// Main draws "Hello World" and returns the filename. This should only be
// used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
// Draw hello world
Draw(gc, fmt.Sprintf("Hello World %d dpi", gc.GetDPI()))
// Return the output filename
return samples.Output("helloworld", ext), nil
}
func (h *spaceFillingImage) drawSnake(gc draw2d.GraphicContext, snake *draw2d.Path) {
gc.SetStrokeColor(h.SnakeColor)
gc.SetLineCap(draw2d.SquareCap)
gc.SetLineJoin(draw2d.MiterJoin)
gc.SetLineWidth(2)
gc.Stroke(snake)
}
// UseImageWithContext specifies both an image
// and a graphic context to create the canvas from.
// The minimum point of the given image
// should probably be 0,0.
func UseImageWithContext(img draw.Image, gc draw2d.GraphicContext) option {
return func(c *Canvas) uint32 {
c.img = img
c.gc = gc
c.dpi = gc.GetDPI()
return setsDPI | setsSize
}
}
func lineCircle(gc d2d.GraphicContext, cx, cy, r float64) {
count := int(1000.0 * r)
trace := traceCircle(count, cx, cy, r)
gc.MoveTo(cx+r, cy)
for _, pos := range trace {
gc.LineTo(pos.X, pos.Y)
}
}
func (ps *PolygonSymbolizer) Draw(gc draw2d.GraphicContext, shape geom.Shape) {
if !ps.Applies(shape) {
return
}
if polygon, ok := shape.(geom.PolygonShape); ok {
gc.SetFillColor(ps.s.Fill)
for _, path := range polygon.Polygon() {
l := ps.r.coordsAsPath(path)
gc.Fill(l)
}
}
}
func (c squareplot) draw(gc d2d.GraphicContext) {
for _, cb := range c.boxes {
gc.SetStrokeColor(black)
gc.SetFillColor(clear)
gc.SetLineWidth(1.0)
side := cb.Radius / 2.0
lineSquare(gc, cb.P.X, cb.P.Y, side)
gc.Close()
gc.FillStroke()
}
}
// Draw "Hello World"
func Draw(gc draw2d.GraphicContext, text string) {
// Draw a rounded rectangle using default colors
draw2dkit.RoundedRectangle(gc, 5, 5, 135, 95, 10, 10)
gc.FillStroke()
// Set the font luximbi.ttf
gc.SetFontData(draw2d.FontData{Name: "luxi", Family: draw2d.FontFamilyMono, Style: draw2d.FontStyleBold | draw2d.FontStyleItalic})
// Set the fill text color to black
gc.SetFillColor(image.Black)
gc.SetFontSize(14)
// Display Hello World
gc.FillStringAt("Hello World", 8, 52)
}
// Main draws vertically spaced lines and returns the filename.
// This should only be used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
gc.SetFillRule(draw2d.FillRuleWinding)
gc.Clear()
// Draw the line
for x := 5.0; x < 297; x += 10 {
Draw(gc, x, 0, x, 210)
}
gc.ClearRect(100, 75, 197, 135)
draw2d.Ellipse(gc, 148.5, 105, 35, 25)
gc.SetFillColor(color.RGBA{0xff, 0xff, 0x44, 0xff})
gc.FillStroke()
// Return the output filename
return samples.Output("line", ext), nil
}
func (h *spaceFillingImage) drawRectange(gc draw2d.GraphicContext, px1, py1, px2, py2 float64) {
gc.SetFillColor(h.BackgroundColor)
gc.SetStrokeColor(h.GridColor)
gc.SetLineWidth(1)
draw2dkit.Rectangle(gc, px1, py1, px2, py2)
gc.FillStroke()
}
func (ex exploder) draw(gc d2d.GraphicContext) {
for _, b := range ex.bombs {
c := ex.palette.Get(b.Color)
// alpha := b.Intensity / 2
