C header file with bitmapped fonts

user_106979 0
Viewed 35008

I need to do some rudimentary text rendering to a pixel buffer, and I think that having a table indexed by char with the representation of the letters as a binary array would be more than enough... Anybody knows about a free header as such?

Example:

char data[256][8][8];
void init()
{
  data['a'] = {
    {0,0,1,1,1,0,0,0},
    {0,1,0,0,0,1,0,0},
    {0,0,0,0,0,0,1,0},
    {0,0,1,1,1,0,1,0},
    {0,1,0,0,0,1,1,0},
    {0,1,0,0,0,0,1,0},
    {0,1,0,0,0,1,1,0},
    {0,0,1,1,1,0,1,0},
  };
}

I could go on with the rest of the alphabet, but then I wouldn't need to ask... ¡But that gives me an idea! if there's no free header with a bitmapped font readily available, each answer could implement a letter and I could assemble the whole file here ^_^

bitmap header fonts c
8 Answers

Update: I tried this approach and the characters come out fairly distorted. Possibly Nimbus is a poor font choice.

Go with the imagemagick approach. You can generate each character with this:

convert -resize 7x13\! -font Nimbus-Mono-Regular -pointsize 10 label:A A.xbm

A.xbm looks like:

#define A_width 7
#define A_height 13
static char A_bits[] = {
  0x00, 0x00, 0x00, 0x00, 0x1C, 0x08, 0x00, 0x3C, 0x00, 0x66, 0x00, 0x00,
  0x00, };

Loop through the characters you need and assemble this into a single header file.

Even though Nimbus-Mono-Regular is a monospace font, sometimes the character widths are off by a pixel. The convert option "-resize 7x13!" forces a 7x13 output size. Again, this might be a problem specifically with the Nimbus font.

user_2472890

I know you can save images as a c header file in gimp. Maybe you can find a tool which does the job on the command line. So you could automate the creation. ImageMagick can at least load ttf fonts.

EDIT: Gimp does only support RGB data as output format, so it's not a solution for you.

Anyway here is an 'b' for you:


/* GIMP RGB C-Source image dump (b.c) */

static const struct {
  unsigned int   width;
  unsigned int   height;
  unsigned int   bytes_per_pixel; /* 3:RGB, 4:RGBA */ 
  char          *comment;
  unsigned char  pixel_data[8 * 8 * 3 + 1];
} gimp_image = {
  8, 8, 3,
  "Created with GIMP",
  "\377\377\377\377\377\377\0\0\0\377\377\377\377\377\377\377\377\377\377\377"
  "\377\377\377\377\377\377\377\377\377\377\0\0\0\377\377\377\377\377\377\377"
  "\377\377\377\377\377\377\377\377\377\377\377\377\377\377\0\0\0\377\377\377"
  "\0\0\0\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\0\0\0"
  "\0\0\0\377\377\377\0\0\0\377\377\377\377\377\377\377\377\377\377\377\377"
  "\0\0\0\377\377\377\377\377\377\377\377\377\0\0\0\377\377\377\377\377\377"
  "\377\377\377\0\0\0\377\377\377\377\377\377\377\377\377\0\0\0\377\377\377"
  "\377\377\377\377\377\377\0\0\0\377\377\377\377\377\377\0\0\0\377\377\377"
  "\377\377\377\377\377\377\377\377\377\0\0\0\0\0\0\0\0\0\0\0\0\377\377\377"
  "\377\377\377",
};
quinmars_186870
user_2472890

I know it doesn't answer your question but I would recommend just using something like http://www.angelcode.com/products/bmfont/ to generate a simple bitmap font. Loading a tga file is pretty simple. I wouldn't expect a crowdsourced font to look very nice.

user_1106720

Coming from Archlinux, I always first look into both the official and user package repos. There's a bunch of bdf fonts that you can use as individual packages, there's also a bdf2c script you can use to convert it.

user_87796430

this site has many different bitmap fonts, and ways to use them:

https://jared.geek.nz/2014/jan/custom-fonts-for-microcontrollers

(its a bit old, but its very useful)

Note: their implementation of DrawChar() didnt work for me, so i used this instead:

#define CHAR_WIDTH 5
#define CHAR_HEIGHT 8

void DrawChar(unsigned char c, int x, int y, int color) {
    if (c < ' ')
        c = 0;
    else 
        c -= ' ';
    const unsigned char* chr = font[c];
    
    // Draw pixels
    for (int j = 0; j < CHAR_WIDTH; j++)
        for (int i = 0; i < CHAR_HEIGHT; i++)
            if (chr[j] & (1 << i))
                drawPoint(x + j, y + i, color);
}
user_190053150
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