make_data.py

#!/usr/bin/env python

# These are the key vertices of "PrexLab"
VERTICES = [
    # P
    [
        (12,  3),
        (12, 59),
        (27, 59),
        (37, 49),
        (37, 32),
        (27, 25),
        (12, 25)
    ],
    # r
    [
        (48,  3),
        (48, 42),
        (48, 35),
        (55, 42),
        (64, 43)
    ],
    # e
    [
        (70, 24),
        (95, 24),
        (95, 33),
        (88, 42),
        (75, 42),
        (69, 33),
        (69, 13),
        (75,  5),
        (85,  1),
        (94,  6)
    ],
    # x
    [
        (105,  3),
        (129, 44)
    ],
    [
        (105, 44),
        (129,  3)
    ],
    # L
    [
        (144,  3),
        (144, 58),
        (144,  3),
        (167,  3)
    ],
    # a
    [
        (175, 39),
        (187, 44),
        (197, 35),
        (197,  3),
        (197, 10),
        (189,  3),
        (178,  3),
        (174,  9),
        (174, 19),
        (180, 26),
        (197, 26)
    ],
    # b
    [
        (213,  3),
        (213, 60),
        (213, 13),
        (231,  3),
        (237, 11),
        (237, 32),
        (231, 41),
        (220, 41),
        (213, 35)
    ]
]

LINE_STEP = 3
ANGLE_STEP = 3

points = []


def append_point(x, y):
    points.append((x, y))


def interpolate(x1, y1, x2, y2):
    if x1 == x2:
        for y in range(y1, y2, LINE_STEP if y2 > y1 else -LINE_STEP):
            append_point(x1, y)
    elif y1 == y2:
        for x in range(x1, x2, LINE_STEP if x2 > x1 else -LINE_STEP):
            append_point(x, y1)
    else:
        for x in range(x1, x2, ANGLE_STEP if x2 > x1 else -ANGLE_STEP):
            y = int(y1 + (y2 - y1)/(float(x2) - x1)  * (x - x1))
            append_point(x, y)


def outputPreamble():
    print (
        '// auto-generated by make_data.py\n\n'
        '#ifndef Points_h\n'
        '#define Points_h\n\n'
        '// x,y coordinates for plotting\n'
        'const static byte VERTICES[][2]  = {'
    )


def outputPoints():
    data = '  {}'.format(
        ',\n  '.join([
            '{{{}, {}}}'.format(point[0], point[1])
            for point in points
        ])
    )
    print data


def outputEpilogue():
    print (
        '};\n\n'
        'int NUM_POINTS = sizeof(VERTICES) / 2;\n\n'
        '#endif'
    )


def build():
    for segment in VERTICES:
        for p in range(len(segment) - 1):
            interpolate(
                segment[p][0],
                segment[p][1],
                segment[p + 1][0],
                segment[p + 1][1]
            )
    outputPreamble()
    outputPoints()
    outputEpilogue()


if __name__ == '__main__':
    build()