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

Macros
#define	DEBUG_BASELINE 0

#define	DEBUG_CHARS 0

#define	DEBUG_FONT_GEN 0

Functions
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)

L_BMF *	bmfCreate (const char *dir, l_int32 fontsize)

void	bmfDestroy (L_BMF **pbmf)

PIX *	bmfGetPix (L_BMF *bmf, char chr)

l_ok	bmfGetWidth (L_BMF bmf, char chr, l_int32 pw)

l_ok	bmfGetBaseline (L_BMF bmf, char chr, l_int32 pbaseline)

PIXA *	pixaGetFont (const char dir, l_int32 fontsize, l_int32 pbl0, l_int32 pbl1, l_int32 pbl2)

l_ok	pixaSaveFont (const char indir, const char outdir, l_int32 fontsize)

Variables
static const l_float32	VertFractSep = 0.3f

Detailed Description


  Acquisition and generation of bitmap fonts.

      L_BMF           *bmfCreate()
      L_BMF           *bmfDestroy()

      PIX             *bmfGetPix()
      l_int32          bmfGetWidth()
      l_int32          bmfGetBaseline()

      PIXA            *pixaGetFont()
      l_int32          pixaSaveFont()
      static PIXA     *pixaGenerateFontFromFile()
      static PIXA     *pixaGenerateFontFromString()
      static PIXA     *pixaGenerateFont()
      static l_int32   pixGetTextBaseline()
      static l_int32   bmfMakeAsciiTables()

  This is not a very general utility, because it only uses bitmap
  representations of a single font, Palatino-Roman, with the
  normal style.  It uses bitmaps generated for nine sizes, from
  4 to 20 pts, rendered at 300 ppi.  Generalization to different
  fonts, styles and sizes is straightforward.

  I chose Palatino-Roman is because I like it.
  The input font images were generated from a set of small
  PostScript files, such as chars-12.ps, which were rendered
  into the inputfont[] bitmap files using GhostScript.  See, for
  example, the bash script prog/ps2tiff, which will "rip" a
  PostScript file into a set of ccitt-g4 compressed tiff files.

  The set of ascii characters from 32 through 126 are the 95
  printable ascii chars.  Palatino-Roman is missing char 92, '\'.
  I have substituted an LR flip of '/', char 47, for 92, so that
  there are no missing printable chars in this set.  The space is
  char 32, and I have given it a width equal to twice the width of '!'.

Definition in file bmf.c.

Macro Definition Documentation

◆ DEBUG_BASELINE

#define DEBUG_BASELINE 0

Definition at line 81 of file bmf.c.

◆ DEBUG_CHARS

#define DEBUG_CHARS 0

Definition at line 82 of file bmf.c.

◆ DEBUG_FONT_GEN

#define DEBUG_FONT_GEN 0

Definition at line 83 of file bmf.c.

Function Documentation

◆ bmfCreate()

L_BMF * bmfCreate	(	const char *	dir,
		l_int32	fontsize )

bmfCreate()

Parameters

[in]	dir	[optional] directory holding pixa of character set
[in]	fontsize	4, 6, 8, ... , 20

Returns: bmf holding the bitmap font and associated information

Notes:
     (1) If dir == null, this generates the font bitmaps from a
         compiled string.
     (2) Otherwise, this tries to read a pre-computed pixa file with the
         95 ascii chars in it.  If the file is not found, it then
         attempts to generate the pixa and associated baseline
         data from a tiff image containing all the characters.  If
         that fails, it uses the compiled string.

Definition at line 118 of file bmf.c.

References L_Bmf::baseline1, L_Bmf::baseline2, L_Bmf::baseline3, bmfDestroy(), bmfMakeAsciiTables(), L_Bmf::directory, L_Bmf::pixa, pixaGenerateFontFromFile(), pixaGenerateFontFromString(), pixaGetFont(), and L_Bmf::size.

◆ bmfDestroy()

void bmfDestroy ( L_BMF ** pbmf )

bmfDestroy()

Parameters

[in,out] pbmf will be set to null before returning

Returns: void

Definition at line 168 of file bmf.c.

References L_Bmf::baselinetab, L_Bmf::directory, L_Bmf::fonttab, and L_Bmf::pixa.

Referenced by bmfCreate().

◆ bmfGetBaseline()

l_ok bmfGetBaseline	(	L_BMF *	bmf,
		char	chr,
		l_int32 *	pbaseline )

bmfGetBaseline()

Parameters

[in]	bmf
[in]	chr	should be one of the 95 supported bitmaps
[out]	pbaseline	distance below UL corner of bitmap char

Returns: 0 if OK, 1 on error

Definition at line 274 of file bmf.c.

