Class Image.Font

Description

Short technical documentation on a font file: This object adds the text-drawing and -creation capabilities of the Image module.

For simple usage, see write and load.

Note

	       struct file_head
	       {
		  unsigned INT32 cookie;   - 0x464f4e54
		  unsigned INT32 version;  - 1
		  unsigned INT32 chars;    - number of chars
		  unsigned INT32 height;   - height of font
		  unsigned INT32 baseline; - font baseline
		  unsigned INT32 o[1];     - position of char_head's
	       } *fh;
	       struct char_head
	       {
		  unsigned INT32 width;    - width of this character
		  unsigned INT32 spacing;  - spacing to next character
		  unsigned char data[1];   - pixmap data (1byte/pixel)
	       } *ch;

            version 2:


            	  On-disk syntax (everything in N.B.O), int is 4 bytes, a byte is 8 bits:

            pos
            	0   int cookie = 'FONT';     or 0x464f4e54
            	4   int version = 2;         1 was the old version without the last four chars
            	8   int numchars;            Always 256 in this version of the dump program
            12   int height;              in (whole) pixels
            16   int baseline;            in (whole) pixels
            20   char direction;          1==right to left, 0 is left to right
            21   char format;             Font format
            22   char colortablep;        Colortable format
            23   char kerningtablep;      Kerning table format

            24   int offsets[numchars];   pointers into the data, realative to &cookie.
            	    [colortable]
            	    [kerningtable]

            	  At each offset:


            0   int width;               in pixels
            4   int spacing;             in 1/1000:th of a pixels
            8   char data[];             Enough data to plot width * font->height pixels
            				    Please note that if width is 0, there is no data.

            Font formats:
            	id type
            	 0 Raw 8bit data
            	 1 RLE encoded data,  char length, char data,   70% more compact than raw data
            	 2 ZLib compressed data                         60% more compact than RLE

            Colortable types:
            	 0 No colortable		 (the data is an alpha channel)
            	 1 24bit RGB with alpha         (index->color, 256*4 bytes, rgba)
            	 2 8bit Greyscale with alpha    (index->color, 256*2 bytes)

            Kerningtable types:
            	 0 No kerning table
            	 1 numchars*numchars entries, each a signed char with the kerning value
            	 2 numchar entries, each with a list of kerning pairs, like this:
            	    int len
            	    len * (short char, short value)
 

See also

Image, Image.Image

Method create

Image.Font Image.Font(string filename)

Description

Loads a font file to this font object. Similar to load().