Beispiel #1
0
// NewMandelbrot returns a mandelbrot-set calculator
// that shows at least the area r within wr.
//
func NewMandelbrot(r crect, wr draw.Rectangle, julia bool, jpoint complex128, iterations int) *Mandelbrot {
	btall := float64(wr.Dy()) / float64(wr.Dx())
	atall := (imag(r.min) - imag(r.min)) / (real(r.max) - real(r.min))
	if btall > atall {
		// bitmap is taller than area, so expand area vertically
		excess := (real(r.max)-real(r.min))*btall - (imag(r.max) - imag(r.min))
		r.min -= cmplx(0, excess/2.0)
		r.max += cmplx(0, excess/2.0)
	} else {
		// area is taller than bitmap, so expand area horizontally
		excess := (imag(r.max)-imag(r.min))/btall - (real(r.max) - real(r.min))
		r.min -= cmplx(excess/2.0, 0)
		r.max += cmplx(excess/2.0, 0)
	}
	var m Mandelbrot
	m.iterations = iterations
	m.palette = makePalette(range0, iterations)
	m.origin = r.min
	m.julia = julia
	m.jpoint = jpoint
	m.cr = r
	m.delta = cmplx(
		(real(r.max)-real(r.min))/float64(wr.Dx()),
		(imag(r.max)-imag(r.min))/float64(wr.Dy()),
	)
	m.r = wr
	return &m
}
Beispiel #2
0
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
}