#include<stdio.h>
#include<string.h>
#include<stdint.h>
/* map holding the pixels for a 200x200 pixel imagebuffer, [x][y] 
 * bits are in braille order within each byte
 */
uint8_t map[100][50];
/* takes char storing the on/off positions of 8 points, in braille encoding
 * order, and prints the corresponding braille char
 */

/* global state bit switch */
uint8_t state = 1;
#define STATE_LOOP 0x01
void printbraille(uint8_t points) {
	/* outputs braille characters, the encoding for braile is:
	 * 1 4
	 * 2 5
	 * 3 6
	 * 7 8
	 * with the block being in U+2800 to U+28FF
	 * in utf8 that's encoded
	 * 1110xxxx 10xxxxxx 10xxxxxx
	 * [1110](0010) [10](1000)87 [10]654321
	 */
	printf("%c%c%c", 
		0b11100010, 
		0b10100000 | (points >> 6),
		0b10000000 | (points & 0b00111111));
}
/* prints the map, clears output before aswell*/
void printmap() {
	uint8_t xi = 0;
	uint8_t yi = 0;
	/*terminal escape code to move the cursor to beginning of screen or 1,1*/
	printf("\033[1;1H");
	while (yi < 50) {
		xi = 0;
		while (xi < 100) {
			printbraille(map[xi][yi]);
			xi++;
		}
		printf("\n");
		yi++;
	}
}
/* sets a pixel in the map, converts x,y coordinates to braille order
 * if set is 0, then set it to 0
 * if 1, set to 1
 * if > 1, flip
 * does not throw errors
 */
void setpixel(uint8_t x, uint8_t y,uint8_t set) {
	/* anchor x and y coordinates, eg the index in map*/
	uint8_t ax;
	uint8_t ay;
	/*bitmask in braille order of the byte in mask*/
	uint8_t shift = 0x01;
	/* check if out of bounds, since the arguments are unsigned, don't have
	 * to check below 0, doesn't throw errors
	 */
	if ( (x >= 200 ) || (y >= 200) ) {
		return;
	}
	/* integer division rounds down, therefore dividing will always get the
	 * index
	 */
	ax = x/2;
	ay = y/4;
	/*
	 * maps to braille order based off of x and y offsets
	 * 1 4
	 * 2 5
	 * 3 6
	 * 7 8
	 */
	switch(x % 2) {
		case 0:
			switch (y % 4) {
				case 0:
					shift = shift << 0;
				break;
				case 1:
					shift = shift << 1;
				break;
				case 2:
					shift = shift << 2;
				break;
				case 3:
					shift = shift << 6;
				break;
			}
		break;
		case 1:
			switch (y % 4) {
				case 0:
					shift = shift << 3;
				break;
				case 1:
					shift = shift << 4;
				break;
				case 2:
					shift = shift << 5;
				break;
				case 3:
					shift = shift << 7;
				break;
			}
		break;
	}
	/* sets the bit based on set*/
	switch (set) {
		case 0:
			map[ax][ay] = map[ax][ay] & (~shift);
		break;
		case 1:
			map[ax][ay] = map[ax][ay] | shift;
		break;
		default:
			map[ax][ay] = ((~map[ax][ay]) & shift) | 
					((~shift) & map[ax][ay]);
		break;
	}
	return;
}
int main (int argc, char * argv[]) {
	/*holds keypress*/
	char input;
	/*zeroing map*/
	memset(map, 0, sizeof(map[0][0]) * 100 * 50);
	printmap();
	while (state & STATE_LOOP) {
		setpixel(0,0,2);
		printmap();
		/* checks input*/
		input = getc(stdin);
		/*haven't set the terminal to raw mode so will still need
 		 * space
		 */
		if (input == 'q') {
			state = state & (~STATE_LOOP);
		}
	}
	return 0;
}