#!/usr/bin/env python

import unittest
import sys
import math
import StringIO
import copy
import re

import testbase

import gradient
import fract4dc
import fractal
import translate
import fractparser

from gradient import Blend, ColorMode

wood='''GIMP Gradient
Name: Wood 2
9
0.000000 0.069491 0.138982 1.000000 0.700000 0.400000 1.000000 0.944844 0.616991 0.289137 1.000000 3 0
0.138982 0.208472 0.277963 0.800000 0.522406 0.244813 1.000000 0.928860 0.592934 0.257008 1.000000 3 0
0.277963 0.347454 0.416945 0.820000 0.523444 0.226888 1.000000 0.922120 0.582791 0.243462 1.000000 3 0
0.416945 0.486436 0.555927 0.770000 0.486649 0.203299 1.000000 0.920000 0.579600 0.239200 1.000000 3 0
0.555927 0.609140 0.662354 0.780000 0.491400 0.202800 1.000000 0.903086 0.568944 0.234802 1.000000 4 0
0.662354 0.715568 0.768781 0.810000 0.510300 0.210600 1.000000 0.850329 0.535708 0.221086 1.000000 4 0
0.768781 0.821995 0.875209 0.760000 0.478800 0.197600 1.000000 0.708598 0.446417 0.184235 1.000000 4 0
0.875209 0.928422 0.981636 0.620000 0.390600 0.161200 1.000000 0.000000 0.000000 0.000000 1.000000 4 0
0.981636 0.991653 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 4 0
'''

class Test(testbase.TestBase):
    def setUp(self):
        self.white = [1.0, 1.0, 1.0, 1.0]
        self.black = [0.0, 0.0, 0.0, 1.0]
        self.grey_33 = [1.0/3.0, 1.0/3.0, 1.0/3.0, 1.0]
        self.mid_grey = [0.5, 0.5, 0.5, 1.0]
        self.grey_66 = [2.0/3.0, 2.0/3.0, 2.0/3.0, 1.0]
        self.red = [1.0, 0.0, 0.0, 1.0]
        self.green = [0.0, 1.0, 0.0, 1.0]
        self.blue = [0.0, 0.0, 1.0, 1.0]
    
    def tearDown(self):
        pass

    def testCreate(self):
        g = gradient.Gradient()

        self.assertEqual(len(g.segments), 1)
        self.assertWellFormedGradient(g)

    def testEquals(self):
        g1 = gradient.Gradient()
        g2 = gradient.Gradient()

        self.failUnless(g1 == g2) # calls __eq__
        self.assertEqual(g1,g2) # calls __ne__

        g1.segments[0].left_color[0] = 0.7
        self.assertNotEqual(g1,g2)
        
    def checkColorMapAndGradientEquivalent(self,colorlist,maxdiff=0):
        grad = gradient.Gradient()
        grad.load_list(colorlist,maxdiff)

        self.assertWellFormedGradient(grad)
        if maxdiff != 0:
            # don't have any robust metric for how close this will be
            return
        
        cmap = fract4dc.cmap_create(colorlist)
        
        for i in xrange(1000):
            fi = i / 1000.0
            (r,g,b,a) = grad.get_color_at(fi)
            cmap_color = fract4dc.cmap_lookup(cmap, fi)
            grad_color = (int(r*255.0), int(g*255.0),
                          int(b*255.0), int(a*255.0))
            self.assertNearlyEqual(
                grad_color,
                cmap_color,
                "colorlist(%s) = %s but gradient(%s) = %s" % \
                (fi, cmap_color, fi, grad_color), 1.5)
        return grad

    def checkCGradientAndPyGradientEquivalent(self,grad):
        # We have 2 sets of gradient-drawing code, in C and Python
        # check they calculate the same answer
        self.assertWellFormedGradient(grad)
        cmap = fract4dc.cmap_create_gradient(grad.segments)
        for i in xrange(1000):
            fi = i / 1000.0
            (r,g,b,a) = grad.get_color_at(fi)
            #print "%d: %.17g, %.17g, %.17g, %.17g" % (i,r,g,b,a)
            cmap_color = fract4dc.cmap_lookup(cmap, fi)
            grad_color = (int(r*255.0), int(g*255.0),
                          int(b*255.0), int(a*255.0))
            self.assertNearlyEqual(
                grad_color,
                cmap_color,
                "colorlist(%s) = %s but gradient(%s) = %s" % \
                (fi, cmap_color, fi, grad_color), 1.5)
        
