X-Git-Url: http://git.tomasm.cz/imago.git/blobdiff_plain/92f288e8b33a67060a4553d8e71d618038885bf9..6043532d944c572b124e0363c416929d74ea8f23:/src/intrsc.py

diff --git a/src/intrsc.py b/src/intrsc.py
index a740212..cbf922a 100644
--- a/src/intrsc.py
+++ b/src/intrsc.py
@@ -8,6 +8,7 @@ import ImageDraw
 import filters
 import k_means
 import output
+import linef
 
 def dst(line):
     """Return normalized line."""
@@ -115,20 +116,28 @@ def mean_luma(cluster):
     """Return mean luma of the *cluster* of points."""
     return sum(c[0][0] for c in cluster) / float(len(cluster))
 
+def to_general(line, size):
+    # TODO comment
+    (x1, y1), (x2, y2) = linef.line_from_angl_dist(line, size)
+    return (y2 - y1, x1 - x2, x2 * y1 - x1 * y2)
+
+def intersection(l1, l2):
+    a1, b1, c1 = l1
+    a2, b2, c2 = l2
+    delim = float(a1 * b2 - b1 * a2)
+    x = (b1 * c2 - c1 * b2) / delim
+    y = (c1 * a2 - a1 * c2) / delim
+    return x, y
+
 def intersections_from_angl_dist(lines, size, get_all=True):
     """Take grid-lines and size of the image. Return intersections."""
+    lines1 = map(lambda l: to_general(l, size), lines[1])
+    lines0 = map(lambda l: to_general(l, size), lines[0])
     intersections = []
-    for (angl1, dist1) in lines[1]:
+    for l1 in lines1:
         line = []
-        for (angl2, dist2) in lines[0]:
-            if abs(angl1 - angl2) > 0.4:
-                i_x =  (- ((dist2 / cos(angl2)) - (dist1 / cos(angl1))) 
-                        / (tan(angl1) - tan(angl2)))
-                i_y = (tan(angl1) * i_x) - (dist1 / cos(angl1))
-                if get_all or (-size[0] / 2 < i_x < size[0] / 2 and 
-                    -size[1] / 2 < i_y < size[1] / 2):
-                    line.append((int(i_x + size[0] / 2),
-                                 int(i_y + size[1] / 2)))
+        for l2 in lines0:
+            line.append(intersection(l1, l2))
         intersections.append(line)
     return intersections