Extend lines at infinity

main_window.py

@@ -36,14 +36,11 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         self.setupUi(self)
 
         # Size of point for drawing
-        self._point_size = 8
+        self._point_size = 4 * self.devicePixelRatio()
 
         self._viewport_width = self.opengl_widget.width() * self.devicePixelRatio()
         self._viewport_height = self.opengl_widget.height() * self.devicePixelRatio()
 
-        print(self.height())
-        print(self.width())
-
         # PointManager is a class that is filled with static methods
         # designed for managing state.
         PointManager.point_set = PointSet(self._point_size,

voronoiview/ui/opengl_widget.py

@@ -13,6 +13,7 @@ It should be split up into a few more separate files eventually...
 Probably even into it's own module folder.
 """
 
+import numpy as np
 from OpenGL.GL import (glBegin, glClearColor, glColor3f, glColor4f,
                        glEnable, glEnd, GL_LINES, GL_LINE_LOOP, GL_LINE_SMOOTH,
                        GL_POINTS, glPointSize, glVertex3f,
@@ -403,22 +404,62 @@ def draw_voronoi_diagram():
     results = PointManager.voronoi_results
 
     vertices = results.vertices
+    ridge_vertices = results.ridge_vertices
+    ridge_points = results.ridge_points
+    points = results.points
+    center = points.mean(axis=0)
 
     color = COLOR_TO_RGBA[Color.BLACK]
 
-    print(results.regions)
+    #
+    # Code for these loops taken from the scipy documentation on plotting and adapted to OpenGL.
+    #
 
-    for region_indices in results.regions:
-        glBegin(GL_LINE_LOOP)
-        for idx in region_indices:
-            vertex = vertices[idx]
+    # Simple case - plot the non-infinity lines
+    for simplex in ridge_vertices:
+        glBegin(GL_LINES)
+        simplex = np.asarray(simplex)
+        if np.all(simplex >= 0):
+            glColor3f(color[0], color[1], color[2])
+            p1 = vertices[simplex, 0]
+            p2 = vertices[simplex, 1]
+
+            glVertex3f(__clamp_x(p1[0]),
+                       __clamp_y(p2[0]),
+                       0.0)
+            glVertex3f(__clamp_x(p1[1]),
+                       __clamp_y(p2[1]),
+                       0.0)
+
+        glEnd()
+
+    # Hard case - points at infinity
+    for pointidx, simplex in zip(ridge_points, ridge_vertices):
+        simplex = np.asarray(simplex)
+        if np.any(simplex < 0):
+            i = simplex[simplex >= 0][0]  # finite end Voronoi vertex
+            t = points[pointidx[1]] - points[pointidx[0]]  # tangent
+            t = t / np.linalg.norm(t)
+            n = np.array([-t[1], t[0]])  # normal
+            midpoint = points[pointidx].mean(axis=0)
+            far_point = vertices[i] + np.sign(np.dot(midpoint - center, n)) * n * 100
 
-            if -1 in region_indices:
-                continue
+            p1 = vertices[i, 0]
+            p2 = far_point[0]
+            p3 = vertices[i, 1]
+            p4 = far_point[1]
+
+            glBegin(GL_LINES)
 
             glColor3f(color[0], color[1], color[2])
-            glVertex3f(__clamp_x(vertex[0]),
-                       __clamp_y(vertex[1]),
-                       0.0)                 # Z is currently fixed to 0
 
-        glEnd()
+            glVertex3f(__clamp_x(p1),
+                       __clamp_y(p3),
+                       0.0)
+
+            # x2000 scaling factor so the far points run off screen
+            glVertex3f(__clamp_x(p2) * 2000,
+                       __clamp_y(p4) * 2000,
+                       0.0)
+
+            glEnd()