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Fixed the transform optimizations, which were all broken (wrong arg order).

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This commit is contained in:
Johan Sundström 2011-02-21 01:13:56 -08:00
parent 438fd06952
commit c6a9336185
1 changed files with 36 additions and 33 deletions
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67
scour.py
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@ -2302,51 +2302,51 @@ def optimizeTransform(transform):
"""
# if there's only one transformation and it's a matrix,
# try to make it a shorter non-matrix transformation
# NOTE: as matrix(a b c d e f) in SVG means the matrix:
# |¯ a c e ¯| make constants |¯ A1 A2 A3 ¯|
# | 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]
# |¯ 1 0 0 ¯|
# | 0 1 0 | Identity matrix (no transformation)
# |_ 0 0 1 _|
if transform[0][1] == [1, 0, 0, 0, 1, 0]:
if matrix == [1, 0, 0, 1, 0, 0]:
del transform[0]
# |¯ 1 0 X ¯|
# | 0 1 Y | Translation by (X, Y).
# |_ 0 0 1 _|
if (transform[0][1][0] == 1 and
transform[0][1][1] == 0 and
transform[0][1][3] == 0 and
transform[0][1][4] == 1):
transform[0] = ('translate', [
transform[0][1][2], transform[0][1][5]
])
elif (A1 == 1 and A2 == 0
and B1 == 0 and B2 == 1):
transform[0] = ('translate', [A3, B3])
# |¯ X 0 0 ¯|
# | 0 Y 0 | Scaling by (X, Y).
# |_ 0 0 1 _|
elif (transform[0][1][1] == 0 and
transform[0][1][2] == 0 and
transform[0][1][3] == 0 and
transform[0][1][5] == 0):
transform[0] = ('scale', [
transform[0][1][0], transform[0][1][4]
])
elif ( A2 == 0 and A3 == 0
and B1 == 0 and B3 == 0):
transform[0] = ('scale', [A1, B2])
# |¯ cos(A) -sin(A) 0 ¯| Rotation by angle A,
# | sin(A) cos(A) 0 | clockwise, about the origin.
# |_ 0 0 1 _| A is in degrees.
elif (transform[0][1][0] == transform[0][1][4] and
transform[0][1][1] == -transform[0][1][3] and
transform[0][1][0] >= 0 and
transform[0][1][0] <= 1 and
transform[0][1][3] == sqrt(1 - transform[0][1][0] ** 2) and
transform[0][1][2] == 0 and
transform[0][1][5] == 0):
transform[0] = ('rotate', [
# What allows us to get the angle from the matrix
# is the inverse sine of sin(A), which is the 4th
# matrix component, or the inverse cosine of cos(A),
# which is the 1st matrix component. I chose sin(A).
# math.asin returns radians, so convert.
# SVG demands degrees.
Decimal(math.degrees(math.asin(transform[0][1][4])))
])
# |_ 0 0 1 _| A is in degrees, [-180...180].
elif (A1 == B2 and -1 <= A1 <= 1 and A3 == 0
and -B1 == A2 and -1 <= B1 <= 1 and B3 == 0
# as cos² A + sin² A == 1 and as decimal trig is approximate:
and abs((B1 ** 2) + (A1 ** 2) - 1) < Decimal("1e-15")):
[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:
# -- => < -90 | -+ => -90..0 | ++ => 0..90 | +- => >= 90
#
# http://en.wikipedia.org/wiki/File:Sine_cosine_plot.svg
# shows asin has the correct angle the middle quadrants:
A = Decimal(str(math.degrees(math.asin(sin_A))))
if cos_A < 0: # otherwise needs adjusting from the edges
if sin_A < 0:
A = -180 - A
else:
A = 180 - A
transform[0] = ('rotate', [A])
# Simplify transformations where numbers are optional.
for singleTransform in transform:
@ -2435,7 +2435,10 @@ def optimizeTransforms(element, options) :
newVal = serializeTransform(transform)
if len(newVal) < len(val):
if len(newVal):
element.setAttribute(transformAttr, newVal)
else:
element.removeAttribute(transformAttr)
num += len(val) - len(newVal)
for child in element.childNodes: