Add examples/fill

examples/fill/main.go

@@ -0,0 +1,94 @@
+// Copyright 2018 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 (
+	"image/color"
+	_ "image/png"
+	"log"
+
+	"github.com/hajimehoshi/ebiten"
+	"github.com/hajimehoshi/ebiten/ebitenutil"
+)
+
+const (
+	screenWidth  = 320
+	screenHeight = 240
+)
+
+var (
+	ebitenImage *ebiten.Image
+	colors      = []color.RGBA{
+		{0xff, 0xff, 0xff, 0xff},
+		{0xff, 0xff, 0x0, 0xff},
+		{0xff, 0x0, 0xff, 0xff},
+		{0xff, 0x0, 0x0, 0xff},
+		{0x0, 0xff, 0xff, 0xff},
+		{0x0, 0xff, 0x0, 0xff},
+		{0x0, 0x0, 0xff, 0xff},
+		{0x0, 0x0, 0x0, 0xff},
+	}
+)
+
+func update(screen *ebiten.Image) error {
+	if ebiten.IsRunningSlowly() {
+		return nil
+	}
+
+	const (
+		ox = 10
+		oy = 10
+		dx = 60
+		dy = 50
+	)
+	screen.Fill(color.NRGBA{0x00, 0x40, 0x80, 0xff})
+
+	op := &ebiten.DrawImageOptions{}
+	op.GeoM.Translate(ox, oy)
+	screen.DrawImage(ebitenImage, op)
+
+	// Fill with solid colors
+	for i, c := range colors {
+		op := &ebiten.DrawImageOptions{}
+		x := i % 4
+		y := i/4 + 1
+		op.GeoM.Translate(ox+float64(dx*x), oy+float64(dy*y))
+
+		// Set RGB (not Alpha) 1 forcibly
+		op.ColorM.Scale(0, 0, 0, 1)
+		op.ColorM.Translate(1, 1, 1, 0)
+
+		// Set color by scaling
+		r := float64(c.R) / 0xff
+		g := float64(c.G) / 0xff
+		b := float64(c.B) / 0xff
+		op.ColorM.Scale(r, g, b, 1)
+		screen.DrawImage(ebitenImage, op)
+	}
+	return nil
+}
+
+func main() {
+	var err error
+	ebitenImage, _, err = ebitenutil.NewImageFromFile(ebitenutil.JoinStringsIntoFilePath("_resources", "images", "ebiten.png"), ebiten.FilterNearest)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Fill with solid colors (Ebiten Demo)"); err != nil {
+		log.Fatal(err)
+	}
+}