    def testFromColormap(self):
        # check that creating a gradient from a colormap produces the same
        # output
        colorlist = [(0.0, 255,255,255, 255), (1.0, 0,0,0,255)]
        g = gradient.Gradient()
        g.load_list(colorlist)
        self.assertEqual(len(g.segments),1)
        self.assertEqual(g.segments[0].left_color, self.white)
        self.assertEqual(g.segments[0].right_color, self.black)

        self.checkColorMapAndGradientEquivalent(colorlist)

    def testFromUgr(self):
        pt = fractparser.parser.parse('''blatte10 {
gradient:
  title="blatte10" smooth=no index=0 color=3085069 index=25 color=3216141
  index=56 color=10761236 index=83 color=1408165 index=92 color=4050153
  index=110 color=18018 index=134 color=0 index=213 color=5183243 index=284
  color=11494485 index=358 color=0 index=384 color=144
opacity:
  smooth=no index=0 opacity=255
}
''')
        t = translate.GradientFunc(pt.children[0])
        g = gradient.Gradient()
        g.load_ugr(t)

        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),12)
            
    def testFromColormap2(self):
        # create a longer one
        colorlist = [
            (0.0, 255,0,0, 255),
            (0.5, 0,255,0, 255),
            (1.0, 0, 0, 255, 255)]
        g = gradient.Gradient()
        g.load_list(colorlist)
        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),2)
        self.assertEqual(g.segments[0].left_color, self.red)
        self.assertEqual(g.segments[0].right_color, self.green)
        self.assertEqual(g.segments[1].left, 0.5)
        self.assertEqual(g.segments[1].left_color, self.green)
        self.assertEqual(g.segments[1].right_color, self.blue)

        self.checkColorMapAndGradientEquivalent(colorlist)            
            
    def testFromColormap3(self):
        # create a short, compressible one
        colorlist = [
            (0.0, 0, 0, 0, 255),
            (0.5, 127, 127, 127, 255),
            (1.0, 255, 255, 255, 255)]

        g = gradient.Gradient()
        g.load_list(colorlist)
        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),1)

    def testfromColormap4(self):
        # this should always produce 255 segments
        colorlist = self.colorMapFromFile("../maps/4zebbowx.map")
        grad = self.checkColorMapAndGradientEquivalent(colorlist)
        self.assertEqual(len(grad.segments),255)

    def testfromColormapHlsrain(self):
        # this map once caused issues
        colorlist = self.colorMapFromFile("../maps/hlsrain5.map")
        grad = self.checkColorMapAndGradientEquivalent(colorlist)

    def testFromColormapCompressible(self):
        colorlist = self.colorMapFromFile("../maps/Gallet02.map")
        grad = self.checkColorMapAndGradientEquivalent(colorlist)
        self.failUnless(len(grad.segments) < 255,"should have been compressed")

    def testFromColormapLossyCompression(self):
        colorlist = self.colorMapFromFile("../maps/Gallet02.map")
        grad = self.checkColorMapAndGradientEquivalent(colorlist, 2)
        
    def colorMapFromFile(self, name):
        f = open(name,"r")
        i = 0
        colorlist = []
        rgb_re = re.compile(r'\s*(\d+)\s+(\d+)\s+(\d+)')
        for line in f:
            m = rgb_re.match(line)
            if m != None:
                (r,g,b) = (int(m.group(1)),
                           int(m.group(2)),
                           int(m.group(3)))

                # in case they're over 255 - as some badly-behaved
                # Fractint gradients are 
                [r,g,b] = map(lambda x: min(x,255), [r,g,b])

                if i == 0:
                    # first color is inside solid color
                    pass 
                else:
                    colorlist.append(((i-1)/255.0,r,g,b,255))
            i += 1

        return colorlist

    def testCopy(self):
        # check that copy.copy() doesn't share state
        g1 = self.create_rgb_gradient()

        s1 = g1.serialize()
        g2 = copy.copy(g1)

        s2 =g2.serialize()
        self.assertEqual(s1,s2)

        g1.segments[0].bmode = gradient.Blend.CURVED

        s3=g2.serialize()
        self.assertEqual(s2,s3)
        
    def testGradientCmap(self):
        g = gradient.Gradient()
        self.checkCGradientAndPyGradientEquivalent(g)

