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authorjaseg <git@jaseg.de>2021-06-06 13:25:45 +0200
committerjaseg <git@jaseg.de>2021-06-06 13:25:45 +0200
commit5a5ba2b709f01b2100cd767a25a41737541ad53c (patch)
tree6362ca960945e08d4a77b7f059e971e6099217c9 /gerber/render/cairo_backend.py
parent8bad573131e4c91782425d81a141dd656b622d7b (diff)
parent72257258edf16cbda691483ef1fa722192ac0d38 (diff)
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Graft pcb-tools upstream onto gerbonara tree
Diffstat (limited to 'gerber/render/cairo_backend.py')
-rw-r--r--gerber/render/cairo_backend.py616
1 files changed, 616 insertions, 0 deletions
diff --git a/gerber/render/cairo_backend.py b/gerber/render/cairo_backend.py
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+++ b/gerber/render/cairo_backend.py
@@ -0,0 +1,616 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+# http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+try:
+ import cairo
+except ImportError:
+ import cairocffi as cairo
+
+from operator import mul
+import tempfile
+import copy
+import os
+
+from .render import GerberContext, RenderSettings
+from .theme import THEMES
+from ..primitives import *
+from ..utils import rotate_point
+
+from io import BytesIO
+
+
+class GerberCairoContext(GerberContext):
+
+ def __init__(self, scale=300):
+ super(GerberCairoContext, self).__init__()
+ self.scale = (scale, scale)
+ self.surface = None
+ self.surface_buffer = None
+ self.ctx = None
+ self.active_layer = None
+ self.active_matrix = None
+ self.output_ctx = None
+ self.has_bg = False
+ self.origin_in_inch = None
+ self.size_in_inch = None
+ self._xform_matrix = None
+ self._render_count = 0
+
+ @property
+ def origin_in_pixels(self):
+ return (self.scale_point(self.origin_in_inch)
+ if self.origin_in_inch is not None else (0.0, 0.0))
+
+ @property
+ def size_in_pixels(self):
+ return (self.scale_point(self.size_in_inch)
+ if self.size_in_inch is not None else (0.0, 0.0))
+
+ def set_bounds(self, bounds, new_surface=False):
+ origin_in_inch = (bounds[0][0], bounds[1][0])
+ size_in_inch = (abs(bounds[0][1] - bounds[0][0]),
+ abs(bounds[1][1] - bounds[1][0]))
+ size_in_pixels = self.scale_point(size_in_inch)
+ self.origin_in_inch = origin_in_inch if self.origin_in_inch is None else self.origin_in_inch
+ self.size_in_inch = size_in_inch if self.size_in_inch is None else self.size_in_inch
+ self._xform_matrix = cairo.Matrix(xx=1.0, yy=-1.0,
+ x0=-self.origin_in_pixels[0],
+ y0=self.size_in_pixels[1])
+ if (self.surface is None) or new_surface:
+ self.surface_buffer = tempfile.NamedTemporaryFile()
+ self.surface = cairo.SVGSurface(self.surface_buffer, size_in_pixels[0], size_in_pixels[1])
+ self.output_ctx = cairo.Context(self.surface)
+
+ def render_layer(self, layer, filename=None, settings=None, bgsettings=None,
+ verbose=False, bounds=None):
+ if settings is None:
+ settings = THEMES['default'].get(layer.layer_class, RenderSettings())
+ if bgsettings is None:
+ bgsettings = THEMES['default'].get('background', RenderSettings())
+
+ if self._render_count == 0:
+ if verbose:
+ print('[Render]: Rendering Background.')
