From d666559481a26b4edba7e74001d0df058f4832c5 Mon Sep 17 00:00:00 2001
From: jacob1 <jfu614@gmail.com>
Date: Sat, 3 Mar 2018 21:15:28 -0500
Subject: [PATCH] more accurate O2 fusion calculation, fixes #505

seemed to only be 3% slower in my tests with a full screen of heated pressurized O2
---
 src/simulation/elements/O2.cpp | 53 +++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/src/simulation/elements/O2.cpp b/src/simulation/elements/O2.cpp
index 6296bfe529..19ded518de 100644
--- a/src/simulation/elements/O2.cpp
+++ b/src/simulation/elements/O2.cpp
@@ -74,37 +74,42 @@ int Element_O2::update(UPDATE_FUNC_ARGS)
 					parts[i].tmp |= 2;
 				}
 			}
-	if (parts[i].temp > 9973.15 && sim->pv[y/CELL][x/CELL] > 250.0f && abs(sim->gravx[((y/CELL)*(XRES/CELL))+(x/CELL)]) + abs(sim->gravy[((y/CELL)*(XRES/CELL))+(x/CELL)]) > 20)
+	if (parts[i].temp > 9973.15 && sim->pv[y/CELL][x/CELL] > 250.0f)
 	{
-		if (!(rand()%5))
+		float gravx = sim->gravx[((y/CELL)*(XRES/CELL))+(x/CELL)];
+		float gravy = sim->gravy[((y/CELL)*(XRES/CELL))+(x/CELL)];
+		if (gravx*gravx + gravy*gravy > 400)
 		{
-			int j;
-			sim->create_part(i,x,y,PT_BRMT);
-
-			j = sim->create_part(-3,x,y,PT_NEUT);
-			if (j != -1)
-				parts[j].temp = MAX_TEMP;
-			j = sim->create_part(-3,x,y,PT_PHOT);
-			if (j != -1)
-			{
-				parts[j].temp = MAX_TEMP;
-				parts[j].tmp = 0x1;
-			}
-			rx = x+rand()%3-1, ry = y+rand()%3-1, r = TYP(pmap[ry][rx]);
-			if (sim->can_move[PT_PLSM][r] || r == PT_O2)
+			if (!(rand()%5))
 			{
-				j = sim->create_part(-3,rx,ry,PT_PLSM);
-				if (j > -1)
+				int j;
+				sim->create_part(i,x,y,PT_BRMT);
+
+				j = sim->create_part(-3,x,y,PT_NEUT);
+				if (j != -1)
+					parts[j].temp = MAX_TEMP;
+				j = sim->create_part(-3,x,y,PT_PHOT);
+				if (j != -1)
 				{
 					parts[j].temp = MAX_TEMP;
-					parts[j].tmp |= 4;
+					parts[j].tmp = 0x1;
+				}
+				rx = x+rand()%3-1, ry = y+rand()%3-1, r = TYP(pmap[ry][rx]);
+				if (sim->can_move[PT_PLSM][r] || r == PT_O2)
+				{
+					j = sim->create_part(-3,rx,ry,PT_PLSM);
+					if (j > -1)
+					{
+						parts[j].temp = MAX_TEMP;
+						parts[j].tmp |= 4;
+					}
 				}
+				j = sim->create_part(-3,x,y,PT_GRVT);
+				if (j != -1)
+					parts[j].temp = MAX_TEMP;
+				parts[i].temp = MAX_TEMP;
+				sim->pv[y/CELL][x/CELL] = 256;
 			}
-			j = sim->create_part(-3,x,y,PT_GRVT);
-			if (j != -1)
-				parts[j].temp = MAX_TEMP;
-			parts[i].temp = MAX_TEMP;
-			sim->pv[y/CELL][x/CELL] = 256;
 		}
 	}
 	return 0;