From f8d60b14d269f486a11a8f4d0db57791e06a0409 Mon Sep 17 00:00:00 2001
From: jacksonmj <mj-pt@jacksonmj.co.uk>
Date: Thu, 14 Jul 2011 03:32:10 +0800
Subject: [PATCH] Avoid division by zero for circle brush

---
 src/graphics.c | 4 +++-
 src/powder.c   | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/graphics.c b/src/graphics.c
index 1d9438e41..f738354ed 100644
--- a/src/graphics.c
+++ b/src/graphics.c
@@ -4268,7 +4268,9 @@ void render_cursor(pixel *vid, int x, int y, int t, int rx, int ry)
 		{
 			for (j=0; j<=ry; j++)
 				for (i=0; i<=rx; i++)
-					if ((pow(i,2))/(pow(rx,2))+(pow(j,2))/(pow(ry,2))<=1 && ((pow(i+1,2))/(pow(rx,2))+(pow(j,2))/(pow(ry,2))>1 || (pow(i,2))/(pow(rx,2))+(pow(j+1,2))/(pow(ry,2))>1))
+					if (pow(i,2)*pow(ry,2)+pow(j,2)*pow(rx,2)<=pow(rx,2)*pow(ry,2) &&
+					  (pow(i+1,2)*pow(ry,2)+pow(j,2)*pow(rx,2)>pow(rx,2)*pow(ry,2) ||
+					   pow(i,2)*pow(ry,2)+pow(j+1,2)*pow(rx,2)>pow(rx,2)*pow(ry,2)))
 					{
 						xor_pixel(x+i, y+j, vid);
 						if (j) xor_pixel(x+i, y-j, vid);
diff --git a/src/powder.c b/src/powder.c
index db6530353..8cdd84c3a 100644
--- a/src/powder.c
+++ b/src/powder.c
@@ -2794,7 +2794,7 @@ int InCurrentBrush(int i, int j, int rx, int ry)
 	switch(CURRENT_BRUSH)
 	{
 		case CIRCLE_BRUSH:
-			return ((pow(i,2))/(pow(rx,2))+(pow(j,2))/(pow(ry,2))<=1);
+			return (pow(i,2)*pow(ry,2)+pow(j,2)*pow(rx,2)<=pow(rx,2)*pow(ry,2));
 			break;
 		case SQUARE_BRUSH:
 			return (i*j<=ry*rx);