References L_Bmf::baselinetab.

◆ bmfGetPix()

PIX * bmfGetPix	(	L_BMF *	bmf,
		char	chr )

bmfGetPix()

Parameters

[in]	bmf
[in]	chr	should be one of the 95 supported printable bitmaps

Returns: pix clone of pix in bmf, or NULL on error

Definition at line 200 of file bmf.c.

References L_Bmf::fonttab, L_CLONE, and L_Bmf::pixa.

Referenced by bmfMakeAsciiTables().

◆ bmfGetWidth()

l_ok bmfGetWidth	(	L_BMF *	bmf,
		char	chr,
		l_int32 *	pw )

bmfGetWidth()

Parameters

[in]	bmf
[in]	chr	should be one of the 95 supported bitmaps
[out]	pw	character width; -1 if not printable

Returns: 0 if OK, 1 on error

Definition at line 235 of file bmf.c.

References L_Bmf::fonttab, and L_Bmf::pixa.

Referenced by bmfMakeAsciiTables().

◆ bmfMakeAsciiTables()

static l_int32 bmfMakeAsciiTables ( L_BMF * bmf )

static

bmfMakeAsciiTables

Parameters

[in] bmf

Returns: 0 if OK, 1 on error

Notes:
     (1) This makes two tables, each of size 128, as follows:
         ~ fonttab is a table containing the index of the Pix
           that corresponds to each input ascii character;
           it maps (ascii-index) --> Pixa index
         ~ baselinetab is a table containing the baseline offset
           for the Pix that corresponds to each input ascii character;
           it maps (ascii-index) --> baseline offset
    (2) This also computes
         ~ lineheight (sum of maximum character extensions above and
                       below the baseline)
         ~ kernwidth (spacing between characters within a word)
         ~ spacewidth (space between words)
         ~ vertlinesep (extra vertical spacing between textlines)
    (3) The baselines apply as follows:
         baseline1   (ascii 32 - 57), ascii 92
         baseline2   (ascii 58 - 91)
         baseline3   (ascii 93 - 126)
    (4) The only array in bmf that is not ascii-based is the
        array of bitmaps in the pixa, which starts at ascii 32.

Definition at line 785 of file bmf.c.

References L_Bmf::baseline1, L_Bmf::baseline2, L_Bmf::baseline3, L_Bmf::baselinetab, bmfGetPix(), bmfGetWidth(), L_Bmf::fonttab, L_Bmf::kernwidth, L_Bmf::lineheight, L_Bmf::spacewidth, and L_Bmf::vertlinesep.

Referenced by bmfCreate().

◆ pixaGenerateFont()

static PIXA * pixaGenerateFont	(	PIX *	pixs,
		l_int32	fontsize,
		l_int32 *	pbl0,
		l_int32 *	pbl1,
		l_int32 *	pbl2 )

static

pixaGenerateFont()

Parameters

[in]	pixs	of 95 characters in 3 rows
[in]	fontsize	4, 6, 8, ... , 20, in pts at 300 ppi
[out]	pbl0	baseline of row 1
[out]	pbl1	baseline of row 2
[out]	pbl2	baseline of row 3

Returns: pixa of font bitmaps for 95 characters, or NULL on error

Notes:
     (1) This does all the work.  See pixaGenerateFontFromFile()
         for an overview.
     (2) The pix is for one of the 9 fonts.  fontsize is only
         used here for debugging.

Definition at line 546 of file bmf.c.

References Box::h, L_CLONE, L_COPY, L_FLIP_PIXELS, L_INSERT, L_SORT_BY_X, L_SORT_INCREASING, pixGetTextBaseline(), Box::w, Box::x, and Box::y.

Referenced by pixaGenerateFontFromFile(), and pixaGenerateFontFromString().

