184 lines
4.3 KiB
Go
184 lines
4.3 KiB
Go
package drawing
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import (
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"image"
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"image/color"
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"github.com/golang/freetype/truetype"
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)
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// StackGraphicContext is a context that does thngs.
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type StackGraphicContext struct {
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current *ContextStack
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}
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// ContextStack is a graphic context implementation.
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type ContextStack struct {
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Tr Matrix
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Path *Path
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LineWidth float64
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Dash []float64
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DashOffset float64
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StrokeColor color.Color
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FillColor color.Color
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FillRule FillRule
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Cap LineCap
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Join LineJoin
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FontSize float64
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Font *truetype.Font
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Scale float64
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Previous *ContextStack
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}
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// NewStackGraphicContext Create a new Graphic context from an image
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func NewStackGraphicContext() *StackGraphicContext {
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gc := &StackGraphicContext{}
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gc.current = new(ContextStack)
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gc.current.Tr = NewIdentityMatrix()
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gc.current.Path = new(Path)
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gc.current.LineWidth = 1.0
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gc.current.StrokeColor = image.Black
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gc.current.FillColor = image.White
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gc.current.Cap = RoundCap
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gc.current.FillRule = FillRuleEvenOdd
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gc.current.Join = RoundJoin
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gc.current.FontSize = 10
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return gc
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}
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func (gc *StackGraphicContext) GetMatrixTransform() Matrix {
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return gc.current.Tr
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}
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func (gc *StackGraphicContext) SetMatrixTransform(Tr Matrix) {
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gc.current.Tr = Tr
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}
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func (gc *StackGraphicContext) ComposeMatrixTransform(Tr Matrix) {
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gc.current.Tr.Compose(Tr)
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}
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func (gc *StackGraphicContext) Rotate(angle float64) {
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gc.current.Tr.Rotate(angle)
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}
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func (gc *StackGraphicContext) Translate(tx, ty float64) {
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gc.current.Tr.Translate(tx, ty)
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}
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func (gc *StackGraphicContext) Scale(sx, sy float64) {
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gc.current.Tr.Scale(sx, sy)
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}
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func (gc *StackGraphicContext) SetStrokeColor(c color.Color) {
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gc.current.StrokeColor = c
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}
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func (gc *StackGraphicContext) SetFillColor(c color.Color) {
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gc.current.FillColor = c
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}
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func (gc *StackGraphicContext) SetFillRule(f FillRule) {
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gc.current.FillRule = f
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}
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func (gc *StackGraphicContext) SetLineWidth(lineWidth float64) {
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gc.current.LineWidth = lineWidth
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}
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func (gc *StackGraphicContext) SetLineCap(cap LineCap) {
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gc.current.Cap = cap
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}
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func (gc *StackGraphicContext) SetLineJoin(join LineJoin) {
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gc.current.Join = join
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}
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func (gc *StackGraphicContext) SetLineDash(dash []float64, dashOffset float64) {
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gc.current.Dash = dash
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gc.current.DashOffset = dashOffset
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}
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func (gc *StackGraphicContext) SetFontSize(fontSize float64) {
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gc.current.FontSize = fontSize
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}
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func (gc *StackGraphicContext) GetFontSize() float64 {
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return gc.current.FontSize
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}
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func (gc *StackGraphicContext) SetFont(f *truetype.Font) {
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gc.current.Font = f
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}
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func (gc *StackGraphicContext) GetFont() *truetype.Font {
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return gc.current.Font
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}
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func (gc *StackGraphicContext) BeginPath() {
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gc.current.Path.Clear()
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}
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func (gc *StackGraphicContext) IsEmpty() bool {
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return gc.current.Path.IsEmpty()
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}
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func (gc *StackGraphicContext) LastPoint() (float64, float64) {
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return gc.current.Path.LastPoint()
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}
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func (gc *StackGraphicContext) MoveTo(x, y float64) {
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gc.current.Path.MoveTo(x, y)
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}
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func (gc *StackGraphicContext) LineTo(x, y float64) {
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gc.current.Path.LineTo(x, y)
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}
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func (gc *StackGraphicContext) QuadCurveTo(cx, cy, x, y float64) {
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gc.current.Path.QuadCurveTo(cx, cy, x, y)
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}
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func (gc *StackGraphicContext) CubicCurveTo(cx1, cy1, cx2, cy2, x, y float64) {
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gc.current.Path.CubicCurveTo(cx1, cy1, cx2, cy2, x, y)
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}
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func (gc *StackGraphicContext) ArcTo(cx, cy, rx, ry, startAngle, angle float64) {
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gc.current.Path.ArcTo(cx, cy, rx, ry, startAngle, angle)
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}
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func (gc *StackGraphicContext) Close() {
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gc.current.Path.Close()
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}
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func (gc *StackGraphicContext) Save() {
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context := new(ContextStack)
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context.FontSize = gc.current.FontSize
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context.Font = gc.current.Font
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context.LineWidth = gc.current.LineWidth
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context.StrokeColor = gc.current.StrokeColor
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context.FillColor = gc.current.FillColor
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context.FillRule = gc.current.FillRule
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context.Dash = gc.current.Dash
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context.DashOffset = gc.current.DashOffset
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context.Cap = gc.current.Cap
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context.Join = gc.current.Join
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context.Path = gc.current.Path.Copy()
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context.Font = gc.current.Font
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context.Scale = gc.current.Scale
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copy(context.Tr[:], gc.current.Tr[:])
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context.Previous = gc.current
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gc.current = context
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}
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func (gc *StackGraphicContext) Restore() {
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if gc.current.Previous != nil {
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oldContext := gc.current
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gc.current = gc.current.Previous
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oldContext.Previous = nil
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}
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}
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