Files
KatauOS/src/drivers/screen.c
T
2025-11-20 21:20:11 +03:00

144 lines
3.4 KiB
C

// screen.c
#include "../include/screen.h"
#include "../include/string.h"
#include "../include/utils.h"
static size_t terminal_row;
static size_t terminal_column;
static uint8_t terminal_color;
static uint16_t* terminal_buffer;
static enum {
STATE_NORMAL,
STATE_ESCAPE,
STATE_BRACKET,
} terminal_state = STATE_NORMAL;
inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg)
{
return fg | bg << 4;
}
inline uint16_t vga_entry(unsigned char uc, uint8_t color)
{
return (uint16_t) uc | (uint16_t) color << 8;
}
void terminal_initialize(void)
{
terminal_row = 0;
terminal_column = 0;
terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
terminal_buffer = (uint16_t*) 0xB8000;
for (size_t y = 0; y < VGA_HEIGHT; y++) {
for (size_t x = 0; x < VGA_WIDTH; x++) {
const size_t index = y * VGA_WIDTH + x;
terminal_buffer[index] = vga_entry(' ', terminal_color);
}
}
}
void terminal_setcolor(uint8_t color)
{
terminal_color = color;
}
uint8_t terminal_getcolor()
{
return terminal_color;
}
void terminal_putentryat(char c, uint8_t color, size_t x, size_t y)
{
const size_t index = y * VGA_WIDTH + x;
terminal_buffer[index] = vga_entry(c, color);
}
void terminal_scroll(void)
{
for (size_t y = 0; y < VGA_HEIGHT - 1; y++) {
for (size_t x = 0; x < VGA_WIDTH; x++) {
const size_t index_from = (y + 1) * VGA_WIDTH + x;
const size_t index_to = y * VGA_WIDTH + x;
terminal_buffer[index_to] = terminal_buffer[index_from];
}
}
for (size_t x = 0; x < VGA_WIDTH; x++) {
const size_t index = (VGA_HEIGHT - 1) * VGA_WIDTH + x;
terminal_buffer[index] = vga_entry(' ', terminal_color);
}
terminal_row = VGA_HEIGHT - 1;
terminal_column = 0;
}
void terminal_putchar(char c)
{
if (terminal_state == STATE_ESCAPE) {
if (c == '[') {
terminal_state = STATE_BRACKET;
} else {
terminal_state = STATE_NORMAL;
}
return;
} else if (terminal_state == STATE_BRACKET) {
if (c == 'H') {
terminal_row = 0;
terminal_column = 0;
update_cursor(0, 0);
}
terminal_state = STATE_NORMAL;
return;
}
if (c == '\033') {//ESC
terminal_state = STATE_ESCAPE;
return;
}
if (c == '\b') {
if (terminal_column > 0) {
terminal_column--;
} else if (terminal_row > 0) {
terminal_row--;
terminal_column = VGA_WIDTH - 1;
}
}
else if (c == '\n') {
terminal_column = 0;
terminal_row++;
} else {
terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
terminal_column++;
}
if (terminal_column > VGA_WIDTH) {
terminal_column = 0;
terminal_row++;
}
if (terminal_row >= VGA_HEIGHT) {
terminal_scroll();
}
update_cursor(terminal_column, terminal_row);
}
void terminal_write(const char* data, size_t size)
{
for (size_t i = 0; i < size; i++)
terminal_putchar(data[i]);
}
void terminal_writestring(const char* data)
{
terminal_write(data, strlen(data));
}
void update_cursor(int x, int y)
{
uint16_t pos = y * VGA_WIDTH + x;
outb(0x3D4, 0x0F);
outb(0x3D5, (uint8_t) (pos & 0xFF));
outb(0x3D4, 0x0E);
outb(0x3D5, (uint8_t) ((pos >> 8) & 0xFF));
}