examples/shader: Add lighting example

Fixes #1234

examples/resources/generate.go

@@ -33,6 +33,8 @@
 //go:generate file2byteslice -package=mascot -input=./images/mascot/out01.png -output=./images/mascot/out01.go -var=Out01_png
 //go:generate file2byteslice -package=mascot -input=./images/mascot/out02.png -output=./images/mascot/out02.go -var=Out02_png
 //go:generate file2byteslice -package=mascot -input=./images/mascot/out03.png -output=./images/mascot/out03.go -var=Out03_png
+//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/normal.png -output=./images/shader/normal.go -var=Normal_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/shader/default.go

@@ -17,7 +17,7 @@
 package main
 
 var Time float
-var Mouse vec2
+var Cursor vec2
 
 // viewportSize is a predefined function.
 
@@ -31,7 +31,7 @@ func Vertex(position vec2, texCoord vec2, color vec4) vec4 {
 }
 
 func Fragment(position vec4) vec4 {
-	pos := position.xy/viewportSize() + Mouse/viewportSize()/4
+	pos := position.xy/viewportSize() + Cursor/viewportSize()/4
 	color := 0.0
 	color += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)
 	color += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)

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 Mouse vec2\n\n// viewportSize is a predefined function.\n\nfunc Vertex(position vec2, texCoord vec2, color vec4) vec4 {\n\treturn mat4(\n\t\t2/viewportSize().x, 0, 0, 0,\n\t\t0, 2/viewportSize().y, 0, 0,\n\t\t0, 0, 1, 0,\n\t\t-1, -1, 0, 1,\n\t) * vec4(position, 0, 1)\n}\n\nfunc Fragment(position vec4) vec4 {\n\tpos := position.xy/viewportSize() + Mouse/viewportSize()/4\n\tcolor := 0.0\n\tcolor += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)\n\tcolor += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)\n\tcolor += sin(pos.x*sin(Time/5)*10) + sin(pos.y*sin(Time/35)*80)\n\tcolor *= sin(Time/10) * 0.5\n\treturn vec4(color, color*0.5, sin(color+Time/3)*0.75, 1)\n}\n")
+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\n// viewportSize is a predefined function.\n\nfunc Vertex(position vec2, texCoord vec2, color vec4) vec4 {\n\treturn mat4(\n\t\t2/viewportSize().x, 0, 0, 0,\n\t\t0, 2/viewportSize().y, 0, 0,\n\t\t0, 0, 1, 0,\n\t\t-1, -1, 0, 1,\n\t) * vec4(position, 0, 1)\n}\n\nfunc Fragment(position vec4) vec4 {\n\tpos := position.xy/viewportSize() + Cursor/viewportSize()/4\n\tcolor := 0.0\n\tcolor += sin(pos.x*cos(Time/15)*80) + cos(pos.y*cos(Time/15)*10)\n\tcolor += sin(pos.y*sin(Time/10)*40) + cos(pos.x*sin(Time/25)*40)\n\tcolor += sin(pos.x*sin(Time/5)*10) + sin(pos.y*sin(Time/35)*80)\n\tcolor *= sin(Time/10) * 0.5\n\treturn vec4(color, color*0.5, sin(color+Time/3)*0.75, 1)\n}\n")

examples/shader/generate.go

@@ -15,4 +15,4 @@
 package main
 
 //go:generate file2byteslice -package=main -input=default.go -output=default_go.go -var=default_go
-//go:generate file2byteslice -package=main -input=image.go -output=image_go.go -var=image_go
+//go:generate file2byteslice -package=main -input=lighting.go -output=lighting_go.go -var=lighting_go

examples/shader/image_go.go

@@ -1,6 +0,0 @@
-// Code generated by file2byteslice. DO NOT EDIT.
-// (gofmt is fine after generating)
-
-package main
-
-var image_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 Vertex(position vec2, texCoord vec2, color vec4) (vec4, vec2) {\n\treturn mat4(\n\t\t2/viewportSize().x, 0, 0, 0,\n\t\t0, 2/viewportSize().y, 0, 0,\n\t\t0, 0, 1, 0,\n\t\t-1, -1, 0, 1,\n\t) * vec4(position, 0, 1), texCoord\n}\n\nfunc Fragment(position vec4, texCoord vec2) vec4 {\n\treturn texture0At(texCoord)\n}\n")

