def drawArrow(e, view, xs, ys, xt, yt, onText=1, startMarker=False, endMarker=False):
u"""Draw curved arrow marker between the two points.
TODO: Add drawing of real arrow-heads, rotated in the right direction."""
fms = e.css('flowMarkerSize')
fmf = e.css('flowCurvatureFactor')
if onText == 1:
c = e.css('flowConnectionStroke2', NO_COLOR)
else:
c = e.css('flowConnectionStroke1', NO_COLOR)
setStrokeColor(c, e.css('flowConnectionStrokeWidth'))
if startMarker:
setFillColor(e.css('flowMarkerFill', NO_COLOR))
oval(xs - fms, ys - fms, 2 * fms, 2 * fms)
xm = (xt + xs)/2
ym = (yt + ys)/2
xb1 = xm + onText * (yt - ys) * fmf
yb1 = ym - onText * (xt - xs) * fmf
xb2 = xm - onText * (yt - ys) * fmf
yb2 = ym + onText * (xt - xs) * fmf
# Arrow head position
arrowSize = 12
arrowAngle = 0.4
angle = atan2(xt-xb2, yt-yb2)
hookedAngle = radians(degrees(angle)-90)
ax1 = xt - cos(hookedAngle+arrowAngle) * arrowSize
ay1 = yt + sin(hookedAngle+arrowAngle) * arrowSize
ax2 = xt - cos(hookedAngle-arrowAngle) * arrowSize
ay2 = yt + sin(hookedAngle-arrowAngle) * arrowSize
newPath()
setFillColor(None)
moveTo((xs, ys))
curveTo((xb1, yb1), (xb2, yb2), ((ax1+ax2)/2, (ay1+ay2)/2)) # End in middle of arrow head.
drawPath()
# Draw the arrow head.
newPath()
setFillColor(c)
setStrokeColor(None)
moveTo((xt, yt))
lineTo((ax1, ay1))
lineTo((ax2, ay2))
closePath()
drawPath()
if endMarker:
oval(xt - fms, yt - fms, 2 * fms, 2 * fms)
import drawBot drawBot.size(200, 200) drawBot.newPath() drawBot.moveTo((20, 20)) drawBot.lineTo((20, 100)) drawBot.lineTo((100, 100)) drawBot.lineTo((100, 180)) drawBot.curveTo((150, 180), (180, 150), (180, 100)) drawBot.lineTo((180, 20)) drawBot.closePath() drawBot.moveTo((40, 40)) drawBot.lineTo((160, 40)) drawBot.curveTo((160, 65), (145, 80), (120, 80)) drawBot.lineTo((40, 80)) drawBot.closePath() drawBot.fill(0.5, 0, 0) drawBot.stroke(None) drawBot.strokeWidth(10) drawBot.drawPath()
def closePath(self):
ctx.closePath()