examples/shader: Add the chromatic aberration example (#1288)

Updates #1284

examples/shader/chromaticaberration.go

@@ -0,0 +1,31 @@
+// 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 ScreenSize vec2
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	center := ScreenSize / 2
+	amount := normalize(center-Cursor).x / 100
+	var clr vec3
+	clr.r = texture2At(vec2(texCoord.x+amount, texCoord.y)).r
+	clr.g = texture2At(texCoord).g
+	clr.b = texture2At(vec2(texCoord.x-amount, texCoord.y)).b
+	return vec4(clr, 1.0)
+}

examples/shader/chromaticaberration_go.go

@@ -0,0 +1,6 @@
+// Code generated by file2byteslice. DO NOT EDIT.
+// (gofmt is fine after generating)
+
+package main
+
+var chromaticaberration_go = []byte("// Copyright 2020 The Ebiten Authors\r\n//\r\n// Licensed under the Apache License, Version 2.0 (the \"License\");\r\n// you may not use this file except in compliance with the License.\r\n// You may obtain a copy of the License at\r\n//\r\n//     http://www.apache.org/licenses/LICENSE-2.0\r\n//\r\n// Unless required by applicable law or agreed to in writing, software\r\n// distributed under the License is distributed on an \"AS IS\" BASIS,\r\n// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r\n// See the License for the specific language governing permissions and\r\n// limitations under the License.\r\n\r\n// +build ignore\r\n\r\npackage main\r\n\r\nvar Time float\r\nvar Cursor vec2\r\nvar ScreenSize vec2\r\n\r\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\r\n\tcenter := ScreenSize / 2\r\n\tamount := normalize(center-Cursor).x / 100\r\n\tvar clr vec3\r\n\tclr.r = texture2At(vec2(texCoord.x+amount, texCoord.y)).r\r\n\tclr.g = texture2At(texCoord).g\r\n\tclr.b = texture2At(vec2(texCoord.x-amount, texCoord.y)).b\r\n\treturn vec4(clr, 1.0)\r\n}\r\n")

examples/shader/default.go

@@ -18,6 +18,7 @@ package main
 
 var Time float
 var Cursor vec2
+var ScreenSize vec2
 
 func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 	pos := position.xy/textureDstSize() + Cursor/textureDstSize()/4

examples/shader/default_go.go

@@ -3,4 +3,4 @@
 
 package main
 
-var default_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\n\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\n\tpos := position.xy/textureDstSize() + Cursor/textureDstSize()/4\n\tclr := 0.0\n\tclr += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)\n\tclr += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)\n\tclr += sin(pos.x*sin(Time/5)*10) + sin(pos.y*sin(Time/35)*80)\n\tclr *= sin(Time/10) * 0.5\n\treturn vec4(clr, clr*0.5, sin(clr+Time/3)*0.75, 1)\n}\n")
+var default_go = []byte("// Copyright 2020 The Ebiten Authors\r\n//\r\n// Licensed under the Apache License, Version 2.0 (the \"License\");\r\n// you may not use this file except in compliance with the License.\r\n// You may obtain a copy of the License at\r\n//\r\n//     http://www.apache.org/licenses/LICENSE-2.0\r\n//\r\n// Unless required by applicable law or agreed to in writing, software\r\n// distributed under the License is distributed on an \"AS IS\" BASIS,\r\n// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r\n// See the License for the specific language governing permissions and\r\n// limitations under the License.\r\n\r\n// +build ignore\r\n\r\npackage main\r\n\r\nvar Time float\r\nvar Cursor vec2\r\nvar ScreenSize vec2\r\n\r\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\r\n\tpos := position.xy/textureDstSize() + Cursor/textureDstSize()/4\r\n\tclr := 0.0\r\n\tclr += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)\r\n\tclr += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)\r\n\tclr += sin(pos.x*sin(Time/5)*10) + sin(pos.y*sin(Time/35)*80)\r\n\tclr *= sin(Time/10) * 0.5\r\n\treturn vec4(clr, clr*0.5, sin(clr+Time/3)*0.75, 1)\r\n}\r\n")

examples/shader/generate.go

@@ -17,3 +17,4 @@ package main
 //go:generate file2byteslice -package=main -input=default.go -output=default_go.go -var=default_go
 //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

examples/shader/lighting.go

@@ -18,6 +18,7 @@ package main
 
 var Time float
 var Cursor vec2
+var ScreenSize vec2
 
 func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 	lightpos := vec3(Cursor, 50)

