added line drawing

1 files changed, 72 insertions, 1 deletions

diff --git a/wsim.c b/wsim.c
index b369b9d..cfaa089 100644
--- a/wsim.c
+++ b/wsim.c
@@ -123,6 +123,71 @@ void setpixel(uint8_t x, uint8_t y,uint8_t set) {
 	}
 	return;
 }
+/*takes two points and draws a line between them, dot specifies that every nth x
+ * point be drawn, if dot != 1, then a dotted line is drawn
+ */
+void drawline(uint8_t x1, uint8_t y1, uint8_t x2, uint8_t y2, uint8_t dot) {
+	/*temporary x and y for switching x1,y1 and x2,y1 if x1>x2*/
+	uint8_t tv;
+	/*number of x values to translate*/
+	uint8_t dx;
+	/*number of y values to translate*/
+	uint8_t dy;
+	/* for whether dy should be positive or negative, 1 pos, 0 neg*/
+	uint8_t dir;
+	/*drawin index*/
+	uint8_t xi = 0;
+	/*makes sure that x1 < x2, otherwise switch them arround*/
+	if (x1 > x2) {
+		tv = x1;
+		x1 = x2;
+		x2 = tv;
+		tv = y1;
+		y1 = y2;
+		y2 = tv;
+	}
+	dx = x2 - x1;
+	/*find absolute
+	 * dir is used since i'm planning to port to a platform that may not
+	 * have signed ints.
+	 */
+	if (y1 > y2) {
+		dir = 0;
+		dy = y1 - y2;
+	} else {
+		dir = 1;
+		dy = y2 - y1;
+	}
+	/*
+	 *For vertical Lines
+	 * Uses xi as a y index now
+	 */
+	if (x1 == x2) {
+		while (xi <= dy) {
+			if (dir) {
+				setpixel(x1, y1 + xi, 1);
+			} else {
+				setpixel(x1, y1 - xi, 1);
+			}
+			xi++;
+		}
+	}
+	/*
+	 * loop through x and draws y in line, dots done with modulus.
+	 */
+	while (xi <= (dx)) {
+		if ((xi % dot) == 0) {
+			if (dir) {
+				setpixel(x1 + xi, y1 + ((dy/dx * xi)),1);
+			} else {
+				setpixel(x1 + xi, y1 - ((dy/dx * xi)) ,1);
+			}
+		}
+		xi++;
+	}
+	
+	return;	
+}
 int main (int argc, char * argv[]) {
 	/*holds keypress*/
 	char input;
@@ -130,8 +195,14 @@ int main (int argc, char * argv[]) {
 	memset(map, 0, sizeof(map[0][0]) * 100 * 50);
 	printmap();
 	while (state & STATE_LOOP) {
-		setpixel(0,0,2);
+		setpixel(10,20,2);
+		drawline(0,0,20,20,1);
+		drawline(0,40,10,20,1);
+		drawline(10,50,0,40,2);
+		drawline(10,0,10,200,1);
+		drawline(10,100,100,100,4);
 		printmap();
+		
 		/* checks input*/
 		input = getc(stdin);
 		/*haven't set the terminal to raw mode so will still need