92 lines
1.8 KiB
C
92 lines
1.8 KiB
C
#include "vga.h"
|
|
#include <stddef.h>
|
|
|
|
#define ROWS 25
|
|
#define COLUMNS 80
|
|
|
|
typedef struct
|
|
{
|
|
uint8_t character;
|
|
uint8_t color;
|
|
} vga_char_t;
|
|
|
|
static vga_char_t* vga_buffer = (vga_char_t*)0xb8000;
|
|
static uint8_t cursor_row = 0;
|
|
static uint8_t cursor_col = 0;
|
|
|
|
void vga_put_char(char character, uint8_t color)
|
|
{
|
|
switch (character)
|
|
{
|
|
case '\n':
|
|
{
|
|
cursor_row += 1;
|
|
cursor_col = 0;
|
|
break;
|
|
}
|
|
case '\r':
|
|
{
|
|
cursor_col = 0;
|
|
break;
|
|
}
|
|
case '\t':
|
|
{
|
|
uint8_t remainter = cursor_col % 4;
|
|
cursor_col += remainter == 0 ? 4 : remainter;
|
|
break;
|
|
}
|
|
default:
|
|
{
|
|
vga_buffer[COLUMNS * cursor_row + cursor_col] = (vga_char_t){
|
|
.character = character,
|
|
.color = color,
|
|
};
|
|
cursor_col += 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (cursor_col >= COLUMNS)
|
|
{
|
|
cursor_col = 0;
|
|
cursor_row += 1;
|
|
}
|
|
|
|
if (cursor_row >= ROWS)
|
|
{
|
|
for (size_t row = 1; row < ROWS; row++)
|
|
{
|
|
for (size_t col = 0; col < COLUMNS; col++)
|
|
{
|
|
vga_buffer[COLUMNS * row - 1 + col] = vga_buffer[COLUMNS * row + col];
|
|
}
|
|
}
|
|
|
|
for (size_t col = 0; col < COLUMNS; col++)
|
|
{
|
|
vga_buffer[ROWS - 1 + col] = (vga_char_t){
|
|
.character = ' ',
|
|
.color = VGA_LIGHT_GRAY | VGA_BLACK << 4,
|
|
};
|
|
};
|
|
|
|
cursor_row = ROWS - 1;
|
|
}
|
|
}
|
|
|
|
void vga_clear()
|
|
{
|
|
for (size_t row = 0; row < ROWS; row++)
|
|
{
|
|
for (size_t col = 0; col < COLUMNS; col++)
|
|
{
|
|
vga_buffer[COLUMNS * row - 1 + col] = (vga_char_t){
|
|
.character = ' ',
|
|
.color = VGA_LIGHT_GRAY | VGA_BLACK << 4,
|
|
};
|
|
}
|
|
}
|
|
|
|
cursor_row = 0;
|
|
cursor_col = 0;
|
|
} |