[ff-cvs] libvob/vob/demo/lava color.py

[Janne V. Kujala]

CVSROOT:        /cvsroot/libvob
Module name:    libvob
Branch:         
Changes by:     Janne V. Kujala <address@hidden>        03/09/01 09:11:17

Modified files:
        vob/demo/lava  : color.py 

Log message:
        better circle

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/libvob/libvob/vob/demo/lava/color.py.diff?tr1=1.1&tr2=1.2&r1=text&r2=text

Patches:
Index: libvob/vob/demo/lava/color.py
diff -u libvob/vob/demo/lava/color.py:1.1 libvob/vob/demo/lava/color.py:1.2
--- libvob/vob/demo/lava/color.py:1.1   Mon Sep  1 08:22:17 2003
+++ libvob/vob/demo/lava/color.py       Mon Sep  1 09:11:17 2003
@@ -27,7 +27,42 @@
 from vob.putil.demokeys import *
 from vob.paper.texcache import getCachedTexture
 
-from vob.color.spaces import YSTtoRGB
+#from vob.color.spaces import YSTtoRGB,gamma
+
+# Luminance weights of the RGB primaries used in YST color space functions
+Wr = 0.212671 
+Wg = 0.715160
+Wb = 0.072169
+
+#Wr,Wg,Wb = 0.3, 0.59, 0.11
+
+# Gamma correction used with the perceptual non-linearity in YtoL and LtoY
+# conversion functions.
+#
+gamma = 2.2
+#
+# The uncorrected display gamma of PC's is typically 2.2, i.e.,
+# RGB values map to physical intensities with an exponent of 2.2.
+# So, gamma correction of 2.2 here should result in linear
+# intensity. (The CIE L* computation assumes linear intensity).
+
+def YSTtoRGB(v):
+    n = 1.0 / (Wr+Wg+Wb)
+    mat =  [ [n, n*(Wg+Wb), n*(Wb - Wg)  / math.sqrt(3) ],
+             [n, n*(-Wr), n*(2*Wb + Wr) / math.sqrt(3) ],
+             [n, n*(-Wr), n*-(2*Wg + Wr) / math.sqrt(3) ] ]
+    
+    return [ mat[0][0] * v[0] + mat[0][1] * v[1] + mat[0][2] * v[2],
+             mat[1][0] * v[0] + mat[1][1] * v[1] + mat[1][2] * v[2],
+             mat[2][0] * v[0] + mat[2][1] * v[1] + mat[2][2] * v[2] ]
+
+
+def getcol(l, x, y):
+    col = YSTtoRGB( (.4, .44 * x, .44 * y) )
+    col = map(lambda x: x**(1./gamma), col)
+
+    return col
+    
 
 class Scene:
     def __init__(self):
@@ -38,7 +73,8 @@
            SlideLin("ang", 0, .1, "Rotation", "Prior", "Next"),
        )
     def scene(self, vs):
-       vs.put( background((0,0,0)) )
+        
+        vs.put( background( getcol(.4, 0, 0) ) )
 
         code = """
         Begin QUAD_STRIP
@@ -47,13 +83,13 @@
         min = [1,1,1]
         max = [0,0,0]
 
-        for ang in range(0,361):
+        for ang in range(0,365,1):
             a = ang / 180. * math.pi
 
             x = math.cos(a)
             y = math.sin(a)
 
-            col = YSTtoRGB( (.5, .55 * x, .55 * y) )
+            col = getcol(.4, .44 * x, .44 * y)
 
             for i in range(0,3):
                 if col[i] < min[i]: min[i] = col[i]
@@ -63,14 +99,14 @@
             Color %s %s %s
             Vertex %s %s
             Vertex %s %s
-            """ % (col[0], col[1], col[2], x, y, .9 * x, .9 * y)
+            """ % (col[0], col[1], col[2], x, y, .5 * x, .5 * y)
         
         code += """
         End
         """
 
-        print "MIN: %4.2f %4.2f %4.2f" % tuple(min)
-        print "MAX: %4.2f %4.2f %4.2f" % tuple(max)
+        print "MIN: %5.3f %5.3f %5.3f" % tuple(min)
+        print "MAX: %5.3f %5.3f %5.3f" % tuple(max)
 
         cs = vs.orthoCS(0, "cs1", 0, 512, 384, 300, 300);