trans := color.RGBA{c.R, c.G, c.B, 255}
gc.SetStrokeColor(trans)
gc.SetFillColor(trans)
gc.SetLineWidth(1.0)
lineCircle(gc, b.P.X, b.P.Y, b.Radius)
gc.Close()
gc.Stroke()
}
}
func Plot(g draw2d.GraphicContext, points []Point) {
g.MoveTo(0, 0)
for _, p := range points {
g.LineTo(p.x*100, p.y*100)
}
g.Close()
g.FillStroke()
}
// Main draws the tiger
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
gc.Save()
// flip the image
gc.Translate(0, 200)
gc.Scale(0.35, -0.35)
gc.Translate(70, -200)
// Tiger postscript drawing
tiger := samples.Resource("image", "tiger.ps", ext)
// Draw tiger
Draw(gc, tiger)
gc.Restore()
// Return the output filename
return samples.Output("postscript", ext), nil
}
func (ts *TextSymbolizer) Draw(gc draw2d.GraphicContext, shape geom.Shape) {
if !ts.Applies(shape) {
return
}
if name := shape.Attribute(ts.s.Attr); name != "" {
gc.SetFontSize(ts.s.Size)
l, t, r, b := gc.GetStringBounds(name)
bb := shape.Bbox()
dx := math.Abs(bb[2] - bb[0])
dy := math.Abs(bb[3] - bb[1])
ox, oy := dx/2, dy/2
x, y := ts.r.matrix.TransformPoint(bb[0]+ox, bb[1]-oy)
gc.SetFillColor(ts.s.Fill)
gc.FillStringAt(name, x-(r-l)/2, y-(t-b)/2)
}
}
func (ps *PathSymbolizer) Draw(gc draw2d.GraphicContext, shape geom.Shape) {
if !ps.Applies(shape) {
return
}
gc.SetStrokeColor(ps.s.Stroke)
gc.SetLineWidth(ps.s.Weight)
switch specific := shape.(type) {
case geom.LineShape:
l := ps.r.coordsAsPath(specific.Path())
gc.Stroke(l)
case geom.MultiLineShape:
for _, path := range specific.Paths() {
l := ps.r.coordsAsPath(path)
gc.Stroke(l)
}
}
}
// Main draws a left hand and ear of a gopher. Afterwards it returns
// the filename. This should only be used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
gc.Save()
gc.Scale(0.5, 0.5)
// Draw a (partial) gopher
Draw(gc)
gc.Restore()
// Return the output filename
return samples.Output("gopher", ext), nil
}
func lineSquare(gc d2d.GraphicContext, x, y, side float64) {
xmin, ymin := x-side, y-side
xmax, ymax := x+side, y+side
gc.MoveTo(xmin, ymin)
gc.LineTo(xmin, ymax)
gc.LineTo(xmax, ymax)
gc.LineTo(xmax, ymin)
gc.LineTo(xmin, ymin)
}
func drawText(gc draw2d.GraphicContext, text string, x, y float64) {
var fontSize float64 = 14
fontSizeHeight := fontSize + 14
if y < fontSizeHeight {
return
}
gc.SetFontData(draw2d.FontData{Name: "luxi", Family: draw2d.FontFamilyMono, Style: draw2d.FontStyleNormal})
// Set the fill text color to black
gc.SetFillColor(image.Black)
gc.SetFontSize(fontSize)
// 9px width each letter and 2px letter spacing at font-size 14
var yPos float64
for ; yPos < y; yPos = yPos + fontSizeHeight {
gc.FillStringAt(text, x, yPos)
}
}
func (h *spaceFillingImage) drawText(gc draw2d.GraphicContext, px1, py1 float64, t int) {
if !h.DrawText {
return
}
text := strconv.Itoa(t)
_, top, _, _ := gc.GetStringBounds(text)
gc.SetFillColor(h.TextColor)
gc.FillStringAt(text, px1+h.TextMargin, py1-top+h.TextMargin)
}
// Arc draws a link between two points