        g.segments[0].mid = 0.2
        self.checkCGradientAndPyGradientEquivalent(g)

        g.segments[0].bmode = gradient.Blend.CURVED
        self.checkCGradientAndPyGradientEquivalent(g)

        g.segments[0].bmode = gradient.Blend.SINE
        self.checkCGradientAndPyGradientEquivalent(g)

        g.segments[0].bmode = gradient.Blend.SPHERE_INCREASING
        self.checkCGradientAndPyGradientEquivalent(g)

        g.segments[0].bmode = gradient.Blend.SPHERE_DECREASING
        self.checkCGradientAndPyGradientEquivalent(g)

        g = self.create_rgb_gradient()
        self.checkCGradientAndPyGradientEquivalent(g)
        
    def create_rgb_gradient(self):
        # make a simple gradient which goes from R -> G -> B
        g = gradient.Gradient()
        g.segments = [
           gradient.Segment(0.0, self.red, 0.333, self.red),
           gradient.Segment(0.333, self.green, 0.667, self.green),
           gradient.Segment(0.667, self.blue, 1.0, self.blue)]
        return g
    
    def testGetSegments(self):
        g = self.create_rgb_gradient()
        self.assertWellFormedGradient(g)
        self.assertEqual(g.get_segment_at(0.0), g.segments[0])
        self.assertEqual(g.get_segment_at(0.5), g.segments[1])
        self.assertEqual(g.get_segment_at(1.0), g.segments[2])

        self.assertEqual(g.get_segment_at(0.333), g.segments[0])
        self.assertEqual(g.get_segment_at(0.667), g.segments[1])
        
        self.assertRaises(IndexError, g.get_segment_at, -1.0)
        self.assertRaises(IndexError, g.get_segment_at, 2.0)

    def testGetSegmentIndexes(self):
        g = self.create_rgb_gradient()
        self.assertWellFormedGradient(g)
        self.assertEqual(g.get_index_at(0.0), 0)
        self.assertEqual(g.get_index_at(0.5), 1)
        self.assertEqual(g.get_index_at(1.0), 2)

        self.assertEqual(g.get_index_at(0.333), 0)
        self.assertEqual(g.get_index_at(0.667), 1)
        
        self.assertRaises(IndexError, g.get_index_at, -1.0)
        self.assertRaises(IndexError, g.get_index_at, 2.0)

    def testLinearSegment(self):
        seg = gradient.Segment(0.0, self.red, 0.333, self.red)
        self.assertEqual(seg.get_linear_factor(0.0, 0.5),0.0)
        self.assertEqual(seg.get_linear_factor(0.5, 0.5),0.5)
        self.assertEqual(seg.get_linear_factor(1.0, 0.5),1.0)

        # middle close to left end
        self.assertEqual(seg.get_linear_factor(0.0, 0.0),0.0)
        self.assertEqual(seg.get_linear_factor(0.5, 0.0),0.75)
        self.assertEqual(seg.get_linear_factor(1.0, 0.0),1.0)

        # middle close to right end
        self.assertEqual(seg.get_linear_factor(0.0, 1.0),0.0)
        self.assertEqual(seg.get_linear_factor(0.5, 1.0),0.25)
        self.assertEqual(seg.get_linear_factor(1.0, 1.0),0.5)

    def testVeryShortSegment(self):
        seg = gradient.Segment(0.0, self.black, 0.0, self.white)
        self.assertEqual(seg.get_color_at(0.0), self.mid_grey)
        self.assertEqual(seg.get_color_at(0.5), self.mid_grey)
        self.assertEqual(seg.get_color_at(1.0), self.mid_grey)
        
    def testGetFlatColors(self):
        g = self.create_rgb_gradient()
        self.assertWellFormedGradient(g)
        self.assertEqual(g.get_color_at(0.0), self.red)
        self.assertEqual(g.get_color_at(0.3), self.red)
        self.assertEqual(g.get_color_at(0.333), self.red)
        self.assertEqual(g.get_color_at(0.334), self.green)
        self.assertEqual(g.get_color_at(0.666), self.green)
        self.assertEqual(g.get_color_at(0.668), self.blue)
        self.assertEqual(g.get_color_at(1.0), self.blue)

    def checkGreyGradient(self, g, midpoint, oracle):
        self.assertWellFormedGradient(g)
        
        for i in xrange(256):
            x = i * 1.0/256.0
            fx = oracle(x,midpoint)

            self.failUnless(0.0 <= fx <= 1.0,
                            "dubious value %f for %x" % (fx,x))
            
            col = g.get_color_at(x)
            expected = [fx,fx,fx,1.0]
            self.assertNearlyEqual(col, expected,
                                   "%s != %s for %s (int %s)" % \
                                   (col, expected, x, i))

