draw2dbase

package
v0.0.0-...-935a01f Latest Latest
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 Go to latest Published: Nov 3, 2016 License: BSD-2-Clause Imports: 11 Imported by: 0

README

draw2d/draw2dbase

Coverage GoDoc

Base package implementation that is used by pdf, svg, img, gl implementations.

Documentation

Index

Constants

View Source 
const (
	// CurveRecursionLimit represents the maximum recursion that is really necessary to subsivide a curve into straight lines
	CurveRecursionLimit = 32
)

Variables

View Source 
var DefaultFontData = draw2d.FontData{Name: "luxi", Family: draw2d.FontFamilySans, Style: draw2d.FontStyleNormal}

Functions

func Bresenham 

func Bresenham(img draw.Image, color color.Color, x0, y0, x1, y1 int)

Bresenham draws a line between (x0, y0) and (x1, y1)

func DrawContour 

func DrawContour(path draw2d.PathBuilder, ps []truetype.Point, dx, dy float64)

DrawContour draws the given closed contour at the given sub-pixel offset.

func Flatten 

func Flatten(path *draw2d.Path, flattener Flattener, scale float64)

Flatten convert curves into straight segments keeping join segments info

func PolylineBresenham 

func PolylineBresenham(img draw.Image, c color.Color, s ...float64)

PolylineBresenham draws a polyline to an image

func SubdivideCubic 

func SubdivideCubic(c, c1, c2 []float64)

SubdivideCubic a Bezier cubic curve in 2 equivalents Bezier cubic curves. c1 and c2 parameters are the resulting curves

func SubdivideQuad 

func SubdivideQuad(c, c1, c2 []float64)

SubdivideQuad a Bezier quad curve in 2 equivalents Bezier quad curves. c1 and c2 parameters are the resulting curves

func TraceArc 

func TraceArc(t Liner, x, y, rx, ry, start, angle, scale float64) (lastX, lastY float64)

TraceArc trace an arc using a Liner

func TraceCubic 

func TraceCubic(t Liner, cubic []float64, flatteningThreshold float64)

TraceCubic generate lines subdividing the cubic curve using a Liner flattening_threshold helps determines the flattening expectation of the curve

func TraceQuad 

func TraceQuad(t Liner, quad []float64, flatteningThreshold float64)

TraceQuad generate lines subdividing the curve using a Liner flattening_threshold helps determines the flattening expectation of the curve

Types

type ContextStack 

type ContextStack struct {
	Tr          draw2d.Matrix
	Path        *draw2d.Path
	LineWidth   float64
	Dash        []float64
	DashOffset  float64
	StrokeColor color.Color
	FillColor   color.Color
	FillRule    draw2d.FillRule
	Cap         draw2d.LineCap
	Join        draw2d.LineJoin
	FontSize    float64
	FontData    draw2d.FontData

	Font *truetype.Font
	// fontSize and dpi are used to calculate scale. scale is the number of
	// 26.6 fixed point units in 1 em.
	Scale float64

	DPI int

	Previous *ContextStack
	// contains filtered or unexported fields
}

type DashVertexConverter 

type DashVertexConverter struct {
	// contains filtered or unexported fields
}

func NewDashConverter 

func NewDashConverter(dash []float64, dashOffset float64, flattener Flattener) *DashVertexConverter

func (*DashVertexConverter) Close 

func (dasher *DashVertexConverter) Close()

func (*DashVertexConverter) End 

func (dasher *DashVertexConverter) End()

func (*DashVertexConverter) LineJoin 

func (dasher *DashVertexConverter) LineJoin()

func (*DashVertexConverter) LineTo 

func (dasher *DashVertexConverter) LineTo(x, y float64)

func (*DashVertexConverter) MoveTo 

func (dasher *DashVertexConverter) MoveTo(x, y float64)

type DemuxFlattener 

type DemuxFlattener struct {
	Flatteners []Flattener
}

func (DemuxFlattener) Close 

func (dc DemuxFlattener) Close()

func (DemuxFlattener) End 

func (dc DemuxFlattener) End()

func (DemuxFlattener) LineJoin 

func (dc DemuxFlattener) LineJoin()

func (DemuxFlattener) LineTo 

func (dc DemuxFlattener) LineTo(x, y float64)

func (DemuxFlattener) MoveTo 

func (dc DemuxFlattener) MoveTo(x, y float64)

type Flattener 

type Flattener interface {
	// MoveTo Start a New line from the point (x, y)
	MoveTo(x, y float64)
	// LineTo Draw a line from the current position to the point (x, y)
	LineTo(x, y float64)
	// LineJoin use Round, Bevel or miter to join points
	LineJoin()
	// Close add the most recent starting point to close the path to create a polygon
	Close()
	// End mark the current line as finished so we can draw caps
	End()
}

