bmf.c

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/*====================================================================*
 -  Copyright (C) 2001 Leptonica.  All rights reserved.
 -
 -  Redistribution and use in source and binary forms, with or without
 -  modification, are permitted provided that the following conditions
 -  are met:
 -  1. Redistributions of source code must retain the above copyright
 -     notice, this list of conditions and the following disclaimer.
 -  2. Redistributions in binary form must reproduce the above
 -     copyright notice, this list of conditions and the following
 -     disclaimer in the documentation and/or other materials
 -     provided with the distribution.
 -
 -  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 -  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 -  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 -  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ANY
 -  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 -  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 -  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 -  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 -  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 -  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 -  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *====================================================================*/

#include <string.h>
#include "allheaders.h"
#include "bmfdata.h"

static const l_float32  VERT_FRACT_SEP = 0.3;

#ifndef  NO_CONSOLE_IO
#define  DEBUG_BASELINE     0
#define  DEBUG_CHARS        0
#define  DEBUG_FONT_GEN     0
#endif  /* ~NO_CONSOLE_IO */

static PIXA *pixaGenerateFontFromFile(const char *dir, l_int32 fontsize,
                                      l_int32 *pbl0, l_int32 *pbl1,
                                      l_int32 *pbl2);
static PIXA *pixaGenerateFontFromString(l_int32 fontsize, l_int32 *pbl0,
                                        l_int32 *pbl1, l_int32 *pbl2);
static PIXA *pixaGenerateFont(PIX *pixs, l_int32 fontsize, l_int32 *pbl0,
                              l_int32 *pbl1, l_int32 *pbl2);
static l_int32 pixGetTextBaseline(PIX *pixs, l_int32 *tab8, l_int32 *py);
static l_int32 bmfMakeAsciiTables(L_BMF *bmf);


/*---------------------------------------------------------------------*/
/*                           Bmf create/destroy                        */
/*---------------------------------------------------------------------*/
L_BMF *
bmfCreate(const char  *dir,
          l_int32      fontsize)
{
L_BMF   *bmf;
PIXA  *pixa;

    PROCNAME("bmfCreate");

    if (fontsize < 4 || fontsize > 20 || (fontsize % 2))
        return (L_BMF *)ERROR_PTR("fontsize must be in {4, 6, ..., 20}",
                                  procName, NULL);
    if ((bmf = (L_BMF *)LEPT_CALLOC(1, sizeof(L_BMF))) == NULL)
        return (L_BMF *)ERROR_PTR("bmf not made", procName, NULL);

    if (!dir) {  /* Generate from a string */
        pixa = pixaGenerateFontFromString(fontsize, &bmf->baseline1,
                                          &bmf->baseline2, &bmf->baseline3);
    } else {  /* Look for the pixa in a directory */
        pixa = pixaGetFont(dir, fontsize, &bmf->baseline1, &bmf->baseline2,
                           &bmf->baseline3);
        if (!pixa) {  /* Not found; make it from a file */
            L_INFO("Generating pixa of bitmap fonts from file\n", procName);
            pixa = pixaGenerateFontFromFile(dir, fontsize, &bmf->baseline1,
                                            &bmf->baseline2, &bmf->baseline3);
            if (!pixa) {  /* Not made; make it from a string after all */
                L_ERROR("Failed to make font; use string\n", procName);
                pixa = pixaGenerateFontFromString(fontsize, &bmf->baseline1,
                                          &bmf->baseline2, &bmf->baseline3);
            }
        }
    }

    if (!pixa) {
        bmfDestroy(&bmf);
        return (L_BMF *)ERROR_PTR("font pixa not made", procName, NULL);
    }

    bmf->pixa = pixa;
    bmf->size = fontsize;
    if (dir) bmf->directory = stringNew(dir);
    bmfMakeAsciiTables(bmf);
    return bmf;
}


void
bmfDestroy(L_BMF  **pbmf)
{
L_BMF  *bmf;

