LabelGenerator.py

#!/usr/bin/env python3

from reportlab.pdfgen.canvas import Canvas
from reportlab.lib.pagesizes import A4, LETTER
from reportlab.lib.units import inch, mm
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont, TTFError
from reportlab.lib.colors import black, toColor, HexColor, gray

import math
import sys

from typing import Tuple, Union, Optional, List

ResistorList = List[Union[Optional[float], List[Optional[float]]]]


def load_font(font_name: str) -> None:
    pdfmetrics.registerFont(TTFont('Arial Bold', font_name))
    print("Using font '{}' ...".format(font_name))


if "--roboto" in sys.argv:
    try:
        load_font('Roboto-Bold.ttf')
    except TTFError as e:
        print("Error: {}".format(e))
        exit(1)

else:
    for font_name in ['ArialBd.ttf', 'Arial_Bold.ttf']:
        try:
            load_font(font_name)
            break
        except TTFError:
            pass
    else:
        print("Error: Unable to load font 'Arial Bold'.")
        print("If you are on Ubuntu, you can install it with:")
        print("    sudo apt install ttf-mscorefonts-installer")
        print("Alternatively, use the 'Roboto' font by invoking this script with")
        print("the '--roboto' flag.")
        print("On Mac OS the '--roboto' flag is mandatory because this script currently")
        print("does not support Arial on Mac OS.")
        exit(1)


class PaperConfig:
    def __init__(
        self,
        paper_name: str,
        pagesize: Tuple[float, float],
        sticker_width: float,
        sticker_height: float,
        sticker_corner_radius: float,
        left_margin: float,
        top_margin: float,
        horizontal_stride: float,
        vertical_stride: float,
        num_stickers_horizontal: int,
        num_stickers_vertical: int,
    ) -> None:
        self.paper_name = paper_name
        self.pagesize = pagesize
        self.sticker_width = sticker_width
        self.sticker_height = sticker_height
        self.sticker_corner_radius = sticker_corner_radius
        self.left_margin = left_margin
        self.top_margin = top_margin
        self.horizontal_stride = horizontal_stride
        self.vertical_stride = vertical_stride
        self.num_stickers_horizontal = num_stickers_horizontal
        self.num_stickers_vertical = num_stickers_vertical


AVERY_5260 = PaperConfig(
    paper_name="Avery 5260",
    pagesize=LETTER,
    sticker_width=(2 + 5/8) * inch,
    sticker_height=1 * inch,
    sticker_corner_radius=0.1 * inch,
    left_margin=3/16 * inch,
    top_margin=0.5 * inch,
    horizontal_stride=(2 + 6/8) * inch,
    vertical_stride=1 * inch,
    num_stickers_horizontal=3,
    num_stickers_vertical=10,
)


AVERY_L7157 = PaperConfig(
    paper_name="Avery L7157",
    pagesize=A4,
    sticker_width=64 * mm,
    sticker_height=24.3 * mm,
    sticker_corner_radius=3 * mm,
    left_margin=6.4 * mm,
    top_margin=14.1 * mm,
    horizontal_stride=66.552 * mm,
    vertical_stride=24.3 * mm,
    num_stickers_horizontal=3,
    num_stickers_vertical=11,
)


EJ_RANGE_24 = PaperConfig(
    paper_name="EJRange 24",
    pagesize=A4,
    sticker_width=63.5 * mm,
    sticker_height=33.9 * mm,
    sticker_corner_radius=2 * mm,
    left_margin=6.5 * mm,
    top_margin=13.2 * mm,
    horizontal_stride=66.45 * mm,
    vertical_stride=33.9 * mm,
    num_stickers_horizontal=3,
    num_stickers_vertical=8,
)


class StickerRect:
    def __init__(self, c: Canvas, layout: PaperConfig, row: int, column: int, mirror: bool):
        self.left = layout.left_margin + layout.horizontal_stride * column
        self.bottom = layout.pagesize[1] - (
            layout.sticker_height + layout.top_margin + layout.vertical_stride * row
        )
        self.width = layout.sticker_width
        self.height = layout.sticker_height
        self.corner = layout.sticker_corner_radius