Flattener receive segment definition

type FontExtents 

type FontExtents struct {
	// Ascent is the distance that the text
	// extends above the baseline.
	Ascent float64

	// Descent is the distance that the text
	// extends below the baseline.  The descent
	// is given as a negative value.
	Descent float64

	// Height is the distance from the lowest
	// descending point to the highest ascending
	// point.
	Height float64
}

FontExtents contains font metric information.

func Extents 

func Extents(font *truetype.Font, size float64) FontExtents

Extents returns the FontExtents for a font. TODO needs to read this https://developer.apple.com/fonts/TrueType-Reference-Manual/RM02/Chap2.html#intro

type Glyph 

type Glyph struct {

	// Width of the glyph
	Width float64
	// contains filtered or unexported fields
}

Glyph represents a rune which has been converted to a Path and width

func FetchGlyph 

func FetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph

FetchGlyph fetches a glyph from the cache, calling renderGlyph first if it doesn't already exist

func (*Glyph) Copy 

func (g *Glyph) Copy() *Glyph

func (*Glyph) Fill 

func (g *Glyph) Fill(gc draw2d.GraphicContext, x, y float64) float64

Fill copies a glyph from the cache, and fills it

func (*Glyph) Stroke 

func (g *Glyph) Stroke(gc draw2d.GraphicContext, x, y float64) float64

Stroke fetches a glyph from the cache, and strokes it

type LineStroker 

type LineStroker struct {
	Flattener     Flattener
	HalfLineWidth float64
	Cap           draw2d.LineCap
	Join          draw2d.LineJoin
	// contains filtered or unexported fields
}

func NewLineStroker 

func NewLineStroker(c draw2d.LineCap, j draw2d.LineJoin, flattener Flattener) *LineStroker

func (*LineStroker) Close 

func (l *LineStroker) Close()

func (*LineStroker) End 

func (l *LineStroker) End()

func (*LineStroker) LineJoin 

func (l *LineStroker) LineJoin()

func (*LineStroker) LineTo 

func (l *LineStroker) LineTo(x, y float64)

func (*LineStroker) MoveTo 

func (l *LineStroker) MoveTo(x, y float64)

type Liner 

type Liner interface {
	// LineTo Draw a line from the current position to the point (x, y)
	LineTo(x, y float64)
}

Liner receive segment definition

type SegmentedPath 

type SegmentedPath struct {
	Points []float64
}

func (*SegmentedPath) Close 

func (p *SegmentedPath) Close()

func (*SegmentedPath) End 

func (p *SegmentedPath) End()

func (*SegmentedPath) LineJoin 

func (p *SegmentedPath) LineJoin()

func (*SegmentedPath) LineTo 

func (p *SegmentedPath) LineTo(x, y float64)

func (*SegmentedPath) MoveTo 

func (p *SegmentedPath) MoveTo(x, y float64)

type StackGraphicContext 

type StackGraphicContext struct {
	Current *ContextStack
}

func NewStackGraphicContext 

func NewStackGraphicContext() *StackGraphicContext

*

  • Create a new Graphic context from an image

func (*StackGraphicContext) ArcTo 

func (gc *StackGraphicContext) ArcTo(cx, cy, rx, ry, startAngle, angle float64)

func (*StackGraphicContext) BeginPath 

func (gc *StackGraphicContext) BeginPath()

func (*StackGraphicContext) Close 

func (gc *StackGraphicContext) Close()

func (*StackGraphicContext) ComposeMatrixTransform 

func (gc *StackGraphicContext) ComposeMatrixTransform(Tr draw2d.Matrix)

func (*StackGraphicContext) CreateStringPath 

func (gc *StackGraphicContext) CreateStringPath(s string, x, y float64) float64

CreateStringPath creates a path from the string s at x, y, and returns the string width. The text is placed so that the left edge of the em square of the first character of s and the baseline intersect at x, y. The majority of the affected pixels will be above and to the right of the point, but some may be below or to the left. For example, drawing a string that starts with a 'J' in an italic font may affect pixels below and left of the point.