    PROCNAME("bmfDestroy");

    if (pbmf == NULL) {
        L_WARNING("ptr address is null!\n", procName);
        return;
    }

    if ((bmf = *pbmf) == NULL)
        return;

    pixaDestroy(&bmf->pixa);
    LEPT_FREE(bmf->directory);
    LEPT_FREE(bmf->fonttab);
    LEPT_FREE(bmf->baselinetab);
    LEPT_FREE(bmf->widthtab);
    LEPT_FREE(bmf);
    *pbmf = NULL;
    return;
}


/*---------------------------------------------------------------------*/
/*                             Bmf accessors                           */
/*---------------------------------------------------------------------*/
PIX *
bmfGetPix(L_BMF  *bmf,
          char    chr)
{
l_int32  i, index;
PIXA    *pixa;

    PROCNAME("bmfGetPix");

    if ((index = (l_int32)chr) == 10)  /* NL */
        return NULL;
    if (!bmf)
        return (PIX *)ERROR_PTR("bmf not defined", procName, NULL);

    i = bmf->fonttab[index];
    if (i == UNDEF) {
        L_ERROR("no bitmap representation for %d\n", procName, index);
        return NULL;
    }

    if ((pixa = bmf->pixa) == NULL)
        return (PIX *)ERROR_PTR("pixa not found", procName, NULL);

    return pixaGetPix(pixa, i, L_CLONE);
}


l_ok
bmfGetWidth(L_BMF    *bmf,
            char      chr,
            l_int32  *pw)
{
l_int32  i, index;
PIXA    *pixa;

    PROCNAME("bmfGetWidth");

    if (!pw)
        return ERROR_INT("&w not defined", procName, 1);
    *pw = -1;
    if (!bmf)
        return ERROR_INT("bmf not defined", procName, 1);
    if ((index = (l_int32)chr) == 10)  /* NL */
        return 0;

    i = bmf->fonttab[index];
    if (i == UNDEF) {
        L_ERROR("no bitmap representation for %d\n", procName, index);
        return 1;
    }

    if ((pixa = bmf->pixa) == NULL)
        return ERROR_INT("pixa not found", procName, 1);

    return pixaGetPixDimensions(pixa, i, pw, NULL, NULL);
}


l_ok
bmfGetBaseline(L_BMF    *bmf,
               char      chr,
               l_int32  *pbaseline)
{
l_int32  bl, index;

    PROCNAME("bmfGetBaseline");

    if (!pbaseline)
        return ERROR_INT("&baseline not defined", procName, 1);
    *pbaseline = 0;
    if (!bmf)
        return ERROR_INT("bmf not defined", procName, 1);
    if ((index = (l_int32)chr) == 10)  /* NL */
        return 0;

    bl = bmf->baselinetab[index];
    if (bl == UNDEF) {
        L_ERROR("no bitmap representation for %d\n", procName, index);
        return 1;
    }

    *pbaseline = bl;
    return 0;
}


/*---------------------------------------------------------------------*/
/*               Font bitmap acquisition and generation                */
/*---------------------------------------------------------------------*/
PIXA *
pixaGetFont(const char  *dir,
            l_int32      fontsize,
            l_int32     *pbl0,
            l_int32     *pbl1,
            l_int32     *pbl2)
{
char     *pathname;
l_int32   fileno;
PIXA     *pixa;

    PROCNAME("pixaGetFont");

    fileno = (fontsize / 2) - 2;
    if (fileno < 0 || fileno >= NUM_FONTS)
        return (PIXA *)ERROR_PTR("font size invalid", procName, NULL);
    if (!pbl0 || !pbl1 || !pbl2)
        return (PIXA *)ERROR_PTR("&bl not all defined", procName, NULL);
    *pbl0 = baselines[fileno][0];
    *pbl1 = baselines[fileno][1];
    *pbl2 = baselines[fileno][2];

    pathname = pathJoin(dir, outputfonts[fileno]);
    pixa = pixaRead(pathname);
    LEPT_FREE(pathname);

    if (!pixa)
        L_WARNING("pixa of char bitmaps not found\n", procName);
    return pixa;
}


l_ok
pixaSaveFont(const char  *indir,
             const char  *outdir,
             l_int32      fontsize)
{
char    *pathname;
l_int32  bl1, bl2, bl3;
PIXA    *pixa;

