scour.py: Modify optimizeTransform to remove superfluous []s and ()s.

testscour.py: Add unit tests for Johan Sundström's fix for bug 722544, "SVG transform matrix() arg order is a1 b1 a2 b2 a3 b3, not a1 a2 a3 b1 b2 b3".

unittests/: Edit the unit tests' support files not to have a second line with the correct transformation. This is customarily in testscour.py.

scour.py

@@ -2315,7 +2315,7 @@ def optimizeTransform(transform):
 	# |   b  d  f   |  translating them  |   B1  B2  B3   |
 	# |_  0  0  1  _|  to more readable  |_  0    0   1  _|
 	if len(transform) == 1 and transform[0][0] == 'matrix':
-		matrix = [A1, B1, A2, B2, A3, B3] = transform[0][1]
+		matrix = A1, B1, A2, B2, A3, B3 = transform[0][1]
 		# |¯  1  0  0  ¯|
 		# |   0  1  0   |  Identity matrix (no transformation)
 		# |_  0  0  1  _|
@@ -2342,7 +2342,7 @@ def optimizeTransform(transform):
 		 # FIXME: the "epsilon" term here should really be some function
 		 #        of the precision of the (sin|cos)_A terms, not 1e-15:
 		 and  abs((B1 ** 2) + (A1 ** 2) - 1) < Decimal("1e-15")):
-			[sin_A, cos_A] = [B1, A1]
+			sin_A, cos_A = B1, A1
 			# while asin(A) and acos(A) both only have an 180° range
 			# the sign of sin(A) and cos(A) varies across quadrants,
 			# letting us hone in on the angle the matrix represents:
@@ -2358,24 +2358,22 @@ def optimizeTransform(transform):
 					A =  180 - A
 			transform[0] = ('rotate', [A])
 	
-		# Simplify transformations where numbers are optional.
+	# Simplify transformations where numbers are optional.
-	for [type, args] in transform:
+	for type, args in transform:
 		if type == 'translate':
 			# Only the X coordinate is required for translations.
 			# If the Y coordinate is unspecified, it's 0.
-			if (len(args) == 2 and args[1] == 0):
+			if len(args) == 2 and args[1] == 0:
 				del args[1]
 		elif type == 'rotate':
 			# Only the angle is required for rotations.
 			# If the coordinates are unspecified, it's the origin (0, 0).
-			if (len(args) == 3 and
+			if len(args) == 3 and args[1] == args[2] == 0:
-			    args[1] == 0 and
-			    args[2] == 0):
 				del args[1:]
 		elif type == 'scale':
 			# Only the X scaling factor is required.
 			# If the Y factor is unspecified, it's the same as X.
-			if (len(args) == 2 and args[0] == args[1]):
+			if len(args) == 2 and args[0] == args[1]:
 				del args[1]
 
 	# Attempt to coalesce runs of the same transformation.
@@ -2396,8 +2394,8 @@ def optimizeTransform(transform):
 	#	 would be safe to multiply together, too.
 	i = 1
 	while i < len(transform):
-		[currType, currArgs] = transform[i]
+		currType, currArgs = transform[i]
-		[prevType, prevArgs] = transform[i - 1]
+		prevType, prevArgs = transform[i - 1]
 		if currType == prevType == 'translate':
 			prevArgs[0] += currArgs[0] # x
 			# for y, only add if the second translation has an explicit y
@@ -2435,9 +2433,9 @@ def optimizeTransform(transform):
 				del transform[i]
 		elif ((currType == 'skewX' or currType == 'skewY')
 		 and  len(currArgs) == 1 and currArgs[0] == 0):
-				# Identity skew!
+			# Identity skew!
-				i -= 1
+			i -= 1
-				del transform[i]
+			del transform[i]
 		else:
 			i += 1
 

testscour.py

@@ -1217,12 +1217,100 @@ class RemoveDefsWithWhitespace(unittest.TestCase):
 		self.assertEquals(doc.getElementsByTagName('defs').length, 0,
 			'Kept defs, although it contains only whitespace or is <defs/>')
 
