def draw_freehand(self):
""" Freehand sketching.
"""
if _ctx._ns["mousedown"]:
x, y = mouse()
if self.show_grid:
x, y = self.grid.snap(x, y)
if self.freehand_move == True:
cmd = MOVETO
self.freehand_move = False
else:
cmd = LINETO
# Add a new LINETO to the path,
# except when starting to draw,
# then a MOVETO is added to the path.
pt = PathElement()
if cmd != MOVETO:
pt.freehand = True # Used when mixed with curve drawing.
else:
pt.freehand = False
pt.cmd = cmd
pt.x = x
pt.y = y
pt.ctrl1 = Point(x,y)
pt.ctrl2 = Point(x,y)
self._points.append(pt)
# Draw the current location of the cursor.
r = 4
_ctx.nofill()
_ctx.stroke(self.handle_color)
_ctx.oval(pt.x-r, pt.y-r, r*2, r*2)
_ctx.fontsize(9)
_ctx.fill(self.handle_color)
_ctx.text(" ("+str(int(pt.x))+", "+str(int(pt.y))+")", pt.x+r, pt.y)
self._dirty = True
else:
# Export the updated drawing,
# remember to do a MOVETO on the next interaction.
self.freehand_move = True
if self._dirty:
self._points[-1].freehand = False
self.export_svg()
self._dirty = False
def draw_freehand(self):
""" Freehand sketching.
"""
if _ctx._ns["mousedown"]:
x, y = mouse()
if self.show_grid:
x, y = self.grid.snap(x, y)
if self.freehand_move == True:
cmd = MOVETO
self.freehand_move = False
else:
cmd = LINETO
# Add a new LINETO to the path,
# except when starting to draw,
# then a MOVETO is added to the path.
pt = PathElement()
if cmd != MOVETO:
pt.freehand = True # Used when mixed with curve drawing.
else:
pt.freehand = False
pt.cmd = cmd
pt.x = x
pt.y = y
pt.ctrl1 = Point(x,y)
pt.ctrl2 = Point(x,y)
self._points.append(pt)
# Draw the current location of the cursor.
r = 4
_ctx.nofill()
_ctx.stroke(self.handle_color)
_ctx.oval(pt.x-r, pt.y-r, r*2, r*2)
_ctx.fontsize(9)
_ctx.fill(self.handle_color)
_ctx.text(" ("+str(int(pt.x))+", "+str(int(pt.y))+")", pt.x+r, pt.y)
self._dirty = True
else:
# Export the updated drawing,
# remember to do a MOVETO on the next interaction.
self.freehand_move = True
if self._dirty:
self._points[-1].freehand = False
self.export_svg()
self._dirty = False
def insert_point(self, x, y):
""" Inserts a point on the path at the mouse location.
We first need to check if the mouse location is on the path.
Inserting point is time intensive and experimental.
"""
try:
bezier = _ctx.ximport("bezier")
except:
from nodebox.graphics import bezier
# Do a number of checks distributed along the path.
# Keep the one closest to the actual mouse location.
# Ten checks works fast but leads to imprecision in sharp corners
# and curves closely located next to each other.
# I prefer the slower but more stable approach.
n = 100
closest = None
dx0 = float(INFINITY)
dy0 = float(INFINITY)
for i in range(n):
t = float(i)/n
pt = self.path.point(t)
dx = abs(pt.x-x)
dy = abs(pt.y-y)
if dx+dy <= dx0+dy0:
dx0 = dx
dy0 = dy
closest = t
# Next, scan the area around the approximation.
# If the closest point is located at 0.2 on the path,
# we need to scan between 0.1 and 0.3 for a better
# approximation. If 1.5 was the best guess, scan
# 1.40, 1.41 ... 1.59 and so on.
# Each decimal precision takes 20 iterations.
decimals = [3,4]
for d in decimals:
d = 1.0/pow(10,d)
for i in range(20):
t = closest-d + float(i)*d*0.1
if t < 0.0: t = 1.0+t
if t > 1.0: t = t-1.0
pt = self.path.point(t)
dx = abs(pt.x-x)
dy = abs(pt.y-y)
if dx <= dx0 and dy <= dy0:
dx0 = dx
dy0 = dy
closest_precise = t
closest = closest_precise
# Update the points list with the inserted point.
p = bezier.insert_point(self.path, closest_precise)
i, t, pt = bezier._locate(self.path, closest_precise)
i += 1
pt = PathElement()
pt.cmd = p[i].cmd
pt.x = p[i].x
pt.y = p[i].y
pt.ctrl1 = Point(p[i].ctrl1.x, p[i].ctrl1.y)
pt.ctrl2 = Point(p[i].ctrl2.x, p[i].ctrl2.y)
pt.freehand = False
self._points.insert(i, pt)
self._points[i-1].ctrl1 = Point(p[i-1].ctrl1.x, p[i-1].ctrl1.y)
self._points[i+1].ctrl1 = Point(p[i+1].ctrl1.x, p[i+1].ctrl1.y)
self._points[i+1].ctrl2 = Point(p[i+1].ctrl2.x, p[i+1].ctrl2.y)
def insert_point(self, x, y):
""" Inserts a point on the path at the mouse location.
We first need to check if the mouse location is on the path.
Inserting point is time intensive and experimental.
"""
try:
bezier = _ctx.ximport("bezier")
except:
from nodebox.graphics import bezier
# Do a number of checks distributed along the path.
# Keep the one closest to the actual mouse location.
# Ten checks works fast but leads to imprecision in sharp corners
# and curves closely located next to each other.
# I prefer the slower but more stable approach.
n = 100
closest = None
dx0 = float(INFINITY)
dy0 = float(INFINITY)
for i in range(n):
t = float(i) / n
pt = self.path.point(t)
dx = abs(pt.x - x)
dy = abs(pt.y - y)
if (dx + dy) <= (dx0 + dy0):
dx0 = dx
dy0 = dy
closest = t
# Next, scan the area around the approximation.
# If the closest point is located at 0.2 on the path,
# we need to scan between 0.1 and 0.3 for a better
# approximation. If 1.5 was the best guess, scan
# 1.40, 1.41 ... 1.59 and so on.
# Each decimal precision takes 20 iterations.
decimals = [3,4]
for d in decimals:
d = 1.0 / pow(10, d)
for i in range(20):
t = (closest - d) + (float(i) * d * 0.1)
if t < 0.0: t = 1.0+t
if t > 1.0: t = t-1.0
pt = self.path.point(t)
dx = abs(pt.x - x)
dy = abs(pt.y - y)
if dx <= dx0 and dy <= dy0:
dx0 = dx
dy0 = dy
closest_precise = t
closest = closest_precise
# Update the points list with the inserted point.
p = bezier.insert_point(self.path, closest_precise)
i, t, pt = bezier._locate(self.path, closest_precise)
i += 1
pt = PathElement()
pt.cmd = p[i].cmd
pt.x = p[i].x
pt.y = p[i].y
pt.ctrl1 = Point(p[i].ctrl1.x, p[i].ctrl1.y)
pt.ctrl2 = Point(p[i].ctrl2.x, p[i].ctrl2.y)
pt.freehand = False
self._points.insert(i, pt)
self._points[i-1].ctrl1 = Point(p[i-1].ctrl1.x, p[i-1].ctrl1.y)
self._points[i+1].ctrl1 = Point(p[i+1].ctrl1.x, p[i+1].ctrl1.y)
self._points[i+1].ctrl2 = Point(p[i+1].ctrl2.x, p[i+1].ctrl2.y)
