Font support

This modules provides functionality for outputting a font to a display.

Modules
	System font
	The system font objects are globally available for a graphical application.

Data Structures
struct	font
	Storage structure for font meta data. More...

Enumerations
enum	font_data_type { FONT_LOC_PROGMEM }
	Valid storage locations for font data. More...
enum	gfx_text_alignment {   TEXT_ALIGN_LEFT,   TEXT_ALIGN_RIGHT,   TEXT_ALIGN_CENTER }
	Text alignment options for text lines within a paragraph. More...
enum	gfx_text_position {   TEXT_POS_TOP = (1 << 0),   TEXT_POS_CENTER_Y = (1 << 1),   TEXT_POS_BOTTOM = (1 << 2),   TEXT_POS_LEFT = (1 << 3),   TEXT_POS_CENTER_X = (1 << 4),   TEXT_POS_RIGHT = (1 << 5),   TEXT_POS_TOP_LEFT = TEXT_POS_TOP | TEXT_POS_LEFT,   TEXT_POS_TOP_CENTER = TEXT_POS_TOP | TEXT_POS_CENTER_X,   TEXT_POS_TOP_RIGHT = TEXT_POS_TOP | TEXT_POS_RIGHT,   TEXT_POS_CENTER_LEFT = TEXT_POS_CENTER_Y | TEXT_POS_LEFT,   TEXT_POS_CENTER = TEXT_POS_CENTER_Y | TEXT_POS_CENTER_X,   TEXT_POS_CENTER_RIGHT = TEXT_POS_CENTER_Y | TEXT_POS_RIGHT,   TEXT_POS_BOTTOM_LEFT = TEXT_POS_BOTTOM | TEXT_POS_LEFT,   TEXT_POS_BOTTOM_CENTER = TEXT_POS_BOTTOM | TEXT_POS_CENTER_X,   TEXT_POS_BOTTOM_RIGHT = TEXT_POS_BOTTOM | TEXT_POS_RIGHT }
	Text paraphraph positioning options. More...

Strings and characters located in RAM
void	gfx_draw_char (const char c, const gfx_coord_t x, const gfx_coord_t y, const struct font *font, const gfx_color_t bg_color, const gfx_color_t text_color)
	Draws a character to the display. More...
void	gfx_draw_string (const char *str, const gfx_coord_t x, const gfx_coord_t y, const struct font *font, const gfx_color_t bg_color, const gfx_color_t text_color)
	Draws a string to the display. More...
void	gfx_draw_string_aligned (const char *str, gfx_coord_t x, gfx_coord_t y, const struct font *font, const gfx_color_t bg_color, const gfx_color_t text_color, enum gfx_text_position text_pos, enum gfx_text_alignment text_align)
	Draws an aligned string to the display. More...
void	gfx_get_string_bounding_box (char const *str, const struct font *font, gfx_coord_t *width, gfx_coord_t *height)
	Computes the bounding box of a string. More...

Strings located in flash
void	gfx_draw_progmem_string (char PROGMEM_PTR_T str, gfx_coord_t x, gfx_coord_t y, const struct font *font, const gfx_color_t bg_color, const gfx_color_t text_color)
	Draws a string located in program memory to the display. More...
void	gfx_draw_progmem_string_aligned (char PROGMEM_PTR_T str, gfx_coord_t x, gfx_coord_t y, const struct font *font, const gfx_color_t bg_color, const gfx_color_t text_color, enum gfx_text_position text_pos, enum gfx_text_alignment text_align)
	Draws an aligned string located in program memory to the display. More...
void	gfx_get_progmem_string_bounding_box (char PROGMEM_PTR_T str, const struct font *font, gfx_coord_t *width, gfx_coord_t *height)
	Computes the bounding box of a string located in program memory. More...

enum font_data_type

Valid storage locations for font data.

Todo:

Add support for fonts in regular ram

Enumerator
FONT_LOC_PROGMEM	Font data stored in program/flash memory.

enum gfx_text_alignment

Text alignment options for text lines within a paragraph.

Enumerator
TEXT_ALIGN_LEFT	Align each line to the left side of the paragraph bounding box. Align each line to the right side of the paragraph bounding box
TEXT_ALIGN_RIGHT	Align each line to the center of the paragraph bounding box.
TEXT_ALIGN_CENTER

enum gfx_text_position

Text paraphraph positioning options.

Enumerator
TEXT_POS_TOP	Position text paragraph vertically below given coordinate. Position text paragraph vertically centered on given coordinate
TEXT_POS_CENTER_Y	Position text paragraph vertically above given coordinate.
TEXT_POS_BOTTOM	Position text paragraph horizontally right to the given coordinate.
TEXT_POS_LEFT	Position text paragraph horizontally centered on given coordinate.
TEXT_POS_CENTER_X	Position text paragraph horizontally left to the given coordinate.
TEXT_POS_RIGHT
TEXT_POS_TOP_LEFT
TEXT_POS_TOP_CENTER
TEXT_POS_TOP_RIGHT
TEXT_POS_CENTER_LEFT
TEXT_POS_CENTER
TEXT_POS_CENTER_RIGHT
TEXT_POS_BOTTOM_LEFT
TEXT_POS_BOTTOM_CENTER
TEXT_POS_BOTTOM_RIGHT

void gfx_draw_char	(	const char	c,
		const gfx_coord_t	x,
		const gfx_coord_t	y,
		const struct font *	font,
		const gfx_color_t	bg_color,
		const gfx_color_t	text_color
	)

Draws a character to the display.

