X-Git-Url: https://git.ao2.it/flexagon-toolkit.git/blobdiff_plain/b0d293a76ed3a595754b643f48b2f2d1b03395f6..aabf42f895331f171651e971661d4d7ace18e0d8:/src/svg_hexaflexagon_editor.py

diff --git a/src/svg_hexaflexagon_editor.py b/src/svg_hexaflexagon_editor.py
index f86ad13..cb65088 100755
--- a/src/svg_hexaflexagon_editor.py
+++ b/src/svg_hexaflexagon_editor.py
@@ -17,7 +17,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from math import pi
 import svgwrite
 
 from diagram.svgwrite_diagram import SvgwriteDiagram
@@ -33,6 +32,7 @@ class SvgwriteHexaflexagonDiagram(HexaflexagonDiagram):
         # create some layers and groups
         layers = {
             "Hexagons": svg.layer(label="Hexagons"),
+            "Backfaces": svg.layer(label="Backfaces"),
             "Hexaflexagon": svg.layer(label="Hexaflexagon"),
             "Folding guide": svg.layer(label="Folding guide"),
             "Template": svg.layer(label="Template")
@@ -61,7 +61,9 @@ class SvgwriteHexaflexagonDiagram(HexaflexagonDiagram):
             # Draw some default content
             old_active_group = self.backend.active_group
             self.backend.active_group = self.groups["hexagon%d-content" % hexagon.index]
-            self.backend.draw_regular_polygon(cx, cy, 6, self.hexagon_radius, pi / 6., fill_color=(0.5, 0.5, 0.5, 0.2), stroke_color=None)
+            self.backend.draw_regular_polygon(cx, cy, 6, self.hexagon_radius,
+                                              stroke_color=None,
+                                              fill_color=(0.5, 0.5, 0.5, 0.2))
             self.backend.active_group = old_active_group
 
             # Add folding guides
@@ -71,9 +73,12 @@ class SvgwriteHexaflexagonDiagram(HexaflexagonDiagram):
             for triangle in hexagon.triangles:
                 cx, cy = self.get_triangle_center(triangle)
                 theta = triangle.get_angle_in_hexagon()
-                self.backend.draw_regular_polygon(cx, cy, 3, self.triangle_radius, theta, (0, 0, 0, 0.2))
+                self.backend.draw_regular_polygon(cx, cy, 3, self.triangle_radius, theta,
+                                                  stroke_color=(0, 0, 0, 0.2),
+                                                  fill_color=None)
                 polygon = self.backend.active_group.elements[-1]
-                polygon['id'] = "hexagon%d-triangle%d-folding" % (triangle.hexagon.index, triangle.index)
+                polygon['id'] = "hexagon%d-triangle%d-folding" % (triangle.hexagon.index,
+                                                                  triangle.index)
 
             self.backend.active_group = old_active_group
 
@@ -111,6 +116,24 @@ class SvgwriteHexaflexagonDiagram(HexaflexagonDiagram):
                 ref['clip-path'] = "url(%s)" % (triangle_href + '-clip-path')
                 group.add(ref)
 
+        # draw the backfaces
+        group = self.groups["Backfaces"]
+        for hexagon in self.hexaflexagon.hexagons:
+            for triangle in hexagon.triangles:
+                m = self.get_triangle_backfaces_transform(triangle)
+                svg_matrix = "matrix(%f, %f, %f, %f, %f, %f)" % (m[0], m[3],
+                                                                 m[1], m[4],
+                                                                 m[2], m[5])
+
+                triangle_href = "#hexagon%d-triangle%d" % (hexagon.index, triangle.index)
+
+                # Reuse the content to draw the backface
+                content_href = "#hexagon%d-content" % hexagon.index
+                ref = self.backend.svg.use(content_href)
+                ref['transform'] = svg_matrix
+                ref['clip-path'] = "url(%s)" % (triangle_href + '-clip-path')
+                group.add(ref)
+
     def draw_triangle_template(self, triangle, cx, cy, theta):
         old_active_group = self.backend.active_group
         group_name = "hexagon%d-triangle%d" % (triangle.hexagon.index, triangle.index)