// rshapes draws shapes with random colors, openvg.Strokes, and sizes.
func rshapes(width, height, n int) {

	var sx, sy, cx, cy, px, py, ex, ey, pox, poy float64

	np := 10
	polyx := make([]float64, np)
	polyy := make([]float64, np)
	openvg.Start(width, height)
	for i := 0; i < n; i++ {
		openvg.FillRGB(randcolor(), randcolor(), randcolor(), rand.Float64())
		openvg.Ellipse(randf(width), randf(height), randf(200), randf(100))
		openvg.Circle(randf(width), randf(height), randf(100))
		openvg.Rect(randf(width), randf(height), randf(200), randf(100))
		openvg.Arc(randf(width), randf(height), randf(200), randf(200), randf(360), randf(360))

		sx = randf(width)
		sy = randf(height)
		openvg.StrokeRGB(randcolor(), randcolor(), randcolor(), 1)
		openvg.StrokeWidth(randf(5))
		openvg.Line(sx, sy, sx+randf(200), sy+randf(100))
		openvg.StrokeWidth(0)

		sx = randf(width)
		sy = randf(height)
		ex = sx + randf(200)
		ey = sy
		cx = sx + ((ex - sx) / 2.0)
		cy = sy + randf(100)
		openvg.Qbezier(sx, sy, cx, cy, ex, ey)

		sx = randf(width)
		sy = randf(height)
		ex = sx + randf(200)
		ey = sy
		cx = sx + ((ex - sx) / 2.0)
		cy = sy + randf(100)
		px = cx
		py = sy - randf(100)
		openvg.Cbezier(sx, sy, cx, cy, px, py, ex, ey)

		pox = randf(width)
		poy = randf(height)
		for j := 0; j < np; j++ {
			polyx[j] = pox + randf(200)
			polyy[j] = poy + randf(100)
		}
		openvg.Polygon(polyx, polyy) // , np)

		pox = randf(width)
		poy = randf(height)
		for j := 0; j < np; j++ {
			polyx[j] = pox + randf(200)
			polyy[j] = poy + randf(100)
		}
		openvg.Polyline(polyx, polyy) // , np)
	}
	openvg.FillRGB(128, 0, 0, 1)
	openvg.Text(20, 20, "OpenVG on the Raspberry Pi", "sans", 32)
	openvg.End()
}

func main() {
	var cx, cy, cw, ch, midy int
	message := "Now is the time for all good men to come to the aid of the party"

	w, h := openvg.Init()
	var speed openvg.VGfloat = 15.0
	var x openvg.VGfloat = 0
	midy = (h / 2)
	fontsize := w / 50
	cx = 0
	ch = fontsize * 2
	cw = w
	cy = midy - (ch / 2)

	rx, ry, rw, rh := openvg.VGfloat(cx), openvg.VGfloat(cy), openvg.VGfloat(cw), openvg.VGfloat(ch)
	// scroll the text, only in the clipping rectangle
	for x = 0; x < rw+speed; x += speed {
		openvg.Start(w, h)
		openvg.Background(255, 255, 255)
		openvg.FillRGB(0, 0, 0, .2)
		openvg.Rect(rx, ry, rw, rh)
		openvg.ClipRect(cx, cy, cw, ch)
		openvg.Translate(x, ry+openvg.VGfloat(fontsize/2))
		openvg.FillRGB(0, 0, 0, 1)
		openvg.Text(0, 0, message, "sans", fontsize)
		openvg.ClipEnd()
		openvg.End()
	}
	bufio.NewReader(os.Stdin).ReadBytes('\n')
	openvg.Finish()
	os.Exit(0)
}