+ self.clear()
+ if bounds is not None:
+ self.set_bounds(bounds)
+ else:
+ self.set_bounds(layer.bounds)
+ self.paint_background(bgsettings)
+ if verbose:
+ print('[Render]: Rendering {} Layer.'.format(layer.layer_class))
+ self._render_count += 1
+ self._render_layer(layer, settings)
+ if filename is not None:
+ self.dump(filename, verbose)
+
+ def render_layers(self, layers, filename, theme=THEMES['default'],
+ verbose=False, max_width=800, max_height=600):
+ """ Render a set of layers
+ """
+ # Calculate scale parameter
+ x_range = [10000, -10000]
+ y_range = [10000, -10000]
+ for layer in layers:
+ bounds = layer.bounds
+ if bounds is not None:
+ layer_x, layer_y = bounds
+ x_range[0] = min(x_range[0], layer_x[0])
+ x_range[1] = max(x_range[1], layer_x[1])
+ y_range[0] = min(y_range[0], layer_y[0])
+ y_range[1] = max(y_range[1], layer_y[1])
+ width = x_range[1] - x_range[0]
+ height = y_range[1] - y_range[0]
+
+ scale = math.floor(min(float(max_width)/width, float(max_height)/height))
+ self.scale = (scale, scale)
+
+ self.clear()
+
+ # Render layers
+ bgsettings = theme['background']
+ for layer in layers:
+ settings = theme.get(layer.layer_class, RenderSettings())
+ self.render_layer(layer, settings=settings, bgsettings=bgsettings,
+ verbose=verbose)
+ self.dump(filename, verbose)
+
+ def dump(self, filename=None, verbose=False):
+ """ Save image as `filename`
+ """
+ try:
+ is_svg = os.path.splitext(filename.lower())[1] == '.svg'
+ except:
+ is_svg = False
+ if verbose:
+ print('[Render]: Writing image to {}'.format(filename))
+ if is_svg:
+ self.surface.finish()
+ self.surface_buffer.flush()
+ with open(filename, "wb") as f:
+ self.surface_buffer.seek(0)
+ f.write(self.surface_buffer.read())
+ f.flush()
+ else:
+ return self.surface.write_to_png(filename)
+
+ def dump_str(self):
+ """ Return a byte-string containing the rendered image.
+ """
+ fobj = BytesIO()
+ self.surface.write_to_png(fobj)
+ return fobj.getvalue()
+
+ def dump_svg_str(self):
+ """ Return a string containg the rendered SVG.
+ """
+ self.surface.finish()
+ self.surface_buffer.flush()
+ return self.surface_buffer.read()
+
+ def clear(self):
+ self.surface = None
+ self.output_ctx = None
+ self.has_bg = False
+ self.origin_in_inch = None
+ self.size_in_inch = None
+ self._xform_matrix = None
+ self._render_count = 0
+ self.surface_buffer = None
+
+ def _new_mask(self):
+ class Mask:
+ def __enter__(msk):
+ size_in_pixels = self.size_in_pixels
+ msk.surface = cairo.SVGSurface(None, size_in_pixels[0],
+ size_in_pixels[1])
+ msk.ctx = cairo.Context(msk.surface)
+ msk.ctx.translate(-self.origin_in_pixels[0], -self.origin_in_pixels[1])
+ return msk
+
+
+ def __exit__(msk, exc_type, exc_val, traceback):
+ if hasattr(msk.surface, 'finish'):
+ msk.surface.finish()
+
+ return Mask()
+
+ def _render_layer(self, layer, settings):
+ self.invert = settings.invert
+ # Get a new clean layer to render on
+ self.new_render_layer(mirror=settings.mirror)
+ for prim in layer.primitives:
+ self.render(prim)
+ # Add layer to image
+ self.flatten(settings.color, settings.alpha)
+
+ def _render_line(self, line, color):
+ start = self.scale_point(line.start)
+ end = self.scale_point(line.end)
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and line.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+
+ with self._clip_primitive(line):
+ with self._new_mask() as mask:
+ if isinstance(line.aperture, Circle):
+ width = line.aperture.diameter
+ mask.ctx.set_line_width(width * self.scale[0])
+ mask.ctx.set_line_cap(cairo.LINE_CAP_ROUND)
+ mask.ctx.move_to(*start)
+ mask.ctx.line_to(*end)
+ mask.ctx.stroke()