func Arc(gc draw2d.GraphicContext, x, y1, y2 float64) {
// Center
yc := (y1 + y2) / 2
// x radius
xRadius := y2 - y1
// y radius
yRadius := y2 - yc
// Start at -45 degrees
startAngle := -math.Pi / 2
// 180 degrees = half a circle
angle := math.Pi
gc.ArcTo(x, yc, xRadius, yRadius, startAngle, angle)
gc.Stroke()
gc.Fill()
}
// Draw a left hand and ear of a gopher using a gc thanks to
// https://github.com/golang-samples/gopher-vector/
func Draw(gc draw2d.GraphicContext) {
// Initialize Stroke Attribute
gc.SetLineWidth(3)
gc.SetLineCap(draw2d.RoundCap)
gc.SetStrokeColor(color.Black)
// Left hand
// <path fill-rule="evenodd" clip-rule="evenodd" fill="#F6D2A2" stroke="#000000" stroke-width="3" stroke-linecap="round" d="
// M10.634,300.493c0.764,15.751,16.499,8.463,23.626,3.539c6.765-4.675,8.743-0.789,9.337-10.015
// c0.389-6.064,1.088-12.128,0.744-18.216c-10.23-0.927-21.357,1.509-29.744,7.602C10.277,286.542,2.177,296.561,10.634,300.493"/>
gc.SetFillColor(color.RGBA{0xF6, 0xD2, 0xA2, 0xff})
gc.MoveTo(10.634, 300.493)
gc.RCubicCurveTo(0.764, 15.751, 16.499, 8.463, 23.626, 3.539)
gc.RCubicCurveTo(6.765, -4.675, 8.743, -0.789, 9.337, -10.015)
gc.RCubicCurveTo(0.389, -6.064, 1.088, -12.128, 0.744, -18.216)
gc.RCubicCurveTo(-10.23, -0.927, -21.357, 1.509, -29.744, 7.602)
gc.CubicCurveTo(10.277, 286.542, 2.177, 296.561, 10.634, 300.493)
gc.FillStroke()
// <path fill-rule="evenodd" clip-rule="evenodd" fill="#C6B198" stroke="#000000" stroke-width="3" stroke-linecap="round" d="
// M10.634,300.493c2.29-0.852,4.717-1.457,6.271-3.528"/>
gc.MoveTo(10.634, 300.493)
gc.RCubicCurveTo(2.29, -0.852, 4.717, -1.457, 6.271, -3.528)
gc.Stroke()
// Left Ear
// <path fill-rule="evenodd" clip-rule="evenodd" fill="#6AD7E5" stroke="#000000" stroke-width="3" stroke-linecap="round" d="
// M46.997,112.853C-13.3,95.897,31.536,19.189,79.956,50.74L46.997,112.853z"/>
gc.MoveTo(46.997, 112.853)
gc.CubicCurveTo(-13.3, 95.897, 31.536, 19.189, 79.956, 50.74)
gc.LineTo(46.997, 112.853)
gc.Close()
gc.Stroke()
}
// ArcNegative draws an arc with a negative angle (anti clockwise).
func ArcNegative(gc draw2d.GraphicContext, xc, yc, width, height float64) {
xc += width / 2
yc += height / 2
radiusX, radiusY := width/2, height/2
startAngle := 45.0 * (math.Pi / 180.0) /* angles are specified */
angle := -225 * (math.Pi / 180.0) /* clockwise in radians */
gc.SetLineWidth(width / 10)
gc.SetLineCap(draw2d.ButtCap)
gc.SetStrokeColor(image.Black)
gc.ArcTo(xc, yc, radiusX, radiusY, startAngle, angle)
gc.Stroke()
// fill a circle
gc.SetStrokeColor(color.NRGBA{255, 0x33, 0x33, 0x80})
gc.SetFillColor(color.NRGBA{255, 0x33, 0x33, 0x80})
gc.SetLineWidth(width / 20)
gc.MoveTo(xc+math.Cos(startAngle)*radiusX, yc+math.Sin(startAngle)*radiusY)
gc.LineTo(xc, yc)
gc.LineTo(xc-radiusX, yc)
gc.Stroke()
gc.ArcTo(xc, yc, width/10.0, height/10.0, 0, 2*math.Pi)
gc.Fill()
}
// CurveRectangle draws a rectangle with bezier curves (not rounded rectangle).
