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Diffstat (limited to 'include/linux/font.h')
| -rw-r--r-- | include/linux/font.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/include/linux/font.h b/include/linux/font.h new file mode 100644 index 000000000..6845f02d7 --- /dev/null +++ b/include/linux/font.h @@ -0,0 +1,163 @@ +/* + * font.h -- `Soft' font definitions + * + * Created 1995 by Geert Uytterhoeven + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#ifndef _VIDEO_FONT_H +#define _VIDEO_FONT_H + +#include <linux/math.h> +#include <linux/types.h> + +struct console_font; + +/* + * Glyphs + */ + +/** + * font_glyph_pitch - Calculates the number of bytes per scanline + * @width: The glyph width in bits per scanline + * + * A glyph's pitch is the number of bytes in a single scanline, rounded + * up to the next full byte. The parameter @width receives the number + * of visible bits per scanline. For example, if width is 14 bytes per + * scanline, the pitch is 2 bytes per scanline. If width is 8 bits per + * scanline, the pitch is 1 byte per scanline. + * + * Returns: + * The number of bytes in a single scanline of the glyph + */ +static inline unsigned int font_glyph_pitch(unsigned int width) +{ + return DIV_ROUND_UP(width, 8); +} + +/** + * font_glyph_size - Calculates the number of bytes per glyph + * @width: The glyph width in bits per scanline + * @vpitch: The number of scanlines in the glyph + * + * The number of bytes in a glyph depends on the pitch and the number + * of scanlines. font_glyph_size automatically calculates the pitch + * from the given width. The parameter @vpitch gives the number of + * scanlines, which is usually the glyph's height in scanlines. Fonts + * coming from user space can sometimes have a different vertical pitch + * with empty scanlines between two adjacent glyphs. + */ +static inline unsigned int font_glyph_size(unsigned int width, unsigned int vpitch) +{ + return font_glyph_pitch(width) * vpitch; +} + +/* + * font_data_t and helpers + */ + +/** + * font_data_t - Raw font data + * + * Values of type font_data_t store a pointer to raw font data. The format + * is monochrome. Each bit sets a pixel of a stored glyph. Font data does + * not store geometry information for the individual glyphs. Users of the + * font have to store glyph size, pitch and character count separately. + * + * Font data in font_data_t is not equivalent to raw u8. Each pointer stores + * an additional hidden header before the font data. The layout is + * + * +------+-----------------------------+ + * | -16 | CRC32 Checksum (optional) | + * | -12 | <Unused> | + * | -8 | Number of data bytes | + * | -4 | Reference count | + * +------+-----------------------------+ + * | 0 | Data buffer | + * | ... | | + * +------+-----------------------------+ + * + * Use helpers to access font_data_t. Use font_data_buf() to get the stored data. + */ +typedef const unsigned char font_data_t; + +/** + * font_data_buf() - Returns the font data as raw bytes + * @fd: The font data + * + * Returns: + * The raw font data. The provided buffer is read-only. + */ +static inline const unsigned char *font_data_buf(font_data_t *fd) +{ + return (const unsigned char *)fd; +} + +font_data_t *font_data_import(const struct console_font *font, unsigned int vpitch, + u32 (*calc_csum)(u32, const void *, size_t)); +void font_data_get(font_data_t *fd); +bool font_data_put(font_data_t *fd); +unsigned int font_data_size(font_data_t *fd); +bool font_data_is_equal(font_data_t *lhs, font_data_t *rhs); +int font_data_export(font_data_t *fd, struct console_font *font, unsigned int vpitch); + +/* font_rotate.c */ +void font_glyph_rotate_90(const unsigned char *glyph, unsigned int width, unsigned int height, + unsigned char *out); +void font_glyph_rotate_180(const unsigned char *glyph, unsigned int width, unsigned int height, + unsigned char *out); +void font_glyph_rotate_270(const unsigned char *glyph, unsigned int width, unsigned int height, + unsigned char *out); +unsigned char *font_data_rotate(font_data_t *fd, unsigned int width, unsigned int height, + unsigned int charcount, unsigned int steps, + unsigned char *buf, size_t *bufsize); + +/* + * Font description + */ + +struct font_desc { + int idx; + const char *name; + unsigned int width, height; + unsigned int charcount; + font_data_t *data; + int pref; +}; + +/* Find a font with a specific name */ + +extern const struct font_desc *find_font(const char *name); + +/* Get the default font for a specific screen size */ + +extern const struct font_desc *get_default_font(int xres, int yres, + unsigned long *font_w, + unsigned long *font_h); + +/* Max. length for the name of a predefined font */ +#define MAX_FONT_NAME 32 + +/* + * Built-in fonts + */ + +extern const struct font_desc font_10x18; +extern const struct font_desc font_6x10; +extern const struct font_desc font_6x8; +extern const struct font_desc font_7x14; +extern const struct font_desc font_acorn_8x8; +extern const struct font_desc font_mini_4x6; +extern const struct font_desc font_pearl_8x8; +extern const struct font_desc font_sun_12x22; +extern const struct font_desc font_sun_8x16; +extern const struct font_desc font_ter_10x18; +extern const struct font_desc font_ter_16x32; +extern const struct font_desc font_vga_6x11; +extern const struct font_desc font_vga_8x16; +extern const struct font_desc font_vga_8x8; + +#endif /* _VIDEO_FONT_H */ |