bmp.py

"""
bmp.py - module for constructing simple BMP graphics files

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including
 without limitation the rights to use, copy, modify, merge, publish,
 distribute, sublicense, and/or sell copies of the Software, and to
 permit persons to whom the Software is furnished to do so, subject to
 the following conditions:

 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

"""
from itertools import groupby
from math import ceil, hypot

__version__ = "0.2"
print("bmp module, version %s, written by Paul McGuire, October, 2003" % __version__)


def short_to_bytes(i):
    hi = (i & 0xff00) >> 8
    lo = i & 0x00ff
    return bytes([lo, hi])


def long_to_bytes(i):
    hi = (i & 0x7fff0000) >> 16
    lo = i & 0x0000ffff
    return short_to_bytes(lo) + short_to_bytes(hi)


class Color(object):
    """class for specifying colors while drawing BitMap elements"""
    __slots__ = ['red', 'grn', 'blu']
    __shade = 32

    def __init__(self, r=0, g=0, b=0):
        self.red = r
        self.grn = g
        self.blu = b

    def __setattr__(self, name, value):
        if hasattr(self, name):
            raise AttributeError("Color is immutable")
        else:
            object.__setattr__(self, name, value)

    def __str__(self):
        return "R:%d G:%d B:%d" % (self.red, self.grn, self.blu)

    def __hash__(self):
        return (self.blu +
                (self.grn << 8) +
                (self.red << 16))

    def __eq__(self, other):
        return (self is other) or (self.toLong == other.toLong)

    def lighten(self):
        return Color(
            min(self.red + Color.__shade, 255),
            min(self.grn + Color.__shade, 255),
            min(self.blu + Color.__shade, 255)
        )

    def darken(self):
        return Color(
            max(self.red - Color.__shade, 0),
            max(self.grn - Color.__shade, 0),
            max(self.blu - Color.__shade, 0)
        )

    def toLong(self):
        return self.__hash__()

    def fromLong(l):
        b = l & 0xff
        l = l >> 8
        g = l & 0xff
        l = l >> 8
        r = l & 0xff
        return Color(r, g, b)

    fromLong = staticmethod(fromLong)


# define class constants for common colors
Color.BLACK = Color(0, 0, 0)
Color.RED = Color(255, 0, 0)
Color.GREEN = Color(0, 255, 0)
Color.BLUE = Color(0, 0, 255)
Color.CYAN = Color(0, 255, 255)
Color.MAGENTA = Color(255, 0, 255)
Color.YELLOW = Color(255, 255, 0)
Color.WHITE = Color(255, 255, 255)
Color.DKRED = Color(128, 0, 0)
Color.DKGREEN = Color(0, 128, 0)
Color.DKBLUE = Color(0, 0, 128)
Color.TEAL = Color(0, 128, 128)
Color.PURPLE = Color(128, 0, 128)
Color.BROWN = Color(128, 128, 0)
Color.GRAY = Color(128, 128, 128)


class BitMap(object):
    """class for drawing and saving simple Windows bitmap files"""

    LINE_SOLID = 0
    LINE_DASHED = 1
    LINE_DOTTED = 2
    LINE_DOT_DASH = 3
    _DASH_LEN = 12.0
    _DOT_LEN = 6.0
    _DOT_DASH_LEN = _DOT_LEN + _DASH_LEN

    def __init__(self, width, height,
                 bkgd=Color.WHITE, frgd=Color.BLACK):
        self.wd = int(ceil(width))
        self.ht = int(ceil(height))
        self.bgcolor = 0
        self.fgcolor = 1
        self.palette = []
        self.palette.append(bkgd.toLong())
        self.palette.append(frgd.toLong())
        self.setDefaultPenColor()

        tmparray = [self.bgcolor] * self.wd
        self.bitarray = [tmparray[:] for _ in range(self.ht)]
        self.currentPen = 1
        self.fontName = "%s-%d-%s" % ("none", 0, "none")

    def setDefaultPenColor(self):
        self.currentPen = self.fgcolor

    def setPenColor(self, pcolor):
        oldColor = self.currentPen
        # look for c in palette
        pcolornum = pcolor.toLong()
        try:
            self.currentPen = self.palette.index(pcolornum)
        except ValueError:
            if len(self.palette) < 256:
                self.palette.append(pcolornum)
                self.currentPen = len(self.palette) - 1
            else:
                self.currentPen = self.fgcolor

        return Color.fromLong(self.palette[oldColor])

    def getPenColor(self):
        return Color.fromLong(self.palette[self.currentPen])

    def plotPoint(self, x, y):
        if 0 <= x < self.wd and 0 <= y < self.ht:
            x = int(x)
            y = int(y)
            self.bitarray[y][x] = self.currentPen

    def drawRect(self, x, y, wid, ht, fill=False):
        x = int(x)
        y = int(y)
        cury = y

