From 0a907c5177ec72b69dcdc10a07fbf1b6973a2bac Mon Sep 17 00:00:00 2001
From: jacob1 <jfu614@gmail.com>
Date: Mon, 28 Sep 2015 11:28:19 -0400
Subject: [PATCH] fix bug if the first space after the DRAY was empty, fix bug
 with DRAY's ctype sometimes not working

---
 src/simulation/elements/DRAY.cpp | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/simulation/elements/DRAY.cpp b/src/simulation/elements/DRAY.cpp
index 2d5c6453c4..06cbef1a73 100644
--- a/src/simulation/elements/DRAY.cpp
+++ b/src/simulation/elements/DRAY.cpp
@@ -83,22 +83,30 @@ int Element_DRAY::update(UPDATE_FUNC_ARGS)
 						for (int xStep = rx*-1, yStep = ry*-1, xCurrent = x+xStep, yCurrent = y+yStep; ; xCurrent+=xStep, yCurrent+=yStep)
 						{
 							int rr;
+							// haven't found a particle yet, keep looking for one
+							// the first particle it sees decides whether it will copy energy particles or not
 							if (!foundParticle)
 							{
 								rr = pmap[yCurrent][xCurrent];
 								if (!rr)
 								{
 									rr = sim->photons[yCurrent][xCurrent];
-									foundParticle = isEnergy = true;
+									if (rr)
+										foundParticle = isEnergy = true;
 								}
 								else
 									foundParticle = true;
 							}
-							else if (isEnergy)
+							// now that it knows what kind of particle it is copying, do some extra stuff here so we can determine when to stop
+							if ((ctype && sim->elements[ctype].Properties&TYPE_ENERGY) || isEnergy)
 								rr = sim->photons[yCurrent][xCurrent];
 							else
 								rr = pmap[yCurrent][xCurrent];
 
+							// Checks for when to stop:
+							//  1: if .tmp isn't set, and the element in this spot is the ctype, then stop
+							//  2: if .tmp is set, stop when the length limit reaches 0
+							//  3. Stop when we are out of bounds
 							if ((!copyLength && (rr&0xFF) == ctype && (ctype != PT_LIFE || parts[rr>>8].ctype == ctypeExtra))
 									|| !(--partsRemaining && InBounds(xCurrent+xStep, yCurrent+yStep)))
 							{
@@ -109,16 +117,18 @@ int Element_DRAY::update(UPDATE_FUNC_ARGS)
 							}
 						}
 
-						//now, actually copy the particles
+						// now, actually copy the particles
 						partsRemaining = copyLength + 1;
 						int type, p;
 						for (int xStep = rx*-1, yStep = ry*-1, xCurrent = x+xStep, yCurrent = y+yStep; InBounds(xCopyTo, yCopyTo) && --partsRemaining; xCurrent+=xStep, yCurrent+=yStep, xCopyTo+=xStep, yCopyTo+=yStep)
 						{
+							// get particle to copy
 							if (isEnergy)
 								type = sim->photons[yCurrent][xCurrent]&0xFF;
 							else
 								type = pmap[yCurrent][xCurrent]&0xFF;
 
+							// if sparked by PSCN, overwrite whatever is in the target location, instead of just ignoring it
 							if (overwrite)
 							{
 								if (isEnergy)
@@ -132,16 +142,17 @@ int Element_DRAY::update(UPDATE_FUNC_ARGS)
 										sim->kill_part(pmap[yCopyTo][xCopyTo]>>8);
 								}
 							}
-							if (type == PT_SPRK) //hack
+							if (type == PT_SPRK) // spark hack
 								p = sim->create_part(-1, xCopyTo, yCopyTo, PT_METL);
 							else if (type)
 								p = sim->create_part(-1, xCopyTo, yCopyTo, type);
 							else
 								continue;
 
+							// if new particle was created successfully
 							if (p >= 0)
 							{
-								if (type == PT_SPRK)
+								if (type == PT_SPRK) // spark hack
 									sim->part_change_type(p, xCopyTo, yCopyTo, PT_SPRK);
 								if (isEnergy)
 									parts[p] = parts[sim->photons[yCurrent][xCurrent]>>8];