File: trafo.py

package info (click to toggle)
pyx3 0.14.1-5
  • links: PTS
  • area: main
  • in suites: stretch
  • size: 8,928 kB
  • ctags: 3,516
  • sloc: python: 21,171; ansic: 127; makefile: 87; sh: 8
file content (252 lines) | stat: -rw-r--r-- 8,785 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
# -*- encoding: utf-8 -*-
#
#
# Copyright (C) 2002-2011 Jörg Lehmann <joergl@users.sourceforge.net>
# Copyright (C) 2002-2011 André Wobst <wobsta@users.sourceforge.net>
#
# This file is part of PyX (http://pyx.sourceforge.net/).
#
# PyX is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PyX is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with PyX; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

import math
from . import attr, baseclasses, unit

# some helper routines

def _rmatrix(angle):
    phi = math.pi*angle/180.0

    return  ((math.cos(phi), -math.sin(phi)), 
             (math.sin(phi),  math.cos(phi)))

def _rvector(angle, x, y):
    phi = math.pi*angle/180.0

    return  ((1-math.cos(phi))*x + math.sin(phi)    *y,
              -math.sin(phi)   *x + (1-math.cos(phi))*y)


def _mmatrix(angle):
    phi = math.pi*angle/180.0

    return ( (math.cos(phi)*math.cos(phi)-math.sin(phi)*math.sin(phi),
              -2*math.sin(phi)*math.cos(phi)                ),
             (-2*math.sin(phi)*math.cos(phi),
              math.sin(phi)*math.sin(phi)-math.cos(phi)*math.cos(phi) ) )


# trafo: affine transformations

class trafo_pt(baseclasses.deformer):

    """affine transformation (coordinates in constructor in pts)

    Note that though the coordinates in the constructor are in
    pts (which is useful for internal purposes), all other
    methods only accept units in the standard user notation.

    """

    def __init__(self, matrix=((1, 0), (0, 1)), vector=(0, 0)):
        """Return trafo with given transformation matrix and vector.
        """
        self.matrix = matrix
        self.vector = vector

    def __mul__(self, other):
        if isinstance(other, trafo_pt):
            matrix = ( ( self.matrix[0][0]*other.matrix[0][0] +
                         self.matrix[0][1]*other.matrix[1][0],
                         self.matrix[0][0]*other.matrix[0][1] +
                         self.matrix[0][1]*other.matrix[1][1] ),
                       ( self.matrix[1][0]*other.matrix[0][0] +
                         self.matrix[1][1]*other.matrix[1][0],
                         self.matrix[1][0]*other.matrix[0][1] +
                         self.matrix[1][1]*other.matrix[1][1] )
                     )

            vector = ( self.matrix[0][0]*other.vector[0] +
                       self.matrix[0][1]*other.vector[1] +
                       self.vector[0],
                       self.matrix[1][0]*other.vector[0] +
                       self.matrix[1][1]*other.vector[1] +
                       self.vector[1] )

            return trafo_pt(matrix=matrix, vector=vector)
        else:
            raise NotImplementedError("can only multiply two transformations")

    def __str__(self):
        return "[%f %f %f %f %f %f]" % \
               ( self.matrix[0][0], self.matrix[1][0],
                 self.matrix[0][1], self.matrix[1][1],
                 self.vector[0], self.vector[1] )

    def processPS(self, file, writer, context, registry):
        file.write("[%f %f %f %f %f %f] concat\n" % \
                    ( self.matrix[0][0], self.matrix[1][0],
                      self.matrix[0][1], self.matrix[1][1],
                      self.vector[0], self.vector[1] ) )

    def processPDF(self, file, writer, context, registry):
        file.write("%f %f %f %f %f %f cm\n" % \
                    ( self.matrix[0][0], self.matrix[1][0],
                      self.matrix[0][1], self.matrix[1][1],
                      self.vector[0], self.vector[1] ) )

    def processSVGattrs(self, attrs, writer, context, registry):
        assert "transform" not in attrs
        attrs["transform"] = "matrix(%f,%f,%f,%f,%f,%f)" % \
                    ( self.matrix[0][0], -self.matrix[1][0],
                      -self.matrix[0][1], self.matrix[1][1],
                      self.vector[0], -self.vector[1] )

    def apply_pt(self, x_pt, y_pt):
        """apply transformation to point (x_pt, y_pt) in pts"""
        return ( self.matrix[0][0]*x_pt + self.matrix[0][1]*y_pt + self.vector[0],
                 self.matrix[1][0]*x_pt + self.matrix[1][1]*y_pt + self.vector[1] )