// tb draws a block of text
func tb(w, h int) {
	para := []string{
		"For lo,",
		"the winter is past,",
		"the rain is over and gone",
		"the flowers appear on the earth;",
		"the time for the singing of birds is come,",
		"and the voice of the turtle is heard in our land",
	}

	tmargin := float64(w) * 0.50
	lmargin := float64(w) * 0.10
	top := float64(h) * .9
	mid := float64(h) * .6
	bot := float64(h) * .3

	fontsize := 24
	leading := 40.0
	lfontsize := fontsize * 2
	midb := ((leading * 2) + (leading / 2)) - float64(lfontsize/2)

	openvg.Start(w, h)
	openvg.FillRGB(49, 79, 79, 1)
	textlines(tmargin, top, para, "serif", fontsize, leading)
	textlines(tmargin, mid, para, "sans", fontsize, leading)
	textlines(tmargin, bot, para, "mono", fontsize, leading)
	openvg.Text(lmargin, top-midb, "Serif", "sans", lfontsize)
	openvg.Text(lmargin, mid-midb, "Sans", "sans", lfontsize)
	openvg.Text(lmargin, bot-midb, "Mono", "sans", lfontsize)
	openvg.End()
}

func paintBG(w, h openvg.VGfloat) {
	if !showTrails {
		openvg.Background(0, 0, 0)
		return
	}
	openvg.FillRGB(0, 0, 0, 0.3)
	openvg.Rect(0, 0, w, h)
}

// sunearth shows the relative sizes of the sun and the earth
func sunearth(w, h int) {
	var sun, earth, x, y float64

	openvg.Start(w, h)
	openvg.Background(0, 0, 0)
	openvg.FillRGB(255, 255, 255, 1)
	for i := 0; i < w/4; i++ {
		x = randf(w)
		y = randf(h)
		openvg.Circle(x, y, 2)
	}
	earth = float64(w) * 0.010
	sun = earth * 109
	openvg.FillRGB(0, 0, 255, 1)
	openvg.Circle(float64(w/3), float64(h-(h/10)), earth)
	openvg.FillRGB(255, 255, 224, 1)
	openvg.Circle(float64(w), 0, sun)
	openvg.End()
}

// advert is an ad for the package
func advert(w, h int) {
	y := (6 * float64(h)) / 10
	fontsize := (w * 4) / 100
	f3 := fontsize / 3
	s := "github.com/ajstarks/openvg"
	a := "[email protected]"

	imw := 110
	imh := 110
	midx := float64(w / 2)

	openvg.Start(w, h)
	openvg.FillRGB(128, 0, 0, 1)
	openvg.TextMid(midx, y-float64(fontsize/4), s, "sans", fontsize)
	y -= 150
	openvg.FillRGB(128, 128, 128, 1)
	openvg.TextMid(midx, y, a, "sans", f3)
	openvg.Image(float64(w/2)-float64(imw/2), y-float64(imh*2), imw, imh, "starx.jpg")
	openvg.End()
}

// raspberry pi, scaled to the screen dimensions
func raspi(w, h int, s string) {
	midx := float64(w) / 2
	midy := float64(h) / 2
	rw := midx
	rh := (rw * 2) / 3
	fontsize := w / 25
	openvg.Start(w, h)
	openvg.Background(255, 255, 255)
	makepi(midx-(rw/2), midy-(rh/2), rw, rh)
	openvg.FillRGB(128, 0, 0, 1)
	openvg.TextMid(midx, midy-(rh/2)-float64(fontsize*2), s, "sans", fontsize)
	openvg.End()
}

func imagetable(w, h int) {
	imgw, imgh := 422, 238
	itable := []it{
		{"desert0.jpg", imgw, imgh},
		{"desert1.jpg", imgw, imgh},
		{"desert2.jpg", imgw, imgh},
		{"desert3.jpg", imgw, imgh},
		{"desert4.jpg", imgw, imgh},
		{"desert5.jpg", imgw, imgh},
		{"desert6.jpg", imgw, imgh},
		{"desert7.jpg", imgw, imgh},
		//{"http://farm4.static.flickr.com/3546/3338566612_9c56bfb53e_m.jpg", 240, 164},
		//{"http://farm4.static.flickr.com/3642/3337734413_e36baba755_m.jpg", 240, 164},
	}
	offset := openvg.VGfloat(50)
	left := offset
	bot := openvg.VGfloat(h-imgh) - offset
	gutter := offset
	x := left
	y := bot
	openvg.Start(w, h)
	openvg.BackgroundColor("black")
	for _, iname := range itable {
		openvg.Image(x, y, iname.width, iname.height, iname.name)
		openvg.FillRGB(255, 255, 255, 0.3)
		openvg.Rect(x, y, openvg.VGfloat(imgw), 32)
		openvg.FillRGB(0, 0, 0, 1)
		openvg.TextMid(x+openvg.VGfloat(imgw/2), y+10, iname.name, "sans", 16)
		x += openvg.VGfloat(iname.width) + gutter
		if x > openvg.VGfloat(w) {
			x = left
			y -= openvg.VGfloat(iname.height) + gutter
		}
	}
	y = openvg.VGfloat(h) * 0.1
	openvg.FillRGB(128, 128, 128, 1)
	openvg.TextMid(openvg.VGfloat(w/2), 100, "Joshua Tree National Park", "sans", 48)
	openvg.End()
}

