Allow negative render of soldermask per #50

Update example code and rendering to show change

1 files changed, 84 insertions, 37 deletions

diff --git a/gerber/render/cairo_backend.py b/gerber/render/cairo_backend.py
index 345f331..6aaffd4 100644
--- a/gerber/render/cairo_backend.py
+++ b/gerber/render/cairo_backend.py
@@ -25,6 +25,7 @@ import tempfile
 

 from ..primitives import *

 

+

 class GerberCairoContext(GerberContext):

     def __init__(self, scale=300):

         GerberContext.__init__(self)

@@ -32,42 +33,72 @@ class GerberCairoContext(GerberContext):
         self.surface = None

         self.ctx = None

         self.bg = False

-        

+        self.mask = None

+        self.mask_ctx = None

+        self.origin_in_pixels = None

+        self.size_in_pixels = None

+

     def set_bounds(self, bounds):

         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 = map(mul, size_in_inch, self.scale)

+        self.origin_in_pixels = tuple(map(mul, origin_in_inch, self.scale)) if self.origin_in_pixels is None else self.origin_in_pixels

+        self.size_in_pixels = size_in_pixels if self.size_in_pixels is None else self.size_in_pixels

 

         if self.surface is None:

+

             self.surface_buffer = tempfile.NamedTemporaryFile()

             self.surface = cairo.SVGSurface(self.surface_buffer, size_in_pixels[0], size_in_pixels[1])

             self.ctx = cairo.Context(self.surface)

             self.ctx.set_fill_rule(cairo.FILL_RULE_EVEN_ODD)

             self.ctx.scale(1, -1)

             self.ctx.translate(-(origin_in_inch[0] * self.scale[0]), (-origin_in_inch[1]*self.scale[0]) - size_in_pixels[1])

-            # self.ctx.translate(-(origin_in_inch[0] * self.scale[0]), -origin_in_inch[1]*self.scale[1])

+

+            self.mask_buffer = tempfile.NamedTemporaryFile()

+            self.mask = cairo.SVGSurface(self.mask_buffer, size_in_pixels[0], size_in_pixels[1])

+            self.mask_ctx = cairo.Context(self.mask)

+            self.mask_ctx.set_fill_rule(cairo.FILL_RULE_EVEN_ODD)

+            self.mask_ctx.scale(1, -1)

+            self.mask_ctx.translate(-(origin_in_inch[0] * self.scale[0]), (-origin_in_inch[1]*self.scale[0]) - size_in_pixels[1])

 

     def _render_line(self, line, color):

         start = map(mul, line.start, self.scale)

         end = map(mul, line.end, self.scale)

-        if isinstance(line.aperture, Circle):

-            width = line.aperture.diameter

+        if not self.invert:

             self.ctx.set_source_rgba(*color, alpha=self.alpha)

             self.ctx.set_operator(cairo.OPERATOR_OVER if (line.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)

-            self.ctx.set_line_width(width * self.scale[0])

-            self.ctx.set_line_cap(cairo.LINE_CAP_ROUND)

-            self.ctx.move_to(*start)

-            self.ctx.line_to(*end)

-            self.ctx.stroke()

-        elif isinstance(line.aperture, Rectangle):

-            points = [tuple(map(mul, x, self.scale)) for x in line.vertices]

-            self.ctx.set_source_rgba(*color, alpha=self.alpha)

-            self.ctx.set_operator(cairo.OPERATOR_OVER if (line.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)

-            self.ctx.set_line_width(0)

-            self.ctx.move_to(*points[0])

-            for point in points[1:]:

-                self.ctx.line_to(*point)

-            self.ctx.fill()

+            if isinstance(line.aperture, Circle):

+                width = line.aperture.diameter

+                self.ctx.set_line_width(width * self.scale[0])

+                self.ctx.set_line_cap(cairo.LINE_CAP_ROUND)

+                self.ctx.move_to(*start)

+                self.ctx.line_to(*end)

+                self.ctx.stroke()

+            elif isinstance(line.aperture, Rectangle):

+                points = [tuple(map(mul, x, self.scale)) for x in line.vertices]

+                self.ctx.set_line_width(0)

+                self.ctx.move_to(*points[0])

+                for point in points[1:]:

+                    self.ctx.line_to(*point)

+                self.ctx.fill()

+        else:

+            self.mask_ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0)

+            self.mask_ctx.set_operator(cairo.OPERATOR_CLEAR)

+            if isinstance(line.aperture, Circle):

+                width = line.aperture.diameter

+                self.mask_ctx.set_line_width(0)

+                self.mask_ctx.set_line_width(width * self.scale[0])

+                self.mask_ctx.set_line_cap(cairo.LINE_CAP_ROUND)

+                self.mask_ctx.move_to(*start)

+                self.mask_ctx.line_to(*end)

+                self.mask_ctx.stroke()

+            elif isinstance(line.aperture, Rectangle):

+                points = [tuple(map(mul, x, self.scale)) for x in line.vertices]

+                self.mask_ctx.set_line_width(0)

+                self.mask_ctx.move_to(*points[0])

+                for point in points[1:]:

+                    self.mask_ctx.line_to(*point)

+                self.mask_ctx.fill()

 

     def _render_arc(self, arc, color):

         center = map(mul, arc.center, self.scale)

@@ -78,7 +109,7 @@ class GerberCairoContext(GerberContext):
         angle2 = arc.end_angle

         width = arc.aperture.diameter if arc.aperture.diameter != 0 else 0.001

         self.ctx.set_source_rgba(*color, alpha=self.alpha)

-        self.ctx.set_operator(cairo.OPERATOR_OVER if (arc.level_polarity == "dark" and not self.invert)else cairo.OPERATOR_CLEAR)        

+        self.ctx.set_operator(cairo.OPERATOR_OVER if (arc.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)

         self.ctx.set_line_width(width * self.scale[0])

         self.ctx.set_line_cap(cairo.LINE_CAP_ROUND)

         self.ctx.move_to(*start)  # You actually have to do this...

