// 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() }
// refcard shows a reference card of shapes func refcard(width, height int) { shapenames := []string{ "Circle", "Ellipse", "Rectangle", "Rounded Rectangle", "Line", "Polyline", "Polygon", "Arc", "Quadratic Bezier", "Cubic Bezier", "Image", } top := float64(height) * .95 sx := float64(width) * 0.10 sy := top sw := float64(width) * .05 sh := float64(height) * .045 dotsize := 7.0 spacing := 2.0 fontsize := int(float64(height) * .033) shapecolor := Color{202, 225, 255, 1.0} openvg.Start(width, height) openvg.FillRGB(128, 0, 0, 1) openvg.TextEnd(float64(width-20), float64(height/2), "OpenVG on the Raspberry Pi", "sans", fontsize+(fontsize/2)) openvg.FillRGB(0, 0, 0, 1) for _, s := range shapenames { openvg.Text(sx+sw+sw/2, sy, s, "sans", fontsize) sy -= sh * spacing } sy = top cx := sx + (sw / 2) ex := sx + sw openvg.FillRGB(shapecolor.red, shapecolor.green, shapecolor.blue, shapecolor.alpha) openvg.Circle(cx, sy, sw) coordpoint(cx, sy, dotsize, shapecolor) sy -= sh * spacing openvg.Ellipse(cx, sy, sw, sh) coordpoint(cx, sy, dotsize, shapecolor) sy -= sh * spacing openvg.Rect(sx, sy, sw, sh) coordpoint(sx, sy, dotsize, shapecolor) sy -= sh * spacing openvg.Roundrect(sx, sy, sw, sh, 20, 20) coordpoint(sx, sy, dotsize, shapecolor) sy -= sh * spacing openvg.StrokeWidth(1) openvg.StrokeRGB(204, 204, 204, 1) openvg.Line(sx, sy, ex, sy) coordpoint(sx, sy, dotsize, shapecolor) coordpoint(ex, sy, dotsize, shapecolor) sy -= sh px := []float64{sx, sx + (sw / 4), sx + (sw / 2), sx + ((sw * 3) / 4), sx + sw} py := []float64{sy, sy - sh, sy, sy - sh, sy} openvg.Polyline(px, py) // , 5) coordpoint(px[0], py[0], dotsize, shapecolor) coordpoint(px[1], py[1], dotsize, shapecolor) coordpoint(px[2], py[2], dotsize, shapecolor) coordpoint(px[3], py[3], dotsize, shapecolor) coordpoint(px[4], py[4], dotsize, shapecolor) sy -= sh * spacing py[0] = sy py[1] = sy - sh py[2] = sy - (sh / 2) py[3] = py[1] - (sh / 4) py[4] = sy openvg.Polygon(px, py) // , 5) sy -= (sh * spacing) + sh openvg.Arc(sx+(sw/2), sy, sw, sh, 0, 180) coordpoint(sx+(sw/2), sy, dotsize, shapecolor) sy -= sh * spacing var cy, ey float64 cy = sy + (sh / 2) ey = sy openvg.Qbezier(sx, sy, cx, cy, ex, ey) coordpoint(sx, sy, dotsize, shapecolor) coordpoint(cx, cy, dotsize, shapecolor) coordpoint(ex, ey, dotsize, shapecolor) sy -= sh * spacing ey = sy cy = sy + sh openvg.Cbezier(sx, sy, cx, cy, cx, sy, ex, ey) coordpoint(sx, sy, dotsize, shapecolor) coordpoint(cx, cy, dotsize, shapecolor) coordpoint(cx, sy, dotsize, shapecolor) coordpoint(ex, ey, dotsize, shapecolor) sy -= (sh * spacing * 1.5) openvg.Image(sx, sy, 110, 110, "starx.jpg") openvg.End() }