//planets is an exploration of scale
func planets(width, height int, message string) {

	w := float64(width)
	h := float64(height)
	y := h / 2

	margin := 100.0
	minsize := 7.0
	labeloc := 100.0
	bgcolor := "black"
	labelcolor := "white"
	maxsize := (h / 2) * 0.05

	origin := sun.distance
	mostDistant := neptune.distance
	firstSize := mercury.radius
	lastSize := neptune.radius

	openvg.Start(width, height)
	openvg.BackgroundColor(bgcolor)

	for _, p := range SolarSystem {
		x := vmap(p.distance, origin, mostDistant, margin, w-margin)
		r := vmap(p.radius, firstSize, lastSize, minsize, maxsize)

		if p.name == "Sun" {
			openvg.FillRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
			openvg.Circle(margin-(r/2), y, r)
		} else {
			light(x, y, r, p.color)
			openvg.Circle(x, y, r)
			if p.name == "Saturn" {
				ringwidth := r * 2.35 // Saturn's rings are over 2x the planet radius
				openvg.StrokeWidth(3)
				openvg.StrokeRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
				openvg.Line((x - ringwidth/2), y, (x + ringwidth/2), y)
				openvg.StrokeWidth(0)
			}
		}
		if p.name == "Earth" && len(message) > 1 {
			openvg.StrokeColor(labelcolor)
			openvg.StrokeWidth(1)
			openvg.Line(x, y+(r/2), x, y+labeloc)
			openvg.StrokeWidth(0)
			openvg.FillColor(labelcolor)
			openvg.TextMid(x, y+labeloc+10, message, "sans", 12)
		}
	}
	openvg.End()
}

// advert is an ad for the package
func advert(w, h int) {
	y := float64(h) / 4
	fontsize := (w * 4) / 100
	f3 := fontsize / 3
	s := "github.com/ajstarks/openvg"
	a := "[email protected]"

	imw := 110
	imh := 110
	rw := float64(w / 4)
	rh := (rw * 2) / 3
	midx := float64(w / 2)

	openvg.Start(w, h)
	makepi(midx-float64(rw/2), float64(h/2), rw, rh)
	openvg.FillRGB(128, 0, 0, 1)
	openvg.TextMid(midx, y-float64(fontsize/4), s, "sans", fontsize)
	y -= 100
	openvg.FillRGB(128, 128, 128, 1)
	openvg.TextMid(midx, y, a, "sans", f3)
	openvg.Image(float64(w/2)-float64(imw/2), 20, imw, imh, "starx.jpg")
	openvg.End()
}

func draw(w, h openvg.VGfloat) {
	paintBG(w, h)

	var p particle
	var grav = openvg.VGfloat(gravity)
	for i := 0; i < nparticles; i++ {
		p = particles[i]
		openvg.FillRGB(p.r, p.g, p.b, 1)
		openvg.Circle(p.x, p.y, p.radius)

		// Apply the velocity
		p.x += p.vx
		p.y += p.vy

		p.vx *= 0.98
		if p.vy > 0 {
			p.vy *= 0.97
		}

		// Gravity
		p.vy -= grav

		// Stop p leaving the canvas
		if p.x < -50 {
			p.x = w + 50
		}
		if p.x > w+50 {
			p.x = -50
		}

