How to make a bitmap font for *nix environments

fonts

I have been softy on windows as a font tool to make a bitmap font, it's essentially a modified version of profont I keep using, mostly because the original version is not perfect to me.

I also made a proportional narrower version of profont, which I find extremely readable.

I want to do the same for my Mac and I also want it to work on any *nix, so I'm opting for a way to make it work for *nix first.

I can't understand why fontforge only allows you to make vectorized fonts, I want to make it pixel by pixel…

Best Answer

You can use gbdfed bitmap font editor to create or modify bitmap fonts for Un*x environments.

If your font is a .pcf, you can use pcf2bdf to convert it to a .bdf before hacking on it. There are packages in the Arch AUR and Debian repos for this.

Use bdftopcf to create your final font package and move it to an Xorg font directory, rebuild the font cache and you are done.

Related Solutions

Bitmap Font data as array in C

You can use convert as shown here: C header file with bitmapped fonts

Probably there are a lot of commands to convert fonts to bitmap, but the freetype API is easy enough to write your own with not much code.

Using the freetype example I wrote something you can use as a start, it output an .xbm file (is a c file but you can use graphics programs like gimp to view/edit it).

Notiche that gimp also support export to .xbm with different bytes per pixel.

The .xbm exported by the example is a 1 bit per pixel format (1 black, 0 white), you need to edit the code in order to handle more colors (the freetype normally use a 8 bit gray scale bitmap buffer to render, if render mode is FT_RENDER_MODE_NORMAL, you may also need to remove the step with the temporary bitmap used to align the FT buffer to 1 byte).

The to_bitmap function is where the conversion from the FT buffer to the destination bitmap is done,

To build the example the freetype dev package is needed, on Debian (maybe also Ubuntu) use:

sudo apt-get install libfreetype6-dev

Simply make to build it.

Use the command with the font path as argument, the output is on stdout

./font2c /usr/share/fonts/X11/misc/9x15-ISO8859-1.pcf.gz >c-bmp-font.xbm

Makefile:

CFLAGS += -O2 -Wall 
CFLAGS += $(shell freetype-config --cflags)
LIBS += $(shell freetype-config --libs)

font2c: font2c.c
    $(CC) $(CFLAGS) -o $@ $^ $(LIBS)

clean:
    -rm -f font2c

font2c.c:

#include <stdio.h>

#include <ft2build.h>
#include FT_FREETYPE_H
#include <ftbitmap.h>

#define WIDTH   640
#define BYTEWIDTH (WIDTH)/8
#define HEIGHT  480

static unsigned char image[HEIGHT][BYTEWIDTH];

static FT_Library library;
static FT_Face face;
static FT_Error err;
static FT_Bitmap tempbitmap;

static void to_bitmap( FT_Bitmap*  bitmap, FT_Int x, FT_Int y) {

    FT_Int  i, j, p, q;
    FT_Int  x_max = x + bitmap->width;
    FT_Int  y_max = y + bitmap->rows;

    for ( i = x, p = 0; i < x_max; i++, p++ ) {
        for ( j = y, q = 0; j < y_max; j++, q++ ) {
            if ( (i < 0) || (j < 0) || (i >= WIDTH || j >= HEIGHT) )
                continue;
            image[j][i >> 3] |= (bitmap->buffer[q * bitmap->width + p]) << (i & 7);
        }
    }
}

static void draw_glyph(unsigned char glyph, int *x, int *y) {
    FT_UInt  glyph_index;
    FT_GlyphSlot  slot = face->glyph;

    glyph_index = FT_Get_Char_Index( face, glyph );

    if ((err = FT_Load_Glyph( face, glyph_index, FT_LOAD_DEFAULT ))) {
        fprintf( stderr, "warning: failed FT_Load_Glyph 0x%x %d\n", glyph, err);
        return;
    }

    if ((err = FT_Render_Glyph( face->glyph, FT_RENDER_MODE_MONO ))) {
        fprintf( stderr, "warning: failed FT_Render_Glyph 0x%x %d\n", glyph, err);
        return;
    }