Parameters

c	Character to be drawn
x	X coordinate on screen.
y	Y coordinate on screen.
font	Font to draw character in
bg_color	Background color to draw behind the text string
text_color	Foreground color to draw the text string in

References Assert, FONT_LOC_PROGMEM, GFX_COLOR_TRANSPARENT, gfx_draw_char_hugemem(), gfx_draw_char_progmem(), gfx_draw_filled_rect, font::height, font::type, and font::width.

Referenced by gfx_draw_progmem_string_aligned(), and gfx_draw_string_aligned().

void gfx_draw_progmem_string	(	char PROGMEM_PTR_T	str,
		gfx_coord_t	x,
		gfx_coord_t	y,
		const struct font *	font,
		const gfx_color_t	bg_color,
		const gfx_color_t	text_color
	)

Draws a string located in program memory to the display.

This function will draw a string located in program memory to the display, this differs from gfx_draw_string() by using constant string data from the program memory instead of string data in RAM.

Using program memory for constant strings will reduce the applications need for RAM, and thus lower the overall size footprint.

Parameters

str	Pointer to string located in program memory
x	X coordinate on screen.
y	Y coordinate on screen.
font	Font to draw string in
bg_color	Background color to draw behind the text string
text_color	Foreground color to draw the text string in

References gfx_draw_progmem_string_aligned(), TEXT_ALIGN_LEFT, and TEXT_POS_LEFT.

void gfx_draw_progmem_string_aligned	(	char PROGMEM_PTR_T	str,
		gfx_coord_t	x,
		gfx_coord_t	y,
		const struct font *	font,
		const gfx_color_t	bg_color,
		const gfx_color_t	text_color,
		enum gfx_text_position	text_pos,
		enum gfx_text_alignment	text_align
	)

Draws an aligned string located in program memory to the display.

This function will draw a string located in program memory to the display with the specified alignment. This differs from gfx_draw_aligned_string() by using constant string data from the program memory instead of string data in RAM.

Parameters

str	Pointer to string located in program memory
x	X coordinate on screen.
y	Y coordinate on screen.
font	Font to draw string in
bg_color	Background color to draw behind the text string
text_color	Foreground color to draw the text string in
text_pos	Position of the coordinate relative to the text paragraph
text_align	Alignment of text lines within the paragraph bounding box

References Assert, gfx_draw_char(), gfx_get_progmem_string_bounding_box(), font::height, PROGMEM_PTR_T, PROGMEM_READ_BYTE, TEXT_ALIGN_CENTER, TEXT_ALIGN_RIGHT, TEXT_POS_BOTTOM, TEXT_POS_CENTER_X, TEXT_POS_CENTER_Y, TEXT_POS_RIGHT, and font::width.

Referenced by gfx_draw_progmem_string().

void gfx_draw_string	(	const char *	str,
		gfx_coord_t	x,
		gfx_coord_t	y,
		const struct font *	font,
		const gfx_color_t	bg_color,
		const gfx_color_t	text_color
	)

Draws a string to the display.

This function will draw a string located in memory to the display.

Parameters

str	Pointer to string
x	X coordinate on screen.
y	Y coordinate on screen.
font	Font to draw string in
bg_color	Background color to draw behind the text string
text_color	Foreground color to draw the text string in

References gfx_draw_string_aligned(), TEXT_ALIGN_LEFT, and TEXT_POS_LEFT.

void gfx_draw_string_aligned	(	const char *	str,
		gfx_coord_t	x,
		gfx_coord_t	y,
		const struct font *	font,
		const gfx_color_t	bg_color,
		const gfx_color_t	text_color,
		enum gfx_text_position	text_pos,
		enum gfx_text_alignment	text_align
	)

Draws an aligned string to the display.

This function will draw a string located in memory to the display with the specified alignment.

Parameters

str	Pointer to string
x	X coordinate on screen.
y	Y coordinate on screen.
font	Font to draw string in
bg_color	Background color to draw behind the text string
text_color	Foreground color to draw the text string in
text_pos	Position of the coordinate relative to the text paragraph
text_align	Alignment of text lines within the paragraph bounding box

References Assert, gfx_draw_char(), gfx_get_string_bounding_box(), font::height, TEXT_ALIGN_CENTER, TEXT_ALIGN_RIGHT, TEXT_POS_BOTTOM, TEXT_POS_CENTER_X, TEXT_POS_CENTER_Y, TEXT_POS_RIGHT, and font::width.

Referenced by gfx_draw_string(), and main().

void gfx_get_progmem_string_bounding_box	(	char PROGMEM_PTR_T	str,
		const struct font *	font,
		gfx_coord_t *	width,
		gfx_coord_t *	height
	)

Computes the bounding box of a string located in program memory.

Note

If string is empty the returned width will be 1 pixel and the height equal to the font height.

Parameters

str	String in program memory to calculate bounding box for
font	Font used
width	Pointer to width result
height	Pointer to height result

References Assert, font::height, PROGMEM_PTR_T, PROGMEM_READ_BYTE, and font::width.

Referenced by gfx_draw_progmem_string_aligned().

void gfx_get_string_bounding_box	(	const char *	str,
		const struct font *	font,
		gfx_coord_t *	width,
		gfx_coord_t *	height
	)

Computes the bounding box of a string.

Note

If string is empty the returned width will be 1 pixel and the height equal to the font height.

Parameters

str	String to calculate bounding box for
font	Font used
width	Pointer to width result
height	Pointer to height result

References Assert, font::height, and font::width.

Referenced by gfx_draw_string_aligned().