examples/shader: Add a new example 'texel'

examples/shader/generate.go

@@ -17,6 +17,7 @@
 package main
 
 //go:generate file2byteslice -package=main -input=default.go -output=default_go.go -var=default_go -buildtags=example
+//go:generate file2byteslice -package=main -input=texel.go -output=texel_go.go -var=texel_go -buildtags=example
 //go:generate file2byteslice -package=main -input=lighting.go -output=lighting_go.go -var=lighting_go -buildtags=example
 //go:generate file2byteslice -package=main -input=radialblur.go -output=radialblur_go.go -var=radialblur_go -buildtags=example
 //go:generate file2byteslice -package=main -input=chromaticaberration.go -output=chromaticaberration_go.go -var=chromaticaberration_go -buildtags=example

examples/shader/main.go

@@ -83,6 +83,7 @@ func init() {
 
 var shaderSrcs = [][]byte{
 	default_go,
+	texel_go,
 	lighting_go,
 	radialblur_go,
 	chromaticaberration_go,

examples/shader/texel.go

@@ -0,0 +1,25 @@
+// 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
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	pos := position.xy / imageDstTextureSize()
+	origin, size := imageDstRegionOnTexture()
+	pos -= origin
+	pos /= size
+	return vec4(pos.x, pos.y, 0, 1)
+}

examples/shader/texel_go.go

@@ -0,0 +1,7 @@
+// Code generated by file2byteslice. DO NOT EDIT.
+
+// +build example
+
+package main
+
+var texel_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\nfunc Fragment(position vec4, texCoord vec2, color vec4) vec4 {\n\tpos := position.xy / imageDstTextureSize()\n\torigin, size := imageDstRegionOnTexture()\n\tpos -= origin\n\tpos /= size\n\treturn vec4(pos.x, pos.y, 0, 1)\n}\n")