const int VGA_WIDTH = 80;
const int VGA_HEIGHT = 25;
const int VGA_BYTES_PER_CHARACTER = 2;

char* const VGA_BUFFER = (char*) 0xb8000;

static int terminal_position = 0;

void clear_terminal() {

	for (int i=0; i<(VGA_WIDTH * VGA_HEIGHT); i++) {
		// Text byte gets nulled
		VGA_BUFFER[i*2] = '\0';
		// Style byte gets 0x07 for white text on a black background?
		VGA_BUFFER[i*2 + 1] = 0x07;
	}

}

void print_character(char c) {
    if (c == '\n') {
        terminal_position = (terminal_position + (VGA_BYTES_PER_CHARACTER * VGA_WIDTH)) - (terminal_position % (VGA_BYTES_PER_CHARACTER * VGA_WIDTH));
    } else {
        VGA_BUFFER[(terminal_position * VGA_BYTES_PER_CHARACTER)] = c;
        VGA_BUFFER[(terminal_position * VGA_BYTES_PER_CHARACTER) + 1] = 0x07;
        terminal_position++;
    }
}

void print_string(char* string) {

    for (int i=0; string[i] != '\0'; i++) {
        print_character(string[i]);
	}

}

void print_line(char* string) {

    print_string(string);
    print_character('\n');

}