/***
* clear vga screen
*/
void vga_clear() {
vga_d_char_t *pos, *end;
end = VGA_BUF + VGA_HEIGHT * VGA_WIDTH * sizeof(vga_d_char_t);
for (pos = VGA_BUF; pos < end; pos++) {
(*pos).c = NULL;
(*pos).color = FORMAT_COLORS(VGA_STATE.fg, VGA_STATE.bg);
}
vga_update_cursor(0, 0);
}
// bug
char * scanf() {
char* tmp = (char*)malloc(150 * sizeof(char));
char inp = ' ';
int i = 0;
vga_enable_cursor();
do {
vga_update_cursor();
kbd_flush_buffer();
inp = kbd_pull_char();
if (inp != 0) {
if (i > 149)
break;
else if (inp != '\b') {
char* str = (char*)malloc(2*sizeof(char));
str[0] = inp;
str[1] = '\0';
kprint_raw(str);
free(str);
if (inp != '\n')
tmp[i] = inp;
i++;
} else {
if (i > 0) {
// Clear character in array
i--;
tmp[i] = 0;
// Remove character from screen
int new_pos = (vga_get_row() * 80 + vga_get_column()) - 1;
vga_set_position(new_pos / 80, new_pos % 80);
print_raw(" ");
vga_set_position(new_pos / 80, new_pos % 80);
}
}
}
} while (inp != '\n');
tmp[i-1] = '\0';
vga_disable_cursor();
char* ret = (char*)malloc(strlen(tmp)+1 * sizeof(char));
for (int ii = 0; ii < strlen(tmp); ii++)
ret[ii] = tmp[ii];
ret[strlen(tmp)] = '\0';
free(tmp);
return ret;
}
// Reposition the cursor, and possibly scroll the screen, so that the
// cursor is in bounds.
void vga_reposition() {
if (vga_column >= kVgaWidth) {
vga_column = 0;
vga_row++;
}
int overhang = vga_row - kVgaHeight + 1;
if (overhang > 0) {
// We'll scroll the screen by 'overhang' rows.
const int bytesToScroll = overhang * kVgaWidth * sizeof(VgaCharacter);
memmove((void *) kVgaBuffer, (void *) (kVgaBuffer + bytesToScroll),
kVgaWidth * kVgaHeight * sizeof(VgaCharacter) - bytesToScroll);
for (unsigned row = kVgaHeight - overhang; row < kVgaHeight; row++) {
vga_erase_row(row);
}
vga_row = kVgaHeight - 1;
}
vga_update_cursor();
}