        # subtract one for line width
        wid -= 1
        ht -= 1

        self.drawLine(x, y, x + wid, y)
        if fill:
            cury = y
            while cury < y + ht:
                self.drawLine(x, cury, x + wid, cury)
                cury += 1
        else:
            self.drawLine(x, y, x, y + ht)
            self.drawLine(x + wid, y, x + wid, y + ht)
        self.drawLine(x, y + ht, x + wid, y + ht)

    def drawSquare(self, x, y, wid, fill=False):
        self.drawRect(x, y, wid, wid, fill)

    def bresLine(x, y, x2, y2):
        """Bresenham line algorithm"""
        steep = 0
        coords = []
        dx = int(abs(x2 - x) + 0.5)
        if (x2 - x) > 0:
            sx = 1
        else:
            sx = -1
        dy = int(abs(y2 - y) + 0.5)
        if (y2 - y) > 0:
            sy = 1
        else:
            sy = -1
        if dy > dx:
            steep = 1
            x, y = y, x
            dx, dy = dy, dx
            sx, sy = sy, sx
        dx2 = dx * 2
        dy2 = dy * 2
        d = dy2 - dx
        for i in range(0, dx):
            coords.append((x, y))
            while d >= 0:
                y += sy
                d -= dx2
            x += sx
            d += dy2

        if steep:  # transpose x's and y's
            coords = [(c[1], c[0]) for c in coords]

        coords.append((x2, y2))

        return coords

    bresLine = staticmethod(bresLine)

    def _drawLine(self, x1, y1, x2, y2):
        # special checks for vert and horiz lines
        if x1 == x2:
            if 0 <= x1 < self.wd:
                if y2 < y1:
                    y1, y2 = y2, y1
                cury = max(y1, 0)
                maxy = min(y2, self.ht - 1)
                while cury <= maxy:
                    self.plotPoint(x1, cury)
                    cury += 1
            return

        if y1 == y2:
            if 0 <= y1 < self.ht:
                if x2 < x1:
                    x1, x2 = x2, x1
                curx = max(x1, 0)
                maxx = min(x2, self.wd - 1)
                while curx <= maxx:
                    self.plotPoint(curx, y1)
                    curx += 1
            return

        for pt in BitMap.bresLine(x1, y1, x2, y2):
            self.plotPoint(pt[0], pt[1])

    def _drawLines(self, lineSegs):
        for x1, y1, x2, y2 in lineSegs:
            self._drawLine(x1, y1, x2, y2)

    def drawLine(self, x1, y1, x2, y2, line_type=LINE_SOLID):
        if line_type == BitMap.LINE_SOLID:
            self._drawLine(x1, y1, x2, y2)
        elif line_type == BitMap.LINE_DASHED:
            # how many segs?
            len = hypot(x2 - x1, y2 - y1)
            numsegs = len / BitMap._DASH_LEN
            dx = (x2 - x1) / numsegs
            dy = (y2 - y1) / numsegs
            dx2 = dx / 2.0
            dy2 = dy / 2.0
            if (x2 < x1):
                x1, x2 = x2, x1
                y1, y2 = y2, y1
            segs = []
            curx = x1
            cury = y1
            for i in range(int(numsegs)):
                segs.append((curx, cury, curx + dx2, cury + dy2))
                curx += dx
                cury += dy
            if curx + dx2 > x2:
                segs.append((curx, cury, x2, y2))
            else:
                segs.append((curx, cury, curx + dx2, cury + dy2))
            self._drawLines(segs)
        elif line_type == BitMap.LINE_DOTTED:
            len = hypot(x2 - x1, y2 - y1)
            numsegs = len / BitMap._DOT_LEN
            dx = (x2 - x1) / numsegs
            dy = (y2 - y1) / numsegs
            dx2 = dx / 2.0
            dy2 = dy / 2.0
            if (x2 < x1):
                x1, x2 = x2, x1
                y1, y2 = y2, y1
            segs = []
            curx = x1
            cury = y1
            for i in range(int(numsegs)):
                segs.append((curx, cury, curx + dx2, cury + dy2))
                curx += dx
                cury += dy
            if curx + dx2 > x2:
                segs.append((curx, cury, x2, y2))
            else:
                segs.append((curx, cury, curx + dx2, cury + dy2))
            self._drawLines(segs)
        elif line_type == BitMap.LINE_DOT_DASH:
            len = hypot(x2 - x1, y2 - y1)
            numsegs = len / BitMap._DOT_DASH_LEN
            dx = (x2 - x1) / numsegs
            dy = (y2 - y1) / numsegs
            dx3 = dx / 3.0
            dy3 = dy / 3.0
            dx23 = 0.62 * dx
            dy23 = 0.62 * dy
            dx56 = 0.78 * dx
            dy56 = 0.78 * dy
            if (x2 < x1):
                x1, x2 = x2, x1
                y1, y2 = y2, y1
            segs = []
            curx = x1
            cury = y1
            for i in range(int(numsegs)):
                segs.append((curx, cury, curx + dx3, cury + dy3))
                segs.append((curx + dx23, cury + dy23, curx + dx56, cury + dy56))
                curx += dx
                cury += dy
            if curx + dx3 > x2:
                segs.append((curx, cury, x2, y2))
            else:
                segs.append((curx, cury, curx + dx3, cury + dy3))
                if curx + dx23 < x2:
                    if curx + dx56 > x2:
                        segs.append((curx + dx23, cury + dy23, x2, y2))
                    else:
                        segs.append((curx + dx23, cury + dy23, curx + dx56, cury + dy56))
                else:
                    pass  # segs.append( ( curx, cury, curx + dx3, cury + dy3 ) )
            segs.append((curx, cury, x2, y2))
            self._drawLines(segs)