        # should be 0 at start, 1 at end
        self.assertEqual(g.get_color_at(0.0), [0.0, 0.0, 0.0, 1.0])
        self.assertEqual(g.get_color_at(1.0), [1.0, 1.0, 1.0, 1.0])
                
        # should be halfway at the midpoint
        self.assertEqual(g.get_color_at(midpoint), [0.5, 0.5, 0.5, 1.0])

    def testGreyGradient(self):
        g = gradient.Gradient()

        # linear, central midpoint
        g.segments[0].mid = 0.5
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        # linear, off-center midpoint
        def predict_025_linear(x, dummy):
            if x <= 0.25:
                fx = 0.5 * x/0.25
            else:
                fx = 0.5 + 0.5 * (x-0.25)/0.75
            return fx

        g.segments[0].mid = 0.25
        self.checkGreyGradient(g, 0.25, predict_025_linear)
        
        # curved, central midpoint
        # (curved = linear if midpoint = 0.5)
        g.segments[0].bmode = Blend.CURVED
        g.segments[0].mid = 0.5
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        # curved, non-central midpoint, sharper at the start
        def predict_025_curved(x, dummy):
            if x == 0.0:
                fx = 0.0
            else:
                fx = math.pow(x,math.log(0.5)/math.log(0.25))
            return fx

        g.segments[0].mid = 0.25
        self.checkGreyGradient(g, 0.25, predict_025_curved)

        # TODO: sine, sphere_increasing/decreasing
        
    def testAlphaChannel(self):
        g = gradient.Gradient()
        g.segments[0].left_color[3] = 0.5
        self.assertWellFormedGradient(g)
        for i in xrange(256):
            x = i * 1.0/256.0
            self.assertEqual(g.get_color_at(x), [x,x,x,0.5+x/2.0])

    def testSaveSegment(self):
        s = gradient.Segment(
            0.0, [0.0, 0.1, 0.2, 0.3],
            0.5, [0.4, 0.5, 0.6, 0.7])
        sio = StringIO.StringIO()
        s.save(sio)
        self.assertEqual(
            "0.000000 0.250000 0.500000 0.000000 0.100000 0.200000 0.300000 0.400000 0.500000 0.600000 0.700000 0 0\n", sio.getvalue())

        s2 = gradient.Segment(
            0.5, [0.4, 0.5, 0.6, 0.7],
            0.8, [0.01, 0.02, 0.03, 0.04])

        self.assertEqual(True,s.left_of(s2))
        self.assertEqual(False,s.left_of(s))
        self.assertEqual(False,s2.left_of(s))

        self.assertEqual(True,s2.right_of(s))
        self.assertEqual(False,s.right_of(s))
        self.assertEqual(False,s.right_of(s2))

        s2.save(sio)
        self.assertEqual(
            """0.000000 0.250000 0.500000 0.000000 0.100000 0.200000 0.300000 0.400000 0.500000 0.600000 0.700000 0 0
0.500000 0.650000 0.800000 0.400000 0.500000 0.600000 0.700000 0.010000 0.020000 0.030000 0.040000 0 0
""", sio.getvalue())

        sio = StringIO.StringIO()
        s.save(sio)
        s2.save(sio,True)

        self.assertEqual(
            """0.000000 0.250000 0.500000 0.000000 0.100000 0.200000 0.300000 0.400000 0.500000 0.600000 0.700000 0 0
+0.650000 0.800000 0.010000 0.020000 0.030000 0.040000 0 0
""", sio.getvalue())
        
    def testSaveMinimal(self):
        g = gradient.Gradient()
        s = StringIO.StringIO()
        g.save(s)
        self.assertEqual(
            s.getvalue(),
            '''GIMP Gradient
1
0.000000 0.500000 1.000000 0.000000 0.000000 0.000000 1.000000 1.000000 1.000000 1.000000 1.000000 0 0
''')

    def testLoadSimple(self):
        g = gradient.Gradient()
        s = StringIO.StringIO(wood)
        g.load(s)
        self.assertEqual(g.name, "Wood 2")
        self.assertEqual(len(g.segments), 9)