    PROCNAME("pixaSaveFont");

    if (fontsize < 4 || fontsize > 20 || (fontsize % 2))
        return ERROR_INT("fontsize must be in {4, 6, ..., 20}", procName, 1);

    if (!indir)  /* Generate from a string */
        pixa = pixaGenerateFontFromString(fontsize, &bl1, &bl2, &bl3);
    else  /* Generate from an image file */
        pixa = pixaGenerateFontFromFile(indir, fontsize, &bl1, &bl2, &bl3);
    if (!pixa)
        return ERROR_INT("pixa not made", procName, 1);

    pathname = pathJoin(outdir, outputfonts[(fontsize - 4) / 2]);
    pixaWrite(pathname, pixa);

#if  DEBUG_FONT_GEN
    L_INFO("Found %d chars in font size %d\n", procName, pixaGetCount(pixa),
           fontsize);
    L_INFO("Baselines are at: %d, %d, %d\n", procName, bl1, bl2, bl3);
#endif  /* DEBUG_FONT_GEN */

    LEPT_FREE(pathname);
    pixaDestroy(&pixa);
    return 0;
}


static PIXA *
pixaGenerateFontFromFile(const char  *dir,
                         l_int32      fontsize,
                         l_int32     *pbl0,
                         l_int32     *pbl1,
                         l_int32     *pbl2)
{
char    *pathname;
l_int32  fileno;
PIX     *pix;
PIXA    *pixa;

    PROCNAME("pixaGenerateFontFromFile");

    if (!pbl0 || !pbl1 || !pbl2)
        return (PIXA *)ERROR_PTR("&bl not all defined", procName, NULL);
    *pbl0 = *pbl1 = *pbl2 = 0;
    if (!dir)
        return (PIXA *)ERROR_PTR("dir not defined", procName, NULL);
    fileno = (fontsize / 2) - 2;
    if (fileno < 0 || fileno >= NUM_FONTS)
        return (PIXA *)ERROR_PTR("font size invalid", procName, NULL);

    pathname = pathJoin(dir, inputfonts[fileno]);
    pix = pixRead(pathname);
    LEPT_FREE(pathname);
    if (!pix) {
        L_ERROR("pix not found for font size %d\n", procName, fontsize);
        return NULL;
    }

    pixa = pixaGenerateFont(pix, fontsize, pbl0, pbl1, pbl2);
    pixDestroy(&pix);
    return pixa;
}


static PIXA *
pixaGenerateFontFromString(l_int32   fontsize,
                           l_int32  *pbl0,
                           l_int32  *pbl1,
                           l_int32  *pbl2)
{
l_uint8  *data;
l_int32   redsize, nbytes;
PIX      *pix;
PIXA     *pixa;

    PROCNAME("pixaGenerateFontFromString");

    if (!pbl0 || !pbl1 || !pbl2)
        return (PIXA *)ERROR_PTR("&bl not all defined", procName, NULL);
    *pbl0 = *pbl1 = *pbl2 = 0;
    redsize = (fontsize / 2) - 2;
    if (redsize < 0 || redsize >= NUM_FONTS)
        return (PIXA *)ERROR_PTR("invalid font size", procName, NULL);

