I'd like to try graphics libraries with Go. I've found the following example:
package main
import (
"image"
"image/color"
"image/png"
"log"
"os"
)
func main() {
width, height := 512, 512
canvas := NewCanvas(image.Rect(0, 0, width, height))
canvas.DrawGradient()
// Draw a series of lines from the top left corner to the bottom of the image
for x := 0; x < width; x += 8 {
canvas.DrawLine(color.RGBA{0, 0, 0, 255},
Vector{0.0, 0.0},
Vector{float64(x), float64(height)})
}
outFilename := "lines.png"
outFile, err := os.Create(outFilename)
if err != nil {
log.Fatal(err)
}
defer outFile.Close()
log.Print("Saving image to: ", outFilename)
png.Encode(outFile, canvas)
}
However, when building it seems that some Classes are missing.
D:\go\work>go build draw.go
# command-line-arguments
.\draw.go:13: undefined: NewCanvas
.\draw.go:19: undefined: Vector
.\draw.go:20: undefined: Vector
My environment worked fine for the HelloWorld example, however it seems something is missing when importing image libraries. Any help to get started a newbie ?