1 files changed, 62 insertions, 0 deletions
diff --git a/ep_colorconstraint_bw.py b/ep_colorconstraint_bw.py
new file mode 100644
index 0000000..a55c511
--- /dev/null
+++ b/ep_colorconstraint_bw.py
@@ -0,0 +1,62 @@
+# coding: UTF8
+# Copyright 2009 Thomas Jourdan
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+import random
+import model_locus
+
+EPSILON = 0.00001
+
+class BwColorConstraint(model_locus.Locus):
+    """BwColorConstraint
+    """
+
+    def __init__(self, trunk):
+        """Color constraint constructor
+        """
+        super(BwColorConstraint, self).__init__(trunk)
+        
+    def filter(self, rgba):
+        """Set constraint to red, green, blue and alpha values.
+        post: len(__return__) == 4
+        """
+        gray = round((rgba[0] + rgba[1] + rgba[2]) / 3.0)
+        alpha = round(rgba[3])
+        return (gray, gray, gray, alpha)
+
+    def randomize(self):
+        """Set black or white and alpha to random values.
+        post: len(__return__) == 4
+        post: __return__[0]  == 0 or __return__[0] == 1
+        post: __return__[3]  == 0 or __return__[3] == 1
+        """
+        gray = 1.0*random.randint(0, 1)
+        alpha = 1.0*random.randint(0, 1)
+        return (gray, gray, gray, alpha)
+
+    def mutate(self, rgba):
+        """Make random switch between black and white.
+        post: len(__return__) == 4
+        """
+        return self.randomize()
+
+    def explain(self, rgba, alfa=True):
+        """
+        pre: len(rgba) == 4
+        """
+        part1 = 'black' if abs(rgba[0]) < EPSILON else 'white'
+        part2 = ', %d%% opaque' % (100*rgba[3]) if alfa else ''
+        return part1 + part2