        self._mirror = mirror
        self._c = c

    def __enter__(self) -> "StickerRect":

        if self._mirror:
            pagewidth = self._c._pagesize[0]
            pageheight = self._c._pagesize[1]
            self._c.saveState()
            self._c.translate(pagewidth, pageheight)
            self._c.rotate(180)
            self.left = pagewidth - self.left - self.width
            self.bottom = pageheight - self.bottom - self.height

        return self

    def __exit__(self, _type: object, _value: object, _traceback: object) -> None:
        if self._mirror:
            self._c.restoreState()


class ResistorValue:
    def __init__(self, ohms: float):
        ohms_exp = 0
        ohms_val = 0

        if ohms != 0:
            # Fixed-point value with 2 decimals precision
            ohms_exp = math.floor(math.log10(ohms))
            ohms_val = round(ohms / math.pow(10, ohms_exp - 2))

            while ohms_val >= 1000:
                ohms_exp += 1
                ohms_val //= 10

        self.ohms_val = ohms_val
        self.ohms_exp = ohms_exp

        # print(self.ohms_val, self.ohms_exp, self.format_value(), self.get_value())

    def get_value(self) -> float:
        return self.ohms_val * math.pow(10, self.ohms_exp - 2)

    def get_prefix(self) -> str:
        if self.ohms_exp >= 12:
            return "T"
        if self.ohms_exp >= 9:
            return "G"
        if self.ohms_exp >= 6:
            return "M"
        if self.ohms_exp >= 3:
            return "k"
        if self.ohms_exp >= 0:
            return ""
        if self.ohms_exp >= -3:
            return "m"
        if self.ohms_exp >= -6:
            return "\u03BC"
        return "n"

    def get_prefixed_number(self) -> str:
        if self.ohms_exp % 3 == 0:
            if self.ohms_val % 100 == 0:
                return str(self.ohms_val // 100)
            elif self.ohms_val % 10 == 0:
                return str(self.ohms_val // 100) + "." + str((self.ohms_val % 100) // 10)
            else:
                return str(self.ohms_val // 100) + "." + str(self.ohms_val % 100)
        elif self.ohms_exp % 3 == 1:
            if self.ohms_val % 10 == 0:
                return str(self.ohms_val // 10)
            else:
                return str(self.ohms_val // 10) + "." + str(self.ohms_val % 10)
        else:
            return str(self.ohms_val)

    def format_value(self) -> str:

        if self.ohms_exp < 0:
            rendered_num = str(self.ohms_val)
            while rendered_num[-1] == "0":
                rendered_num = rendered_num[:-1]
            if self.ohms_exp == -1:
                return "0." + rendered_num
            if self.ohms_exp == -2:
                return "0.0" + rendered_num
            if self.ohms_exp == -3:
                return "0.00" + rendered_num

        return self.get_prefixed_number() + self.get_prefix()


def resistor_color_table(num: int) -> HexColor:
    return [
        HexColor("#000000"),
        HexColor("#964B00"),
        HexColor("#FF3030"),
        HexColor("#FFA500"),
        HexColor("#FFFF00"),
        HexColor("#00FF00"),
        HexColor("#0000FF"),
        HexColor("#C520F6"),
        HexColor("#808080"),
        HexColor("#FFFFFF"),
    ][num]


def draw_fancy_resistor_stripe(
    c: Canvas,
    x: float,
    y: float,
    width: float,
    height: float,
    color_table: List[HexColor]
) -> None:
    c.setFillColor(color_table[2])
    c.rect(x, y+height*5/6, width, height/6, fill=1, stroke=0)
    c.setFillColor(color_table[1])
    c.rect(x, y+height*4/6, width, height/6, fill=1, stroke=0)
    c.setFillColor(color_table[0])
    c.rect(x, y+height*3/6, width, height/6, fill=1, stroke=0)
    c.setFillColor(color_table[1])
    c.rect(x, y+height*2/6, width, height/6, fill=1, stroke=0)
    c.setFillColor(color_table[2])
    c.rect(x, y+height*1/6, width, height/6, fill=1, stroke=0)
    c.setFillColor(color_table[3])
    c.rect(x, y+height*0/6, width, height/6, fill=1, stroke=0)