        # check round trip
        s2 = StringIO.StringIO()
        g.save(s2)
        self.assertEqual(wood,s2.getvalue())

        g2 = gradient.Gradient()
        s2.seek(0,0)
        g2.load(s2)

        self.assertEqual(g,g2)
        
    def testLoadCompressed(self):
        g = gradient.Gradient()
        s = StringIO.StringIO(wood)
        g.load(s)

        s2 = StringIO.StringIO()
        g.save(s2,True)

        s2.seek(0,0)

        g_from_comp = gradient.Gradient()
        g_from_comp.load(s2)

        self.assertEqual(g,g_from_comp)
        
    def checkBadLoad(self, str):
        g = gradient.Gradient()
        s = StringIO.StringIO(str)
        self.assertRaises(Exception, g.load,s)
        self.assertWellFormedGradient(g)
        
    def testBadLoad(self):        
        bad_files=[
            '''xxx''',
            '''GIMP Gradient''',
            '''GIMP Gradient
17
0.000000 0.500000 1.000000 0.000000 0.000000 0.000000 1.000000 1.000000 1.000000 1.000000 1.000000 0 0
''',
            '''GIMP Gradient
1
0.000000 0.500000 1.000000 0.000000 
''',
            '''GIMP Gradient
1
0.000000 0.500000 1.000000 0.000000 0.000000 0.000000 1.000000 1.000000 1.000000 1.000000 1.000000 foo 0
''']
        for file in bad_files:
            self.checkBadLoad(file)

    def testSetLeft(self):
        g = gradient.Gradient()

        g.add(0)

        # shouldn't be able to move leftmost segment
        self.assertEqual(g.set_left(0, -1.0),0.0)
        self.assertEqual(g.set_left(0,0.2),0.0)

        # should be able to move other one
        self.assertEqual(g.set_left(1,0.4),0.4)
        self.assertEqual(g.set_left(1,0.6),0.6)

        # but no further than midpoints
        self.assertEqual(g.set_left(1,0.2),0.25 + gradient.Segment.EPSILON)
        self.assertEqual(g.set_left(1,0.8),0.75 - gradient.Segment.EPSILON)

    def testSetRight(self):
        g = gradient.Gradient()

        g.add(0)

        # shouldn't be able to move rightmost segment
        self.assertEqual(g.set_right(1, -1.0),1.0)
        self.assertEqual(g.set_right(1,0.2),1.0)

        # should be able to move other one
        self.assertEqual(g.set_right(0,0.4),0.4)
        self.assertEqual(g.set_right(0,0.6),0.6)

        # but no further than midpoints
        self.assertEqual(g.set_right(0,0.2),0.25 + gradient.Segment.EPSILON)
        self.assertEqual(g.set_right(0,0.8),0.75 - gradient.Segment.EPSILON)

    def testSetMiddle(self):
        g = gradient.Gradient()

        # should be able to move 
        self.assertEqual(g.set_middle(0,0.4),0.4)
        self.assertEqual(g.set_middle(0,0.6),0.6)

        # but no further than endpoints
        self.assertEqual(g.set_middle(0,0.0),0.0 + gradient.Segment.EPSILON)
        self.assertEqual(g.set_middle(0,1.0),1.0 - gradient.Segment.EPSILON)
        
    def testAddSegment(self):
        # add some segments, ensure invariants hold and correct
        # outcome occurs.
        g = gradient.Gradient()

        # add a segment at left-hand end
        g.add(0)
        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),2)
        left = g.segments[0]
        right = g.segments[1]
        self.assertEqual(left.right_color, right.left_color)
        self.assertEqual(left.right_color,[0.5,0.5,0.5,1.0])
        self.assertEqual(right.right_color, [1.0, 1.0, 1.0, 1.0])
        self.assertEqual(left.mid, 0.25)
        self.assertEqual(left.right, 0.5)
        self.assertEqual(right.mid, 0.75)
        self.assertEqual(right.right, 1.0)

        # should have no effect on resulting pattern
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)
        
        # add another one
        g.add(0)
        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),3)
        left = g.segments[0]
        right = g.segments[1]
        self.assertEqual(left.right_color, right.left_color)
        self.assertEqual(left.right_color,[0.25,0.25,0.25,1.0])
        self.assertEqual(left.mid, 0.125)
        self.assertEqual(left.right, 0.25)
        self.assertEqual(right.mid, 0.375)
        self.assertEqual(right.right, 0.5)

