Rotate transforms now optimize angles, and have test coverage.

scour.py

@@ -2328,6 +2328,28 @@ def reducePrecision(element) :
 	
 	return num
 
+def optimizeAngle(angle):
+	"""
+	Because any rotation can be expressed within 360 degrees
+	of any given number, and since negative angles sometimes
+	are one character longer than corresponding positive angle,
+	we shorten the number to one in the range to [-90, 270[.
+	"""
+	# First, we put the new angle in the range ]-360, 360[.
+	# The modulo operator yields results with the sign of the
+	# divisor, so for negative dividends, we preserve the sign
+	# of the angle.
+	if angle < 0:     angle %= -360
+	else:             angle %=  360
+	# 720 degrees is unneccessary, as 360 covers all angles.
+	# As "-x" is shorter than "35x" and "-xxx" one character
+	# longer than positive angles <= 260, we constrain angle
+	# range to [-90, 270[ (or, equally valid: ]-100, 260]).
+	if  angle >= 270: angle -=  360
+	elif angle < -90: angle +=  360
+	return angle
+
+
 def optimizeTransform(transform):
 	"""
 	Optimises a series of transformations parsed from a single
@@ -2401,6 +2423,7 @@ def optimizeTransform(transform):
 			if len(args) == 2 and args[1] == 0:
 				del args[1]
 		elif type == 'rotate':
+			args[0] = optimizeAngle(args[0]) # angle
 			# Only the angle is required for rotations.
 			# If the coordinates are unspecified, it's the origin (0, 0).
 			if len(args) == 3 and args[1] == args[2] == 0:
@@ -2447,14 +2470,7 @@ def optimizeTransform(transform):
 		elif (currType == prevType == 'rotate'
 		      and len(prevArgs) == len(currArgs) == 1):
 			# Only coalesce if both rotations are from the origin.
-			prevArgs[0] += currArgs[0] # angle
+			prevArgs[0] = optimizeAngle(prevArgs[0] + currArgs[0])
-			# Put the new angle in the range ]-360, 360[.
-			# The modulo operator yields results with the sign of the
-			# divisor, so for negative dividends, we preserve the sign
-			# of the angle.
-			if prevArgs[0] < 0: prevArgs[0] = prevArgs[0] % -360
-			else:               prevArgs[0] = prevArgs[0] %  360
-
 			del transform[i]
 		elif currType == prevType == 'scale':
 			prevArgs[0] *= currArgs[0] # x

testscour.py

@@ -1243,9 +1243,9 @@ class TransformRotate90(unittest.TestCase):
 
 class TransformRotateCCW135(unittest.TestCase):
 	def runTest(self):
-		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-neg-135.svg')
+		doc = scour.scourXmlFile('unittests/transform-matrix-is-rotate-225.svg')
-		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(-135)',
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(225)',
-			'Counter-clockwise rotation matrix not converted to rotate(-135)')
+			'Counter-clockwise rotation matrix not converted to rotate(225)')
 
 class TransformRotateCCW45(unittest.TestCase):
 	def runTest(self):
@@ -1277,6 +1277,18 @@ class TransformTranslate(unittest.TestCase):
 		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'translate(2 3)',
 			'Translation matrix not converted to translate(2 3)')
 
+class TransformRotationRange719_5(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-rotate-trim-range-719.5.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(-.5)',
+			'Transform containing rotate(719.5) not shortened to rotate(-.5)')
+
+class TransformRotationRangeCCW540_0(unittest.TestCase):
+	def runTest(self):
+		doc = scour.scourXmlFile('unittests/transform-rotate-trim-range-neg-540.0.svg')
+		self.assertEquals(doc.getElementsByTagName('line')[0].getAttribute('transform'), 'rotate(180)',
+			'Transform containing rotate(-540.0) not shortened to rotate(180)')
+
 class TransformRotation3Args(unittest.TestCase):
 	def runTest(self):
 		doc = scour.scourXmlFile('unittests/transform-rotate-fold-3args.svg')

unittests/transform-rotate-trim-range-719.5.svg

@@ -0,0 +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(719.5)"/>
+ <!--  all rotation angles can be mapped to the shorter range [-90, 270[ -->
+</svg>

unittests/transform-rotate-trim-range-neg-540.0.svg

@@ -0,0 +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(-540.0) rotate(0)"/>
+ <!--  all rotation angles can be mapped to the shorter range [-90, 270[ -->
+</svg>