+
+ elif hasattr(line, 'vertices') and line.vertices is not None:
+ points = [self.scale_point(x) for x in line.vertices]
+ mask.ctx.set_line_width(0)
+ mask.ctx.move_to(*points[-1])
+ for point in points:
+ mask.ctx.line_to(*point)
+ mask.ctx.fill()
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_arc(self, arc, color):
+ center = self.scale_point(arc.center)
+ start = self.scale_point(arc.start)
+ end = self.scale_point(arc.end)
+ radius = self.scale[0] * arc.radius
+ two_pi = 2 * math.pi
+ angle1 = (arc.start_angle + two_pi) % two_pi
+ angle2 = (arc.end_angle + two_pi) % two_pi
+ if angle1 == angle2 and arc.quadrant_mode != 'single-quadrant':
+ # Make the angles slightly different otherwise Cario will draw nothing
+ angle2 -= 0.000000001
+ if isinstance(arc.aperture, Circle):
+ width = arc.aperture.diameter if arc.aperture.diameter != 0 else 0.001
+ else:
+ width = max(arc.aperture.width, arc.aperture.height, 0.001)
+
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and arc.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(arc):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(width * self.scale[0])
+ mask.ctx.set_line_cap(cairo.LINE_CAP_ROUND if isinstance(arc.aperture, Circle) else cairo.LINE_CAP_SQUARE)
+ mask.ctx.move_to(*start) # You actually have to do this...
+ if arc.direction == 'counterclockwise':
+ mask.ctx.arc(center[0], center[1], radius, angle1, angle2)
+ else:
+ mask.ctx.arc_negative(center[0], center[1], radius,
+ angle1, angle2)
+ mask.ctx.move_to(*end) # ...lame
+ mask.ctx.stroke()
+
+ #if isinstance(arc.aperture, Rectangle):
+ # print("Flash Rectangle Ends")
+ # print(arc.aperture.rotation * 180/math.pi)
+ # rect = arc.aperture
+ # width = self.scale[0] * rect.width
+ # height = self.scale[1] * rect.height
+ # for point, angle in zip((start, end), (angle1, angle2)):
+ # print("{} w {} h{}".format(point, rect.width, rect.height))
+ # mask.ctx.rectangle(point[0] - width/2.0,
+ # point[1] - height/2.0, width, height)
+ # mask.ctx.fill()
+
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_region(self, region, color):
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert) and region.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(region):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(0)
+ mask.ctx.set_line_cap(cairo.LINE_CAP_ROUND)
+ mask.ctx.move_to(*self.scale_point(region.primitives[0].start))
+ for prim in region.primitives:
+ if isinstance(prim, Line):
+ mask.ctx.line_to(*self.scale_point(prim.end))
+ else:
+ center = self.scale_point(prim.center)
+ radius = self.scale[0] * prim.radius
+ angle1 = prim.start_angle
+ angle2 = prim.end_angle
+ if prim.direction == 'counterclockwise':
+ mask.ctx.arc(center[0], center[1], radius,
+ angle1, angle2)
+ else:
+ mask.ctx.arc_negative(center[0], center[1], radius,
+ angle1, angle2)
+ mask.ctx.fill()
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_circle(self, circle, color):
+ center = self.scale_point(circle.position)
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and circle.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(circle):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(0)
+ mask.ctx.arc(center[0], center[1], (circle.radius * self.scale[0]), 0, (2 * math.pi))
+ mask.ctx.fill()
+
+ if hasattr(circle, 'hole_diameter') and circle.hole_diameter is not None and circle.hole_diameter > 0:
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR)
+ mask.ctx.arc(center[0], center[1], circle.hole_radius * self.scale[0], 0, 2 * math.pi)
+ mask.ctx.fill()
+
+ if (hasattr(circle, 'hole_width') and hasattr(circle, 'hole_height')