func CurveRectangle(gc draw2d.GraphicContext, x0, y0,
rectWidth, rectHeight float64, stroke, fill color.Color) {
radius := (rectWidth + rectHeight) / 4
x1 := x0 + rectWidth
y1 := y0 + rectHeight
if rectWidth/2 < radius {
if rectHeight/2 < radius {
gc.MoveTo(x0, (y0+y1)/2)
gc.CubicCurveTo(x0, y0, x0, y0, (x0+x1)/2, y0)
gc.CubicCurveTo(x1, y0, x1, y0, x1, (y0+y1)/2)
gc.CubicCurveTo(x1, y1, x1, y1, (x1+x0)/2, y1)
gc.CubicCurveTo(x0, y1, x0, y1, x0, (y0+y1)/2)
} else {
gc.MoveTo(x0, y0+radius)
gc.CubicCurveTo(x0, y0, x0, y0, (x0+x1)/2, y0)
gc.CubicCurveTo(x1, y0, x1, y0, x1, y0+radius)
gc.LineTo(x1, y1-radius)
gc.CubicCurveTo(x1, y1, x1, y1, (x1+x0)/2, y1)
gc.CubicCurveTo(x0, y1, x0, y1, x0, y1-radius)
}
} else {
if rectHeight/2 < radius {
gc.MoveTo(x0, (y0+y1)/2)
gc.CubicCurveTo(x0, y0, x0, y0, x0+radius, y0)
gc.LineTo(x1-radius, y0)
gc.CubicCurveTo(x1, y0, x1, y0, x1, (y0+y1)/2)
gc.CubicCurveTo(x1, y1, x1, y1, x1-radius, y1)
gc.LineTo(x0+radius, y1)
gc.CubicCurveTo(x0, y1, x0, y1, x0, (y0+y1)/2)
} else {
gc.MoveTo(x0, y0+radius)
gc.CubicCurveTo(x0, y0, x0, y0, x0+radius, y0)
gc.LineTo(x1-radius, y0)
gc.CubicCurveTo(x1, y0, x1, y0, x1, y0+radius)
gc.LineTo(x1, y1-radius)
gc.CubicCurveTo(x1, y1, x1, y1, x1-radius, y1)
gc.LineTo(x0+radius, y1)
gc.CubicCurveTo(x0, y1, x0, y1, x0, y1-radius)
}
}
gc.Close()
gc.SetStrokeColor(stroke)
gc.SetFillColor(fill)
gc.SetLineWidth(10.0)
gc.FillStroke()
}
// Dash draws a line with a dash pattern
func Dash(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/162, height/205
gc.SetStrokeColor(image.Black)
gc.SetLineDash([]float64{height / 10, height / 50, height / 50, height / 50}, -50.0)
gc.SetLineCap(draw2d.ButtCap)
gc.SetLineJoin(draw2d.RoundJoin)
gc.SetLineWidth(height / 50)
gc.MoveTo(x+sx*60.0, y)
gc.LineTo(x+sx*60.0, y)
gc.LineTo(x+sx*162, y+sy*205)
gc.RLineTo(sx*-102.4, 0.0)
gc.CubicCurveTo(x+sx*-17, y+sy*205, x+sx*-17, y+sy*103, x+sx*60.0, y+sy*103.0)
gc.Stroke()
gc.SetLineDash(nil, 0.0)
}
// Bubble draws a text balloon.
func Bubble(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/100, height/100
gc.MoveTo(x+sx*50, y)
gc.QuadCurveTo(x, y, x, y+sy*37.5)
gc.QuadCurveTo(x, y+sy*75, x+sx*25, y+sy*75)
gc.QuadCurveTo(x+sx*25, y+sy*95, x+sx*5, y+sy*100)
gc.QuadCurveTo(x+sx*35, y+sy*95, x+sx*40, y+sy*75)
gc.QuadCurveTo(x+sx*100, y+sy*75, x+sx*100, y+sy*37.5)
gc.QuadCurveTo(x+sx*100, y, x+sx*50, y)
gc.Stroke()
}
// Star draws many lines from a center.
func Star(gc draw2d.GraphicContext, x, y, width, height float64) {
gc.Save()
gc.Translate(x+width/2, y+height/2)
gc.SetLineWidth(width / 40)
for i := 0.0; i < 360; i = i + 10 { // Go from 0 to 360 degrees in 10 degree steps
gc.Save() // Keep rotations temporary
gc.Rotate(i * (math.Pi / 180.0)) // Rotate by degrees on stack from 'for'
gc.MoveTo(0, 0)
gc.LineTo(width/2, 0)
gc.Stroke()
gc.Restore()
}
gc.Restore()
}
// PathTransform scales a path differently in horizontal and vertical direction.
func PathTransform(gc draw2d.GraphicContext, x, y, width, height float64) {
gc.Save()
gc.SetLineWidth(width / 10)
gc.Translate(x+width/2, y+height/2)
gc.Scale(1, 4)
gc.ArcTo(0, 0, width/8, height/8, 0, math.Pi*2)
gc.Close()
gc.Stroke()
gc.Restore()
}
// FillStyle demonstrates the difference between even odd and non zero winding rule.
