From 3aa547849989d623cbf04bc1a7d2529df6bdef6d Mon Sep 17 00:00:00 2001
From: faiface <faiface@ksp.sk>
Date: Sat, 18 Mar 2017 16:18:05 +0100
Subject: [PATCH] add IMDraw drawing methods
---
graphics.go | 414 +++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 344 insertions(+), 70 deletions(-)
diff --git a/graphics.go b/graphics.go
index f2ce5f4..eab6881 100644
--- a/graphics.go
+++ b/graphics.go
@@ -67,7 +67,7 @@ func (s *Sprite) Draw(t Target) {
// IMDraw is an immediate-like-mode shape drawer.
//
-// TODO: mode doc
+// TODO: doc
type IMDraw struct {
points []point
opts point
@@ -85,7 +85,6 @@ type point struct {
col NRGBA
pic Vec
in float64
- width float64
precision int
endshape EndShape
}
@@ -94,8 +93,11 @@ type point struct {
type EndShape int
const (
- // SharpEndShape is a square end shape.
- SharpEndShape EndShape = iota
+ // NoEndShape leaves a line point with no special end shape.
+ NoEndShape EndShape = iota
+
+ // SharpEndShape is a sharp triangular end shape.
+ SharpEndShape
// RoundEndShape is a circular end shape.
RoundEndShape
@@ -140,15 +142,14 @@ func (imd *IMDraw) Draw(t Target) {
// the position.
func (imd *IMDraw) Push(pts ...Vec) {
for _, pt := range pts {
- imd.pushPt(pt)
+ imd.pushPt(pt, imd.opts)
}
}
-func (imd *IMDraw) pushPt(pt Vec) {
- point := imd.opts
- point.pos = imd.matrix.Project(pt)
- point.col = imd.mask.Mul(point.col)
- imd.points = append(imd.points, point)
+func (imd *IMDraw) pushPt(pos Vec, pt point) {
+ pt.pos = imd.matrix.Project(pos)
+ pt.col = imd.mask.Mul(pt.col)
+ imd.points = append(imd.points, pt)
}
// Color sets the color of the next Pushed points.
@@ -166,13 +167,6 @@ func (imd *IMDraw) Intensity(in float64) {
imd.opts.in = in
}
-// Width sets the with property of the next Pushed points.
-//
-// Note that this property does not apply to filled shapes.
-func (imd *IMDraw) Width(w float64) {
- imd.opts.width = w
-}
-
// Precision sets the curve/circle drawing precision of the next Pushed points.
//
// It is the number of segments per 360 degrees.
@@ -207,88 +201,368 @@ func (imd *IMDraw) MakePicture(p Picture) TargetPicture {
return imd.batch.MakePicture(p)
}
-// FillConvexPolygon takes all points Pushed into the IM's queue and fills the convex polygon formed
-// by them.
+// Polygon draws a polygon from the Pushed points. If the thickness is 0, the convex polygon will be
+// filled. Otherwise, an outline of the specified thickness will be drawn. The outline does not have
+// to be convex.
+//
+// Note, that the filled polygon does not have to be strictly convex. The way it's drawn is that a
+// triangle is drawn between each two adjacent points and the first Pushed point. You can use this
+// property to draw certain kinds of concave polygons.
+func (imd *IMDraw) Polygon(thickness float64) {
+ if thickness == 0 {
+ imd.fillPolygon()
+ } else {
+ imd.polyline(thickness, true)
+ }
+}
+
+// Circle draws a circle of the specified radius around each Pushed point. If the thickness is 0,
+// the circle will be filled, otherwise a circle outline of the specified thickness will be drawn.
