Merge pull request #2 from dim13/main

Implement draw.Image

.github/workflows/go.yml

@@ -0,0 +1,28 @@
+# This workflow will build a golang project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+
+name: Go
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.x
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Test
+      run: go test -v ./...

examples/example.go

@@ -1,3 +1,5 @@
+//go:build example
+
 package main
 
 import (
@@ -20,11 +22,11 @@ func main() {
 		// Fill screen with random noise
 		for i := 0; i < 240; i++ {
 			for j := 0; j < 320; j++ {
-				f.SetPixel(j, i, rand.Uint32())
+				f.Set(j, i, fenster.RGB(rand.Uint32()))
 			}
 		}
 		// Wait for FPS rate
-		sleep := 16*time.Millisecond - time.Now().Sub(lastFrame)
+		sleep := 16*time.Millisecond - time.Since(lastFrame)
 		if sleep > 0 {
 			time.Sleep(sleep)
 		}

examples/testimage.go

@@ -0,0 +1,58 @@
+//go:build example
+
+package main
+
+import (
+	"image"
+	"image/color/palette"
+	"image/draw"
+	"image/png"
+	"log"
+	"os"
+	"time"
+
+	"github.com/zserge/fenster"
+)
+
+func openImage(fname string) (image.Image, error) {
+	fd, err := os.Open(fname)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+	return png.Decode(fd)
+}
+
+func main() {
+	f := fenster.New()
+	f.Open(320, 240, "Hello")
+	defer f.Close()
+	lastFrame := time.Now()
+
+	img, err := openImage("testdata/Testbild.png")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// convert to paletted image
+	pimg := image.NewPaletted(img.Bounds(), palette.Plan9)
+	draw.Draw(pimg, pimg.Bounds(), img, image.Point{}, draw.Src)
+
+	for f.Loop() {
+		// If escape is pressed - exit
+		if f.Key(27) {
+			break
+		}
+
+		// rotate palette
+		pimg.Palette = append(pimg.Palette[1:], pimg.Palette[0])
+		draw.Draw(f, f.Bounds(), pimg, image.Point{}, draw.Src)
+
+		// Wait for FPS rate
+		sleep := 16*time.Millisecond - time.Since(lastFrame)
+		if sleep > 0 {
+			time.Sleep(sleep)
+		}
+		lastFrame = time.Now()
+	}
+}

fenster.go

@@ -9,6 +9,9 @@ package fenster
 import "C"
 import (
 	"fmt"
+	"image"
+	"image/color"
+	"image/draw"
 	"runtime"
 	"unsafe"
 )
@@ -22,10 +25,33 @@ type Fenster interface {
 	Open(w, h int, title string) error
 	Loop() bool
 	Close()
-	Pixel(x int, y int) uint32
-	SetPixel(x int, y int, rgb uint32)
 	Key(byte) bool
 	Mod() Mods
+	draw.Image
+}
+
+// RGB Color 00RRGGBB
+type RGB uint32
+
+func (c RGB) RGBA() (r uint32, g uint32, b uint32, a uint32) {
+	r = uint32(c>>16) & 0xff
+	r |= r << 8
+	g = uint32(c>>8) & 0xff
+	g |= g << 8
+	b = uint32(c) & 0xff
+	b |= b << 8
+	a = 0xffff
+	return r, g, b, a
+}
+
+var RGBModel = color.ModelFunc(rgbModel)
+
+func rgbModel(c color.Color) color.Color {
+	if _, ok := c.(RGB); ok {
+		return c
+	}
+	r, g, b, _ := c.RGBA()
+	return RGB((r>>8)<<16 | (g>>8)<<8 | (b >> 8))
 }
 
 type Mods int
@@ -35,6 +61,11 @@ type fenster struct {
 	buf []uint32
 }
 
+func (f *fenster) ColorModel() color.Model { return RGBModel }
+func (f *fenster) Bounds() image.Rectangle {
+	return image.Rect(0, 0, int(f.f.width), int(f.f.height))
+}
+
 func New() Fenster { return &fenster{} }
 func (f *fenster) Open(w, h int, title string) error {
 	f.f.title = C.CString(title)
@@ -54,5 +85,7 @@ func (f *fenster) Close()     { C.fenster_close(&f.f) }
 func (f *fenster) Key(code byte) bool { return f.f.keys[code] != 0 }
 func (f *fenster) Mod() Mods          { return Mods(f.f.mod) }
 
-func (f *fenster) Pixel(x, y int) uint32           { return f.buf[y*int(f.f.width)+x] }
-func (f *fenster) SetPixel(x, y int, color uint32) { f.buf[y*int(f.f.width)+x] = color }
+func (f *fenster) At(x, y int) color.Color { return RGB(f.buf[y*int(f.f.width)+x]) }
+func (f *fenster) Set(x, y int, c color.Color) {
+	f.buf[y*int(f.f.width)+x] = uint32(f.ColorModel().Convert(c).(RGB))
+}