boxespy/boxes/drawing.py

521 lines
15 KiB
Python

import math
from affine import Affine
from boxes.extents import Extents
EPS = 1e-4
PADDING = 10
RANDOMIZE_COLORS = False # enable to ease check for continuity of pathes
def points_equal(x1, y1, x2, y2):
return abs(x1 - x2) < EPS and abs(y1 - y2) < EPS
def pdiff(p1, p2):
x1, y1 = p1
x2, y2 = p2
return (x1 - x2, y1 - y2)
class Surface:
def __init__(self, fname, width, height):
self._fname = fname
self.parts = []
self._p = self.new_part("default")
def flush(self):
pass
def finish(self):
pass
def render(self, renderer):
renderer.init(**self.args)
for p in self.parts:
p.render(renderer)
renderer.finish()
def move_offset(self, dx, dy):
for p in self.parts:
p.move_offset(dx, dy)
def new_part(self, name="part"):
if self.parts and len(self.parts[-1].pathes) == 0:
return self._p
p = Part(name)
self.parts.append(p)
self._p = p
return p
def append(self, *path):
self._p.append(*path)
def stroke(self, **params):
return self._p.stroke(**params)
def move_to(self, *xy):
self._p.move_to(*xy)
def extents(self):
if not self.parts:
return Extents()
return sum([p.extents() for p in self.parts])
class Part:
def __init__(self, name):
self.pathes = []
self.path = []
def extents(self):
if not self.pathes:
return Extents()
return sum([p.extents() for p in self.pathes])
def move_offset(self, dx, dy):
assert(not self.path)
for p in self.pathes:
p.move_offset(dx, dy)
def append(self, *path):
self.path.append(list(path))
def stroke(self, **params):
if len(self.path) == 0:
return
# search for path ending at new start coordinates to append this path to
xy0 = self.path[0][1:3]
for p in reversed(self.pathes):
if self.path[0][0] == "T":
break
xy1 = p.path[-1][1:3]
if points_equal(*xy0, *xy1):
# todo: check for same color and linewidth
p.path.extend(self.path[1:])
self.path = []
return p
p = Path(self.path, params)
self.pathes.append(p)
self.path = []
return p
def move_to(self, *xy):
if len(self.path) == 0:
self.path.append(["M", *xy])
elif self.path[-1][0] == "M":
self.path[-1] = ["M", *xy]
else:
xy0 = self.path[-1][1:3]
if not points_equal(*xy0, *xy):
self.path.append(["M", *xy])
class Path:
def __init__(self, path, params):
self.path = path
self.params = params
# self._extents = None
def __repr__(self):
l = len(self.path)
# x1,y1 = self.path[0][1:3]
x2, y2 = self.path[-1][1:3]
return f"Path[{l}] to ({x2:.2f},{y2:.2f})"
def extents(self):
# if self._extents is not None: return self._extents
e = Extents()
for p in self.path:
e.add(*p[1:3])
return e
def move_offset(self, dx, dy):
for c in self.path:
C = c[0]
c[1] += dx
c[2] += dy
if C == 'C':
c[3] += dx
c[4] += dy
c[5] += dx
c[6] += dy
def faster_edges(self):
for (i, p) in enumerate(self.path):
if p[0] == "C" and i > 1 and i < len(self.path) - 1:
if self.path[i - 1][0] == "L" and self.path[i + 1][0] == "L":
p11 = self.path[i - 2][1:3]
p12 = self.path[i - 1][1:3]
p21 = p[1:3]
p22 = self.path[i + 1][1:3]
if (((p12[0]-p21[0])**2 + (p12[1]-p21[1])**2) >
self.params["lw"]**2):
continue
lines_intersect, x, y = line_intersection((p11, p12), (p21, p22))
if lines_intersect:
self.path[i - 1] = ("L", x, y)
self.path[i] = ("C", x, y, *p12, *p21)
class Context:
def __init__(self, surface, *al, **ad):
