func Start(im *image.RGBA, num int, vpx, vpy, d float64, ch chan<- point) {
share := im.Height() / num
for i := 0; i < num; i += 1 {
go Mandelbrot(im, i*share, (i+1)*share, vpx, vpy, d, ch)
}
}
func handleChans(im *image.RGBA, ch <-chan point) {
counter := 0
pixCount := im.Height() * im.Width()
for counter < pixCount {
counter += 1
p := <-ch
im.Pixel[p.x][p.y] = p.color
}
}
func Mandelbrot(im *image.RGBA, lineMin, lineMax int, vpx, vpy, d float64, ch chan<- point) {
width := float64(im.Width())
height := float64(im.Height())
for i := lineMin; i < lineMax; i++ {
for j := 0; j < im.Height(); j++ {
x0 := float64(i)/(width/d) - d/2.0 + vpx
y0 := float64(j)/(height/d) - d/2.0 + vpy
ch <- point{i, j, getPixelAt(y0, x0)}
}
}
}
func NewTile(r draw.Rectangle, calc Fractal, img *image.RGBA, wait bool) *Tile {
t := new(Tile)
t.r = r
t.nrows = 0
if img == nil {
img = image.NewRGBA(image.Rect(0, 0, r.Dx(), r.Dy()))
}
t.calc = calc
t.image = img
if wait {
t.calculate(nil, nil)
t.nrows = img.Height()
} else {
// choose some vaguely appropriate colour
col := calc.At(centre(r))
draw.Draw(t.image, draw.Rect(0, 0, r.Dx(), r.Dy()), image.Uniform{col}, draw.ZP)
}
return t
}