		// When particle reaches the bottom of screen reset velocity & start posn
		if p.y < -50 {
			p.x = 0
			p.y = 0
			p.vx = openvg.VGfloat(rand.Intn(maxrand)%30) + 30
			p.vy = openvg.VGfloat(rand.Intn(maxrand)%20) + 40

			if directionRTL {
				p.vx *= -1
				p.x = w
			}
		}

		if p.y > h+50 {
			p.y = -50
		}
		particles[i] = p
	}
	openvg.End()
}

// fontrange shows a range of fonts
func fontrange(w, h int) {
	var x, lx, length float64
	y := float64(h) / 2.0
	w2 := float64(w) / 2.0
	spacing := 50.0
	s2 := spacing / 2.0
	sizes := []int{6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 21, 24, 36, 48, 60, 72, 96}

	openvg.Start(w, h)
	openvg.Background(255, 255, 255)

	// compute the length so we can center
	length = 0.0
	for _, s := range sizes {
		length += float64(s) + spacing
	}
	length -= spacing
	lx = w2 - (length / 2) // center point

	// for each size, display a character and label
	x = lx
	for _, s := range sizes {
		openvg.FillRGB(128, 0, 0, 1)
		openvg.TextMid(x, y, "a", "serif", s)
		openvg.FillRGB(128, 128, 128, 1)
		openvg.TextMid(x, y-spacing, fmt.Sprintf("%d", s), "sans", 16)
		x += float64(s) + spacing
	}
	// draw a openvg.Line below the characters, a curve above
	x -= spacing
	openvg.StrokeRGB(150, 150, 150, 0.5)
	openvg.StrokeWidth(2)
	openvg.Line(lx, y-s2, x, y-s2)
	openvg.FillRGB(255, 255, 255, 1)
	openvg.Qbezier(lx, y+s2, x, y+s2, x, y+(spacing*3))
	openvg.End()
}

// raspberry pi, scaled to the screen dimensions
func main() {
	w, h := openvg.Init()
	midx := openvg.VGfloat(w) / 2
	midy := openvg.VGfloat(h) / 2
	rw := midx
	rh := (rw * 2) / 3
	fontsize := w / 25
	openvg.Start(w, h)
	openvg.Background(255, 255, 255)
	makepi(midx-(rw/2), midy-(rh/2), rw, rh)
	makepi(200, 100, 75, 50)
	openvg.FillRGB(128, 0, 0, 1)
	openvg.TextMid(midx, midy-(rh/2)-openvg.VGfloat(fontsize*2), "The Raspberry Pi", "sans", fontsize)
	WaitEnd()
}

func imagetable(w, h int) {
	imgw, imgh := 422, 238
	itable := []string{
		"desert0.jpg",
		"desert1.jpg",
		"desert2.jpg",
		"desert3.jpg",
		"desert4.jpg",
		"desert5.jpg",
		"desert6.jpg",
		"desert7.jpg",
	}
	left := 50.0
	bot := float64(h-imgh) - 50.0
	gutter := 50.0
	x := left
	y := bot
	openvg.Start(w, h)
	openvg.BackgroundColor("black")
	for _, iname := range itable {
		openvg.Image(x, y, imgw, imgh, iname)
		openvg.FillRGB(255, 255, 255, 0.3)
		openvg.Rect(x, y, float64(imgw), 32)
		openvg.FillRGB(0, 0, 0, 1)
		openvg.TextMid(x+float64(imgw/2), y+10, iname, "sans", 16)
		x += float64(imgw) + gutter
		if x > float64(w) {
			x = left
			y -= float64(imgh) + gutter
		}
	}
	y = float64(h) * 0.1
	openvg.FillRGB(128, 128, 128, 1)
	openvg.TextMid(float64(w/2), 100, "Joshua Tree National Park", "sans", 48)
	openvg.End()
}

func main() {

	width, height := openvg.Init()

	w := openvg.VGfloat(width)
	h := openvg.VGfloat(height)
	y := h / 2
	var (
		margin  openvg.VGfloat = 100.0
		minsize openvg.VGfloat = 7.0
		labeloc openvg.VGfloat = 100.0
	)
	bgcolor := "black"
	labelcolor := "white"
	maxsize := (h / 2) * 0.05

	origin := sun.distance
	mostDistant := neptune.distance
	firstSize := mercury.radius
	lastSize := neptune.radius

	openvg.Start(width, height)
	openvg.BackgroundColor(bgcolor)

	for _, p := range solarSystem {
		x := vmap(p.distance, origin, mostDistant, margin, w-margin)
		r := vmap(p.radius, firstSize, lastSize, minsize, maxsize)

