#include<stdio.h>
#include<stdlib.h>

typedef struct {
	int x;
	int y;
} point;

void
bresenham(point* start, point* end, int** pixels) {
	int dx = end->x - start->x;
	int dy = end->y - start->y;
	int x = start->x;
	int y = start->y;

	pixels[x][y] = 1;

	double fehler = dx / 2.0;

	while (x < end->x) {
		x++;
		fehler = fehler - dy;
		if (fehler < 0) {
			y++;
			fehler = fehler + dx;
		}
		pixels[x][y] = 1;
	}
}

int**
empty(int width, int height) {
	int** result = malloc(width * sizeof(int*));
	for (int i = 0; i < width; i++) {
		int* column = malloc(height * sizeof(int));
		result[i] = column;
		for (int j = 0; j < height; j++) {
			result[i][j] = 0;
		}
	}
	return result;
}

void
freepixels(int** pixels, int width) {
	for (int i = 0; i < width; i++) {
		free(pixels[i]);
	}
	free(pixels);
}

void
printpixels(int** pixels, int width, int height) {
	for (int j = 0; j < height; j++) {
		for (int i = 0; i < width; i++) {
			printf("%d", pixels[i][j]);
		}
		printf("\n");
	}
}

int
main() {
	int width = 11;
	int height = 9;
	int** pixels = empty(width, height);

	point* start = malloc(sizeof(point));
	point* end = malloc(sizeof(point));

	start->x = 1;
	start->y = 2;
	end->x = 9;
	end->y = 6;

	bresenham(start, end, pixels);

	printpixels(pixels, width, height);

	freepixels(pixels, width);

	free(start);
	free(end);
}