问填充Golang draw2d包中的一个像素

EN

 package main

impenter code hereort (
        "bufio"
        "fmt"
        "log"
        "os"

        "code.google.com/p/draw2d/draw2d"
        "image"
        "image/png"
)

func saveToPngFile(filePath string, m image.Image) {
        f, err := os.Create(filePath)
        if err != nil {
                log.Println(err)
                os.Exit(1)
        }
        defer f.Close()
        b := bufio.NewWriter(f)
        err = png.Encode(b, m)
        if err != nil {
                log.Println(err)
                os.Exit(1)
        }
        err = b.Flush()
        if err != nil {
                log.Println(err)
                os.Exit(1)
        }
        fmt.Printf("Wrote %s OK.\n", filePath)
}

func main() {
        i := image.NewRGBA(image.Rect(0, 0, 200, 200))
        gc := draw2d.NewGraphicContext(i)
        gc.MoveTo(10.0, 10.0)
        gc.LineTo(100.0, 10.0)
        gc.Stroke()
        saveToPngFile("TestPath.png", i)
}