+func (imd *IMDraw) Circle(radius, thickness float64) {
+ if thickness == 0 {
+ imd.fillEllipseArc(V(radius, radius), 0, 2*math.Pi)
+ } else {
+ imd.outlineEllipseArc(V(radius, radius), 0, 2*math.Pi, thickness, false)
+ }
+}
+
+// CircleArc draws a circle arc of the specified radius around each Pushed point. If the thickness
+// is 0, the arc will be filled, otherwise will be outlined. The arc starts at the low angle and
+// continues to the high angle. If low<high, the arc will be drawn counterclockwise. Otherwise it
+// will be clockwise. The angles are not normalized by any means.
//
-// The polygon does not need to be exactly convex. The way it's drawn is that for each two adjacent
-// points, a triangle is constructed from those two points and the first Pushed point. You can use
-// this property to draw specific concave polygons.
-func (imd *IMDraw) FillConvexPolygon() {
+// imd.CircleArc(40, 0, 8*math.Pi, 0)
+//
+// This line will fill the whole circle 4 times.
+func (imd *IMDraw) CircleArc(radius, low, high, thickness float64) {
+ if thickness == 0 {
+ imd.fillEllipseArc(V(radius, radius), low, high)
+ } else {
+ imd.outlineEllipseArc(V(radius, radius), low, high, thickness, true)
+ }
+}
+
+// Ellipse draws an ellipse of the specified radius in each axis around each Pushed points. If the
+// thickness is 0, the ellipse will be filled, otherwise an ellipse outline of the specified
+// thickness will be drawn.
+func (imd *IMDraw) Ellipse(radius Vec, thickness float64) {
+ if thickness == 0 {
+ imd.fillEllipseArc(radius, 0, 2*math.Pi)
+ } else {
+ imd.outlineEllipseArc(radius, 0, 2*math.Pi, thickness, false)
+ }
+}
+
+// EllipseArc draws an ellipse arc of the specified radius in each axis around each Pushed point. If
+// the thickness is 0, the arc will be filled, otherwise will be outlined. The arc starts at the low
+// angle and continues to the high angle. If low<high, the arc will be drawn counterclockwise.
+// Otherwise it will be clockwise. The angles are not normalized by any means.
+//
+// imd.EllipseArc(pixel.V(100, 50), 0, 8*math.Pi, 0)
+//
+// This line will fill the whole ellipse 4 times.
+func (imd *IMDraw) EllipseArc(radius Vec, low, high, thickness float64) {
+ if thickness == 0 {
+ imd.fillEllipseArc(radius, low, high)
+ } else {
+ imd.outlineEllipseArc(radius, low, high, thickness, true)
+ }
+}
+
+// Line draws a polyline of the specified thickness between the Pushed points.
+func (imd *IMDraw) Line(thickness float64) {
+ imd.polyline(thickness, false)
+}
+
+func (imd *IMDraw) getAndClearPoints() []point {
points := imd.points
imd.points = nil
+ return points
+}
+
+func (imd *IMDraw) fillPolygon() {
+ points := imd.getAndClearPoints()
if len(points) < 3 {
return
}
- i := imd.tri.Len()
+ off := imd.tri.Len()
imd.tri.SetLen(imd.tri.Len() + 3*(len(points)-2))
- for j := 1; j+1 < len(points); j++ {
- (*imd.tri)[i+0].Position = points[0].pos
- (*imd.tri)[i+0].Color = points[0].col
- (*imd.tri)[i+0].Picture = points[0].pic
- (*imd.tri)[i+0].Intensity = points[0].in
+ for i := 1; i+1 < len(points); i++ {
+ (*imd.tri)[off].Position = points[0].pos
+ (*imd.tri)[off].Color = points[0].col
+ (*imd.tri)[off].Picture = points[0].pic
+ (*imd.tri)[off].Intensity = points[0].in
- (*imd.tri)[i+1].Position = points[j].pos
- (*imd.tri)[i+1].Color = points[j].col
- (*imd.tri)[i+1].Picture = points[j].pic
- (*imd.tri)[i+1].Intensity = points[j].in
+ (*imd.tri)[off+1].Position = points[i].pos
+ (*imd.tri)[off+1].Color = points[i].col
+ (*imd.tri)[off+1].Picture = points[i].pic
+ (*imd.tri)[off+1].Intensity = points[i].in
- (*imd.tri)[i+2].Position = points[j+1].pos
- (*imd.tri)[i+2].Color = points[j+1].col
- (*imd.tri)[i+2].Picture = points[j+1].pic
- (*imd.tri)[i+2].Intensity = points[j+1].in
+ (*imd.tri)[off+2].Position = points[i+1].pos
+ (*imd.tri)[off+2].Color = points[i+1].col
+ (*imd.tri)[off+2].Picture = points[i+1].pic
+ (*imd.tri)[off+2].Intensity = points[i+1].in
- i += 3
+ off += 3
}
imd.batch.Dirty()
}
-// FillCircle draws a filled circle around each point in the IM's queue.