examples/shader/lighting.go

@@ -29,5 +29,10 @@ func Vertex(position vec2, texCoord vec2, color vec4) (vec4, vec2) {
 }
 
 func Fragment(position vec4, texCoord vec2) vec4 {
-	return texture0At(texCoord)
+	lightpos := vec3(Cursor, 50)
+	lightdir := normalize(lightpos - position.xyz)
+	normal := normalize(texture1At(texCoord) - 0.5)
+	ambient := 0.25
+	diffuse := 0.75 * max(0.0, dot(normal.xyz, lightdir))
+	return texture0At(texCoord) * (ambient + diffuse)
 }

examples/shader/lighting_go.go

@@ -0,0 +1,6 @@
+// Code generated by file2byteslice. DO NOT EDIT.
+// (gofmt is fine after generating)
+
+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 Vertex(position vec2, texCoord vec2, color vec4) (vec4, vec2) {\n\treturn mat4(\n\t\t2/viewportSize().x, 0, 0, 0,\n\t\t0, 2/viewportSize().y, 0, 0,\n\t\t0, 0, 1, 0,\n\t\t-1, -1, 0, 1,\n\t) * vec4(position, 0, 1), texCoord\n}\n\nfunc Fragment(position vec4, texCoord vec2) 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")

examples/shader/main.go

@@ -19,12 +19,12 @@ package main
 import (
 	"bytes"
 	"image"
-	_ "image/jpeg"
+	_ "image/png"
 	"log"
 
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/ebitenutil"
-	"github.com/hajimehoshi/ebiten/examples/resources/images"
+	resources "github.com/hajimehoshi/ebiten/examples/resources/images/shader"
 	"github.com/hajimehoshi/ebiten/inpututil"
 )
 
@@ -33,7 +33,10 @@ const (
 	screenHeight = 480
 )
 
-var gophersImage *ebiten.Image
+var (
+	gopherImage *ebiten.Image
+	normalImage *ebiten.Image
+)
 
 func init() {
 	// Decode image from a byte slice instead of a file so that
@@ -45,16 +48,24 @@ func init() {
 	//    This works even on browsers.
 	// 3) Use ebitenutil.NewImageFromFile to create an ebiten.Image directly from a file.
 	//    This also works on browsers.
-	img, _, err := image.Decode(bytes.NewReader(images.Gophers_jpg))
+	img, _, err := image.Decode(bytes.NewReader(resources.Gopher_png))
 	if err != nil {
 		log.Fatal(err)
 	}
-	gophersImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
+	gopherImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
+}
+
+func init() {
+	img, _, err := image.Decode(bytes.NewReader(resources.Normal_png))
+	if err != nil {
+		log.Fatal(err)
+	}
+	normalImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
 }
 
 var shaderSrcs = [][]byte{
 	default_go,
-	image_go,
+	lighting_go,
 }
 
 type Game struct {
@@ -93,6 +104,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 		return
 	}
 
+	sw, sh := gopherImage.Size()
 	w, h := screen.Size()
 	vs := []ebiten.Vertex{
 		{
@@ -104,20 +116,20 @@ func (g *Game) Draw(screen *ebiten.Image) {
 		{
 			DstX: float32(w),
 			DstY: 0,
-			SrcX: float32(w),
+			SrcX: float32(sw),
 			SrcY: 0,
 		},
 		{
 			DstX: 0,
 			DstY: float32(h),
 			SrcX: 0,
-			SrcY: float32(h),
+			SrcY: float32(sh),
 		},
 		{
 			DstX: float32(w),
 			DstY: float32(h),
-			SrcX: float32(w),
-			SrcY: float32(h),
+			SrcX: float32(sw),
+			SrcY: float32(sh),
 		},
 	}
 	is := []uint16{0, 1, 2, 1, 2, 3}
@@ -130,7 +142,8 @@ func (g *Game) Draw(screen *ebiten.Image) {
 		[]float32{float32(cx), float32(cy)}, // Cursor
 	}
 	if g.idx != 0 {
-		op.Images[0] = gophersImage
+		op.Images[0] = gopherImage
+		op.Images[1] = normalImage
 	}
 	screen.DrawTrianglesWithShader(vs, is, s, op)