+ and circle.hole_width is not None and circle.hole_height is not None
+ and circle.hole_width > 0 and circle.hole_height > 0):
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if circle.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+ width, height = self.scale_point((circle.hole_width, circle.hole_height))
+ lower_left = rotate_point(
+ (center[0] - width / 2.0, center[1] - height / 2.0),
+ circle.rotation, center)
+ lower_right = rotate_point((center[0] + width / 2.0, center[1] - height / 2.0),
+ circle.rotation, center)
+ upper_left = rotate_point((center[0] - width / 2.0, center[1] + height / 2.0),
+ circle.rotation, center)
+ upper_right = rotate_point((center[0] + width / 2.0, center[1] + height / 2.0),
+ circle.rotation, center)
+ points = (lower_left, lower_right, upper_right, upper_left)
+ mask.ctx.move_to(*points[-1])
+ for point in points:
+ mask.ctx.line_to(*point)
+ mask.ctx.fill()
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_rectangle(self, rectangle, color):
+ lower_left = self.scale_point(rectangle.lower_left)
+ width, height = tuple([abs(coord) for coord in
+ self.scale_point((rectangle.width,
+ rectangle.height))])
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and rectangle.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(rectangle):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(0)
+ mask.ctx.rectangle(lower_left[0], lower_left[1], width, height)
+ mask.ctx.fill()
+
+ center = self.scale_point(rectangle.position)
+ if rectangle.hole_diameter > 0:
+ # Render the center clear
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if rectangle.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+
+ mask.ctx.arc(center[0], center[1], rectangle.hole_radius * self.scale[0], 0, 2 * math.pi)
+ mask.ctx.fill()
+
+ if rectangle.hole_width > 0 and rectangle.hole_height > 0:
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if rectangle.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+ width, height = self.scale_point((rectangle.hole_width, rectangle.hole_height))
+ lower_left = rotate_point((center[0] - width/2.0, center[1] - height/2.0), rectangle.rotation, center)
+ lower_right = rotate_point((center[0] + width/2.0, center[1] - height/2.0), rectangle.rotation, center)
+ upper_left = rotate_point((center[0] - width / 2.0, center[1] + height / 2.0), rectangle.rotation, center)
+ upper_right = rotate_point((center[0] + width / 2.0, center[1] + height / 2.0), rectangle.rotation, center)
+ points = (lower_left, lower_right, upper_right, upper_left)
+ mask.ctx.move_to(*points[-1])
+ for point in points:
+ mask.ctx.line_to(*point)
+ mask.ctx.fill()
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_obround(self, obround, color):
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and obround.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(obround):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(0)
+
+ # Render circles
+ for circle in (obround.subshapes['circle1'], obround.subshapes['circle2']):
+ center = self.scale_point(circle.position)
+ mask.ctx.arc(center[0], center[1], (circle.radius * self.scale[0]), 0, (2 * math.pi))
+ mask.ctx.fill()
+
+ # Render Rectangle
+ rectangle = obround.subshapes['rectangle']
+ lower_left = self.scale_point(rectangle.lower_left)
+ width, height = tuple([abs(coord) for coord in
+ self.scale_point((rectangle.width,
+ rectangle.height))])
+ mask.ctx.rectangle(lower_left[0], lower_left[1], width, height)
+ mask.ctx.fill()
+
+ center = self.scale_point(obround.position)
+ if obround.hole_diameter > 0:
+ # Render the center clear
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR)