    def apply(self, x, y):
        # for the transformation we have to convert to points
        tx, ty = self.apply_pt(unit.topt(x), unit.topt(y))
        return tx * unit.t_pt, ty * unit.t_pt

    def deform(self, path):
        return path.transformed(self)

    def inverse(self):
        det = 1.0*(self.matrix[0][0]*self.matrix[1][1] - self.matrix[0][1]*self.matrix[1][0])
        matrix = ( ( self.matrix[1][1]/det, -self.matrix[0][1]/det),
                   (-self.matrix[1][0]/det,  self.matrix[0][0]/det) )
        return ( trafo_pt(matrix=matrix) *
                 trafo_pt(vector=(-self.vector[0], -self.vector[1])) )

    def mirrored(self, angle):
        return mirror(angle) * self

    def rotated_pt(self, angle, x=None, y=None):
        return rotate_pt(angle, x, y) * self

    def rotated(self, angle, x=None, y=None):
        return rotate(angle, x, y) * self

    def scaled_pt(self, sx, sy=None, x=None, y=None):
        return scale_pt(sx, sy, x, y) * self

    def scaled(self, sx, sy=None, x=None, y=None):
        return scale(sx, sy, x, y) * self

    def slanted_pt(self, a, angle=0, x=None, y=None):
        return slant_pt(a, angle, x, y) * self

    def slanted(self, a, angle=0, x=None, y=None):
        return slant(a, angle, x, y) * self

    def translated_pt(self, x, y):
        return translate_pt(x, y) * self

    def translated(self, x, y):
        return translate(x, y) * self


class trafo(trafo_pt):

    """affine transformation"""

    def __init__(self, matrix=((1,0), (0,1)), vector=(0, 0)):
        trafo_pt.__init__(self,
                          matrix, (unit.topt(vector[0]), unit.topt(vector[1])))

#
# some standard transformations 
#

identity = trafo()

class mirror(trafo):
    def __init__(self, angle=0):
        trafo.__init__(self, matrix=_mmatrix(angle))


class rotate_pt(trafo_pt):
    def __init__(self, angle, x=None, y=None):
        vector = 0, 0
        if x is not None or y is not None:
            if x is None or y is None:
                raise TrafoException("either specify both x and y or none of them")
            vector=_rvector(angle, x, y)

        trafo_pt.__init__(self, matrix=_rmatrix(angle), vector=vector)


class rotate(trafo_pt):
    def __init__(self, angle, x=None, y=None):
        vector = 0, 0 
        if x is not None or y is not None:
            if x is None or y is None:
                raise TrafoException("either specify both x and y or none of them")
            vector=_rvector(angle, unit.topt(x), unit.topt(y))

        trafo_pt.__init__(self, matrix=_rmatrix(angle), vector=vector)


class scale_pt(trafo_pt):
    def __init__(self, sx, sy=None, x=None, y=None):
        if sy is None:
            sy = sx
        vector = 0, 0
        if x is not None or y is not None:
            if x is None or y is None:
                raise TrafoException("either specify both x and y or none of them")
            vector = (1-sx)*x, (1-sy)*y
        trafo_pt.__init__(self, matrix=((sx, 0), (0, sy)), vector=vector)


class scale(trafo):
    def __init__(self, sx, sy=None, x=None, y=None):
        if sy is None:
            sy = sx
        vector = 0, 0
        if x is not None or y is not None:
            if x is None or y is None:
                raise TrafoException("either specify both x and y or none of them")
            vector = (1-sx)*x, (1-sy)*y
        trafo.__init__(self, matrix=((sx, 0), (0, sy)), vector=vector)


class slant_pt(trafo_pt):
    def __init__(self, a, angle=0, x=None, y=None):
        t = ( rotate_pt(-angle, x, y) *
              trafo(matrix=((1, a), (0, 1))) *
              rotate_pt(angle, x, y) )
        trafo_pt.__init__(self, t.matrix, t.vector)


class slant(trafo):
    def __init__(self, a, angle=0, x=None, y=None):
        t = ( rotate(-angle, x, y) *
              trafo(matrix=((1, a), (0, 1))) *
              rotate(angle, x, y) )
        trafo.__init__(self, t.matrix, t.vector)


class translate_pt(trafo_pt):
    def __init__(self, x, y):
        trafo_pt.__init__(self, vector=(x, y))


class translate(trafo):
    def __init__(self, x, y):
        trafo.__init__(self, vector=(x, y))