◆ pixaGenerateFontFromFile()

static PIXA * pixaGenerateFontFromFile	(	const char *	dir,
		l_int32	fontsize,
		l_int32 *	pbl0,
		l_int32 *	pbl1,
		l_int32 *	pbl2 )

static

pixaGenerateFontFromFile()

Parameters

[in]	dir	directory holding image of character set
[in]	fontsize	4, 6, 8, ... , 20, in pts at 300 ppi
[out]	pbl0	baseline of row 1
[out]	pbl1	baseline of row 2
[out]	pbl2	baseline of row 3

Returns: pixa of font bitmaps for 95 characters, or NULL on error

These font generation functions use 9 sets, each with bitmaps of 94 ascii characters, all in Palatino-Roman font. Each input bitmap has 3 rows of characters. The range of ascii values in each row is as follows: row 0: 32-57 32 is a space row 1: 58-91 92, '\', is not represented in this font row 2: 93-126 We LR flip the '/' char to generate a bitmap for the missing '\' character, so that we have representations of all 95 printable chars.

Typically, use pixaGetFont() to generate the character bitmaps in memory for a bmf. This will simply access the bitmap files in a serialized pixa that were produced in prog/genfonts.c using this function.

Definition at line 428 of file bmf.c.

References pixaGenerateFont().

Referenced by bmfCreate(), and pixaSaveFont().

◆ pixaGenerateFontFromString()

static PIXA * pixaGenerateFontFromString	(	l_int32	fontsize,
		l_int32 *	pbl0,
		l_int32 *	pbl1,
		l_int32 *	pbl2 )

static

pixaGenerateFontFromString()

Parameters

[in]	fontsize	4, 6, 8, ... , 20, in pts at 300 ppi
[out]	pbl0	baseline of row 1
[out]	pbl1	baseline of row 2
[out]	pbl2	baseline of row 3

Returns: pixa of font bitmaps for 95 characters, or NULL on error

Notes:
     (1) See pixaGenerateFontFromFile() for details.

Definition at line 477 of file bmf.c.

References pixaGenerateFont().

Referenced by bmfCreate(), and pixaSaveFont().

◆ pixaGetFont()

PIXA * pixaGetFont	(	const char *	dir,
		l_int32	fontsize,
		l_int32 *	pbl0,
		l_int32 *	pbl1,
		l_int32 *	pbl2 )

pixaGetFont()

Parameters

[in]	dir	directory holding pixa of character set
[in]	fontsize	4, 6, 8, ... , 20
[out]	pbl0	baseline of row 1
[out]	pbl1	baseline of row 2
[out]	pbl2	baseline of row 3

Returns: pixa of font bitmaps for 95 characters, or NULL on error

Notes:
     (1) This reads a pre-computed pixa file with the 95 ascii chars.

Definition at line 320 of file bmf.c.

Referenced by bmfCreate().

◆ pixaSaveFont()

l_ok pixaSaveFont	(	const char *	indir,
		const char *	outdir,
		l_int32	fontsize )

pixaSaveFont()

Parameters

[in]	indir	[optional] directory holding image of character set
[in]	outdir	directory into which the output pixa file will be written
[in]	fontsize	in pts, at 300 ppi

Returns: 0 if OK, 1 on error

Notes:
     (1) This saves a font of a particular size.
     (2) If indir == null, this generates the font bitmaps from a
         compiled string.
     (3) prog/genfonts calls this function for each of the
         nine font sizes, to generate all the font pixa files.

Definition at line 368 of file bmf.c.

References pixaGenerateFontFromFile(), and pixaGenerateFontFromString().

◆ pixGetTextBaseline()

static l_int32 pixGetTextBaseline	(	PIX *	pixs,
		l_int32 *	tab8,
		l_int32 *	py )

static

pixGetTextBaseline()

Parameters

[in]	pixs	1 bpp, one textline character set
[in]	tab8	[optional] pixel sum table
[out]	py	baseline value

Returns: 0 if OK, 1 on error

Notes:
     (1) Method: find the largest difference in pixel sums from one
         raster line to the next one below it.  The baseline is the
         upper raster line for the pair of raster lines that
         maximizes this function.

Definition at line 715 of file bmf.c.

Referenced by pixaGenerateFont().

Variable Documentation

◆ VertFractSep

const l_float32 VertFractSep = 0.3f

static

Definition at line 78 of file bmf.c.

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DEBUG_BASELINE

◆ DEBUG_CHARS

◆ DEBUG_FONT_GEN

Function Documentation

◆ bmfCreate()

◆ bmfDestroy()

◆ bmfGetBaseline()

◆ bmfGetPix()

◆ bmfGetWidth()

◆ bmfMakeAsciiTables()

◆ pixaGenerateFont()

◆ pixaGenerateFontFromFile()

◆ pixaGenerateFontFromString()

◆ pixaGetFont()

◆ pixaSaveFont()

◆ pixGetTextBaseline()

Variable Documentation

◆ VertFractSep