示例#1
0
// ValidateImgParams validates desired output image parameters.
func ValidateImgParams(imgP *ImgParams) error {
	if imgP.Width%constants.TileSize != 0 || imgP.Height%constants.TileSize != 0 {
		return fmt.Errorf("width(%d) and height(%d) of the resulting picture"+
			" should be multiples of tile size(%d)\n", imgP.Width,
			imgP.Height, constants.TileSize)
	}

	ratioXY := float64(constants.YMax-constants.YMin) / float64(constants.XMax-constants.XMin)
	ratioPxPy := float64(imgP.Height) / float64(imgP.Width)
	if ratioXY != ratioPxPy {
		sugestedWidth := int(float64(imgP.Height) / ratioXY)
		msgFmt := "pixel ratio (%2.2f) differs from XY ratio(%2.2f), try" +
			" adjusting width to %d\n\n"
		return fmt.Errorf(msgFmt, ratioPxPy, ratioXY, sugestedWidth)
	}

	if imgP.Scaling < 1 {
		msgFmt := "scaling factor must be >= 1, currently: `%d`\n"
		return fmt.Errorf(msgFmt, imgP.Scaling)
	}

	if _, err := algos.MapStr2Func(imgP.Algo); err != nil {
		return err
	}

	return nil
}
示例#2
0
// BuildImg coordinates tasks between individual tile-processors. It does not
// directly write pixels, only sends tile numbers to calculate to processors.
func BuildImg(imgP *cmdline.ImgParams) *image.RGBA {

	f, _ := algos.MapStr2Func(imgP.Algo)
	img := image.NewRGBA(image.Rect(0, 0, imgP.Width, imgP.Height))
	waitGroup, workerCh := spawnProcessors(imgP.Scaling, img, f)

	for py := 0; py < imgP.Height; py += constants.TileSize {
		for px := 0; px < imgP.Width; px += constants.TileSize {
			// (sur) should I worry about generating to many objects for GC ?
			workerCh <- [2]int{py, px}
		}
	}

	close(workerCh)
	waitGroup.Wait()

	return img
}