rulimine/drivers/vga_textmode.c

280 lines
7.0 KiB
C

#include <stdint.h>
#include <stddef.h>
#include <lib/cio.h>
#include <drivers/vga_textmode.h>
#define VIDEO_BOTTOM ((VD_ROWS * VD_COLS) - 1)
#define VD_COLS (80 * 2)
#define VD_ROWS 25
static void escape_parse(char c);
static void text_putchar(char c);
static char *video_mem = (char *)0xb8000;
static size_t cursor_offset = 0;
static int cursor_status = 1;
static uint8_t text_palette = 0x07;
static uint8_t cursor_palette = 0x70;
static int escape = 0;
static int esc_value0 = 0;
static int esc_value1 = 0;
static int *esc_value = &esc_value0;
static int esc_default0 = 1;
static int esc_default1 = 1;
static int *esc_default = &esc_default0;
static void clear_cursor(void) {
video_mem[cursor_offset + 1] = text_palette;
return;
}
static void draw_cursor(void) {
if (cursor_status) {
video_mem[cursor_offset + 1] = cursor_palette;
}
return;
}
static void scroll(void) {
// move the text up by one row
for (size_t i = 0; i <= VIDEO_BOTTOM - VD_COLS; i++)
video_mem[i] = video_mem[i + VD_COLS];
// clear the last line of the screen
for (size_t i = VIDEO_BOTTOM; i > VIDEO_BOTTOM - VD_COLS; i -= 2) {
video_mem[i] = text_palette;
video_mem[i - 1] = ' ';
}
return;
}
static void text_clear(void) {
clear_cursor();
for (size_t i = 0; i < VIDEO_BOTTOM; i += 2) {
video_mem[i] = ' ';
video_mem[i + 1] = text_palette;
}
cursor_offset = 0;
draw_cursor();
return;
}
static void text_clear_no_move(void) {
clear_cursor();
for (size_t i = 0; i < VIDEO_BOTTOM; i += 2) {
video_mem[i] = ' ';
video_mem[i + 1] = text_palette;
}
draw_cursor();
return;
}
void init_vga_textmode(void) {
port_out_b(0x3d4, 0x0a);
port_out_b(0x3d5, 0x20);
text_clear();
return;
}
static void text_enable_cursor(void) {
cursor_status = 1;
draw_cursor();
return;
}
static void text_disable_cursor(void) {
cursor_status = 0;
clear_cursor();
return;
}
static void text_set_cursor_palette(uint8_t c) {
cursor_palette = c;
draw_cursor();
return;
}
static uint8_t text_get_cursor_palette(void) {
return cursor_palette;
}
static void text_set_text_palette(uint8_t c) {
text_palette = c;
return;
}
static uint8_t text_get_text_palette(void) {
return text_palette;
}
static int text_get_cursor_pos_x(void) {
return (cursor_offset % VD_COLS) / 2;
}
static int text_get_cursor_pos_y(void) {
return cursor_offset / VD_COLS;
}
static void text_set_cursor_pos(int x, int y) {
clear_cursor();
cursor_offset = y * VD_COLS + x * 2;
draw_cursor();
return;
}
void text_write(const char *buf, size_t count) {
for (size_t i = 0; i < count; i++)
text_putchar(buf[i]);
}
static void text_putchar(char c) {
if (escape) {
escape_parse(c);
return;
}
switch (c) {
case 0x00:
break;
case 0x1B:
escape = 1;
return;
case 0x0A:
if (text_get_cursor_pos_y() == (VD_ROWS - 1)) {
clear_cursor();
scroll();
text_set_cursor_pos(0, (VD_ROWS - 1));
} else {
text_set_cursor_pos(0, (text_get_cursor_pos_y() + 1));
}
break;
case 0x08:
if (cursor_offset) {
clear_cursor();
cursor_offset -= 2;
video_mem[cursor_offset] = ' ';
draw_cursor();
}
break;
default:
clear_cursor();
video_mem[cursor_offset] = c;
if (cursor_offset >= (VIDEO_BOTTOM - 1)) {
scroll();
cursor_offset = VIDEO_BOTTOM - (VD_COLS - 1);
} else
cursor_offset += 2;
draw_cursor();
}
return;
}
static uint8_t ansi_colours[] = { 0, 4, 2, 6, 1, 5, 3, 7 };
static void sgr(void) {
if (esc_value0 >= 30 && esc_value0 <= 37) {
uint8_t pal = text_get_text_palette();
pal = (pal & 0xf0) + ansi_colours[esc_value0 - 30];
text_set_text_palette(pal);
return;
}
if (esc_value0 >= 40 && esc_value0 <= 47) {
uint8_t pal = text_get_text_palette();
pal = (pal & 0x0f) + ansi_colours[esc_value0 - 40] * 0x10;
text_set_text_palette(pal);
return;
}
return;
}
static void escape_parse(char c) {
if (c >= '0' && c <= '9') {
*esc_value *= 10;
*esc_value += c - '0';
*esc_default = 0;
return;
}
switch (c) {
case '[':
return;
case ';':
esc_value = &esc_value1;
esc_default = &esc_default1;
return;
case 'A':
if (esc_default0)
esc_value0 = 1;
if (esc_value0 > text_get_cursor_pos_y())
esc_value0 = text_get_cursor_pos_y();
text_set_cursor_pos(text_get_cursor_pos_x(),
text_get_cursor_pos_y() - esc_value0);
break;
case 'B':
if (esc_default0)
esc_value0 = 1;
if ((text_get_cursor_pos_y() + esc_value0) > (VD_ROWS - 1))
esc_value0 = (VD_ROWS - 1) - text_get_cursor_pos_y();
text_set_cursor_pos(text_get_cursor_pos_x(),
text_get_cursor_pos_y() + esc_value0);
break;
case 'C':
if (esc_default0)
esc_value0 = 1;
if ((text_get_cursor_pos_x() + esc_value0) > (VD_COLS / 2 - 1))
esc_value0 = (VD_COLS / 2 - 1) - text_get_cursor_pos_x();
text_set_cursor_pos(text_get_cursor_pos_x() + esc_value0,
text_get_cursor_pos_y());
break;
case 'D':
if (esc_default0)
esc_value0 = 1;
if (esc_value0 > text_get_cursor_pos_x())
esc_value0 = text_get_cursor_pos_x();
text_set_cursor_pos(text_get_cursor_pos_x() - esc_value0,
text_get_cursor_pos_y());
break;
case 'H':
esc_value0--;
esc_value1--;
if (esc_default0)
esc_value0 = 0;
if (esc_default1)
esc_value1 = 0;
if (esc_value1 >= (VD_COLS / 2))
esc_value1 = (VD_COLS / 2) - 1;
if (esc_value0 >= VD_ROWS)
esc_value0 = VD_ROWS - 1;
text_set_cursor_pos(esc_value1, esc_value0);
break;
case 'm':
sgr();
break;
case 'J':
switch (esc_value0) {
case 2:
text_clear_no_move();
break;
default:
break;
}
break;
default:
escape = 0;
text_putchar('?');
break;
}
esc_value = &esc_value0;
esc_value0 = 0;
esc_value1 = 0;
esc_default = &esc_default0;
esc_default0 = 1;
esc_default1 = 1;
escape = 0;
return;
}