def draw_resistor_stripe_border(c: Canvas, x: float, y: float, width: float, height: float) -> None:
    c.setLineWidth(0.3)
    c.setFillColor(black, 0.0)
    c.setStrokeColorRGB(0.2, 0.2, 0.2, 0.5)
    c.rect(x, y, width, height, fill=0, stroke=1)


def draw_resistor_stripe(c: Canvas, x: float, y: float, width: float, height: float, stripe_value: int) -> None:
    if 0 <= stripe_value <= 9:
        c.setFillColor(resistor_color_table(stripe_value))
        c.rect(x, y, width, height, fill=1, stroke=0)
        draw_resistor_stripe_border(c, x, y, width, height)
        return

    elif stripe_value == -1:
        gold_table = [
            HexColor("#FFF0A0"),
            HexColor("#FFE55C"),
            HexColor("#FFD700"),
            HexColor("#D1B000"),
        ]

        draw_fancy_resistor_stripe(c, x, y, width, height, gold_table)
        draw_resistor_stripe_border(c, x, y, width, height)
        return

    elif stripe_value == -2:
        silver_table = [
            HexColor("#D0D0D0"),
            HexColor("#A9A9A9"),
            HexColor("#929292"),
            HexColor("#7B7B7B"),
        ]

        draw_fancy_resistor_stripe(c, x, y, width, height, silver_table)
        draw_resistor_stripe_border(c, x, y, width, height)
        return

    else:

        c.setLineWidth(0.5)
        c.setFillColor(gray, 0.3)
        c.setStrokeColorRGB(0.5, 0.5, 0.5, 1.0)
        c.rect(x, y, width, height, fill=1, stroke=1)
        c.line(x, y, x + width, y + height)
        c.line(x + width, y, x, y + height)
        return


def draw_resistor_colorcode(
        c: Canvas,
        value: ResistorValue,
        color1: object,
        color2: object,
        x: float,
        y: float,
        width: float,
        height: float,
        num_codes: int
) -> None:

    if value.ohms_exp < num_codes - 4:
        return

    border = height/6
    corner = (height-2*border)/4

    c.saveState()
    p = c.beginPath()
    p.roundRect(x+border, y+border, width-2*border, height-2*border, corner)
    c.clipPath(p, stroke=0)
    c.linearGradient(x+width/2, y+border+height, x+width/2, y+border, (color1, color2))
    c.restoreState()

    width_without_corner = width - 2*border - 2*corner
    stripe_width = width_without_corner/10

    if value.ohms_val == 0:
        draw_resistor_stripe(c,
                             x + border + corner + stripe_width / 2 + 2 * stripe_width * 2,
                             y + border,
                             stripe_width,
                             height - 2 * border,
                             0)
    else:
        for i in range(num_codes):

            if i == num_codes - 1:
                stripe_value = value.ohms_exp + 2 - num_codes
            else:
                stripe_value = value.ohms_val
                for _ in range(2-i):
                    stripe_value //= 10
                stripe_value %= 10

            draw_resistor_stripe(c,
                                 x + border + corner + stripe_width / 2 + 2 * stripe_width * i,
                                 y + border,
                                 stripe_width,
                                 height - 2 * border,
                                 stripe_value)

        draw_resistor_stripe(c,
                             x + width - border - corner - stripe_width * 1.5,
                             y + border,
                             stripe_width,
                             height - 2 * border,
                             -3)

    c.setFillColor(black)
    c.setStrokeColor(black, 1)
    c.setLineWidth(0.5)
    c.roundRect(x+border, y+border, width-2*border, height-2*border, corner)


def get_3digit_code(value: ResistorValue) -> str:
    if value.ohms_val % 10 != 0:
        return ""

    if value.ohms_val == 0:
        return "000"

    digits = str(value.ohms_val // 10)

    if value.ohms_exp > 0:
        multiplier = str(value.ohms_exp - 1)
        return digits + multiplier

