package draw2dgl import ( "image" "image/color" "image/draw" "runtime" "code.google.com/p/freetype-go/freetype/raster" "github.com/go-gl/gl/v2.1/gl" "gopkg.in/llgcode/draw2d.v1" ) func init() { runtime.LockOSThread() } type Painter struct { // The Porter-Duff composition operator. Op draw.Op // The 16-bit color to paint the spans. cr, cg, cb uint8 ca uint32 colors []uint8 vertices []int32 } const M16 uint32 = 1<<16 - 1 // Paint satisfies the Painter interface by painting ss onto an image.RGBA. func (p *Painter) Paint(ss []raster.Span, done bool) { //gl.Begin(gl.LINES) sslen := len(ss) clenrequired := sslen * 8 vlenrequired := sslen * 4 if clenrequired >= (cap(p.colors) - len(p.colors)) { p.Flush() if clenrequired >= cap(p.colors) { p.vertices = make([]int32, 0, vlenrequired+(vlenrequired/2)) p.colors = make([]uint8, 0, clenrequired+(clenrequired/2)) } } vi := len(p.vertices) ci := len(p.colors) p.vertices = p.vertices[0 : vi+vlenrequired] p.colors = p.colors[0 : ci+clenrequired] var ( colors []uint8 vertices []int32 ) for _, s := range ss { ma := s.A >> 16 a := uint8((ma * p.ca / M16) >> 8) colors = p.colors[ci:] colors[0] = p.cr colors[1] = p.cg colors[2] = p.cb colors[3] = a colors[4] = p.cr colors[5] = p.cg colors[6] = p.cb colors[7] = a ci += 8 vertices = p.vertices[vi:] vertices[0] = int32(s.X0) vertices[1] = int32(s.Y) vertices[2] = int32(s.X1) vertices[3] = int32(s.Y) vi += 4 } } func (p *Painter) Flush() { if len(p.vertices) != 0 { gl.EnableClientState(gl.COLOR_ARRAY) gl.EnableClientState(gl.VERTEX_ARRAY) gl.ColorPointer(4, gl.UNSIGNED_BYTE, 0, gl.Ptr(p.colors)) gl.VertexPointer(2, gl.INT, 0, gl.Ptr(p.vertices)) // draw lines gl.DrawArrays(gl.LINES, 0, int32(len(p.vertices)/2)) gl.DisableClientState(gl.VERTEX_ARRAY) gl.DisableClientState(gl.COLOR_ARRAY) p.vertices = p.vertices[0:0] p.colors = p.colors[0:0] } } // SetColor sets the color to paint the spans. func (p *Painter) SetColor(c color.Color) { r, g, b, a := c.RGBA() if a == 0 { p.cr = 0 p.cg = 0 p.cb = 0 p.ca = a } else { p.cr = uint8((r * M16 / a) >> 8) p.cg = uint8((g * M16 / a) >> 8) p.cb = uint8((b * M16 / a) >> 8) p.ca = a } } // NewRGBAPainter creates a new RGBAPainter for the given image. func NewPainter() *Painter { p := new(Painter) p.vertices = make([]int32, 0, 1024) p.colors = make([]uint8, 0, 1024) return p } type GraphicContext struct { *draw2d.StackGraphicContext painter *Painter fillRasterizer *raster.Rasterizer strokeRasterizer *raster.Rasterizer } // NewGraphicContext creates a new Graphic context from an image. func NewGraphicContext(width, height int) *GraphicContext { gc := &GraphicContext{ draw2d.NewStackGraphicContext(), NewPainter(), raster.NewRasterizer(width, height), raster.NewRasterizer(width, height), } return gc } func (gc *GraphicContext) CreateStringPath(s string, x, y float64) float64 { panic("not implemented") } func (gc *GraphicContext) FillStringAt(text string, x, y float64) (cursor float64) { panic("not implemented") } func (gc *GraphicContext) GetStringBounds(s string) (left, top, right, bottom