    if (fontsize == 4) {
        data = decodeBase64(fontdata_4, strlen(fontdata_4), &nbytes);
    } else if (fontsize == 6) {
        data = decodeBase64(fontdata_6, strlen(fontdata_6), &nbytes);
    } else if (fontsize == 8) {
        data = decodeBase64(fontdata_8, strlen(fontdata_8), &nbytes);
    } else if (fontsize == 10) {
        data = decodeBase64(fontdata_10, strlen(fontdata_10), &nbytes);
    } else if (fontsize == 12) {
        data = decodeBase64(fontdata_12, strlen(fontdata_12), &nbytes);
    } else if (fontsize == 14) {
        data = decodeBase64(fontdata_14, strlen(fontdata_14), &nbytes);
    } else if (fontsize == 16) {
        data = decodeBase64(fontdata_16, strlen(fontdata_16), &nbytes);
    } else if (fontsize == 18) {
        data = decodeBase64(fontdata_18, strlen(fontdata_18), &nbytes);
    } else {  /* fontsize == 20 */
        data = decodeBase64(fontdata_20, strlen(fontdata_20), &nbytes);
    }
    if (!data)
        return (PIXA *)ERROR_PTR("data not made", procName, NULL);

    pix = pixReadMem(data, nbytes);
    LEPT_FREE(data);
    if (!pix)
        return (PIXA *)ERROR_PTR("pix not made", procName, NULL);

    pixa = pixaGenerateFont(pix, fontsize, pbl0, pbl1, pbl2);
    pixDestroy(&pix);
    return pixa;
}


static PIXA *
pixaGenerateFont(PIX      *pixs,
                 l_int32   fontsize,
                 l_int32  *pbl0,
                 l_int32  *pbl1,
                 l_int32  *pbl2)
{
l_int32   i, j, nrows, nrowchars, nchars, h, yval;
l_int32   width, height;
l_int32   baseline[3];
l_int32  *tab = NULL;
BOX      *box, *box1, *box2;
BOXA     *boxar, *boxac, *boxacs;
PIX      *pix1, *pix2, *pixr, *pixrc, *pixc;
PIXA     *pixa;
l_int32   n, w, inrow, top;
l_int32  *ia;
NUMA     *na;

    PROCNAME("pixaGenerateFont");

    if (!pbl0 || !pbl1 || !pbl2)
        return (PIXA *)ERROR_PTR("&bl not all defined", procName, NULL);
    *pbl0 = *pbl1 = *pbl2 = 0;
    if (!pixs)
        return (PIXA *)ERROR_PTR("pixs not defined", procName, NULL);

        /* Locate the 3 rows of characters */
    w = pixGetWidth(pixs);
    na = pixCountPixelsByRow(pixs, NULL);
    boxar = boxaCreate(0);
    n = numaGetCount(na);
    ia = numaGetIArray(na);
    inrow = 0;
    for (i = 0; i < n; i++) {
        if (!inrow && ia[i] > 0) {
            inrow = 1;
            top = i;
        } else if (inrow && ia[i] == 0) {
            inrow = 0;
            box = boxCreate(0, top, w, i - top);
            boxaAddBox(boxar, box, L_INSERT);
        }
    }
    LEPT_FREE(ia);
    numaDestroy(&na);
    nrows = boxaGetCount(boxar);
#if  DEBUG_FONT_GEN
    L_INFO("For fontsize %s, have %d rows\n", procName, fontsize, nrows);
#endif  /* DEBUG_FONT_GEN */
    if (nrows != 3) {
        L_INFO("nrows = %d; skipping fontsize %d\n", procName, nrows, fontsize);
        boxaDestroy(&boxar);
        return (PIXA *)ERROR_PTR("3 rows not generated", procName, NULL);
    }

        /* Grab the character images and baseline data */
#if DEBUG_BASELINE
    lept_rmdir("baseline");
    lept_mkdir("baseline");
#endif  /* DEBUG_BASELINE */
    tab = makePixelSumTab8();
    pixa = pixaCreate(95);
    for (i = 0; i < nrows; i++) {
        box = boxaGetBox(boxar, i, L_CLONE);
        pixr = pixClipRectangle(pixs, box, NULL);  /* row of chars */
        pixGetTextBaseline(pixr, tab, &yval);
        baseline[i] = yval;

