package patterns

import "math"

var sineoffset int = 0
var lastSineSpeed uint16 = 0

func Sinewave(w int, h int, bgColor RGBcolor, fgColor RGBcolor, speed uint16) [][]RGBcolor  {
	if speed != lastSineSpeed {
		lastSineSpeed = speed
		sineoffset = 0
	}
    sineoffset += int(speed/40)
	background := FillPanelRGB(w,h,bgColor)
	for x := 0; x < w; x++ {
		y := int(math.Round((math.Sin(float64(x+sineoffset))+1) / 2 * float64(h-1)))
		background[x][y] = fgColor
	}
	return background
}

var lastSinePos int = 0

func SineChase(w int, h int, bgColor RGBcolor, fgColor RGBcolor, speed uint16) [][]RGBcolor  {
	if speed != lastSineSpeed {
		lastSineSpeed = speed
		lastSinePos = 0
	}
	background := FillPanelRGB(w,h,bgColor)
	y := int(math.Round((math.Sin(float64(lastSinePos))+1) / 2 * float64(h-1)))
	background[lastSinePos][y] = fgColor
	lastSinePos += 1
	if lastSinePos >= w {
		lastSinePos = 0
	}
	return background
}

func ZigZag(w int, h int) [][]RGBcolor  {
	var bgColor = [3]byte{0,0,0}
	var fgColor = [3]byte{255,0,0}
	//var a = [5]int{2, 4, 6, 8, 10}
	background := FillPanelRGB(w,h,bgColor)
	for x := 0; x < w; x++ {
		y := x % (h-1)
		background[x][y] = fgColor
	}
	return background
}