diff options
Diffstat (limited to 'gerbonara/gerber/graphic_primitives.py')
| -rw-r--r-- | gerbonara/gerber/graphic_primitives.py | 259 |
1 files changed, 225 insertions, 34 deletions
diff --git a/gerbonara/gerber/graphic_primitives.py b/gerbonara/gerber/graphic_primitives.py index 966cac1..3052322 100644 --- a/gerbonara/gerber/graphic_primitives.py +++ b/gerbonara/gerber/graphic_primitives.py @@ -10,7 +10,6 @@ from .gerber_statements import * class GraphicPrimitive: _ : KW_ONLY polarity_dark : bool = True - unit : str = None def rotate_point(x, y, angle, cx=0, cy=0): @@ -19,6 +18,26 @@ def rotate_point(x, y, angle, cx=0, cy=0): return (cx + (x - cx) * math.cos(-angle) - (y - cy) * math.sin(-angle), cy + (x - cx) * math.sin(-angle) + (y - cy) * math.cos(-angle)) +def min_none(a, b): + if a is None: + return b + if b is None: + return a + return min(a, b) + +def max_none(a, b): + if a is None: + return b + if b is None: + return a + return max(a, b) + +def add_bounds(b1, b2): + (min_x_1, min_y_1), (max_x_1, max_y_1) = b1 + (min_x_2, min_y_2), (max_x_2, max_y_2) = b2 + min_x, min_y = min_none(min_x_1, min_x_2), min_none(min_y_1, min_y_2) + max_x, max_y = max_none(max_x_1, max_x_2), max_none(max_y_1, max_y_2) + return ((min_x, min_y), (max_x, max_y)) @dataclass class Circle(GraphicPrimitive): @@ -26,9 +45,12 @@ class Circle(GraphicPrimitive): y : float r : float # Here, we use radius as common in modern computer graphics, not diameter as gerber uses. - def bounds(self): + def bounding_box(self): return ((self.x-self.r, self.y-self.r), (self.x+self.r, self.y+self.r)) + def to_svg(self): + return 'circle', (), dict(cx=x, cy=y, r=r) + @dataclass class Obround(GraphicPrimitive): @@ -38,30 +60,121 @@ class Obround(GraphicPrimitive): h : float rotation : float # radians! - def decompose(self): - ''' decompose obround to two circles and one rectangle ''' - - cx = self.x + self.w/2 - cy = self.y + self.h/2 - + def to_line(self): if self.w > self.h: - x = self.x + self.h/2 - yield Circle(x, cy, self.h/2) - yield Circle(x + self.w, cy, self.h/2) - yield Rectangle(x, self.y, self.w - self.h, self.h) + w, a, b = self.h, self.w, 0 + else: + w, a, b = self.w, 0, self.h + return Line( + *rotate_point(self.x-a/2, self.y-b/2, self.rotation, self.x, self.y), + *rotate_point(self.x+a/2, self.y+b/2, self.rotation, self.x, self.y), + w) + + def bounding_box(self): + return self.to_line().bounding_box() + + def to_svg(self): + return self.to_line().to_svg() + + +def arc_bounds(x1, y1, x2, y2, cx, cy, clockwise): + # This is one of these problems typical for computer geometry where out of nowhere a seemingly simple task just + # happens to be anything but in practice. + # + # Online there are a number of algorithms to be found solving this problem. Often, they solve the more general + # problem for elliptic arcs. We can keep things simple here since we only have circular arcs. + # + # This solution manages to handle circular arcs given in gerber format (with explicit center and endpoints, plus + # sweep direction instead of a format with e.g. angles and radius) without any trigonometric functions (e.g. atan2). + + # Center arc on cx, cy + x1 -= cx + x2 -= cx + y1 -= cy + y2 -= cy + clockwise = bool(clockwise) # bool'ify for XOR/XNOR below + + # Calculate radius + r = math.sqrt(x1**2 + y1**2) + + # Calculate in which half-planes (north/south, west/east) P1 and P2 lie. + # Note that we assume the y axis points upwards, as in Gerber and maths. + # SVG has its y axis pointing downwards. + p1_west = x1 < 0 + p1_north = y1 > 0 + p2_west = x2 < 0 + p2_north = y2 > 0 + + # Calculate bounding box of P1 and P2 + min_x = min(x1, x2) + min_y = min(y1, y2) + max_x = max(x1, x2) + max_y = max(y1, y2) + + # North + # ^ + # | + # |(0,0) + # West <-----X-----> East + # | + # +Y | + # ^ v + # | South + # | + # +-----> +X + # + # Check whether the arc sweeps over any coordinate axes. If it does, add the intersection point to the bounding box. + # Note that, since this intersection point is at radius r, it has coordinate e.g. (0, r) for the north intersection. + # Since we know that the points lie on either side of the coordinate axis, the '0' coordinate of the intersection + # point will not change the bounding box in that axis--only its 'r' coordinate matters. We also know that the + # absolute value of that coordinate will be greater than or equal to the old coordinate in that direction since the + # intersection with the axis is the point where the full circle is tangent to the AABB. Thus, we can blindly set the + # corresponding coordinate of the bounding box without min()/max()'ing first. + + # Handle north/south halfplanes + if p1_west != p2_west: # arc starts in west half-plane, ends in east half-plane + if p1_west == clockwise: # arc is clockwise west -> east or counter-clockwise east -> west + max_y = r # add north to bounding box + else: # arc is counter-clockwise west -> east or clockwise east -> west + min_y = -r # south + else: # Arc starts and ends in same halfplane west/east + # Since both points are on the arc (at same radius) in one halfplane, we can use the y coord as a proxy for + # angle comparisons. + small_arc_is_north_to_south = y1 > y2 + small_arc_is_clockwise = small_arc_is_north_to_south == p1_west + if small_arc_is_clockwise != clockwise: + min_y, max_y = -r, r # intersect aabb with both north and south + + # Handle west/east halfplanes + if p1_north != p2_north: + if p1_north == clockwise: + max_x = r # east + else: + min_x = -r # west + else: + small_arc_is_west_to_east = x1 < x2 + small_arc_is_clockwise = small_arc_is_west_to_east == p1_north + if small_arc_is_clockwise != clockwise: + min_x, max_x = -r, r # intersect aabb with both north and south - elif self.h > self.w: - y = self.y + self.w/2 - yield Circle(cx, y, self.w/2) - yield Circle(cx, y + self.h, self.w/2) - yield Rectangle(self.x, y, self.w, self.h - self.w) + return (min_x+cx, min_y+cy), (max_x+cx, max_y+cy) - else: - yield Circle(cx, cy, self.w/2) - def bounds(self): - return ((self.x-self.w/2, self.y-self.h/2), (self.x+self.w/2, self.y+self.h/2)) +def point_distance(a, b): + return math.sqrt((b[0] - a[0])**2 + (b[1] - a[1])**2) +def point_line_distance(l1, l2, p): + x1, y1 = l1 + x2, y2 = l2 + x0, y0 = p + return abs((x2-x1)*(y1-y0) - (x1-x0)*(y2-y1))/point_distance(l1, l2) + +def svg_arc(old, new, center, clockwise): + r = point_distance(old, new) + d = point_line_distance(old, new, center) + sweep_flag = int(clockwise) + large_arc = int((d > 0) == clockwise) # FIXME check signs + return f'A {r:.6} {r:.6} {large_arc} {sweep_flag} {new[0]:.6} {new[1]:.6}' @dataclass class ArcPoly(GraphicPrimitive): @@ -72,15 +185,23 @@ class ArcPoly(GraphicPrimitive): outline : [(float,)] # list of radii of segments, must be either None (all segments are straight lines) or same length as outline. # Straight line segments have None entry. - arc_centers : [(float,)] + arc_centers : [(float,)] = None @property def segments(self): - return itertools.zip_longest(self.outline[:-1], self.outline[1:], self.radii or []) + ol = self.outline + return itertools.zip_longest(ol, ol[1:] + [ol[0]], self.arc_centers) + + def bounding_box(self): + bbox = (None, None), (None, None) + for (x1, y1), (x2, y2), arc in self.segments: + if arc: + clockwise, center = arc + bbox = add_bounds(bbox, arc_bounds(x1, y1, x2, y2, *center, clockwise)) - def bounds(self): - for (x1, y1), (x2, y2), radius in self.segments: - return + else: + line_bounds = (min(x1, x2), min(y1, y2)), (max(x1, x2), max(y1, y2)) + bbox = add_bounds(bbox, line_bounds) def __len__(self): return len(self.outline) @@ -88,6 +209,21 @@ class ArcPoly(GraphicPrimitive): def __bool__(self): return bool(len(self)) + def _path_d(self): + if len(self.outline) == 0: + return + + yield f'M {outline[0][0]:.6}, {outline[0][1]:.6}' + for old, new, arc in self.segments: + if not arc: + yield f'L {new[0]:.6} {new[1]:.6}' + else: + clockwise, center = arc + yield svg_arc(old, new, center, clockwise) + + def to_svg(self): + return 'path', [], {'d': ' '.join(self._path_d())} + @dataclass class Line(GraphicPrimitive): @@ -97,7 +233,14 @@ class Line(GraphicPrimitive): y2 : float width : float - # FIXME bounds + def bounding_box(self): + r = self.width / 2 + return add_bounds(Circle(self.x1, self.y1, r).bounding_box(), Circle(self.x2, self.y2, r).bounding_box()) + + def to_svg(self): + return 'path', [], dict( + d=f'M {self.x1:.6} {self.y1:.6} L {self.x2:.6} {self.y2:.6}', + style=f'stroke-width: {self.width:.6}; stroke-linecap: round') @dataclass class Arc(GraphicPrimitive): @@ -107,10 +250,36 @@ class Arc(GraphicPrimitive): y2 : float cx : float cy : float - flipped : bool + clockwise : bool width : float - # FIXME bounds + def bounding_box(self): + r = self.w/2 + endpoints = add_bounds(Circle(self.x1, self.y1, r).bounding_box(), Circle(self.x2, self.y2, r).bounding_box()) + + arc_r = point_distance((self.cx, self.cy), (self.x1, self.y1)) + + # extend C -> P1 line by line width / 2 along radius + dx, dy = self.x1 - self.cx, self.y1 - self.cy + x1 = self.x1 + dx/arc_r * r + y1 = self.y1 + dy/arc_r * r + + # same for C -> P2 + dx, dy = self.x2 - self.cx, self.y2 - self.cy + x2 = self.x2 + dx/arc_r * r + y2 = self.y2 + dy/arc_r * r + + arc = arc_bounds(x1, y1, x2, y2, cx, cy, self.clockwise) + return add_bounds(endpoints, arc) # FIXME add "include_center" switch + + def to_svg(self): + arc = svg_arc((self.x1, self.y1), (self.x2, self.y2), (self.cx, self.cy), self.clockwise) + return 'path', [], dict( + d=f'M {self.x1:.6} {self.y1:.6} {arc}', + style=f'stroke-width: {self.width:.6}; stroke-linecap: round') + +def svg_rotation(angle_rad): + return f'rotation({angle_rad/math.pi*180:.4})' @dataclass class Rectangle(GraphicPrimitive): @@ -121,13 +290,29 @@ class Rectangle(GraphicPrimitive): h : float rotation : float # radians, around center! - def bounds(self): - return ((self.x, self.y), (self.x+self.w, self.y+self.h)) + def bounding_box(self): + return self.to_arc_poly().bounding_box() + + def to_arc_poly(self): + sin, cos = math.sin(self.rotation), math.cos(self.rotation) + sw, cw = sin*self.w/2, cos*self.w/2 + sh, ch = sin*self.h/2, cos*self.h/2 + x, y = self.x, self.y + return ArcPoly([ + (x - (cw+sh), y - (ch+sw)), + (x - (cw+sh), y + (ch+sw)), + (x + (cw+sh), y + (ch+sw)), + (x + (cw+sh), y - (ch+sw)), + ]) @property def center(self): return self.x + self.w/2, self.y + self.h/2 + def to_svg(self): + x, y = self.x - self.w/2, self.y - self.h/2 + return 'rect', [], dict(x=x, y=y, w=self.w, h=self.h, transform=svg_rotation(self.rotation)) + class RegularPolygon(GraphicPrimitive): x : float @@ -136,13 +321,19 @@ class RegularPolygon(GraphicPrimitive): n : int rotation : float # radians! - def decompose(self): - ''' convert n-sided gerber polygon to normal Region defined by outline ''' + def to_arc_poly(self): + ''' convert n-sided gerber polygon to normal ArcPoly defined by outline ''' delta = 2*math.pi / self.n - yield Region([ + return ArcPoly([ (self.x + math.cos(self.rotation + i*delta) * self.r, self.y + math.sin(self.rotation + i*delta) * self.r) for i in range(self.n) ]) + def bounding_box(self): + return self.to_arc_poly().bounding_box() + + def to_svg(self): + return self.to_arc_poly().to_svg() + |