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calculate circle steps dynamically

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This commit is contained in:
Thomas Friedel 2018-02-06 10:57:02 +01:00
parent 0bd060ae1b
commit e5bdee1d67
1 changed files with 11 additions and 2 deletions
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13
paths.go
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@ -90,7 +90,12 @@ func (cv *Canvas) Arc(x, y, radius, startAngle, endAngle float32, anticlockwise
startAngle += math.Pi * 2 startAngle += math.Pi * 2
startAngle, endAngle = endAngle, startAngle startAngle, endAngle = endAngle, startAngle
} }
for a := startAngle; a < endAngle; a += 0.1 { tr := cv.tf(lm.Vec2{radius, radius})
step := 6 / fmath.Max(tr[0], tr[1])
if step > 0.8 {
step = 0.8
}
for a := startAngle; a < endAngle; a += step {
s, c := fmath.Sincos(a) s, c := fmath.Sincos(a)
cv.LineTo(x+radius*c, y+radius*s) cv.LineTo(x+radius*c, y+radius*s)
} }
@ -269,7 +274,11 @@ func (cv *Canvas) lineJoint(p pathPoint, p0, p1, p2, l0p0, l0p1, l0p2, l0p3 lm.V
func (cv *Canvas) addCircleTris(p lm.Vec2, radius float32, tris []float32) []float32 { func (cv *Canvas) addCircleTris(p lm.Vec2, radius float32, tris []float32) []float32 {
cxf, cyf := cv.vecToGL(p) cxf, cyf := cv.vecToGL(p)
p0x, p0y := cv.vecToGL(lm.Vec2{p[0], p[1] + radius}) p0x, p0y := cv.vecToGL(lm.Vec2{p[0], p[1] + radius})
for angle := float32(0.1); angle <= math.Pi*2+0.1; angle += 0.1 { step := 6 / radius
if step > 0. {
step = 0.8
}
for angle := step; angle <= math.Pi*2+step; angle += step {
s, c := fmath.Sincos(angle) s, c := fmath.Sincos(angle)
p1x, p1y := cv.vecToGL(lm.Vec2{p[0] + s*radius, p[1] + c*radius}) p1x, p1y := cv.vecToGL(lm.Vec2{p[0] + s*radius, p[1] + c*radius})
tris = append(tris, cxf, cyf, p0x, p0y, p1x, p1y) tris = append(tris, cxf, cyf, p0x, p0y, p1x, p1y)