README
¶
scanFT
scanFT is an antialiaser derived from the golang freetype translation.
scanFT encodes the ScannerFT struct that satisfies the Scanner interface of the rasterx rasterizer package which implements full SVG2.0 path functions, including the newer 'arc' join-mode.
Documentation
¶
Index ¶
- type AlphaOverPainter
- type AlphaSrcPainter
- type ClipRectPainter
- type GammaCorrectionPainter
- type MonochromePainter
- type Painter
- type PainterFunc
- type RGBAColFuncPainter
- type RGBAPainter
- type ScannerFT
- func (s *ScannerFT) Clear()
- func (s *ScannerFT) Draw()
- func (s *ScannerFT) GetPathExtent() fixed.Rectangle26_6
- func (s *ScannerFT) Line(b fixed.Point26_6)
- func (s *ScannerFT) SetBounds(width, height int)
- func (s *ScannerFT) SetClip(rect image.Rectangle)
- func (s *ScannerFT) SetColor(clr interface{})
- func (s *ScannerFT) SetWinding(useNonZeroWinding bool)
- func (s *ScannerFT) Start(a fixed.Point26_6)
- type Span
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type AlphaOverPainter ¶
An AlphaOverPainter is a Painter that paints Spans onto a *image.Alpha using the Over Porter-Duff composition operator.
func NewAlphaOverPainter ¶
func NewAlphaOverPainter(m *image.Alpha) AlphaOverPainter
NewAlphaOverPainter creates a new AlphaOverPainter for the given image.
type AlphaSrcPainter ¶
An AlphaSrcPainter is a Painter that paints Spans onto a *image.Alpha using the Src Porter-Duff composition operator.
func NewAlphaSrcPainter ¶
func NewAlphaSrcPainter(m *image.Alpha) AlphaSrcPainter
NewAlphaSrcPainter creates a new AlphaSrcPainter for the given image.
type ClipRectPainter ¶
type ClipRectPainter struct {
// Painter is the wrapped Painter.
Painter Painter
// a is the precomputed alpha values for linear interpolation, with fully
// opaque == 0xffff.
ClipRect image.Rectangle
}
A ClipRectPainter wraps another Painter, but restricts painting to within the ClipRect
type GammaCorrectionPainter ¶
type GammaCorrectionPainter struct {
// Painter is the wrapped Painter.
Painter Painter
// contains filtered or unexported fields
}
A GammaCorrectionPainter wraps another Painter, performing gamma-correction on each Span's alpha value.
func NewGammaCorrectionPainter ¶
func NewGammaCorrectionPainter(p Painter, gamma float64) *GammaCorrectionPainter
NewGammaCorrectionPainter creates a new GammaCorrectionPainter that wraps the given Painter.
func (*GammaCorrectionPainter) Paint ¶
func (g *GammaCorrectionPainter) Paint(ss []Span, done bool, clip image.Rectangle)
Paint delegates to the wrapped Painter after performing gamma-correction on each Span.
func (*GammaCorrectionPainter) SetGamma ¶
func (g *GammaCorrectionPainter) SetGamma(gamma float64)
SetGamma sets the gamma value.
type MonochromePainter ¶
type MonochromePainter struct {
Painter Painter
// contains filtered or unexported fields
}
A MonochromePainter wraps another Painter, quantizing each Span's alpha to be either fully opaque or fully transparent.
func NewMonochromePainter ¶
func NewMonochromePainter(p Painter) *MonochromePainter
NewMonochromePainter creates a new MonochromePainter that wraps the given Painter.
type Painter ¶
A Painter knows how to paint a batch of Spans. Rasterization may involve Painting multiple batches, and done will be true for the final batch. The Spans' Y values are monotonically increasing during a rasterization. Paint may use all of ss as scratch space during the call.
type PainterFunc ¶
The PainterFunc type adapts an ordinary function to the Painter interface.
type RGBAColFuncPainter ¶
type RGBAColFuncPainter struct {
RGBAPainter
// contains filtered or unexported fields
}
RGBAColFuncPainter is a Painter that paints Spans onto a *image.RGBA, and uses a color function as a the color source, or the composed RGBA paint func for a solid color
type RGBAPainter ¶
type RGBAPainter struct {
// Image is the image to compose onto.
Image *image.RGBA
// Op is the Porter-Duff composition operator.
Op draw.Op
// contains filtered or unexported fields
}
An RGBAPainter is a Painter that paints Spans onto a *image.RGBA.
func NewRGBAPainter ¶
func NewRGBAPainter(m *image.RGBA) *RGBAPainter
NewRGBAPainter creates a new RGBAPainter for the given image.
func (*RGBAPainter) Paint ¶
func (r *RGBAPainter) Paint(ss []Span, done bool, clip image.Rectangle)
Paint satisfies the Painter interface.
func (*RGBAPainter) SetColor ¶
func (r *RGBAPainter) SetColor(c color.Color)
SetColor sets the color to paint the spans.
type ScannerFT ¶
type ScannerFT struct {
// If false, the behavior is to use the even-odd winding fill
// rule during Rasterize.
UseNonZeroWinding bool
// An offset (in pixels) to the painted spans.
Dx, Dy int
Pntr *RGBAColFuncPainter
// contains filtered or unexported fields
}
Rasterizer converts a path to a raster using the grainless algorithm.
func NewScannerFT ¶
func NewScannerFT(width, height int, p *RGBAPainter) *ScannerFT
NewScanner creates a new Scanner with the given bounds.
func (*ScannerFT) Draw ¶
func (s *ScannerFT) Draw()
Draw converts r's accumulated curves into Spans for p. The Spans passed to the painter are non-overlapping, and sorted by Y and then X. They all have non-zero width (and 0 <= X0 < X1 <= r.width) and non-zero A, except for the final Span, which has Y, X0, X1 and A all equal to zero.
func (*ScannerFT) GetPathExtent ¶
func (s *ScannerFT) GetPathExtent() fixed.Rectangle26_6
func (*ScannerFT) SetBounds ¶
SetBounds sets the maximum width and height of the rasterized image and calls Clear. The width and height are in pixels, not fixed.Int26_6 units.
func (*ScannerFT) SetClip ¶
SetClip sets an optional clipping rectangle to restrict rendering only to that region -- if size is 0 then ignored (set to image.ZR to clear)
Source Files