func FillStyle(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/232, height/220
gc.SetLineWidth(width / 40)
draw2d.Rect(gc, x+sx*0, y+sy*12, x+sx*232, y+sy*70)
wheel1 := new(draw2d.PathStorage)
wheel1.ArcTo(x+sx*52, y+sy*70, sx*40, sy*40, 0, 2*math.Pi)
wheel2 := new(draw2d.PathStorage)
wheel2.ArcTo(x+sx*180, y+sy*70, sx*40, sy*40, 0, -2*math.Pi)
gc.SetFillRule(draw2d.FillRuleEvenOdd)
gc.SetFillColor(color.NRGBA{0, 0xB2, 0, 0xFF})
gc.SetStrokeColor(image.Black)
gc.FillStroke(wheel1, wheel2)
draw2d.Rect(gc, x, y+sy*140, x+sx*232, y+sy*198)
wheel1 = new(draw2d.PathStorage)
wheel1.ArcTo(x+sx*52, y+sy*198, sx*40, sy*40, 0, 2*math.Pi)
wheel2 = new(draw2d.PathStorage)
wheel2.ArcTo(x+sx*180, y+sy*198, sx*40, sy*40, 0, -2*math.Pi)
gc.SetFillRule(draw2d.FillRuleWinding)
gc.SetFillColor(color.NRGBA{0, 0, 0xE5, 0xFF})
gc.FillStroke(wheel1, wheel2)
}
// FillStroke first fills and afterwards strokes a path.
func FillStroke(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/210, height/215
gc.MoveTo(x+sx*113.0, y)
gc.LineTo(x+sx*215.0, y+sy*215)
gc.RLineTo(sx*-100, 0)
gc.CubicCurveTo(x+sx*35, y+sy*215, x+sx*35, y+sy*113, x+sx*113.0, y+sy*113)
gc.Close()
gc.MoveTo(x+sx*50.0, y)
gc.RLineTo(sx*51.2, sy*51.2)
gc.RLineTo(sx*-51.2, sy*51.2)
gc.RLineTo(sx*-51.2, sy*-51.2)
gc.Close()
gc.SetLineWidth(width / 20.0)
gc.SetFillColor(color.NRGBA{0, 0, 0xFF, 0xFF})
gc.SetStrokeColor(image.Black)
gc.FillStroke()
}
// FillString draws a filled and stroked string.
func FillString(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/100, height/100
gc.Save()
gc.SetStrokeColor(image.Black)
gc.SetLineWidth(1)
draw2d.RoundRect(gc, x+sx*5, y+sy*5, x+sx*95, y+sy*95, sx*10, sy*10)
gc.FillStroke()
gc.SetFillColor(image.Black)
gc.SetFontSize(height / 6)
gc.Translate(x+sx*6, y+sy*52)
gc.SetFontData(draw2d.FontData{
Name: "luxi",
Family: draw2d.FontFamilyMono,
Style: draw2d.FontStyleBold | draw2d.FontStyleItalic})
w := gc.FillString("Hug")
gc.Translate(w+sx, 0)
left, top, right, bottom := gc.GetStringBounds("cou")
gc.SetStrokeColor(color.NRGBA{255, 0x33, 0x33, 0x80})
draw2d.Rect(gc, left, top, right, bottom)
gc.SetLineWidth(height / 50)
gc.Stroke()
gc.SetFillColor(color.NRGBA{0x33, 0x33, 0xff, 0xff})
gc.SetStrokeColor(color.NRGBA{0x33, 0x33, 0xff, 0xff})
gc.SetLineWidth(height / 100)
gc.StrokeString("Hug")
gc.Restore()
}
// CubicCurve draws a cubic curve with its control points.
func CubicCurve(gc draw2d.GraphicContext, x, y, width, height float64) {
sx, sy := width/162, height/205
x0, y0 := x, y+sy*100.0
x1, y1 := x+sx*75, y+sy*205
x2, y2 := x+sx*125, y
x3, y3 := x+sx*205, y+sy*100
gc.SetStrokeColor(image.Black)
gc.SetFillColor(color.NRGBA{0xAA, 0xAA, 0xAA, 0xFF})
gc.SetLineWidth(width / 10)
gc.MoveTo(x0, y0)
gc.CubicCurveTo(x1, y1, x2, y2, x3, y3)
gc.Stroke()
gc.SetStrokeColor(color.NRGBA{0xFF, 0x33, 0x33, 0x88})
gc.SetLineWidth(width / 20)
// draw segment of curve
gc.MoveTo(x0, y0)
gc.LineTo(x1, y1)
gc.LineTo(x2, y2)
gc.LineTo(x3, y3)
gc.Stroke()
}