    if value.ohms_exp == 0:
        return digits[0] + "R" + digits[1]

    if value.ohms_exp == -1:
        return "R" + digits

    if value.ohms_exp == -2:
        if value.ohms_val % 100 != 0:
            return ""
        return "R0" + digits[0]

    return ""


def get_4digit_code(value: ResistorValue) -> str:
    digits = str(value.ohms_val)

    if value.ohms_val == 0:
        return "0000"

    if value.ohms_exp > 1:
        multiplier = str(value.ohms_exp - 2)
        return digits + multiplier

    if value.ohms_exp == 1:
        return digits[0] + digits[1] + "R" + digits[2]

    if value.ohms_exp == 0:
        return digits[0] + "R" + digits[1] + digits[2]

    if value.ohms_exp == -1:
        return "R" + digits

    if value.ohms_exp == -2:
        if value.ohms_val % 10 != 0:
            return ""
        return "R0" + digits[0] + digits[1]

    if value.ohms_exp == -3:
        if value.ohms_val % 100 != 0:
            return ""
        return "R00" + digits[0]

    return ""


def get_eia98_code(value: ResistorValue) -> str:
    eia98_coding_table = {
        100: "01", 178: "25", 316: "49", 562: "73",
        102: "02", 182: "26", 324: "50", 576: "74",
        105: "03", 187: "27", 332: "51", 590: "75",
        107: "04", 191: "28", 340: "52", 604: "76",
        110: "05", 196: "29", 348: "53", 619: "77",
        113: "06", 200: "30", 357: "54", 634: "78",
        115: "07", 205: "31", 365: "55", 649: "79",
        118: "08", 210: "32", 374: "56", 665: "80",
        121: "09", 215: "33", 383: "57", 681: "81",
        124: "10", 221: "34", 392: "58", 698: "82",
        127: "11", 226: "35", 402: "59", 715: "83",
        130: "12", 232: "36", 412: "60", 732: "84",
        133: "13", 237: "37", 422: "61", 750: "85",
        137: "14", 243: "38", 432: "62", 768: "86",
        140: "15", 249: "39", 442: "63", 787: "87",
        143: "16", 255: "40", 453: "64", 806: "88",
        147: "17", 261: "41", 464: "65", 825: "89",
        150: "18", 267: "42", 475: "66", 845: "90",
        154: "19", 274: "43", 487: "67", 866: "91",
        158: "20", 280: "44", 499: "68", 887: "92",
        162: "21", 287: "45", 511: "69", 909: "93",
        165: "22", 294: "46", 523: "70", 931: "94",
        169: "23", 301: "47", 536: "71", 953: "95",
        174: "24", 309: "48", 549: "72", 976: "96",
    }

    if value.ohms_val not in eia98_coding_table:
        return ""

    digits = eia98_coding_table[value.ohms_val]

    multiplier_table = ["Z", "Y", "X", "A", "B", "C", "D", "E", "F"]
    if not (0 <= value.ohms_exp+1 < len(multiplier_table)):
        return ""

    multiplier = multiplier_table[value.ohms_exp+1]

    return digits + multiplier


def draw_resistor_sticker(
        c: Canvas,
        layout: PaperConfig,
        row: int,
        column: int,
        ohms: float,
        draw_center_line: bool,
        mirror: bool
) -> None:
    with StickerRect(c, layout, row, column, mirror) as rect:

        # Squish horizontally by a bit, to prevent clipping
        rect.width -= 0.1*inch
        rect.left += 0.05*inch

        # Draw middle line
        if draw_center_line:
            c.setStrokeColor(black, 0.25)
            c.setLineWidth(0.7)
            c.line(rect.left,
                   rect.bottom + rect.height/2,
                   rect.left + rect.width,
                   rect.bottom + rect.height/2)