self._renderer = self._dwg = surface
self._bounds = Extents()
self._padding = PADDING
self._stack = []
self._m = Affine.translation(0, 0)
self._xy = (0, 0)
self._mxy = self._m * self._xy
self._lw = 0
self._rgb = (0, 0, 0)
self._ff = "sans-serif"
self._last_path = None
def _update_bounds_(self, mx, my):
self._bounds.update(mx, my)
def save(self):
self._stack.append(
(self._m, self._xy, self._lw, self._rgb, self._mxy, self._last_path)
)
self._xy = (0, 0)
def restore(self):
(
self._m,
self._xy,
self._lw,
self._rgb,
self._mxy,
self._last_path,
) = self._stack.pop()
## transformations
def translate(self, x, y):
self._m *= Affine.translation(x, y)
self._xy = (0, 0)
def scale(self, sx, sy):
self._m *= Affine.scale(sx, sy)
def rotate(self, r):
self._m *= Affine.rotation(180 * r / math.pi)
def set_line_width(self, lw):
self._lw = lw
def set_source_rgb(self, r, g, b):
self._rgb = (r, g, b)
## path methods
def _line_to(self, x, y):
self._add_move()
x1, y1 = self._mxy
self._xy = x, y
x2, y2 = self._mxy = self._m * self._xy
if not points_equal(x1, y1, x2, y2):
self._dwg.append("L", x2, y2)
def _add_move(self):
self._dwg.move_to(*self._mxy)
def move_to(self, x, y):
self._xy = (x, y)
self._mxy = self._m * self._xy
def line_to(self, x, y):
self._line_to(x, y)
def _arc(self, xc, yc, radius, angle1, angle2, direction):
x1, y1 = radius * math.cos(angle1) + xc, radius * math.sin(angle1) + yc
x4, y4 = radius * math.cos(angle2) + xc, radius * math.sin(angle2) + yc
# XXX direction seems not needed for small arcs
ax = x1 - xc
ay = y1 - yc
bx = x4 - xc
by = y4 - yc
q1 = ax * ax + ay * ay
q2 = q1 + ax * bx + ay * by
k2 = 4/3 * ((2 * q1 * q2)**0.5 - q2) / (ax * by - ay * bx)
x2 = xc + ax - k2 * ay
y2 = yc + ay + k2 * ax
x3 = xc + bx + k2 * by
y3 = yc + by - k2 * bx
mx1, my1 = self._m * (x1, y1)
mx2, my2 = self._m * (x2, y2)
mx3, my3 = self._m * (x3, y3)
mx4, my4 = self._m * (x4, y4)
mxc, myc = self._m * (xc, yc)
self._add_move()
self._dwg.append("C", mx4, my4, mx2, my2, mx3, my3)
self._xy = (x4, y4)
self._mxy = (mx4, my4)
def arc(self, xc, yc, radius, angle1, angle2):
self._arc(xc, yc, radius, angle1, angle2, 1)
def arc_negative(self, xc, yc, radius, angle1, angle2):
self._arc(xc, yc, radius, angle1, angle2, -1)
def curve_to(self, x1, y1, x2, y2, x3, y3):
# mx0,my0 = self._m*self._xy
mx1, my1 = self._m * (x1, y1)
mx2, my2 = self._m * (x2, y2)
mx3, my3 = self._m * (x3, y3)
self._add_move()
self._dwg.append("C", mx3, my3, mx1, my1, mx2, my2) # destination first!
self._xy = (x3, y3)
def stroke(self):
# print('stroke stack-level=',len(self._stack),'lastpath=',self._last_path,)
self._last_path = self._dwg.stroke(rgb=self._rgb, lw=self._lw)
self._xy = (0, 0)
def fill(self):
self._xy = (0, 0)
raise NotImplementedError()
def select_font_face(self, ff):
self._ff = ff
def set_font_size(self, fs):
self._fs = fs
def show_text(self, text, **args):
params = {"ff": self._ff, "fs": self._fs, "lw": self._lw, "rgb": self._rgb}
params.update(args)
mx0, my0 = self._m * self._xy
self._dwg.append("T", mx0, my0, text, params)
def text_extents(self, text):
fs = self._fs
# XXX ugly hack! Fix Boxes.text() !
return (0, 0, 0.6 * fs * len(text), 0.65 * fs, fs * 0.1, 0)
def rectangle(self, x, y, width, height):