        # still no effect
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        # one more at the other end
        g.add(len(g.segments)-1)
        self.assertWellFormedGradient(g)
        self.assertEqual(len(g.segments),4)
        left = g.segments[2]
        right = g.segments[3]
        self.assertEqual(left.right_color, right.left_color)
        self.assertEqual(left.right_color,[0.75,0.75,0.75,1.0])
        self.assertEqual(left.mid, 0.625)
        self.assertEqual(left.right, 0.75)
        self.assertEqual(right.mid, 0.875)
        self.assertEqual(right.right, 1.0)

        # still no effect
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

    def three_segments(self):
        # set up 3 equal segments
        return [
            gradient.Segment(0,self.black, 1.0/3.0, self.grey_33),
            gradient.Segment(1.0/3.0,self.grey_33, 2.0/3.0, self.grey_66),
            gradient.Segment(2.0/3.0,self.grey_66, 1.0, self.white)]

    def testRemove(self):
        # test removal of segments
        g = gradient.Gradient()

        # shouldn't be able to remove last segment
        self.assertRaises(gradient.Error, g.remove, 0.0)

        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        # remove middle one
        g.remove(1)

        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.assertEqual(g.segments[0].right, 0.5)

        # recreate and remove left one
        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        g.remove(0)
        
        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.assertEqual(g.segments[0].right, 2.0/3.0)

        # recreate and remove right one
        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        g.remove(2)
        
        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.assertEqual(g.segments[1].left, 1.0/3.0)

    def testRemoveSmooth(self):
        # test removal of segments
        g = gradient.Gradient()

        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        # remove middle one
        g.remove(1, True)
        
        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)
        self.assertEqual(g.segments[0].right, 0.5)

        # recreate and remove left one
        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        g.remove(0,True)
        
        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)
        self.assertEqual(g.segments[0].right, 2.0/3.0)

        # recreate and remove right one
        g.segments = self.three_segments()
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)

        g.remove(2,True)
        
        self.assertEqual(len(g.segments),2)
        self.assertWellFormedGradient(g)
        self.checkGreyGradient(g, 0.5, lambda x,mid : x)
        self.assertEqual(g.segments[1].left, 1.0/3.0)

    def testLoadCS(self):
        g = gradient.Gradient()
        f = open("../testdata/test.cs")

        g.load_cs(f)
        self.assertEqual(8,len(g.segments))
        self.assertEqual(
            [ 0x1d/255.0 , 0x10/255.0, 0x10/255.0, 1.0],
            g.segments[0].left_color)

        f.seek(0)
        g.load(f)
        
    def assertNearlyEqual(self,a,b,msg, epsilon=1.0e-12):
        # check that each element is within epsilon of expected value
        for (ra,rb) in zip(a,b):
            d = abs(ra-rb)
            self.failUnless(d < epsilon,msg)

    def assertWellFormedGradient(self, g):
        # check starts and sends at 0 and 1
        first_seg = g.segments[0]
        last_seg = g.segments[-1]
        self.assertEqual(first_seg.left, 0.0)
        self.assertEqual(last_seg.right, 1.0)

        # check segments line up and types are in range
        previous_seg = g.segments[0]
        for seg in g.segments[1:]:
            # check offsets
            self.failUnless(0.0 <= seg.left <= 1.0)
            self.failUnless(0.0 <= seg.right <= 1.0)
            self.failUnless(
                seg.left <= seg.mid <= seg.right,
                "midpoint %g not between endpoints %g,%g" % \
                (seg.mid, seg.left, seg.right))

            # check colors
            self.assertEquals(len(seg.left_color),4)
            self.assertEquals(len(seg.right_color),4)
            for x in seg.left_color + seg.right_color:
                self.failUnless(0.0 <= x <= 1.0)

            # check modes
            self.failUnless(Blend.LINEAR <= seg.bmode <= Blend.SPHERE_DECREASING)
            self.failUnless(ColorMode.RGB <= seg.cmode <= ColorMode.HSV_CW)

            # check offset chaining
            self.failUnless(seg.right > seg.left)
            self.assertEqual(seg.left, previous_seg.right)
            previous_seg = seg


def suite():
    return unittest.makeSuite(Test,'test')

if __name__ == '__main__':
    unittest.main(defaultTest='suite')