        # Draw resistor value
        resistor_value = ResistorValue(ohms)
        print("Generating sticker '{}'".format(resistor_value.format_value()))

        value_font_size = 0.25 * inch
        ohm_font_size = 0.15 * inch
        smd_font_size = 0.08 * inch
        space_between = 5

        value_string = resistor_value.format_value()
        ohm_string = "\u2126"
        value_width = c.stringWidth(value_string, 'Arial Bold', value_font_size * 1.35)
        ohm_width = c.stringWidth(ohm_string, 'Arial Bold', ohm_font_size * 1.35)
        total_text_width = ohm_width + value_width + space_between
        text_left = rect.left + rect.width/4 - total_text_width/2
        text_bottom = rect.bottom + rect.height/4 - value_font_size/2

        c.setFont('Arial Bold', value_font_size * 1.35)
        c.drawString(text_left, text_bottom, value_string)
        c.setFont('Arial Bold', ohm_font_size * 1.35)
        c.drawString(text_left + value_width + space_between, text_bottom, ohm_string)

        # Draw resistor color code
        draw_resistor_colorcode(c, resistor_value,
                                toColor("hsl(55, 54%, 100%)"), toColor("hsl(55, 54%, 70%)"),
                                rect.left + rect.width/2,
                                rect.bottom + rect.height/4 - rect.height/45,
                                rect.width/4, rect.height/4,
                                3)

        draw_resistor_colorcode(c, resistor_value,
                                toColor("hsl(197, 59%, 100%)"), toColor("hsl(197, 59%, 73%)"),
                                rect.left + rect.width * 0.75,
                                rect.bottom + rect.height/4 - rect.height/45,
                                rect.width/4, rect.height/4,
                                4)

        c.setFont('Arial Bold', smd_font_size * 1.35)
        c.drawString(rect.left + rect.width/2 + rect.width/32, rect.bottom +
                     rect.height/13, get_3digit_code(resistor_value))
        c.drawCentredString(rect.left + rect.width*3/4, rect.bottom +
                            rect.height/13, get_4digit_code(resistor_value))
        c.drawRightString(rect.left + rect.width - rect.width/32, rect.bottom +
                          rect.height/13, get_eia98_code(resistor_value))


def begin_page(c: Canvas, layout: PaperConfig, draw_outlines: bool) -> None:
    # Draw the outlines of the stickers. Not recommended for the actual print.
    if draw_outlines:
        render_outlines(c, layout)


def end_page(c: Canvas) -> None:
    c.showPage()


def render_stickers(
    c: Canvas,
    layout: PaperConfig,
    values: ResistorList,
    draw_outlines: bool,
    draw_center_line: bool,
    draw_both_sides: bool
) -> None:
    def flatten(elem: Union[Optional[float], List[Optional[float]]]) -> List[Optional[float]]:
        if isinstance(elem, list):
            return elem
        else:
            return [elem]

    # Flatten
    values_flat: List[Optional[float]] = [elem for nested in values for elem in flatten(nested)]

    # Set the title
    c.setTitle(f"Resistor Labels - {layout.paper_name}")

    # Begin the first page
    begin_page(c, layout, draw_outlines)

    for (position, value) in enumerate(values_flat):
        rowId = (position // layout.num_stickers_horizontal) % layout.num_stickers_vertical
        columnId = position % layout.num_stickers_horizontal

        # If we are at the first sticker of a new page, change the page
        if rowId == 0 and columnId == 0 and position != 0:
            end_page(c)
            begin_page(c, layout, draw_outlines)

        if value is not None:
            draw_resistor_sticker(c, layout, rowId, columnId, value, draw_center_line, False)
            if draw_both_sides:
                draw_resistor_sticker(c, layout, rowId, columnId, value, False, True)

    # End the page one final time
    end_page(c)


def render_outlines(c: Canvas, layout: PaperConfig) -> None:
    for row in range(layout.num_stickers_vertical):
        for column in range(layout.num_stickers_horizontal):
            with StickerRect(c, layout, row, column, False) as rect:
                c.setStrokeColor(black, 0.1)
                c.setLineWidth(0)
                c.roundRect(rect.left, rect.bottom, rect.width, rect.height, rect.corner)