		if p.name == "Sun" {
			openvg.FillRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
			openvg.Circle(margin-(r/2), y, r)
		} else {
			light(x, y, r, p.color)
			openvg.Circle(x, y, r)
		}
		if p.name == "Earth" && len(os.Args) > 1 {
			openvg.StrokeColor(labelcolor)
			openvg.StrokeWidth(1)
			openvg.Line(x, y+(r/2), x, y+labeloc)
			openvg.StrokeWidth(0)
			openvg.FillColor(labelcolor)
			openvg.TextMid(x, y+labeloc+10, os.Args[1], "sans", 12)
		}
	}
	openvg.End()
	bufio.NewReader(os.Stdin).ReadByte()
	openvg.Finish()
}

// makepi draws the Raspberry Pi
func makepi(x, y, w, h openvg.VGfloat) {
	// dimensions
	socw := h / 5
	compw := h / 5
	cjw := h / 10
	cjh := h / 8
	audw := h / 5
	aujw := h / 10
	aujh := cjh / 2
	hdw := w / 6
	hdh := w / 10
	gpw := w / 3
	gph := h / 8
	pw := h / 10
	usw := w / 5
	ush := h / 5
	etw := w / 5
	eth := h / 5
	sdw := w / 6
	sdh := w / 4
	offset := (w / 2) / 10
	w34 := (w * 3) / 4
	w2 := w / 2
	h2 := h / 2
	h40 := (h * 2) / 5

	openvg.FillRGB(0, 128, 0, 1)
	openvg.Rect(x, y, w, h) // board

	openvg.FillRGB(255, 255, 0, 1)
	openvg.Rect(x+w2, (y+h)-compw, compw, compw) // composite
	openvg.FillRGB(192, 192, 192, 1)
	openvg.Rect(x+w2+(cjw/2), y+h, cjw, cjh) // composite jack

	openvg.FillRGB(0, 0, 0, 1)
	openvg.Rect(x+w34, y+h-audw, audw, audw)     // audio
	openvg.Rect(x+w34+(aujw/2), y+h, aujw, aujh) // audio jack

	openvg.FillRGB(192, 192, 192, 1)
	openvg.Rect(x+w2, y, hdw, hdh)                 // HDMI
	openvg.Rect((x+w)-etw, y, etw, eth)            // Ethernet
	openvg.Rect((x+w+offset)-usw, y+h40, usw, ush) // USB
	openvg.Rect(x, y, pw, pw)                      // Power

	openvg.FillRGB(0, 0, 0, 1)
	openvg.Rect(x+(w*2)/5, y+h40, socw, socw) // SoC
	openvg.Rect(x, (y+h)-gph, gpw, gph)       // GPIO
	openvg.FillRGB(0, 0, 255, 1)
	openvg.Rect(x-sdw, (y+h2)-(sdh/2), sdw, sdh) // SD card
}

func main() {
	width, height := openvg.Init() // OpenGL, etc initialization

	w2 := float64(width / 2)
	h2 := float64(height / 2)
	w := float64(width)

	openvg.Start(width, height)                               // Start the picture
	openvg.BackgroundColor("black")                           // Black background
	openvg.FillRGB(44, 77, 232, 1)                            // Big blue marble
	openvg.Circle(w2, 0, w)                                   // The "world"
	openvg.FillColor("white")                                 // White text
	openvg.TextMid(w2, h2, "hello, world", "serif", width/10) // Greetings
	openvg.SaveEnd("hello.raw")                               // End the picture
	bufio.NewReader(os.Stdin).ReadBytes('\n')                 // Pause until [RETURN]
	openvg.Finish()                                           // Graphics cleanup
}

func gradient(width, height int) {
	w := float64(width)
	h := float64(height)
	stops := []openvg.Offcolor{
		{0.0, openvg.RGB{255, 255, 255}, 1.0},
		{0.5, openvg.RGB{128, 128, 128}, 1.0},
		{1.0, openvg.RGB{0, 0, 0}, 1.0},
	}

