
-	p1 := texCoord + texelSize/2 + texelSize/512
-
-{{if eq .Address .AddressRpeat}}
-	p0 = adjustTexelForAddressRepeat(p0)
-	p1 = adjustTexelForAddressRepeat(p1)
-{{end}}
-
-{{if eq .Address .AddressUnsafe}}
-	c0 := imageSrc0UnsafeAt(p0)
-	c1 := imageSrc0UnsafeAt(vec2(p1.x, p0.y))
-	c2 := imageSrc0UnsafeAt(vec2(p0.x, p1.y))
-	c3 := imageSrc0UnsafeAt(p1)
-{{else}}
-	c0 := imageSrc0At(p0)
-	c1 := imageSrc0At(vec2(p1.x, p0.y))
-	c2 := imageSrc0At(vec2(p0.x, p1.y))
-	c3 := imageSrc0At(p1)
-{{end}}
-
-	rate := fract(p0 * sourceSize)
-	clr := mix(mix(c0, c1, rate.x), mix(c2, c3, rate.x), rate.y)
-{{end}}
-
-{{if .UseColorM}}
-	// Un-premultiply alpha.
-	// When the alpha is 0, 1-sign(alpha) is 1.0, which means division does nothing.
-	clr.rgb /= clr.a + (1-sign(clr.a))
-	// Apply the clr matrix or scale.
-	clr = (ColorMBody * clr) + ColorMTranslation
-	// Premultiply alpha
-	clr.rgb *= clr.a
-	// Do not apply the color scale assuming the scale is (1, 1, 1, 1).
-	// Clamp the output.
-	clr.rgb = min(clr.rgb, clr.a)
-{{else}}
-	// Apply the color scale.
-	clr *= color
-{{end}}
-
-	return clr
-}
-
-`))
-
-// Shader returns the built-in shader based on the given parameters.
-//
-// The returned shader always uses a color matrix so far.
-func Shader(filter graphicsdriver.Filter, address graphicsdriver.Address) []byte {
-	shadersM.Lock()
-	defer shadersM.Unlock()
-
-	// Now UseColorM is always true. When UseColorM is true, the color scale in vertices is not used.
-	// In the built-in shaders, the color scale is modified at the vertex shader (#1996),
-	// and this modification cannot be represented in a Kage program.
-	// A custom vertex shader in Kage (#2209), or changing the interpretation of scales (#2365) would solve the issue.
-	const useColorM = true
-
-	k := key{
-		Filter:    filter,
-		Address:   address,
-		UseColorM: useColorM,
-	}
-	if s, ok := shaders[k]; ok {
-		return s
-	}
-
-	var buf bytes.Buffer
-	if err := tmpl.Execute(&buf, map[string]interface{}{
-		"Filter":             filter,
-		"FilterNearest":      graphicsdriver.FilterNearest,
-		"FilterLinear":       graphicsdriver.FilterLinear,
-		"Address":            address,
-		"AddressUnsafe":      graphicsdriver.AddressUnsafe,
-		"AddressClampToZero": graphicsdriver.AddressClampToZero,
-		"AddressRepeat":      graphicsdriver.AddressRepeat,
-		"UseColorM":          useColorM,
-	}); err != nil {
-		panic(fmt.Sprintf("builtinshader: tmpl.Execute failed: %v", err))
-	}
-
-	b := buf.Bytes()
-	shaders[k] = b
-	return b
-}

shader.go

@@ -15,12 +15,7 @@
 package ebiten
 
 import (
-	"fmt"
-	"sync"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/ui"
 )
 
@@ -56,34 +51,3 @@ func (s *Shader) Dispose() {
 func (s *Shader) convertUniforms(uniforms map[string]interface{}) [][]float32 {
 	return s.shader.ConvertUniforms(uniforms)
 }
-
-type builtinShaderKey struct {
-	filter  graphicsdriver.Filter
-	address graphicsdriver.Address
-}
-
-var (
-	builtinShaders  = map[builtinShaderKey]*Shader{}
-	builtinShadersM sync.Mutex
-)
-
-func builtinShader(filter graphicsdriver.Filter, address graphicsdriver.Address) *Shader {
-	builtinShadersM.Lock()
-	defer builtinShadersM.Unlock()
-
-	key := builtinShaderKey{
-		filter:  filter,
-		address: address,
-	}
-	if s, ok := builtinShaders[key]; ok {
-		return s
-	}
-
-	src := builtinshader.Shader(filter, address)
-	s, err := NewShader(src)
-	if err != nil {
-		panic(fmt.Sprintf("ebiten: NewShader for a built-in shader failed: %v", err))
-	}
-	builtinShaders[key] = s
-	return s
-}