-func (imd *IMDraw) FillCircle(radius float64) {
- imd.FillEllipseArc(V(radius, radius), 0, 2*math.Pi)
-}
+func (imd *IMDraw) fillEllipseArc(radius Vec, low, high float64) {
+ points := imd.getAndClearPoints()
-// FillCircleArc draws a filled circle arc around each point in the IM's queue.
-func (imd *IMDraw) FillCircleArc(radius, low, high float64) {
- imd.FillEllipseArc(V(radius, radius), low, high)
-}
+ for _, pt := range points {
+ num := math.Ceil(math.Abs(high-low) / (2 * math.Pi) * float64(pt.precision))
+ delta := (high - low) / num
+
+ off := imd.tri.Len()
+ imd.tri.SetLen(imd.tri.Len() + 3*int(num))
+
+ for i := range (*imd.tri)[off:] {
+ (*imd.tri)[off+i].Color = pt.col
+ (*imd.tri)[off+i].Picture = 0
+ (*imd.tri)[off+i].Intensity = 0
+ }
+
+ for i := 0.0; i < num; i++ {
+ angle := low + i*delta
+ sin, cos := math.Sincos(angle)
+ a := pt.pos + V(
+ radius.X()*cos,
+ radius.Y()*sin,
+ )
+
+ angle = low + (i+1)*delta
+ sin, cos = math.Sincos(angle)
+ b := pt.pos + V(
+ radius.X()*cos,
+ radius.Y()*sin,
+ )
-// FillEllipse draws a filled ellipse around each point in the IM's queue.
-func (imd *IMDraw) FillEllipse(radius Vec) {
- imd.FillEllipseArc(radius, 0, 2*math.Pi)
+ (*imd.tri)[off+0].Position = pt.pos
+ (*imd.tri)[off+1].Position = a
+ (*imd.tri)[off+2].Position = b
+
+ off += 3
+ }
+
+ imd.batch.Dirty()
+ }
}
-// FillEllipseArc draws a filled ellipse arc around each point in the IM's queue. Low and high
-// angles are in radians.
-//
-// The arc is drawn starting at the low angle continuing to the high angle. If the high angle is
-// numerically greater than the low angle, the arc will be drawn counterclockwise, otherwise it will
-// be drawn clockwise.
