Merge pull request #874 from hugovk/GimpGradientFile

Tests for GimpGradientFile

PIL/GimpGradientFile.py

@@ -24,6 +24,7 @@ from PIL._binary import o8
 
 EPSILON = 1e-10
 
+
 def linear(middle, pos):
     if pos <= middle:
         if middle < EPSILON:
@@ -38,25 +39,30 @@ def linear(middle, pos):
         else:
             return 0.5 + 0.5 * pos / middle
 
+
 def curved(middle, pos):
     return pos ** (log(0.5) / log(max(middle, EPSILON)))
 
+
 def sine(middle, pos):
     return (sin((-pi / 2.0) + pi * linear(middle, pos)) + 1.0) / 2.0
 
+
 def sphere_increasing(middle, pos):
     return sqrt(1.0 - (linear(middle, pos) - 1.0) ** 2)
 
+
 def sphere_decreasing(middle, pos):
     return 1.0 - sqrt(1.0 - linear(middle, pos) ** 2)
 
-SEGMENTS = [ linear, curved, sine, sphere_increasing, sphere_decreasing ]
+SEGMENTS = [linear, curved, sine, sphere_increasing, sphere_decreasing]
+
 
 class GradientFile:
 
     gradient = None
 
-    def getpalette(self, entries = 256):
+    def getpalette(self, entries=256):
 
         palette = []
 
@@ -89,6 +95,7 @@ class GradientFile:
 
         return b"".join(palette), "RGBA"
 
+
 ##
 # File handler for GIMP's gradient format.
 
@@ -99,7 +106,13 @@ class GimpGradientFile(GradientFile):
         if fp.readline()[:13] != b"GIMP Gradient":
             raise SyntaxError("not a GIMP gradient file")
 
-        count = int(fp.readline())
+        line = fp.readline()
+
+        # GIMP 1.2 gradient files don't contain a name, but GIMP 1.3 files do
+        if line.startswith(b"Name: "):
+            line = fp.readline().strip()
+
+        count = int(line)
 
         gradient = []
 

Tests/images/gimp_gradient.ggr

@@ -0,0 +1,6 @@
+GIMP Gradient
+4
+0.000000 0.351923 0.534893 1.000000 1.000000 1.000000 0.910000 0.730303 0.510606 1.000000 0.480000 1 0
+0.501504 0.611002 0.637730 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 1.000000 1 0
+0.931891 0.951264 1.000000 0.531255 0.316078 1.031173 1.000000 0.000000 0.000000 0.000000 1.000000 0 0
+0.810551 0.881217 0.921883 0.717576 0.441331 0.081217 1.000000 0.751576 0.410331 0.081217 1.000000 0 0

Tests/images/gimp_gradient_with_name.ggr

@@ -0,0 +1,7 @@
+GIMP Gradient
+Name: A GIMP 1.3 gradient file
+4
+0.000000 0.351923 0.534893 1.000000 1.000000 1.000000 0.910000 0.730303 0.510606 1.000000 0.480000 1 0
+0.501504 0.611002 0.637730 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 1.000000 1 0
+0.931891 0.951264 1.000000 0.531255 0.316078 1.031173 1.000000 0.000000 0.000000 0.000000 1.000000 0 0
+0.810551 0.881217 0.921883 0.717576 0.441331 0.081217 1.000000 0.751576 0.410331 0.081217 1.000000 0 0

Tests/test_file_gimpgradient.py

@@ -0,0 +1,127 @@
+from helper import unittest, PillowTestCase
+
+from PIL import GimpGradientFile
+
+
+class TestImage(PillowTestCase):
+
+    def test_linear_pos_le_middle(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.25
+
+        # Act
+        ret = GimpGradientFile.linear(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.25)
+
+    def test_linear_pos_le_small_middle(self):
+        # Arrange
+        middle = 1e-11
+        pos = 1e-12
+
+        # Act
+        ret = GimpGradientFile.linear(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.0)
+
+    def test_linear_pos_gt_middle(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.75
+
+        # Act
+        ret = GimpGradientFile.linear(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.75)
+
+    def test_linear_pos_gt_small_middle(self):
+        # Arrange
+        middle = 1 - 1e-11
+        pos = 1 - 1e-12
+
+        # Act
+        ret = GimpGradientFile.linear(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 1.0)
+
+    def test_curved(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.75
+
+        # Act
+        ret = GimpGradientFile.curved(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.75)
+
+    def test_sine(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.75
+
+        # Act
+        ret = GimpGradientFile.sine(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.8535533905932737)
+
+    def test_sphere_increasing(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.75
+
+        # Act
+        ret = GimpGradientFile.sphere_increasing(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.9682458365518543)
+
+    def test_sphere_decreasing(self):
+        # Arrange
+        middle = 0.5
+        pos = 0.75
+
+        # Act
+        ret = GimpGradientFile.sphere_decreasing(middle, pos)
+
+        # Assert
+        self.assertEqual(ret, 0.3385621722338523)
+
+    def test_load_via_imagepalette(self):
+        # Arrange
+        from PIL import ImagePalette
+        test_file = "Tests/images/gimp_gradient.ggr"
+
+        # Act
+        palette = ImagePalette.load(test_file)
+
+        # Assert
+        # load returns raw palette information
+        self.assertEqual(len(palette[0]), 1024)
+        self.assertEqual(palette[1], "RGBA")
+
+    def test_load_1_3_via_imagepalette(self):
+        # Arrange
+        from PIL import ImagePalette
+        # GIMP 1.3 gradient files contain a name field
+        test_file = "Tests/images/gimp_gradient_with_name.ggr"
+
+        # Act
+        palette = ImagePalette.load(test_file)
+
+        # Assert
+        # load returns raw palette information
+        self.assertEqual(len(palette[0]), 1024)
+        self.assertEqual(palette[1], "RGBA")
+
+
+if __name__ == '__main__':
+    unittest.main()
+
+# End of file