    def drawCircle(self, cx, cy, r, fill=False):
        x = 0
        y = r
        d = 1 - r

        self.plotPoint(cx, cy + y)
        self.plotPoint(cx, cy - y)
        if fill:
            self.drawLine(cx - y, cy, cx + y, cy)
        else:
            self.plotPoint(cx + y, cy)
            self.plotPoint(cx - y, cy)

        while y > x:
            if d < 0:
                d += (2 * x + 3)
            else:
                d += (2 * (x - y) + 5)
                y -= 1
            x += 1

            if fill:
                self.drawLine(cx + x - 1, cy + y, cx - x + 1, cy + y)
                self.drawLine(cx - x + 1, cy - y, cx + x - 1, cy - y)
                self.drawLine(cx + y - 1, cy + x, cx - y + 1, cy + x)
                self.drawLine(cx - y + 1, cy - x, cx + y - 1, cy - x)
            else:
                self.plotPoint(cx + x, cy + y)
                self.plotPoint(cx + y, cy + x)
                self.plotPoint(cx - x, cy - y)
                self.plotPoint(cx - y, cy - x)
                self.plotPoint(cx + x, cy - y)
                self.plotPoint(cx - y, cy + x)
                self.plotPoint(cx - x, cy + y)
                self.plotPoint(cx + y, cy - x)

    def _saveBitMapNoCompression(self, filename):
        # open file
        f = open(filename, "wb")

        # write bitmap header
        f.write(b"BM")
        f.write(long_to_bytes(54 + 256 * 4 + self.ht * self.wd))  # DWORD size in bytes of the file
        f.write(long_to_bytes(0))  # DWORD 0
        f.write(long_to_bytes(54 + 256 * 4))  # DWORD offset to the data
        f.write(long_to_bytes(40))  # DWORD header size = 40
        f.write(long_to_bytes(self.wd))  # DWORD image width
        f.write(long_to_bytes(self.ht))  # DWORD image height
        f.write(short_to_bytes(1))  # WORD planes = 1
        f.write(short_to_bytes(8))  # WORD bits per pixel = 8
        f.write(long_to_bytes(0))  # DWORD compression = 0
        f.write(long_to_bytes(self.wd * self.ht))  # DWORD sizeimage = size in bytes of the bitmap = width * height
        f.write(long_to_bytes(0))  # DWORD horiz pixels per meter (?)
        f.write(long_to_bytes(0))  # DWORD ver pixels per meter (?)
        f.write(long_to_bytes(256))  # DWORD number of colors used = 256
        f.write(long_to_bytes(len(self.palette)))  # DWORD number of colors

        # write bitmap palette
        for clr in self.palette:
            f.write(long_to_bytes(clr))
        f.write(bytes([0, 0, 0, 0] * (256-len(self.palette))))

        # write pixels
        for row in self.bitarray:
            f.write(bytes(row))
            padding = (4 - len(row) % 4) % 4
            f.write(bytes(0) * padding)

        # close file
        f.close()

    def _saveBitMapWithCompression(self, filename):
        """
        """
        # open file
        f = open(filename, "wb")

        # write bitmap header
        f.write(b"BM")
        f.write(long_to_bytes(54 + 256 * 4 + self.ht * self.wd))  # DWORD size in bytes of the file
        f.write(long_to_bytes(0))  # DWORD 0
        f.write(long_to_bytes(54 + 256 * 4))  # DWORD offset to the data
        f.write(long_to_bytes(40))  # DWORD header size = 40
        f.write(long_to_bytes(self.wd))  # DWORD image width
        f.write(long_to_bytes(self.ht))  # DWORD image height
        f.write(short_to_bytes(1))  # WORD planes = 1
        f.write(short_to_bytes(8))  # WORD bits per pixel = 8
        f.write(long_to_bytes(1))  # DWORD compression = 1=RLE8
        f.write(long_to_bytes(self.wd * self.ht))  # DWORD sizeimage = size in bytes of the bitmap = width * height
        f.write(long_to_bytes(0))  # DWORD horiz pixels per meter (?)
        f.write(long_to_bytes(0))  # DWORD ver pixels per meter (?)
        f.write(long_to_bytes(256))  # DWORD number of colors used = 256
        f.write(long_to_bytes(len(self.palette)))  # DWORD number of colors