#if DEBUG_BASELINE
        L_INFO("Baseline info: row %d, yval = %d, h = %d\n", procName,
               i, yval, pixGetHeight(pixr));
        pix1 = pixCopy(NULL, pixr);
        pixRenderLine(pix1, 0, yval, pixGetWidth(pix1), yval, 1,
                      L_FLIP_PIXELS);
        if (i == 0 )
            pixWriteDebug("/tmp/baseline/row0.png", pix1, IFF_PNG);
        else if (i == 1)
            pixWriteDebug("/tmp/baseline/row1.png", pix1, IFF_PNG);
        else
            pixWriteDebug("/tmp/baseline/row2.png", pix1, IFF_PNG);
        pixDestroy(&pix1);
#endif  /* DEBUG_BASELINE */

        boxDestroy(&box);
        pixrc = pixCloseSafeBrick(NULL, pixr, 1, 35);
        boxac = pixConnComp(pixrc, NULL, 8);
        boxacs = boxaSort(boxac, L_SORT_BY_X, L_SORT_INCREASING, NULL);
        if (i == 0) {  /* consolidate the two components of '"' */
            box1 = boxaGetBox(boxacs, 1, L_CLONE);
            box2 = boxaGetBox(boxacs, 2, L_CLONE);
            box1->w = box2->x + box2->w - box1->x;  /* increase width */
            boxDestroy(&box1);
            boxDestroy(&box2);
            boxaRemoveBox(boxacs, 2);
        }
        h = pixGetHeight(pixr);
        nrowchars = boxaGetCount(boxacs);
        for (j = 0; j < nrowchars; j++) {
            box = boxaGetBox(boxacs, j, L_COPY);
            if (box->w <= 2 && box->h == 1) {  /* skip 1x1, 2x1 components */
                boxDestroy(&box);
                continue;
            }
            box->y = 0;
            box->h = h - 1;
            pixc = pixClipRectangle(pixr, box, NULL);
            boxDestroy(&box);
            if (i == 0 && j == 0)  /* add a pix for the space; change later */
                pixaAddPix(pixa, pixc, L_COPY);
            if (i == 2 && j == 0)  /* add a pix for the '\'; change later */
                pixaAddPix(pixa, pixc, L_COPY);
            pixaAddPix(pixa, pixc, L_INSERT);
        }
        pixDestroy(&pixr);
        pixDestroy(&pixrc);
        boxaDestroy(&boxac);
        boxaDestroy(&boxacs);
    }
    LEPT_FREE(tab);

    nchars = pixaGetCount(pixa);
    if (nchars != 95)
        return (PIXA *)ERROR_PTR("95 chars not generated", procName, NULL);

    *pbl0 = baseline[0];
    *pbl1 = baseline[1];
    *pbl2 = baseline[2];

        /* Fix the space character up; it should have no ON pixels,
         * and be about twice as wide as the '!' character.    */
    pix1 = pixaGetPix(pixa, 0, L_CLONE);
    width = 2 * pixGetWidth(pix1);
    height = pixGetHeight(pix1);
    pixDestroy(&pix1);
    pix1 = pixCreate(width, height, 1);
    pixaReplacePix(pixa, 0, pix1, NULL);

        /* Fix up the '\' character; use a LR flip of the '/' char */
    pix1 = pixaGetPix(pixa, 15, L_CLONE);
    pix2 = pixFlipLR(NULL, pix1);
    pixDestroy(&pix1);
    pixaReplacePix(pixa, 60, pix2, NULL);

#if DEBUG_CHARS
    pix1 = pixaDisplayTiled(pixa, 1500, 0, 10);
    pixDisplay(pix1, 100 * i, 200);
    pixDestroy(&pix1);
#endif  /* DEBUG_CHARS */

    boxaDestroy(&boxar);
    return pixa;
}


static l_int32
pixGetTextBaseline(PIX      *pixs,
                   l_int32  *tab8,
                   l_int32  *py)
{
l_int32   i, h, val1, val2, diff, diffmax, ymax;
l_int32  *tab;
NUMA     *na;

