From e91f44430d7b829b7dc6635e08d4c5be36747320 Mon Sep 17 00:00:00 2001
From: joachimschmidt557 <joachim.schmidt557@outlook.com>
Date: Thu, 10 Oct 2019 18:59:06 +0200
Subject: [PATCH] Add bresenham

---
 bresenham/Makefile |  7 ++++
 bresenham/main.c   | 84 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+)
 create mode 100644 bresenham/Makefile
 create mode 100644 bresenham/main.c

diff --git a/bresenham/Makefile b/bresenham/Makefile
new file mode 100644
index 0000000..a3504dd
--- /dev/null
+++ b/bresenham/Makefile
@@ -0,0 +1,7 @@
+CFLAGS+=-Wall
+CFLAGS+=-Wextra
+
+all: main
+
+main: main.c
+	$(CC) -o main main.c $(CFLAGS)
diff --git a/bresenham/main.c b/bresenham/main.c
new file mode 100644
index 0000000..6af260f
--- /dev/null
+++ b/bresenham/main.c
@@ -0,0 +1,84 @@
+#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);
+}