Tests/misc/psCharStrings_test.py

from fontTools.cffLib import PrivateDict
from fontTools.cffLib.specializer import stringToProgram
from fontTools.misc.testTools import getXML, parseXML
from fontTools.misc.psCharStrings import (
    T2CharString,
    encodeFloat,
    encodeFixed,
    read_fixed1616,
    read_realNumber,
)
import unittest


def hexenc(s):
    return ' '.join('%02x' % x for x in s)


class T2CharStringTest(unittest.TestCase):

    @classmethod
    def stringToT2CharString(cls, string):
        return T2CharString(program=stringToProgram(string), private=PrivateDict())

    def test_calcBounds_empty(self):
        cs = self.stringToT2CharString("endchar")
        bounds = cs.calcBounds(None)
        self.assertEqual(bounds, None)

    def test_calcBounds_line(self):
        cs = self.stringToT2CharString("100 100 rmoveto 40 10 rlineto -20 50 rlineto endchar")
        bounds = cs.calcBounds(None)
        self.assertEqual(bounds, (100, 100, 140, 160))

    def test_calcBounds_curve(self):
        cs = self.stringToT2CharString("100 100 rmoveto -50 -150 200 0 -50 150 rrcurveto endchar")
        bounds = cs.calcBounds(None)
        self.assertEqual(bounds, (91.90524980688875, -12.5, 208.09475019311125, 100))

    def test_charstring_bytecode_optimization(self):
        cs = self.stringToT2CharString(
            "100.0 100 rmoveto -50.0 -150 200.5 0.0 -50 150 rrcurveto endchar")
        cs.isCFF2 = False
        cs.private._isCFF2 = False
        cs.compile()
        cs.decompile()
        self.assertEqual(
            cs.program, [100, 100, 'rmoveto', -50, -150, 200.5, 0, -50, 150,
                         'rrcurveto', 'endchar'])

        cs2 = self.stringToT2CharString(
            "100.0 rmoveto -50.0 -150 200.5 0.0 -50 150 rrcurveto")
        cs2.isCFF2 = True
        cs2.private._isCFF2 = True
        cs2.compile(isCFF2=True)
        cs2.decompile()
        self.assertEqual(
            cs2.program, [100, 'rmoveto', -50, -150, 200.5, 0, -50, 150,
                          'rrcurveto'])

    def test_encodeFloat(self):
        testNums = [
            # value                expected result
            (-9.399999999999999,   '1e e9 a4 ff'),  # -9.4
            (9.399999999999999999, '1e 9a 4f'),  # 9.4
            (456.8,                '1e 45 6a 8f'),  # 456.8
            (0.0,                  '1e 0f'),  # 0
            (-0.0,                 '1e 0f'),  # 0
            (1.0,                  '1e 1f'),  # 1
            (-1.0,                 '1e e1 ff'),  # -1
            (98765.37e2,           '1e 98 76 53 7f'),  # 9876537
            (1234567890.0,         '1e 1a 23 45 67 9b 09 ff'),  # 1234567890
            (9.876537e-4,          '1e a0 00 98 76 53 7f'),  # 9.876537e-24
            (9.876537e+4,          '1e 98 76 5a 37 ff'),  # 9.876537e+24
        ]

        for sample in testNums:
            encoded_result = encodeFloat(sample[0])

            # check to see if we got the expected bytes
            self.assertEqual(hexenc(encoded_result), sample[1])

            # check to see if we get the same value by decoding the data
            decoded_result = read_realNumber(
                None,
                None,
                encoded_result,
                1,
            )
            self.assertEqual(decoded_result[0], float('%.8g' % sample[0]))
            # We limit to 8 digits of precision to match the implementation
            # of encodeFloat.

    def test_encode_decode_fixed(self):
        testNums = [
            # value                expected hex      expected float
            (-9.399999999999999,   'ff ff f6 99 9a', -9.3999939),
            (-9.4,                 'ff ff f6 99 9a', -9.3999939),
            (9.399999999999999999, 'ff 00 09 66 66', 9.3999939),
            (9.4,                  'ff 00 09 66 66', 9.3999939),
            (456.8,                'ff 01 c8 cc cd', 456.8000031),
            (-456.8,               'ff fe 37 33 33', -456.8000031),
        ]

        for (value, expected_hex, expected_float) in testNums:
            encoded_result = encodeFixed(value)

            # check to see if we got the expected bytes
            self.assertEqual(hexenc(encoded_result), expected_hex)

            # check to see if we get the same value by decoding the data
            decoded_result = read_fixed1616(
                None,
                None,
                encoded_result,
                1,
            )
            self.assertAlmostEqual(decoded_result[0], expected_float)

    def test_toXML(self):
        program = [
            '107 53.4004 166.199 hstem',
            '174.6 163.801 vstem',
            '338.4 142.8 rmoveto',
            '28 0 21.9 9 15.8 18 15.8 18 7.9 20.79959 0 23.6 rrcurveto',
            'endchar'
        ]
        cs = self.stringToT2CharString(" ".join(program))

        self.assertEqual(getXML(cs.toXML), program)

    def test_fromXML(self):
        cs = T2CharString()
        for name, attrs, content in parseXML(
            [
                '<CharString name="period">'
                '  338.4 142.8 rmoveto',
                '  28 0 21.9 9 15.8 18 15.8 18 7.9 20.79959 0 23.6 rrcurveto',
                '  endchar'
                '</CharString>'
            ]
        ):
            cs.fromXML(name, attrs, content)

        expected_program = [
            338.3999939, 142.8000031, 'rmoveto',
            28, 0, 21.8999939, 9, 15.8000031,
            18, 15.8000031, 18, 7.8999939,
            20.7995911, 0, 23.6000061, 'rrcurveto',
            'endchar'
        ]

        self.assertEqual(len(cs.program), len(expected_program))
        for arg, expected_arg in zip(cs.program, expected_program):
            if isinstance(arg, str):
                self.assertIsInstance(expected_arg, str)
                self.assertEqual(arg, expected_arg)
            else:
                self.assertNotIsInstance(expected_arg, str)
                self.assertAlmostEqual(arg, expected_arg)


if __name__ == "__main__":
    import sys
    sys.exit(unittest.main())