@@ -112,20 +143,34 @@ class GerberCairoContext(GerberContext):
 

     def _render_circle(self, circle, color):

         center = tuple(map(mul, circle.position, self.scale))

-        self.ctx.set_source_rgba(*color, alpha=self.alpha)

-        self.ctx.set_operator(cairo.OPERATOR_OVER if (circle.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)        

-        self.ctx.set_line_width(0)

-        self.ctx.arc(*center, radius=circle.radius * self.scale[0], angle1=0, angle2=2 * math.pi)

-        self.ctx.fill()

+        if not self.invert:

+            self.ctx.set_source_rgba(*color, alpha=self.alpha)

+            self.ctx.set_operator(cairo.OPERATOR_OVER if (circle.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)

+            self.ctx.set_line_width(0)

+            self.ctx.arc(*center, radius=circle.radius * self.scale[0], angle1=0, angle2=2 * math.pi)

+            self.ctx.fill()

+        else:

+            self.mask_ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0)

+            self.mask_ctx.set_operator(cairo.OPERATOR_CLEAR)

+            self.mask_ctx.set_line_width(0)

+            self.mask_ctx.arc(*center, radius=circle.radius * self.scale[0], angle1=0, angle2=2 * math.pi)

+            self.mask_ctx.fill()

 

     def _render_rectangle(self, rectangle, color):

         ll = map(mul, rectangle.lower_left, self.scale)

         width, height = tuple(map(mul, (rectangle.width, rectangle.height), map(abs, self.scale)))

-        self.ctx.set_source_rgba(*color, alpha=self.alpha)

-        self.ctx.set_operator(cairo.OPERATOR_OVER if (rectangle.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)        

-        self.ctx.set_line_width(0)

-        self.ctx.rectangle(*ll,width=width, height=height)

-        self.ctx.fill()

+        if not self.invert:

+            self.ctx.set_source_rgba(*color, alpha=self.alpha)

+            self.ctx.set_operator(cairo.OPERATOR_OVER if (rectangle.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)

+            self.ctx.set_line_width(0)

+            self.ctx.rectangle(*ll, width=width, height=height)

+            self.ctx.fill()

+        else:

+            self.mask_ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0)

+            self.mask_ctx.set_operator(cairo.OPERATOR_CLEAR)

+            self.mask_ctx.set_line_width(0)

+            self.mask_ctx.rectangle(*ll, width=width, height=height)

+            self.mask_ctx.fill()

 

     def _render_obround(self, obround, color):

         self._render_circle(obround.subshapes['circle1'], color)

@@ -140,17 +185,23 @@ class GerberCairoContext(GerberContext):
         self.ctx.set_font_size(200)

         self._render_circle(Circle(primitive.position, 0.01), color)

         self.ctx.set_source_rgb(*color)

-        self.ctx.set_operator(cairo.OPERATOR_OVER if (primitive.level_polarity == "dark" and not self.invert) else cairo.OPERATOR_CLEAR)        

+        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 + 0.01) for coord in primitive.position])

         self.ctx.scale(1, -1)

         self.ctx.show_text(primitive.net_name)

         self.ctx.scale(1, -1)

 

     def _paint_inverted_layer(self):

-        self.ctx.set_source_rgba(*self.background_color)

+        self.mask_ctx.set_operator(cairo.OPERATOR_OVER)

+        self.mask_ctx.set_source_rgba(*self.color, alpha=self.alpha)

+        self.mask_ctx.paint()

+

+    def _render_mask(self):

         self.ctx.set_operator(cairo.OPERATOR_OVER)

+        ptn = cairo.SurfacePattern(self.mask)

+        ptn.set_matrix(cairo.Matrix(xx=1.0, yy=-1.0, x0=-self.origin_in_pixels[0], y0=self.size_in_pixels[1] + self.origin_in_pixels[1]))

+        self.ctx.set_source(ptn)

         self.ctx.paint()

-        self.ctx.set_operator(cairo.OPERATOR_CLEAR)

 

     def _paint_background(self):

         if not self.bg:

@@ -160,21 +211,17 @@ class GerberCairoContext(GerberContext):
 

     def dump(self, filename):

         is_svg = filename.lower().endswith(".svg")

-

         if is_svg:

             self.surface.finish()

             self.surface_buffer.flush()

-

             with open(filename, "w") as f:

                 self.surface_buffer.seek(0)

                 f.write(self.surface_buffer.read())

                 f.flush()

-

         else:

             self.surface.write_to_png(filename)

-            

+

     def dump_svg_str(self):

         self.surface.finish()

         self.surface_buffer.flush()

         return self.surface_buffer.read()

-    
\ No newline at end of file