-//
-// The angles are not normalized by any means. This will rotate four times in a full circle:
-//
-// imd.FillEllipseArc(pixel.V(100, 100), 0, 8*math.Pi)
-func (imd *IMDraw) FillEllipseArc(radius Vec, low, high float64) {
- points := imd.points
- imd.points = nil
+func (imd *IMDraw) outlineEllipseArc(radius Vec, low, high, thickness float64, doEndShape bool) {
+ points := imd.getAndClearPoints()
for _, pt := range points {
- imd.pushPt(pt.pos) // center
-
num := math.Ceil(math.Abs(high-low) / (2 * math.Pi) * float64(pt.precision))
delta := (high - low) / num
- for i := 0.0; i <= num; i++ {
+
+ off := imd.tri.Len()
+ imd.tri.SetLen(imd.tri.Len() + 6*int(num))
+
+ for i := range (*imd.tri)[off:] {
+ (*imd.tri)[off+i].Color = pt.col
+ (*imd.tri)[off+i].Picture = 0
+ (*imd.tri)[off+i].Intensity = 0
+ }
+
+ for i := 0.0; i < num; i++ {
angle := low + i*delta
sin, cos := math.Sincos(angle)
- imd.pushPt(pt.pos + V(
- radius.X()*cos,
- radius.Y()*sin,
- ))
+ normalSin, normalCos := V(sin, cos).ScaledXY(radius).Unit().XY()
+ a := pt.pos + V(
+ radius.X()*cos-thickness/2*normalCos,
+ radius.Y()*sin-thickness/2*normalSin,
+ )
+ b := pt.pos + V(
+ radius.X()*cos+thickness/2*normalCos,
+ radius.Y()*sin+thickness/2*normalSin,
+ )
+
+ angle = low + (i+1)*delta
+ sin, cos = math.Sincos(angle)
+ normalSin, normalCos = V(sin, cos).ScaledXY(radius).Unit().XY()
+ c := pt.pos + V(
+ radius.X()*cos-thickness/2*normalCos,
+ radius.Y()*sin-thickness/2*normalSin,
+ )
+ d := pt.pos + V(
+ radius.X()*cos+thickness/2*normalCos,
+ radius.Y()*sin+thickness/2*normalSin,
+ )
+
+ (*imd.tri)[off+0].Position = a
+ (*imd.tri)[off+1].Position = b
+ (*imd.tri)[off+2].Position = c
+ (*imd.tri)[off+3].Position = c
+ (*imd.tri)[off+4].Position = b
+ (*imd.tri)[off+5].Position = d
+
+ off += 6
}
- imd.FillConvexPolygon()
+ imd.batch.Dirty()
+
+ if doEndShape {
+ lowSin, lowCos := math.Sincos(low)
+ lowCenter := pt.pos + V(
+ radius.X()*lowCos,
+ radius.Y()*lowSin,
+ )
+ normalLowSin, normalLowCos := V(lowSin, lowCos).ScaledXY(radius).Unit().XY()
+ normalLow := V(normalLowCos, normalLowSin).Angle()
+
+ highSin, highCos := math.Sincos(high)
+ highCenter := pt.pos + V(
+ radius.X()*highCos,
+ radius.Y()*highSin,
+ )
+ normalHighSin, normalHighCos := V(highSin, highCos).ScaledXY(radius).Unit().XY()
+ normalHigh := V(normalHighCos, normalHighSin).Angle()
+
+ orientation := 1.0
+ if low > high {
+ orientation = -1.0
+ }
+
+ switch pt.endshape {
+ case NoEndShape:
+ // nothing
+ case SharpEndShape:
+ thick := X(thickness / 2).Rotated(normalLow)
+ imd.pushPt(lowCenter+thick, pt)
+ imd.pushPt(lowCenter-thick, pt)
+ imd.pushPt(lowCenter-thick.Rotated(math.Pi/2*orientation), pt)
+ imd.fillPolygon()
+ thick = X(thickness / 2).Rotated(normalHigh)
+ imd.pushPt(highCenter+thick, pt)
+ imd.pushPt(highCenter-thick, pt)
+ imd.pushPt(highCenter+thick.Rotated(math.Pi/2*orientation), pt)
+ imd.fillPolygon()
+ case RoundEndShape:
+ imd.pushPt(lowCenter, pt)
+ imd.fillEllipseArc(V(thickness, thickness)/2, normalLow, normalLow-math.Pi*orientation)
+ imd.pushPt(highCenter, pt)
+ imd.fillEllipseArc(V(thickness, thickness)/2, normalHigh, normalHigh+math.Pi*orientation)