# todo: better check for empty path?
self.stroke()
self.move_to(x, y)
self.line_to(x + width, y)
self.line_to(x + width, y + height)
self.line_to(x, y + height)
self.line_to(x, y)
self.stroke()
def get_current_point(self):
return self._xy
def flush(self):
pass
# todo: check, if needed
# self.stroke()
## additional methods
def new_part(self):
self._dwg.new_part()
class SVGSurface(Surface):
def finish(self):
import svgwrite
extents = self.extents()
self.move_offset(-extents.xmin + PADDING,
-extents.ymin + PADDING)
w = extents.width + 2 * PADDING
h = extents.height + 2 * PADDING
dwg = svgwrite.Drawing(filename=self._fname, debug=False)
# dwg.debug = False
dwg["width"] = f"{w:.2f}mm"
dwg["height"] = f"{h:.2f}mm"
dwg["viewBox"] = f"0.0 0.0 {w:.2f} {h:.2f}"
for i, part in enumerate(self.parts):
if not part.pathes:
continue
g = dwg.add(
dwg.g(
id=f"p-{i}",
style="fill:none;stroke-linecap:round;stroke-linejoin:round;",
)
)
for j, path in enumerate(part.pathes):
p = []
x, y = 0, 0
path.faster_edges()
for c in path.path:
x0, y0 = x, y
C, x, y = c[0:3]
if C == "M":
p.append(f"M {x:.3f} {y:.3f}")
elif C == "L":
p.append(f"L {x:.3f} {y:.3f}")
elif C == "C":
x1, y1, x2, y2 = c[3:]
p.append(
f"C {x1:.3f} {y1:.3f} {x2:.3f} {y2:.3f} {x:.3f} {y:.3f}"
)
elif C == "T":
text, params = c[3:]
style = f"font: {params['ff']} ; fill: {rgb_to_svg_color(*params['rgb'])}"
g.add(
dwg.text(
text,
x=[x],
y=[y],
font_size=f"{params['fs']}px",
style=style,
)
)
else:
print("Unknown", c)
color = (
random_svg_color()
if RANDOMIZE_COLORS
else rgb_to_svg_color(*path.params["rgb"])
)
if p: # todo: might be empty since text is not implemented yet
g.add(
dwg.path(
d=" ".join(p), stroke=color, stroke_width=path.params["lw"]
)
)
dwg.save(pretty=True)
class PSSurface(Surface):
def finish(self):
extents = self.extents()
self.move_offset(-extents.xmin + PADDING,
-extents.ymin + PADDING)
w = extents.width + 2 * PADDING
h = extents.height + 2 * PADDING
f = open(self._fname, "w")
f.write("%!PS-Adobe-2.0\n")
f.write(
f"%%BoundingBox: 0 0 {w:.0f} {h:.0f}\n\n"
)
# f.write(f"%%DocumentMedia: \d+x\d+mm ((\d+) (\d+)) 0 \("
# dwg['width']=f'{w:.2f}mm'
# dwg['height']=f'{h:.2f}mm'
for i, part in enumerate(self.parts):
if not part.pathes:
continue
# g = dwg.add( dwg.g(id=f'p-{i}',style='fill:none;stroke-linecap:round;stroke-linejoin:round;') )
for j, path in enumerate(part.pathes):
p = []
x, y = 0, 0
path.faster_edges()
for c in path.path:
x0, y0 = x, y
C, x, y = c[0:3]
if C == "M":
p.append(f"{x:.3f} {y:.3f} moveto")
elif C == "L":
p.append(f"{x:.3f} {y:.3f} lineto")
elif C == "C":
x1, y1, x2, y2 = c[3:]
p.append(
f"{x1:.3f} {y1:.3f} {x2:.3f} {y2:.3f} {x:.3f} {y:.3f} curveto"
)
elif C == "T":
text, params = c[3:]
text = text.replace("(", "r\(").replace(")", r"\)")
color = " ".join((f"{c:.2f}"
for c in params["rgb"]))
f.write(f"/{params['ff']} findfont\n")
f.write(f"{params['fs']*72 / 25.4} scalefont\n")
f.write("setfont\n")
f.write(f"{color} setrgbcolor\n")
f.write(f"{x:.3f} {y:.3f} moveto\n")
f.write(f"({text}) show\n\n")
else:
print("Unknown", c)
color = (
random_svg_color()
if RANDOMIZE_COLORS
else rgb_to_svg_color(*path.params["rgb"])
)
if p: # todo: might be empty since text is not implemented yet
color = " ".join((f"{c:.2f}"
for c in path.params["rgb"]))
f.write("newpath\n")
f.write("\n".join(p))
f.write("\n")
f.write(f"{path.params['lw']} setlinewidth\n")
f.write(f"{color} setrgbcolor\n")
f.write("stroke\n\n")
f.write(
"""
showpage
%%Trailer
%%EOF
"""
)
f.close()
from random import random
def random_svg_color():
r, g, b = random(), random(), random()
return f"rgb({r*255:.0f},{g*255:.0f},{b*255:.0f})"
def rgb_to_svg_color(r, g, b):
return f"rgb({r*255:.0f},{g*255:.0f},{b*255:.0f})"
def line_intersection(line1, line2):
xdiff = (line1[0][0] - line1[1][0], line2[0][0] - line2[1][0])
ydiff = (line1[0][1] - line1[1][1], line2[0][1] - line2[1][1])
def det(a, b):
return a[0] * b[1] - a[1] * b[0]
div = det(xdiff, ydiff)
if div == 0:
# todo: deal with paralel line intersection / overlay
return False, None, None
d = (det(*line1), det(*line2))
x = det(d, xdiff) / div
y = det(d, ydiff) / div
on_segments = (
(x + EPS >= min(line1[0][0], line1[1][0])),
(x + EPS >= min(line2[0][0], line2[1][0])),
(x - EPS <= max(line1[0][0], line1[1][0])),
(x - EPS <= max(line2[0][0], line2[1][0])),
(y + EPS >= min(line1[0][1], line1[1][1])),
(y + EPS >= min(line2[0][1], line2[1][1])),
(y - EPS <= max(line1[0][1], line1[1][1])),
(y - EPS <= max(line2[0][1], line2[1][1])),
)
return min(on_segments), x, y