# Resistor values typically come from an "E series of preferred numbers". This is why apparently
# random values such as 22, 39, or 47 are common, but some round numbers like 25, 40, or 50
# are rarely seen. 10% resistors usually come from the E12 series, while 5% resistors usually
# come from an abridged version of the E24 series.
#
# The list constants below can be used with the generate_values function to quickly create sets of
# common resistor values.
E12_VALUES = [1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2]
E24_COMMON_VALUES = [1.0,      1.2,      1.5,      1.8, 2.0, 2.2, 2.4, 2.7, 3.0,
                     3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1]
E24_ALL_VALUES = [1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0,
                  3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1]


# Scales a list of values by a power of 10. The list may be one of the E constants above, or your
# own list of values.
#
# Examples:
#   scale_values([1.0, 4.7, 7.5], 2) -> [100, 470, 750]
#
#   scale_values(E12_VALUES, 1) -> [ 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 ]
def scale_values(
        series: List[float],  # the base series of resistor values
        power: int            # the power of 10 to scale the series by
) -> List[float]:
    scalar = 10 ** power
    return [scalar * x for x in series]


# Expands a list of values into several lists, each scaled by increasing powers of 10. The list may
# be one of the E constants above, or your own list of values.
#
# Examples:
#   generate_values([1.0, 4.7, 7.5], 0, 2) -> [
#      [ 1.0,  4.7, 7.5 ], # 10 ** 0 -> x1
#      [  10,   47,  75 ], # 10 ** 1 -> x10
#      [ 100,  470, 750 ]  # 10 ** 2 -> x100
#    ]
#
#   generate_values(E12_VALUES, 1, 2) -> [
#      [  10,  12,  15,  18,  22,  27,  33,  39,  47,  56,  68,  82 ], # 10 ** 1 -> x10
#      [ 100, 120, 150, 180, 220, 270, 330, 390, 470, 560, 680, 820 ]  # 10 ** 2 -> x100
#    ]
def generate_values(
        series: List[float],  # the base series of resistor values
        first_power: int,     # the first power of 10 to scale the series by
        last_power: int       # the last power of 10 to scale the series by
) -> List[List[float]]:
    return [scale_values(series, x) for x in range(first_power, last_power)]


def main() -> None:

    # ############################################################################
    # Select the correct type of paper you want to print on.
    # ############################################################################
    layout = AVERY_5260
    # layout = AVERY_L7157
    # layout = EJ_RANGE_24

    # ############################################################################
    # Put your own resistor values in here!
    #
    # This has to be either a 2D grid or a 1D array.
    #
    # Add "None" if no label should get generated at a specific position.
    # ############################################################################
    resistor_values: ResistorList = [
        [0,            0.02,         .1],
        [1,            12,           13],
        [210,          220,          330],
        [3100,         3200,         3300],
        [41000,        42000,        43000],
        [510000,       None,         530000],
        [6100000,      6200000,      6300000],
        [71000000,     72000000,     73000000],
        [810000000,    820000000,    830000000],
        [9100000000,   9200000000,   3300000000],
    ]

    # ############################################################################
    # Alternatively, a set of common resistor values can be generated by the
    # generate_values function.
    # ############################################################################
    # resistor_values: ResistorList = [ 0, 0.01 ] + generate_values(E24_COMMON_VALUES, 0, 6)

    # ############################################################################
    # Further configuration options
    #
    # Change the following options as you desire.
    # ############################################################################

    # Enables drawing the resistor values on the other side of the sticker fold line
    # as well, so that the finished resistor plastic bags are labeled on both sides.
    draw_both_sides = False

    # Draws the line where the stickers should be folded.
    # Disable this if you don't like the line.
    draw_center_line = True

    # Draw the outlines of the stickers.
    # This is primarily a debugging option and should most likely not be enabled
    # for the actual printing.
    draw_outlines = False

    # ############################################################################
    # PDF generation
    #
    # The following is the actual functionality of this script - to generate
    # the ResistorLabels PDF file.
    # ############################################################################

    # Create the render canvas
    c = Canvas("ResistorLabels.pdf", pagesize=layout.pagesize)

    # Render the stickers
    render_stickers(c, layout, resistor_values, draw_outlines, draw_center_line, draw_both_sides)

    # Store canvas to PDF file
    c.save()


if __name__ == "__main__":
    main()