float64) { panic("not implemented") } func (gc *GraphicContext) StrokeString(text string) (cursor float64) { return gc.StrokeStringAt(text, 0, 0) } func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (cursor float64) { width := gc.CreateStringPath(text, x, y) gc.Stroke() return width } func (gc *GraphicContext) SetDPI(dpi int) { } func (gc *GraphicContext) GetDPI() int { return -1 } func (gc *GraphicContext) Clear() { } func (gc *GraphicContext) ClearRect(x1, y1, x2, y2 int) { } func (gc *GraphicContext) DrawImage(img image.Image) { } func (gc *GraphicContext) FillString(text string) (cursor float64) { return 0 } func (gc *GraphicContext) paint(rasterizer *raster.Rasterizer, color color.Color) { gc.painter.SetColor(color) rasterizer.Rasterize(gc.painter) rasterizer.Clear() gc.painter.Flush() } func (gc *GraphicContext) Stroke(paths ...*draw2d.PathStorage) { paths = append(paths, gc.Current.Path) gc.strokeRasterizer.UseNonZeroWinding = true stroker := draw2d.NewLineStroker(gc.Current.Cap, gc.Current.Join, draw2d.NewVertexMatrixTransform(gc.Current.Tr, draw2d.NewVertexAdder(gc.strokeRasterizer))) stroker.HalfLineWidth = gc.Current.LineWidth / 2 var pathConverter *draw2d.PathConverter if gc.Current.Dash != nil && len(gc.Current.Dash) > 0 { dasher := draw2d.NewDashConverter(gc.Current.Dash, gc.Current.DashOffset, stroker) pathConverter = draw2d.NewPathConverter(dasher) } else { pathConverter = draw2d.NewPathConverter(stroker) } pathConverter.ApproximationScale = gc.Current.Tr.GetScale() // From agg code pathConverter.Convert(paths...) gc.paint(gc.strokeRasterizer, gc.Current.StrokeColor) gc.Current.Path = draw2d.NewPathStorage() } func (gc *GraphicContext) Fill(paths ...*draw2d.PathStorage) { paths = append(paths, gc.Current.Path) gc.fillRasterizer.UseNonZeroWinding = gc.Current.FillRule.UseNonZeroWinding() pathConverter := draw2d.NewPathConverter(draw2d.NewVertexMatrixTransform(gc.Current.Tr, draw2d.NewVertexAdder(gc.fillRasterizer))) pathConverter.ApproximationScale = gc.Current.Tr.GetScale() // From agg code pathConverter.Convert(paths...) gc.paint(gc.fillRasterizer, gc.Current.FillColor) gc.Current.Path = draw2d.NewPathStorage() } func (gc *GraphicContext) FillStroke(paths ...*draw2d.PathStorage) { gc.fillRasterizer.UseNonZeroWinding = gc.Current.FillRule.UseNonZeroWinding() gc.strokeRasterizer.UseNonZeroWinding = true filler := draw2d.NewVertexMatrixTransform(gc.Current.Tr, draw2d.NewVertexAdder(gc.fillRasterizer)) stroker := draw2d.NewLineStroker(gc.Current.Cap, gc.Current.Join, draw2d.NewVertexMatrixTransform(gc.Current.Tr, draw2d.NewVertexAdder(gc.strokeRasterizer))) stroker.HalfLineWidth = gc.Current.LineWidth / 2 demux := draw2d.NewDemuxConverter(filler, stroker) paths = append(paths, gc.Current.Path) pathConverter := draw2d.NewPathConverter(demux) pathConverter.ApproximationScale = gc.Current.Tr.GetScale() // From agg code pathConverter.Convert(paths...) gc.paint(gc.fillRasterizer, gc.Current.FillColor) gc.paint(gc.strokeRasterizer, gc.Current.StrokeColor) gc.Current.Path = draw2d.NewPathStorage() }