ActiveGo 1.8Package vector
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type Rasterizer ¶
Raster is a 2-D vector graphics rasterizer.
The zero value is usable, in that it is a Rasterizer whose rendered mask image has zero width and zero height. Call Reset to change its bounds.
type Rasterizer struct {
// DrawOp is the operator used for the Draw method.
//
// The zero value is draw.Over.
DrawOp draw.Op
// contains filtered or unexported fields
}
func NewRasterizer ¶
func NewRasterizer(w, h int) *Rasterizer
NewRasterizer returns a new Rasterizer whose rendered mask image is bounded by the given width and height.
func (*Rasterizer) Bounds ¶
func (z *Rasterizer) Bounds() image.Rectangle
Bounds returns the rectangle from (0, 0) to the width and height passed to NewRasterizer or Reset.
func (*Rasterizer) ClosePath ¶
func (z *Rasterizer) ClosePath()
ClosePath closes the current path.
func (*Rasterizer) CubeTo ¶
func (z *Rasterizer) CubeTo(bx, by, cx, cy, dx, dy float32)
CubeTo adds a cubic Bézier segment, from the pen via (bx, by) and (cx, cy) to (dx, dy), and moves the pen to (dx, dy).
The coordinates are allowed to be out of the Rasterizer's bounds.
func (*Rasterizer) Draw ¶
func (z *Rasterizer) Draw(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point)
Draw implements the Drawer interface from the standard library's image/draw package.
The vector paths previously added via the XxxTo calls become the mask for drawing src onto dst.
func (*Rasterizer) LineTo ¶
func (z *Rasterizer) LineTo(bx, by float32)
LineTo adds a line segment, from the pen to (bx, by), and moves the pen to (bx, by).
The coordinates are allowed to be out of the Rasterizer's bounds.
func (*Rasterizer) MoveTo ¶
func (z *Rasterizer) MoveTo(ax, ay float32)
MoveTo starts a new path and moves the pen to (ax, ay).
The coordinates are allowed to be out of the Rasterizer's bounds.
func (*Rasterizer) Pen ¶
func (z *Rasterizer) Pen() (x, y float32)
Pen returns the location of the path-drawing pen: the last argument to the most recent XxxTo call.
func (*Rasterizer) QuadTo ¶
func (z *Rasterizer) QuadTo(bx, by, cx, cy float32)
QuadTo adds a quadratic Bézier segment, from the pen via (bx, by) to (cx, cy), and moves the pen to (cx, cy).
The coordinates are allowed to be out of the Rasterizer's bounds.
func (*Rasterizer) Reset ¶
func (z *Rasterizer) Reset(w, h int)
Reset resets a Rasterizer as if it was just returned by NewRasterizer.
This includes setting z.DrawOp to draw.Over.
func (*Rasterizer) Size ¶
func (z *Rasterizer) Size() image.Point
Size returns the width and height passed to NewRasterizer or Reset.