+class TransformIdentityMatrix(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-identity.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), '',
+			'Transform containing identity matrix not removed')
+
+class TransformRotate135(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-135.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(135)',
+			'Rotation matrix not converted to rotate(135)')
+
+class TransformRotate45(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-45.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(45)',
+			'Rotation matrix not converted to rotate(45)')
+
+class TransformRotate90(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-90.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(90)',
+			'Rotation matrix not converted to rotate(90)')
+
+class TransformRotateCCW135(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-neg-135.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(-135)',
+			'Counter-clockwise rotation matrix not converted to rotate(-135)')
+
+class TransformRotateCCW45(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-neg-45.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(-45)',
+			'Counter-clockwise rotation matrix not converted to rotate(-45)')
+
+class TransformRotateCCW90(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-neg-90.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(-90)',
+			'Counter-clockwise rotation matrix not converted to rotate(-90)')
+
+class TransformScale2by3(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-scale-2-3.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'scale(2 3)',
+			'Scaling matrix not converted to scale(2 3)')
+
+class TransformScaleMinus1(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-scale-neg-1.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'scale(-1)',
+			'Scaling matrix not converted to scale(-1)')
+
+class TransformTranslate(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-translate.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'translate(2 3)',
+			'Translation matrix not converted to translate(2 3)')
+
+class TransformRotation3Args(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-rotate-fold-3args.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(90)',
+			'Optional zeroes in rotate(angle 0 0) not removed')
+
+class TransformIdentityRotation(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-rotate-is-identity.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), '',
+			'Transform containing identity rotation not removed')
+
+class TransformIdentitySkewX(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-skewX-is-identity.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), '',
+			'Transform containing identity X-axis skew not removed')
+
+class TransformIdentitySkewY(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-skewY-is-identity.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), '',
+			'Transform containing identity Y-axis skew not removed')
+
+class TransformIdentityTranslate(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-translate-is-identity.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), '',
+			'Transform containing identity translation not removed')
+
 # TODO: write tests for --enable-viewboxing
 # TODO; write a test for embedding rasters
 # TODO: write a test for --disable-embed-rasters
 # TODO: write tests for --keep-editor-data
-# TODO: write tests for scouring transformations
-#   progress: the unittests/transform-* files list expected before/after behaviour
 
 if __name__ == '__main__':
 	testcss = __import__('testcss')

unittests/transform-matrix-is-identity.svg

@@ -1,4 +1,3 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(1 0 0 1 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9"/>
 </svg>

unittests/transform-matrix-is-rotate-135.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(-0.70710678118654746 0.70710678118654757 -0.70710678118654757 -0.70710678118654746 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(135)"/>
 </svg>

unittests/transform-matrix-is-rotate-45.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(0.70710678118654757 0.70710678118654746 -0.70710678118654746 0.70710678118654757 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(45)"/>
 </svg>

unittests/transform-matrix-is-rotate-90.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(0 1 -1 0 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(90)"/>
 </svg>

unittests/transform-matrix-is-rotate-neg-135.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(-0.70710678118654746 -0.70710678118654757 0.70710678118654757 -0.70710678118654746 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(-135)"/>
 </svg>

unittests/transform-matrix-is-rotate-neg-45.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(0.70710678118654757 -0.70710678118654746 0.70710678118654746 0.70710678118654757 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(-45)"/>
 </svg>

unittests/transform-matrix-is-rotate-neg-90.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(0 -1 1 0 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(-90)"/>
 </svg>

unittests/transform-matrix-is-scale-2-3.svg

@@ -1,4 +1,3 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 18 27">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(2 0 0 3 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="scale(2 3)"/>
 </svg>

unittests/transform-matrix-is-scale-neg-1.svg

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 -9 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(-1 0 0 -1 0 0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="scale(-1)"/>
 </svg>

unittests/transform-matrix-is-translate.svg

@@ -1,4 +1,3 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="2 3 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="matrix(1 0 0 1 2 3)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="translate(2 3)"/>
 </svg>

unittests/transform-rotate-fold-3args.svg

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="-9 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="rotate(90 0 0.0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9" transform="rotate(90)"/>
  <!--  optional zero trailing args to transform type rotate get removed -->
 </svg>

unittests/transform-skewX-is-identity.svg

@@ -1,5 +1,4 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="skewX(0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9"/>
  <!--  skewX(0) is the identity transform, which can safely be removed -->
 </svg>

unittests/transform-skewY-is-identity.svg

@@ -1,5 +1,4 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 9 9">
  <line stroke="rgba(255,0,0,0.5)" y1="9" x1="9" transform="skewY(0)"/>
- <line stroke="rgba(0,0,255,0.5)" y1="9" x1="9"/>
  <!--  skewY(0) is the identity transform, which can safely be removed -->
 </svg>