	x1 := w / 8
	x2 := (w * 3) / 8
	y1 := h / 3
	y2 := (h * 2) / 3
	cx := (w * 3) / 4
	cy := (h / 2)
	r := (x2 - x1)
	fx := cx + (r / 4)
	fy := cy + (r / 4)
	openvg.Start(width, height)
	openvg.BackgroundRGB(128, 128, 128, 1)
	openvg.FillLinearGradient(x1, y1, x2, y2, stops)
	openvg.Rect(x1, y1, x2-x1, y2-y1)
	openvg.FillRadialGradient(cx, cy, fx, fy, r, stops)
	openvg.Circle(cx, cy, r)

	openvg.FillRGB(0, 0, 0, 0.3)
	openvg.Circle(x1, y1, 10)
	openvg.Circle(x2, y2, 10)
	openvg.Circle(cx, cy, 10)
	openvg.Circle(cx+r/2, cy, 10)
	openvg.Circle(fx, fy, 10)

	openvg.FillColor("black")
	SansTypeface := "sans"
	openvg.TextMid(x1, y1-20, "(x1, y1)", SansTypeface, 18)
	openvg.TextMid(x2, y2+10, "(x2, y2)", SansTypeface, 18)
	openvg.TextMid(cx, cy, "(cx, cy)", SansTypeface, 18)
	openvg.TextMid(fx, fy, "(fx, fy)", SansTypeface, 18)
	openvg.TextEnd(cx+(r/2)+20, cy, "r", SansTypeface, 18)

	openvg.TextMid(x1+((x2-x1)/2), h/6, "Linear Gradient", SansTypeface, 36)
	openvg.TextMid(cx, h/6, "Radial Gradient", SansTypeface, 36)
	openvg.End()
}

// rotext draws text, rotated around the center of the screen, progressively faded
func rotext(w, h, n int, s string) {
	fade := (100.0 / float64(n)) / 100.0
	deg := 360.0 / float64(n)
	x := float64(w) / 2.0
	y := float64(h) / 2.0
	alpha := 1.0
	size := w / 8

	openvg.Start(w, h)
	openvg.Background(0, 0, 0)
	openvg.Translate(x, y)
	for i := 0; i < n; i++ {
		openvg.FillRGB(255, 255, 255, alpha)
		openvg.Text(0, 0, s, "serif", size)
		alpha -= fade // fade
		size += n     // enlarge
		openvg.Rotate(deg)
	}
	openvg.End()
}

// testpattern shows a test pattern
func testpattern(w, h int, s string) {
	var midx, midy1, midy2, midy3 float64
	fontsize := 256
	h2 := float64(h / 2)
	by := float64(h - 100)
	bx := float64(w - 100)
	tw1 := &FW{"mono", 0, fontsize}
	tw2 := &FW{"sans", 0, fontsize}
	tw3 := &FW{"serif", 0, fontsize}

	openvg.Start(w, h)

	// colored squares in the corners
	openvg.FillRGB(255, 0, 0, 1)
	openvg.Rect(0, 0, 100, 100)
	openvg.FillRGB(0, 255, 0, 1)
	openvg.Rect(0, by, 100, 100)
	openvg.FillRGB(0, 0, 255, 1)
	openvg.Rect(bx, 0, 100, 100)
	openvg.FillRGB(128, 128, 128, 1)
	openvg.Rect(bx, by, 100, 100)

	// for each font, (Sans, Serif, Mono), adjust the string to the w
	tw1.fitwidth(w, 20, s)
	tw2.fitwidth(w, 20, s)
	tw3.fitwidth(w, 20, s)

	midx = float64(w / 2)

	// Adjust the baselines to be medial
	midy1 = h2 + 20 + float64((tw1.fontsize)/2)
	midy2 = h2 - float64((tw2.fontsize)/2)
	midy3 = h2 - 20 - float64(tw2.fontsize) - float64((tw3.fontsize)/2)

	openvg.FillRGB(128, 128, 128, 1)
	openvg.TextMid(midx, midy1, s, tw1.font, tw1.fontsize)
	openvg.FillRGB(128, 0, 0, 1)
	openvg.TextMid(midx, midy2, s, tw2.font, tw2.fontsize)
	openvg.FillRGB(0, 0, 128, 1)
	openvg.TextMid(midx, midy3, s, tw3.font, tw3.fontsize)
	openvg.End()
}