+ }
+ }
+ }
+}
+
+func (imd *IMDraw) polyline(thickness float64, closed bool) {
+ points := imd.getAndClearPoints()
+
+ // filter identical adjacent points
+ filtered := points[:0]
+ for i := 0; i < len(points); i++ {
+ if closed || i+1 < len(points) {
+ j := (i + 1) % len(points)
+ if points[i].pos != points[j].pos {
+ filtered = append(filtered, points[i])
+ }
+ }
+ }
+ points = filtered
+
+ if len(points) < 2 {
+ return
+ }
+
+ // first point
+ j, i := 0, 1
+ normal := (points[i].pos - points[j].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
+
+ if !closed {
+ switch points[j].endshape {
+ case NoEndShape:
+ // nothing
+ case SharpEndShape:
+ imd.pushPt(points[j].pos+normal, points[j])
+ imd.pushPt(points[j].pos-normal, points[j])
+ imd.pushPt(points[j].pos+normal.Rotated(math.Pi/2), points[j])
+ imd.fillPolygon()
+ case RoundEndShape:
+ imd.pushPt(points[j].pos, points[j])
+ imd.fillEllipseArc(V(thickness, thickness)/2, normal.Angle(), normal.Angle()+math.Pi)
+ }
+ }
+
+ imd.pushPt(points[j].pos+normal, points[j])
+ imd.pushPt(points[j].pos-normal, points[j])
+
+ // middle points
+ for i := 0; i < len(points); i++ {
+ j, k := i+1, i+2
+
+ closing := false
+ if j >= len(points) {
+ if !closed {
+ break
+ }
+ j %= len(points)
+ closing = true
+ }
+ if k >= len(points) {
+ k %= len(points)
+ }
+
+ ijNormal := (points[j].pos - points[i].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
+ jkNormal := (points[k].pos - points[j].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
+
+ orientation := 1.0
+ if ijNormal.Cross(jkNormal) > 0 {
+ orientation = -1.0
+ }
+
+ imd.pushPt(points[j].pos-ijNormal, points[j])
+ imd.pushPt(points[j].pos+ijNormal, points[j])
+ imd.fillPolygon()
+
+ switch points[j].endshape {
+ case NoEndShape:
+ // nothing
+ case SharpEndShape:
+ imd.pushPt(points[j].pos, points[j])
+ imd.pushPt(points[j].pos+ijNormal.Scaled(orientation), points[j])
+ imd.pushPt(points[j].pos+jkNormal.Scaled(orientation), points[j])
+ imd.fillPolygon()
+ case RoundEndShape:
+ imd.pushPt(points[j].pos, points[j])
+ imd.fillEllipseArc(V(thickness, thickness)/2, ijNormal.Angle(), ijNormal.Angle()-math.Pi)
+ imd.pushPt(points[j].pos, points[j])
+ imd.fillEllipseArc(V(thickness, thickness)/2, jkNormal.Angle(), jkNormal.Angle()+math.Pi)
+ }
+
+ if !closing {
+ imd.pushPt(points[j].pos+jkNormal, points[j])
+ imd.pushPt(points[j].pos-jkNormal, points[j])
+ }
+ }
+
+ // last point
+ i, j = len(points)-2, len(points)-1
+ normal = (points[j].pos - points[i].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
+
+ imd.pushPt(points[j].pos-normal, points[j])
+ imd.pushPt(points[j].pos+normal, points[j])
+ imd.fillPolygon()
+
+ if !closed {
+ switch points[j].endshape {
+ case NoEndShape:
+ // nothing
+ case SharpEndShape:
+ imd.pushPt(points[j].pos+normal, points[j])
+ imd.pushPt(points[j].pos-normal, points[j])
+ imd.pushPt(points[j].pos+normal.Rotated(-math.Pi/2), points[j])
+ imd.fillPolygon()
+ case RoundEndShape:
+ imd.pushPt(points[j].pos, points[j])
+ imd.fillEllipseArc(V(thickness, thickness)/2, normal.Angle(), normal.Angle()-math.Pi)
+ }
}
}
--
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