    FT_Bitmap_New(&tempbitmap);
    FT_Bitmap_Convert( library, &slot->bitmap, &tempbitmap, 1);

    to_bitmap( &tempbitmap, *x, *y );

    FT_Bitmap_Done( library, &tempbitmap );

    *x += slot->advance.x >> 6;
}

static void out_xbm(int w, int h) {
    int x, y;
    printf("#define BMP_width %d\n", WIDTH);
    printf("#define BMP_height %d\n", h);
    printf("static char BMP_bits[] = {\n");
    for (y=0; y < h; y++) {
        printf("\t");
        for (x=0; x < w; x++) {
            printf("0x%x, ", image[y][x]);
        }
        printf("\n");
    }
    printf("\n}\n");
}

int main(int argc, char **argv) {
    char *filename;
    int x = 0, y = 0;
    int g;

    memset (image, 0, BYTEWIDTH*HEIGHT);

    if (argc < 2) {
        fprintf( stderr, "usage: font2c [font]\n");
        exit(1);
    }
    filename = argv[1];

    if ((err = FT_Init_FreeType( &library ))) {
        fprintf( stderr, "error: Init_Freetype failed %d\n", err);
        exit(1);
    }
    if ((err = FT_New_Face( library, filename, 0, &face ))) {
        fprintf( stderr, "error: FT_New_Face failed %d\n", err);
        exit(1);
    }

    for (g = 0; g < 256; g++) {
        if (x+8 >= WIDTH) {
                x = 0;
                y += 15; // FIXME get ascender
        }
        draw_glyph(g, &x, &y);
    }

    out_xbm(BYTEWIDTH, HEIGHT);

    FT_Done_Face( face );
    FT_Done_FreeType( library );

    return 0;

}

Larger “xterm” fonts on HIDPI displays

You have hinted the answer yourself by referencing https://en.wikipedia.org/wiki/Fixed_(typeface)

This is the standard fixed bitmap font which has been expanded by Markus Kuhn to have a rather complete character set. The question is then how to scale a bitmap.

What you have achieved so far is scaling a vector font and converting it to a bitmap (ttf → bdf → pcf). That is a fine strategy but as you mention it lacks some language support. That seems strange as Courier New is one of the more unicode complete fonts but I digress! Maybe try using Mono which is a clone.

I do however not understand why you are doing this as xterm does support truetype.

Modify ~/.Xresources such as this (note that you'll need to reload it using xrdb as seen in another answer to this question):

XTerm*renderFont: true
XTerm*faceName: VeraMono
XTerm*faceSize: 10

But back to the task: You want a larger bitmap font.

The largest available bitmap available is:

10x20   -Misc-Fixed-Medium-R-Normal--20-200-75-75-C-100-ISO10646-1

Markus have been so nice that he supplies the source BDF files. If your distribution does not have the most recent updates (from April 2009) you can grab the package directly from him.

The "-misc-fixed-*" font package:

http://www.cl.cam.ac.uk/~mgk25/download/ucs-fonts.tar.gz

Rather than converting back and forth between pcf and bdf you could/should stick to the source format. You can use a BDF font editor to resize the font. Do not expect any antialiasing or such trickery - but at least you can get a readable size.

Or you can use bdfresize by Hiroto Kagotani (also found in some package systems).

UPDATE:

I do not know of a way to scale just one window (never had the need). You could track this Superuser question. When I have had the need I have scaled the entire environment.

You can downgrade a 3200x1800 display to 1920x1080 using:

xrandr --dpi 141
xrandr --output eDP1 --scale 0.6x0.6

Other tricks for screen scaling in different window managers can be found here. They suggest using VNC:

One approach is to run the application full screen and without decoration in its own VNC desktop. Then scale the viewer. With Vncdesk (vncdesk-git from the AUR) you can set up a desktop per application, then start server and client with a simple command such as vncdesk 2.

x11vnc has an experimental option -appshare, which opens one viewer per application window. Perhaps something could be hacked up with that.

Best Answer

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Bitmap Font data as array in C

Larger “xterm” fonts on HIDPI displays

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