func (*StackGraphicContext) CubicCurveTo 

func (gc *StackGraphicContext) CubicCurveTo(cx1, cy1, cx2, cy2, x, y float64)

func (*StackGraphicContext) GetDPI 

func (gc *StackGraphicContext) GetDPI() int

func (*StackGraphicContext) GetFontData 

func (gc *StackGraphicContext) GetFontData() draw2d.FontData

func (*StackGraphicContext) GetFontName 

func (gc *StackGraphicContext) GetFontName() string

func (*StackGraphicContext) GetFontSize 

func (gc *StackGraphicContext) GetFontSize() float64

func (*StackGraphicContext) GetMatrixTransform 

func (gc *StackGraphicContext) GetMatrixTransform() draw2d.Matrix

func (*StackGraphicContext) GetPath 

func (gc *StackGraphicContext) GetPath() draw2d.Path

func (*StackGraphicContext) GetStringBounds 

func (gc *StackGraphicContext) GetStringBounds(s string) (left, top, right, bottom float64)

GetStringBounds returns the approximate pixel bounds of the string s at x, y. The the left edge of the em square of the first character of s and the baseline intersect at 0, 0 in the returned coordinates. Therefore the top and left coordinates may well be negative.

func (*StackGraphicContext) IsEmpty 

func (gc *StackGraphicContext) IsEmpty() bool

func (*StackGraphicContext) LastPoint 

func (gc *StackGraphicContext) LastPoint() (float64, float64)

func (*StackGraphicContext) LineTo 

func (gc *StackGraphicContext) LineTo(x, y float64)

func (*StackGraphicContext) MoveTo 

func (gc *StackGraphicContext) MoveTo(x, y float64)

func (*StackGraphicContext) QuadCurveTo 

func (gc *StackGraphicContext) QuadCurveTo(cx, cy, x, y float64)

func (*StackGraphicContext) Restore 

func (gc *StackGraphicContext) Restore()

func (*StackGraphicContext) Rotate 

func (gc *StackGraphicContext) Rotate(angle float64)

func (*StackGraphicContext) Save 

func (gc *StackGraphicContext) Save()

func (*StackGraphicContext) Scale 

func (gc *StackGraphicContext) Scale(sx, sy float64)

func (*StackGraphicContext) SetDPI 

func (gc *StackGraphicContext) SetDPI(dpi int)

func (*StackGraphicContext) SetFillColor 

func (gc *StackGraphicContext) SetFillColor(c color.Color)

func (*StackGraphicContext) SetFillRule 

func (gc *StackGraphicContext) SetFillRule(f draw2d.FillRule)

func (*StackGraphicContext) SetFont 

func (gc *StackGraphicContext) SetFont(font *truetype.Font)

SetFont sets the font used to draw text

func (*StackGraphicContext) SetFontData 

func (gc *StackGraphicContext) SetFontData(fontData draw2d.FontData)

func (*StackGraphicContext) SetFontSize 

func (gc *StackGraphicContext) SetFontSize(fontSize float64)

SetFontSize sets the font size in points (as in “a 12 point font”).

func (*StackGraphicContext) SetLineCap 

func (gc *StackGraphicContext) SetLineCap(cap draw2d.LineCap)

func (*StackGraphicContext) SetLineDash 

func (gc *StackGraphicContext) SetLineDash(dash []float64, dashOffset float64)

func (*StackGraphicContext) SetLineJoin 

func (gc *StackGraphicContext) SetLineJoin(join draw2d.LineJoin)

func (*StackGraphicContext) SetLineWidth 

func (gc *StackGraphicContext) SetLineWidth(lineWidth float64)

func (*StackGraphicContext) SetMatrixTransform 

func (gc *StackGraphicContext) SetMatrixTransform(Tr draw2d.Matrix)

func (*StackGraphicContext) SetStrokeColor 

func (gc *StackGraphicContext) SetStrokeColor(c color.Color)

func (*StackGraphicContext) Translate 

func (gc *StackGraphicContext) Translate(tx, ty float64)

type Transformer 

type Transformer struct {
	Tr        draw2d.Matrix
	Flattener Flattener
}

Transformer apply the Matrix transformation tr

func (Transformer) Close 

func (t Transformer) Close()

func (Transformer) End 

func (t Transformer) End()

func (Transformer) LineJoin 

func (t Transformer) LineJoin()

func (Transformer) LineTo 

func (t Transformer) LineTo(x, y float64)

func (Transformer) MoveTo 

func (t Transformer) MoveTo(x, y float64)

Source Files

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