        # write bitmap palette
        for clr in self.palette:
            f.write(long_to_bytes(clr))
        f.write(bytes([0, 0, 0, 0] * (256-len(self.palette))))

        # write pixels
        pixelBytes = 0
        for row in self.bitarray:
            for cur_pixel, pixels in groupby(row):
                pixels = sum(1 for _ in pixels)
                while pixels:
                    rle = min(pixels, 255)
                    f.write(bytes([rle, cur_pixel]))
                    pixels -= rle
                    pixelBytes += 2

            # end of line code
            f.write(bytes([0, 0]))
            pixelBytes += 2

        # end of bitmap code
        f.write(bytes([0, 1]))
        pixelBytes += 2

        # now fix sizes in header
        f.seek(2)
        f.write(long_to_bytes(54 + 256 * 4 + pixelBytes))  # DWORD size in bytes of the file
        f.seek(34)
        f.write(long_to_bytes(pixelBytes))  # DWORD size in bytes of the image

        # close file
        f.close()

    def saveFile(self, filename, compress=True):
        if compress:
            self._saveBitMapWithCompression(filename)
        else:
            self._saveBitMapNoCompression(filename)


if __name__ == "__main__":

    # set test to run
    #  1 - line and shape drawing
    #  2 - text display
    test = 1
    if test == 1:
        bmp = BitMap(400, 400, Color.TEAL.lighten())
        bmp.drawSquare(0, 0, 400)

        # draw variety of colors
        colors = [Color.BLACK, Color.RED, Color.GREEN, Color.BLUE,
                  Color.CYAN, Color.MAGENTA, Color.YELLOW, Color.BLUE,
                  Color.DKRED, Color.DKGREEN, Color.DKBLUE, Color.TEAL,
                  Color.PURPLE, Color.BROWN, Color.GRAY]
        for i, c in enumerate(colors):
            bmp.setPenColor(c)
            for j in range(8):
                bmp.drawRect(i * 25, j * 45, 25, 45, True)
                bmp.setPenColor(bmp.getPenColor().lighten())
            bmp.setDefaultPenColor()
            bmp.drawRect(i * 25, 0, 25, 360, False)

        # test drawing lines at various angles
        bmp.setPenColor(Color.WHITE)
        bmp.drawSquare(10, 10, 380)
        bmp.drawSquare(9, 9, 382)
        bmp.drawLine(10, 10, 389, 389)
        bmp.drawLine(10, 10, 70, 389)
        bmp.drawLine(10, 10, 389, 70)
        bmp.drawLine(10, 389, 389, 10)
        bmp.drawLine(10, 389, 70, 10)
        bmp.drawLine(10, 70, 389, 10)

        # test saving and restoring pen color
        saveColor = bmp.setPenColor(Color.DKGREEN)
        bmp.drawRect(90, 100, 40, 30, fill=True)
        bmp.setPenColor(saveColor)
        bmp.drawRect(95, 105, 30, 20, fill=True)

        # test drawing circles
        bmp.setPenColor(Color.DKRED)
        bmp.drawCircle(250, 150, 40, fill=True)
        bmp.setPenColor(Color.WHITE)
        bmp.drawCircle(250, 150, 25, fill=True)
        bmp.setPenColor(Color.BLUE)
        bmp.drawCircle(250, 150, 20, fill=True)
        bmp.setPenColor(Color.WHITE)
        bmp.drawCircle(250, 150, 18, fill=True)
        bmp.setPenColor(Color.BLUE)
        bmp.drawCircle(250, 150, 8)

        # test lines of different types
        bmp.setPenColor(Color.BLACK)
        bmp.drawLine(10, 380, 389, 380, BitMap.LINE_DASHED)
        bmp.drawLine(10, 373, 389, 373, BitMap.LINE_DOTTED)
        bmp.drawLine(10, 365, 389, 365, BitMap.LINE_DOT_DASH)
        bmp.drawLine(10, 358, 389, 325, BitMap.LINE_DASHED)
        bmp.drawLine(10, 353, 389, 320, BitMap.LINE_DOTTED)
        bmp.drawLine(10, 348, 389, 315, BitMap.LINE_DOT_DASH)

    bmp.saveFile("C:\\temp\\test.bmp")
    bmp.saveFile("C:\\temp\\test_nocompress.bmp", compress=False)