    PROCNAME("pixGetTextBaseline");

    if (!pixs)
        return ERROR_INT("pixs not defined", procName, 1);
    if (!py)
        return ERROR_INT("&y not defined", procName, 1);
    *py = 0;
    if (!tab8)
        tab = makePixelSumTab8();
    else
        tab = tab8;

    na = pixCountPixelsByRow(pixs, tab);
    h = numaGetCount(na);
    diffmax = 0;
    ymax = 0;
    for (i = 1; i < h; i++) {
        numaGetIValue(na, i - 1, &val1);
        numaGetIValue(na, i, &val2);
        diff = L_MAX(0, val1 - val2);
        if (diff > diffmax) {
            diffmax = diff;
            ymax = i - 1;  /* upper raster line */
        }
    }
    *py = ymax;

    if (!tab8)
        LEPT_FREE(tab);
    numaDestroy(&na);
    return 0;
}


static l_int32
bmfMakeAsciiTables(L_BMF  *bmf)
{
l_int32   i, maxh, height, charwidth, xwidth, kernwidth;
l_int32  *fonttab, *baselinetab, *widthtab;
PIX      *pix;

    PROCNAME("bmfMakeAsciiTables");

    if (!bmf)
        return ERROR_INT("bmf not defined", procName, 1);

        /* First get the fonttab; we use this later for the char widths */
    if ((fonttab = (l_int32 *)LEPT_CALLOC(128, sizeof(l_int32))) == NULL)
        return ERROR_INT("fonttab not made", procName, 1);
    bmf->fonttab = fonttab;
    for (i = 0; i < 128; i++)
        fonttab[i] = UNDEF;
    for (i = 32; i < 127; i++)
        fonttab[i] = i - 32;

    if ((baselinetab = (l_int32 *)LEPT_CALLOC(128, sizeof(l_int32))) == NULL)
        return ERROR_INT("baselinetab not made", procName, 1);
    bmf->baselinetab = baselinetab;
    for (i = 0; i < 128; i++)
        baselinetab[i] = UNDEF;
    for (i = 32; i <= 57; i++)
        baselinetab[i] = bmf->baseline1;
    for (i = 58; i <= 91; i++)
        baselinetab[i] = bmf->baseline2;
    baselinetab[92] = bmf->baseline1;  /* the '\' char */
    for (i = 93; i < 127; i++)
        baselinetab[i] = bmf->baseline3;

        /* Generate array of character widths; req's fonttab to exist */
    if ((widthtab = (l_int32 *)LEPT_CALLOC(128, sizeof(l_int32))) == NULL)
        return ERROR_INT("widthtab not made", procName, 1);
    bmf->widthtab = widthtab;
    for (i = 0; i < 128; i++)
        widthtab[i] = UNDEF;
    for (i = 32; i < 127; i++) {
        bmfGetWidth(bmf, i, &charwidth);
        widthtab[i] = charwidth;
    }

        /* Get the line height of text characters, from the highest
         * ascender to the lowest descender; req's fonttab to exist. */
    pix =  bmfGetPix(bmf, 32);
    maxh =  pixGetHeight(pix);
    pixDestroy(&pix);
    pix =  bmfGetPix(bmf, 58);
    height =  pixGetHeight(pix);
    pixDestroy(&pix);
    maxh = L_MAX(maxh, height);
    pix =  bmfGetPix(bmf, 93);
    height =  pixGetHeight(pix);
    pixDestroy(&pix);
    maxh = L_MAX(maxh, height);
    bmf->lineheight = maxh;

        /* Get the kern width (distance between characters).
         * We let it be the same for all characters in a given
         * font size, and scale it linearly with the size;
         * req's fonttab to be built first. */
    bmfGetWidth(bmf, 120, &xwidth);
    kernwidth = (l_int32)(0.08 * (l_float32)xwidth + 0.5);
    bmf->kernwidth = L_MAX(1, kernwidth);

        /* Save the space width (between words) */
    bmfGetWidth(bmf, 32, &charwidth);
    bmf->spacewidth = charwidth;

        /* Save the extra vertical space between lines */
    bmf->vertlinesep = (l_int32)(VERT_FRACT_SEP * bmf->lineheight + 0.5);

    return 0;
}