joejulian/gio
1
0
Fork 1
mirror of https://git.sr.ht/~eliasnaur/gio synced 2026-07-05 17:35:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

op/clip: add RoundRect

Browse Source 
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit is contained in:
Elias Naur
2019-11-09 19:20:47 +01:00
parent e864ac3fc3
commit 4f30b985eb
3 changed files with 38 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files
op/clip/clip.go
+24
View File
@@ -289,6 +289,30 @@ func Rect(r image.Rectangle) Op {
return Op{bounds: toRectF(r)}
}
// RoundRect returns the clip area of a rectangle with rounded
// corners defined by their radii. The origin is in the upper left
// corner.
// Specify a square with corner radii equal to half the square size to
// construct a circular clip area.
func RoundRect(ops *op.Ops, r f32.Rectangle, se, sw, nw, ne float32) Op {
size := r.Size()
// https://pomax.github.io/bezierinfo/#circles_cubic.
w, h := float32(size.X), float32(size.Y)
const c = 0.55228475 // 4*(sqrt(2)-1)/3
var p Path
p.Begin(ops)
p.Move(r.Min)
p.Move(f32.Point{X: w, Y: h - se})
p.Cube(f32.Point{X: 0, Y: se * c}, f32.Point{X: -se + se*c, Y: se}, f32.Point{X: -se, Y: se}) // SE
p.Line(f32.Point{X: sw - w + se, Y: 0})
p.Cube(f32.Point{X: -sw * c, Y: 0}, f32.Point{X: -sw, Y: -sw + sw*c}, f32.Point{X: -sw, Y: -sw}) // SW
p.Line(f32.Point{X: 0, Y: nw - h + sw})
p.Cube(f32.Point{X: 0, Y: -nw * c}, f32.Point{X: nw - nw*c, Y: -nw}, f32.Point{X: nw, Y: -nw}) // NW
p.Line(f32.Point{X: w - ne - nw, Y: 0})
p.Cube(f32.Point{X: ne * c, Y: 0}, f32.Point{X: ne, Y: ne - ne*c}, f32.Point{X: ne, Y: ne}) // NE
return p.End()
}
func toRectF(r image.Rectangle) f32.Rectangle {
return f32.Rectangle{
Min: f32.Point{X: float32(r.Min.X), Y: float32(r.Min.Y)},