video.c File Reference

Video functions and costants. More...

Classes
struct	ansi_color_map_t
	Stores the association between ANSI colors and pure VIDEO colors. More...

Macros
#define	HEIGHT   25
	The height of the.
#define	WIDTH   80
	The width of the.
#define	W2   (WIDTH * 2)
	The width of the.
#define	TOTAL_SIZE   (HEIGHT * WIDTH * 2)
	The total size of the screen.
#define	ADDR   (char *)0xB8000U
	The address of the.
#define	STORED_PAGES   3
	The number of stored pages.

Functions
static unsigned	__get_x (void)
	Get the current column number. More...
static unsigned	__get_y (void)
	Get the current row number. More...
static void	__draw_char (char c)
	Draws the given character. More...
static void	__set_color (uint8_t ansi_code)
	Sets the provided ansi code. More...
static void	__move_cursor_backward (int erase, int amount)
	Moves the cursor backward. More...
static void	__move_cursor_forward (int erase, int amount)
	Moves the cursor forward. More...
static void	__video_set_cursor (unsigned int x, unsigned int y)
	Issue the vide to move the cursor to the given position. More...
void	video_init (void)
	Initialize the video.
void	video_update (void)
	Updates the video.
void	video_putc (int c)
	Print the given character on the screen. More...
void	video_puts (const char *str)
	Prints the given string on the screen. More...
void	video_set_cursor_auto (void)
	When something is written in another position, update the cursor.
void	video_move_cursor (unsigned int x, unsigned int y)
	Move the cursor at the position x, y on the screen. More...
void	video_get_cursor_position (unsigned int *x, unsigned int *y)
	Returns cursor's position on the screen. More...
void	video_get_screen_size (unsigned int *width, unsigned int *height)
	Returns screen size. More...
void	video_clear (void)
	Clears the screen.
void	video_new_line (void)
	Move to the following line (the effect of character).
void	video_cartridge_return (void)
	Move to the up line (the effect of character).
void	video_shift_one_line_up (void)
	The whole screen is shifted up by one line. Used when the cursor reaches the last position of the screen.
void	video_shift_one_page_up (void)
	The whole screen is shifted up by one page.
void	video_shift_one_page_down (void)
	The whole screen is shifted down by one page.

Variables
struct ansi_color_map_t	ansi_color_map []
	The mapping.
char *	pointer = ADDR
	Pointer to a position of the screen writer.
unsigned char	color = 7
	The current color.
int	escape_index = -1
	Used to write on the escape_buffer. If -1, we are not parsing an escape sequence.
char	escape_buffer [256]
	Used to store an escape sequence.
char	upper_buffer [STORED_PAGES *TOTAL_SIZE] = { 0 }
	Buffer where we store the upper scroll history.
char	original_page [TOTAL_SIZE] = { 0 }
	Buffer where we store the lower scroll history.
int	scrolled_page = 0
	Determines if the screen is currently scrolled.

Detailed Description

Video functions and costants.

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Function Documentation

__draw_char()

static void __draw_char ( char  c )

inlinestatic

Draws the given character.

Parameters

c	The character to draw.

__get_x()

static unsigned __get_x ( void  )

inlinestatic

Get the current column number.

Returns

The column number.

__get_y()

static unsigned __get_y ( void  )

inlinestatic

Get the current row number.

Returns

The row number.

__move_cursor_backward()

static void __move_cursor_backward ( int  erase, int  amount  )

inlinestatic

Moves the cursor backward.

Parameters

erase	If 1 also erase the character.
amount	How many times we move backward.

__move_cursor_forward()

static void __move_cursor_forward ( int  erase, int  amount  )

inlinestatic

Moves the cursor forward.

Parameters

erase	If 1 also erase the character.
amount	How many times we move forward.

__set_color()

static void __set_color ( uint8_t  ansi_code )

inlinestatic

Sets the provided ansi code.

Parameters

ansi_code

The ansi code describing background and foreground color.

__video_set_cursor()

static void __video_set_cursor ( unsigned int  x, unsigned int  y  )

inlinestatic

Issue the vide to move the cursor to the given position.

Parameters

x	The x coordinate.
y	The y coordinate.

video_get_cursor_position()

void video_get_cursor_position	(	unsigned int *	x,
		unsigned int *	y
	)

Returns cursor's position on the screen.

Parameters

x	The output x coordinate.
y	The output y coordinate.

video_get_screen_size()

void video_get_screen_size	(	unsigned int *	width,
		unsigned int *	height
	)

Returns screen size.

Parameters

width	The screen width.
height	The screen height.

video_move_cursor()

void video_move_cursor	(	unsigned int	x,
		unsigned int	y
	)

Move the cursor at the position x, y on the screen.

Parameters

x	The x coordinate.
y	The y coordinate.

video_putc()

void video_putc

(

int

c

)

Print the given character on the screen.

Parameters

c	The character to print.

video_puts()

void video_puts

(

const char *

str

)

Prints the given string on the screen.

Parameters

str	The string to print.