+ mask.ctx.arc(center[0], center[1], obround.hole_radius * self.scale[0], 0, 2 * math.pi)
+ mask.ctx.fill()
+
+ if obround.hole_width > 0 and obround.hole_height > 0:
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if rectangle.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+ width, height =self.scale_point((obround.hole_width, obround.hole_height))
+ lower_left = rotate_point((center[0] - width / 2.0, center[1] - height / 2.0),
+ obround.rotation, center)
+ lower_right = rotate_point((center[0] + width / 2.0, center[1] - height / 2.0),
+ obround.rotation, center)
+ upper_left = rotate_point((center[0] - width / 2.0, center[1] + height / 2.0),
+ obround.rotation, center)
+ upper_right = rotate_point((center[0] + width / 2.0, center[1] + height / 2.0),
+ obround.rotation, center)
+ points = (lower_left, lower_right, upper_right, upper_left)
+ mask.ctx.move_to(*points[-1])
+ for point in points:
+ mask.ctx.line_to(*point)
+ mask.ctx.fill()
+
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_polygon(self, polygon, color):
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if (not self.invert)
+ and polygon.level_polarity == 'dark'
+ else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(polygon):
+ with self._new_mask() as mask:
+
+ vertices = polygon.vertices
+ mask.ctx.set_line_width(0)
+ mask.ctx.set_line_cap(cairo.LINE_CAP_ROUND)
+ # Start from before the end so it is easy to iterate and make sure
+ # it is closed
+ mask.ctx.move_to(*self.scale_point(vertices[-1]))
+ for v in vertices:
+ mask.ctx.line_to(*self.scale_point(v))
+ mask.ctx.fill()
+
+ center = self.scale_point(polygon.position)
+ if polygon.hole_radius > 0:
+ # Render the center clear
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if polygon.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+ mask.ctx.set_line_width(0)
+ mask.ctx.arc(center[0],
+ center[1],
+ polygon.hole_radius * self.scale[0], 0, 2 * math.pi)
+ mask.ctx.fill()
+
+ if polygon.hole_width > 0 and polygon.hole_height > 0:
+ mask.ctx.set_operator(cairo.OPERATOR_CLEAR
+ if polygon.level_polarity == 'dark'
+ and (not self.invert)
+ else cairo.OPERATOR_OVER)
+ width, height = self.scale_point((polygon.hole_width, polygon.hole_height))
+ lower_left = rotate_point((center[0] - width / 2.0, center[1] - height / 2.0),
+ polygon.rotation, center)
+ lower_right = rotate_point((center[0] + width / 2.0, center[1] - height / 2.0),
+ polygon.rotation, center)
+ upper_left = rotate_point((center[0] - width / 2.0, center[1] + height / 2.0),
+ polygon.rotation, center)
+ upper_right = rotate_point((center[0] + width / 2.0, center[1] + height / 2.0),
+ polygon.rotation, center)
+ points = (lower_left, lower_right, upper_right, upper_left)
+ mask.ctx.move_to(*points[-1])
+ for point in points:
+ mask.ctx.line_to(*point)
+ mask.ctx.fill()
+
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_drill(self, circle, color=None):
+ color = color if color is not None else self.drill_color
+ self._render_circle(circle, color)
+
+ def _render_slot(self, slot, color):
+ start = map(mul, slot.start, self.scale)
+ end = map(mul, slot.end, self.scale)
+
+ width = slot.diameter
+
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if slot.level_polarity == 'dark' and
+ (not self.invert) else cairo.OPERATOR_CLEAR)
+ with self._clip_primitive(slot):
+ with self._new_mask() as mask:
+ mask.ctx.set_line_width(width * self.scale[0])
+ mask.ctx.set_line_cap(cairo.LINE_CAP_ROUND)
+ mask.ctx.move_to(*start)
+ mask.ctx.line_to(*end)
+ mask.ctx.stroke()
+ self.ctx.mask_surface(mask.surface, self.origin_in_pixels[0])
+
+ def _render_amgroup(self, amgroup, color):
+ for primitive in amgroup.primitives:
+ self.render(primitive)
+
+ def _render_test_record(self, primitive, color):
+ position = [pos + origin for pos, origin in
+ zip(primitive.position, self.origin_in_inch)]
+ self.ctx.select_font_face(
+ 'monospace', cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
+ self.ctx.set_font_size(13)
+ self._render_circle(Circle(position, 0.015), color)
+ self.ctx.set_operator(cairo.OPERATOR_OVER
+ if primitive.level_polarity == 'dark' and
+ (not self.invert) else cairo.OPERATOR_CLEAR)
+ self.ctx.move_to(*[self.scale[0] * (coord + 0.015) for coord in position])
+ self.ctx.scale(1, -1)
+ self.ctx.show_text(primitive.net_name)
+ self.ctx.scale(1, -1)
+
+ def new_render_layer(self, color=None, mirror=False):
+ size_in_pixels = self.scale_point(self.size_in_inch)
+ matrix = copy.copy(self._xform_matrix)
+ layer = cairo.SVGSurface(None, size_in_pixels[0], size_in_pixels[1])
+ ctx = cairo.Context(layer)
+
+ if self.invert:
+ ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0)
+ ctx.set_operator(cairo.OPERATOR_OVER)
+ ctx.paint()
+ if mirror:
+ matrix.xx = -1.0
+ matrix.x0 = self.origin_in_pixels[0] + self.size_in_pixels[0]
+ self.ctx = ctx
+ self.ctx.set_matrix(matrix)
+ self.active_layer = layer
+ self.active_matrix = matrix
+
+ def flatten(self, color=None, alpha=None):
+ color = color if color is not None else self.color
+ alpha = alpha if alpha is not None else self.alpha
+ self.output_ctx.set_source_rgba(color[0], color[1], color[2], alpha)
+ self.output_ctx.mask_surface(self.active_layer)
+ self.ctx = None
+ self.active_layer = None
+ self.active_matrix = None
+
+ def paint_background(self, settings=None):
+ color = settings.color if settings is not None else self.background_color
+ alpha = settings.alpha if settings is not None else 1.0
+ if not self.has_bg:
+ self.has_bg = True
+ self.output_ctx.set_source_rgba(color[0], color[1], color[2], alpha)
+ self.output_ctx.paint()
+
+ def _clip_primitive(self, primitive):
+ """ Clip rendering context to pixel-aligned bounding box
+
+ Calculates pixel- and axis- aligned bounding box, and clips current
+ context to that region. Improves rendering speed significantly. This
+ returns a context manager, use as follows:
+
+ with self._clip_primitive(some_primitive):
+ do_rendering_stuff()
+ do_more_rendering stuff(with, arguments)
+
+ The context manager will reset the context's clipping region when it
+ goes out of scope.
+
+ """
+ class Clip:
+ def __init__(clp, primitive):
+ x_range, y_range = primitive.bounding_box
+ xmin, xmax = x_range
+ ymin, ymax = y_range
+
+ # Round bounds to the nearest pixel outside of the primitive
+ clp.xmin = math.floor(self.scale[0] * xmin)
+ clp.xmax = math.ceil(self.scale[0] * xmax)
+
+ # We need to offset Y to take care of the difference in y-pos
+ # caused by flipping the axis.
+ clp.ymin = math.floor(
+ (self.scale[1] * ymin) - math.ceil(self.origin_in_pixels[1]))
+ clp.ymax = math.floor(
+ (self.scale[1] * ymax) - math.floor(self.origin_in_pixels[1]))
+
+ # Calculate width and height, rounded to the nearest pixel
+ clp.width = abs(clp.xmax - clp.xmin)
+ clp.height = abs(clp.ymax - clp.ymin)
+
+ def __enter__(clp):
+ # Clip current context to primitive's bounding box
+ self.ctx.rectangle(clp.xmin, clp.ymin, clp.width, clp.height)
+ self.ctx.clip()
+
+ def __exit__(clp, exc_type, exc_val, traceback):
+ # Reset context clip region
+ self.ctx.reset_clip()
+
+ return Clip(primitive)
+
+ def scale_point(self, point):
+ return tuple([coord * scale for coord, scale in zip(point, self.scale)])