examples/shader: dissolve shader (#1291)

Updates #1284

examples/resources/generate.go

@@ -36,6 +36,7 @@
 //go:generate file2byteslice -package=shader -input=./images/shader/gopher.png -output=./images/shader/gopher.go -var=Gopher_png
 //go:generate file2byteslice -package=shader -input=./images/shader/gopherbg.png -output=./images/shader/gopherbg.go -var=GopherBg_png
 //go:generate file2byteslice -package=shader -input=./images/shader/normal.png -output=./images/shader/normal.go -var=Normal_png
+//go:generate file2byteslice -package=shader -input=./images/shader/noise.png -output=./images/shader/noise.go -var=Noise_png
 //go:generate file2byteslice -package=platformer -input=./images/platformer/background.png -output=./images/platformer/background.go -var=Background_png
 //go:generate file2byteslice -package=platformer -input=./images/platformer/left.png -output=./images/platformer/left.go -var=Left_png
 //go:generate file2byteslice -package=platformer -input=./images/platformer/mainchar.png -output=./images/platformer/mainchar.go -var=MainChar_png

examples/resources/images/license.md

@@ -117,6 +117,13 @@ By Håkan Svensson Xauxa
 The Creative Commons Attribution-Share Alike 3.0 Unported license
 ```
 
+## shader/noise.png
+
+```
+Generated by Magnus Wahlstrand (https://github.com/kyeett)
+MIT License
+```
+
 ## Other image files
 
 ```

examples/shader/dissolve.go

@@ -0,0 +1,35 @@
+// 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.
+
+// +build ignore
+
+package main
+
+var Time float
+var Cursor vec2
+var ScreenImage vec2
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	// Triangle wave to go 0-->1-->0...
+	limit := abs(2*fract(Time/3) - 1)
+	level := image3TextureAt(texCoord).x
+
+	// Add a white border
+	if limit-0.1 < level && level < limit {
+		alpha := image0TextureAt(texCoord).w
+		return vec4(alpha)
+	}
+
+	return step(limit, level) * image0TextureAt(texCoord)
+}

examples/shader/dissolve_go.go

@@ -0,0 +1,6 @@
+// Code generated by file2byteslice. DO NOT EDIT.
+// (gofmt is fine after generating)
+
+package main
+
+var dissolve_go = []byte("// Copyright 2020 The Ebiten Authors\n//\n// Licensed under the Apache License, Version 2.0 (the \"License\");\n// you may not use this file except in compliance with the License.\n// You may obtain a copy of the License at\n//\n//     http://www.apache.org/licenses/LICENSE-2.0\n//\n// Unless required by applicable law or agreed to in writing, software\n// distributed under the License is distributed on an \"AS IS\" BASIS,\n// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n// See the License for the specific language governing permissions and\n// limitations under the License.\n\n// +build ignore\n\npackage main\n\nvar Time float\nvar Cursor vec2\nvar ScreenImage vec2\n\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\n\t// Triangle wave to go 0-->1-->0...\n\tlimit := abs(2*fract(Time/3) - 1)\n\tlevel := image3TextureAt(texCoord).x\n\n\t// Add a white border\n\tif limit-0.1 < level && level < limit {\n\t\talpha := image0TextureAt(texCoord).w\n\t\treturn vec4(alpha)\n\t}\n\n\treturn step(limit, level) * image0TextureAt(texCoord)\n}\n")

examples/shader/generate.go

@@ -18,3 +18,4 @@ package main
 //go:generate file2byteslice -package=main -input=lighting.go -output=lighting_go.go -var=lighting_go
 //go:generate file2byteslice -package=main -input=radialblur.go -output=radialblur_go.go -var=radialblur_go
 //go:generate file2byteslice -package=main -input=chromaticaberration.go -output=chromaticaberration_go.go -var=chromaticaberration_go
+//go:generate file2byteslice -package=main -input=dissolve.go -output=dissolve_go.go -var=dissolve_go

examples/shader/main.go

@@ -37,6 +37,7 @@ var (
 	gopherImage   *ebiten.Image
 	gopherBgImage *ebiten.Image
 	normalImage   *ebiten.Image
+	noiseImage    *ebiten.Image
 )
 
 func init() {
@@ -72,11 +73,20 @@ func init() {
 	normalImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
 }
 
+func init() {
+	img, _, err := image.Decode(bytes.NewReader(resources.Noise_png))
+	if err != nil {
+		log.Fatal(err)
+	}
+	noiseImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
+}
+
 var shaderSrcs = [][]byte{
 	default_go,
 	lighting_go,
 	radialblur_go,
 	chromaticaberration_go,
+	dissolve_go,
 }
 
 type Game struct {
@@ -127,6 +137,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 	op.Images[0] = gopherImage
 	op.Images[1] = normalImage
 	op.Images[2] = gopherBgImage
+	op.Images[3] = noiseImage
 	screen.DrawRectShader(w, h, s, op)
 
 	msg := "Press Up/Down to switch the shader."