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Diffstat (limited to 'src/gdisp/mcufont/mf_font.h')
| -rw-r--r-- | src/gdisp/mcufont/mf_font.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/gdisp/mcufont/mf_font.h b/src/gdisp/mcufont/mf_font.h new file mode 100644 index 00000000..591ebab6 --- /dev/null +++ b/src/gdisp/mcufont/mf_font.h @@ -0,0 +1,118 @@ +/* Generic font type that supports fonts with multiple kinds of compression. + * Provides an interface for decoding and rendering single characters. + */ + +#ifndef _MF_FONT_H_ +#define _MF_FONT_H_ + +#include "mf_encoding.h" + +/* Callback function that writes pixels to screen / buffer / whatever. + * + * x: X coordinate of the first pixel to write. + * y: Y coordinate of the first pixel to write. + * count: Number of pixels to fill (horizontally). + * alpha: The "opaqueness" of the pixels, 0 for background, 255 for text. + * state: Free variable that was passed to render_character(). + */ +typedef void (*mf_pixel_callback_t) (int16_t x, int16_t y, uint8_t count, + uint8_t alpha, void *state); + +/* General information about a font. */ +struct mf_font_s +{ + /* Full name of the font, comes from the original font file. */ + const char *full_name; + + /* Short name of the font, comes from file name. */ + const char *short_name; + + /* Width and height of the character bounding box. */ + uint8_t width; + uint8_t height; + + /* Minimum and maximum tracking width of characters. */ + uint8_t min_x_advance; + uint8_t max_x_advance; + + /* Location of the text baseline relative to character. */ + uint8_t baseline_x; + uint8_t baseline_y; + + /* Line height of the font (vertical advance). */ + uint8_t line_height; + + /* Flags identifying various aspects of the font. */ + uint8_t flags; + + /* Fallback character to use for missing glyphs. */ + mf_char fallback_character; + + /* Function to get character width. Should return 0 if character is + * not found. */ + uint8_t (*character_width)(const struct mf_font_s *font, mf_char character); + + /* Function to render a character. Returns the character width or 0 if + * character is not found. */ + uint8_t (*render_character)(const struct mf_font_s *font, + int16_t x0, int16_t y0, + mf_char character, + mf_pixel_callback_t callback, + void *state); +}; + +/* The flag definitions for the font.flags field. */ +#define MF_FONT_FLAG_MONOSPACE 0x01 +#define MF_FONT_FLAG_BW 0x02 + +/* Lookup structure for searching fonts by name. */ +struct mf_font_list_s +{ + const struct mf_font_list_s *next; + const struct mf_font_s *font; +}; + + +/* Function to decode and render a single character. + * + * font: Pointer to the font definition. + * x0, y0: Upper left corner of the target area. + * character: The character code (unicode) to render. + * callback: Callback function to write out the pixels. + * state: Free variable for caller to use (can be NULL). + * + * Returns width of the character. + */ +MF_EXTERN uint8_t mf_render_character(const struct mf_font_s *font, + int16_t x0, int16_t y0, + mf_char character, + mf_pixel_callback_t callback, + void *state); + +/* Function to get the width of a single character. + * This is not necessarily the bounding box of the character + * data, but rather the tracking width. + * + * font: Pointer to the font definition. + * character: The character code (unicode) to render. + * + * Returns width of the character in pixels. + */ +MF_EXTERN uint8_t mf_character_width(const struct mf_font_s *font, + mf_char character); + +/* Find a font based on name. The name can be either short name or full name. + * Note: You can pass MF_INCLUDED_FONTS to search among all the included .h + * files. + * + * name: Font name to search for. + * fonts: Pointer to the first font search entry. + * + * Returns a pointer to the font or NULL if not found. + */ +MF_EXTERN const struct mf_font_s *mf_find_font(const char *name); + +/* Get the list of included fonts */ +MF_EXTERN const struct mf_font_list_s *mf_get_font_list(); + +#endif
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