From bc44af6a0b555f8b578024163b245318a8f02c07 Mon Sep 17 00:00:00 2001
From: jacksonmj <mj-pt@jacksonmj.co.uk>
Date: Tue, 31 May 2011 17:25:40 +0100
Subject: [PATCH] INVS should leave photons alone when under pressure

---
 src/powder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/powder.c b/src/powder.c
index c7354bcfe..0348cf3b5 100644
--- a/src/powder.c
+++ b/src/powder.c
@@ -270,7 +270,7 @@ int try_move(int i, int x, int y, int nx, int ny)
 			if (rand() < RAND_MAX/10)
 				create_cherenkov_photon(i);
 		}
-		if (parts[i].type == PT_PHOT && (r&0xFF)==PT_INVIS) {
+		if (parts[i].type == PT_PHOT && (r&0xFF)==PT_INVIS && pv[ny/CELL][nx/CELL]<=4.0f && pv[ny/CELL][nx/CELL]>=-4.0f) {
 			part_change_type(i,x,y,PT_NEUT);
 			parts[i].ctype = 0;
 		}