Add examples/moire

examples/moire/main.go

@@ -0,0 +1,129 @@
+// Copyright 2017 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 example
+
+package main
+
+import (
+	"log"
+
+	"github.com/hajimehoshi/ebiten"
+)
+
+const (
+	initScreenWidth  = 320
+	initScreenHeight = 240
+	initScreenScale  = 2
+)
+
+var (
+	gophersImage *ebiten.Image
+	keyStates    = map[ebiten.Key]int{
+		ebiten.KeyUp:    0,
+		ebiten.KeyDown:  0,
+		ebiten.KeyLeft:  0,
+		ebiten.KeyRight: 0,
+		ebiten.KeyS:     0,
+		ebiten.KeyF:     0,
+	}
+)
+
+var (
+	dots       []uint8
+	dotsWidth  int
+	dotsHeight int
+)
+
+func getDots(width, height int) []uint8 {
+	if dotsWidth == width && dotsHeight == height {
+		return dots
+	}
+	dotsWidth = width
+	dotsHeight = height
+	dots = make([]uint8, width*height*4)
+	for j := 0; j < height; j++ {
+		for i := 0; i < width; i++ {
+			if (i+j)%2 == 0 {
+				dots[(i+j*width)*4+0] = 0xff
+				dots[(i+j*width)*4+1] = 0xff
+				dots[(i+j*width)*4+2] = 0xff
+				dots[(i+j*width)*4+3] = 0xff
+			}
+		}
+	}
+	return dots
+}
+
+func update(screen *ebiten.Image) error {
+	for key := range keyStates {
+		if !ebiten.IsKeyPressed(key) {
+			keyStates[key] = 0
+			continue
+		}
+		keyStates[key]++
+	}
+	screenScale := ebiten.ScreenScale()
+	d := int(32 / screenScale)
+	screenWidth, screenHeight := screen.Size()
+	fullscreen := ebiten.IsFullscreen()
+
+	if keyStates[ebiten.KeyUp] == 1 {
+		screenHeight += d
+	}
+	if keyStates[ebiten.KeyDown] == 1 {
+		if 16 < screenHeight && d < screenHeight {
+			screenHeight -= d
+		}
+	}
+	if keyStates[ebiten.KeyLeft] == 1 {
+		if 16 < screenWidth && d < screenWidth {
+			screenWidth -= d
+		}
+	}
+	if keyStates[ebiten.KeyRight] == 1 {
+		screenWidth += d
+	}
+	if keyStates[ebiten.KeyS] == 1 {
+		switch screenScale {
+		case 1:
+			screenScale = 1.5
+		case 1.5:
+			screenScale = 2
+		case 2:
+			screenScale = 1
+		default:
+			panic("not reached")
+		}
+	}
+	if keyStates[ebiten.KeyF] == 1 {
+		fullscreen = !fullscreen
+	}
+	ebiten.SetScreenSize(screenWidth, screenHeight)
+	ebiten.SetScreenScale(screenScale)
+	ebiten.SetFullscreen(fullscreen)
+
+	if ebiten.IsRunningSlowly() {
+		return nil
+	}
+
+	screen.ReplacePixels(getDots(screen.Size()))
+	return nil
+}
+
+func main() {
+	if err := ebiten.Run(update, initScreenWidth, initScreenHeight, initScreenScale, "Moire (Ebiten Demo)"); err != nil {
+		log.Fatal(err)
+	}
+}