examples/shader/lighting_go.go

@@ -3,4 +3,4 @@
 
 package main
 
-var lighting_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\n\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\n\tlightpos := vec3(Cursor, 50)\n\tlightdir := normalize(lightpos - position.xyz)\n\tnormal := normalize(texture1At(texCoord) - 0.5)\n\tambient := 0.25\n\tdiffuse := 0.75 * max(0.0, dot(normal.xyz, lightdir))\n\treturn texture0At(texCoord) * (ambient + diffuse)\n}\n")
+var lighting_go = []byte("// Copyright 2020 The Ebiten Authors\r\n//\r\n// Licensed under the Apache License, Version 2.0 (the \"License\");\r\n// you may not use this file except in compliance with the License.\r\n// You may obtain a copy of the License at\r\n//\r\n//     http://www.apache.org/licenses/LICENSE-2.0\r\n//\r\n// Unless required by applicable law or agreed to in writing, software\r\n// distributed under the License is distributed on an \"AS IS\" BASIS,\r\n// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r\n// See the License for the specific language governing permissions and\r\n// limitations under the License.\r\n\r\n// +build ignore\r\n\r\npackage main\r\n\r\nvar Time float\r\nvar Cursor vec2\r\nvar ScreenSize vec2\r\n\r\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\r\n\tlightpos := vec3(Cursor, 50)\r\n\tlightdir := normalize(lightpos - position.xyz)\r\n\tnormal := normalize(texture1At(texCoord) - 0.5)\r\n\tambient := 0.25\r\n\tdiffuse := 0.75 * max(0.0, dot(normal.xyz, lightdir))\r\n\treturn texture0At(texCoord) * (ambient + diffuse)\r\n}\r\n")

examples/shader/main.go

@@ -76,6 +76,7 @@ var shaderSrcs = [][]byte{
 	default_go,
 	lighting_go,
 	radialblur_go,
+	chromaticaberration_go,
 }
 
 type Game struct {
@@ -121,6 +122,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 	op.Uniforms = []interface{}{
 		float32(g.time) / 60,                // Time
 		[]float32{float32(cx), float32(cy)}, // Cursor
+		[]float32{float32(w), float32(h)},   // ScreenSize
 	}
 	op.Images[0] = gopherImage
 	op.Images[1] = normalImage

examples/shader/radialblur.go

@@ -18,6 +18,7 @@ package main
 
 var Time float
 var Cursor vec2
+var ScreenSize vec2
 
 func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 	dir := normalize(position.xy - Cursor)

examples/shader/radialblur_go.go

@@ -3,4 +3,4 @@
 
 package main
 
-var radialblur_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\n\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\n\tdir := normalize(position.xy - Cursor)\n\tclr := texture2At(texCoord)\n\n\tsamples := [10]float{\n\t\t-22, -14, -8, -4, -2, 2, 4, 8, 14, 22,\n\t}\n\t// TODO: Add len(samples)\n\tsum := clr\n\tfor i := 0; i < 10; i++ {\n\t\t// TODO: Consider the source region not to violate the region.\n\t\tsum += texture2At(texCoord + dir*samples[i]/texture2Size())\n\t}\n\tsum /= 10 + 1\n\n\tdist := distance(position.xy, Cursor)\n\tt := clamp(dist/256, 0, 1)\n\treturn mix(clr, sum, t)\n}\n")
+var radialblur_go = []byte("// Copyright 2020 The Ebiten Authors\r\n//\r\n// Licensed under the Apache License, Version 2.0 (the \"License\");\r\n// you may not use this file except in compliance with the License.\r\n// You may obtain a copy of the License at\r\n//\r\n//     http://www.apache.org/licenses/LICENSE-2.0\r\n//\r\n// Unless required by applicable law or agreed to in writing, software\r\n// distributed under the License is distributed on an \"AS IS\" BASIS,\r\n// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r\n// See the License for the specific language governing permissions and\r\n// limitations under the License.\r\n\r\n// +build ignore\r\n\r\npackage main\r\n\r\nvar Time float\r\nvar Cursor vec2\r\nvar ScreenSize vec2\r\n\r\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\r\n\tdir := normalize(position.xy - Cursor)\r\n\tclr := texture2At(texCoord)\r\n\r\n\tsamples := [10]float{\r\n\t\t-22, -14, -8, -4, -2, 2, 4, 8, 14, 22,\r\n\t}\r\n\t// TODO: Add len(samples)\r\n\tsum := clr\r\n\tfor i := 0; i < 10; i++ {\r\n\t\t// TODO: Consider the source region not to violate the region.\r\n\t\tsum += texture2At(texCoord + dir*samples[i]/texture2Size())\r\n\t}\r\n\tsum /= 10 + 1\r\n\r\n\tdist := distance(position.xy, Cursor)\r\n\tt := clamp(dist/256, 0, 1)\r\n\treturn mix(clr, sum, t)\r\n}\r\n")