From 0f6c06002fad439c5d5a72f9078a7aab3a5b280f Mon Sep 17 00:00:00 2001
From: Evan Debenham <Evan@ShatteredPixel.com>
Date: Mon, 16 Nov 2020 19:50:31 -0500
Subject: [PATCH] v0.9.1: fixed rare cases of artifacting in the shadowcaster

---
 .../mechanics/ShadowCaster.java                     | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/mechanics/ShadowCaster.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/mechanics/ShadowCaster.java
index 212c9e18a..6fda87361 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/mechanics/ShadowCaster.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/mechanics/ShadowCaster.java
@@ -80,9 +80,6 @@ public final class ShadowCaster {
 	                               int x, int y, double lSlope, double rSlope,
 	                               int mX, int mY, boolean mXY){
 		
-		//if we have negative space to traverse, just quit.
-		if (rSlope < lSlope) return;
-		
 		boolean inBlocking = false;
 		int start, end;
 		int col;
@@ -91,6 +88,9 @@ public final class ShadowCaster {
 		
 		//for each row, starting with the current one
 		for (; row <= distance; row++){
+
+			//if we have negative space to traverse, just quit.
+			if (rSlope < lSlope) return;
 			
 			//we offset by slightly less than 0.5 to account for slopes just touching a cell
 			if (lSlope == 0)    start = 0;
@@ -109,6 +109,13 @@ public final class ShadowCaster {
 			
 			//for each column in this row, which
 			for (col = start; col <= end; col++){
+
+
+				//handles the error case of the slope value at the end of a cell being 1 farther
+				// along then at the beginning of the cell, and that earlier cell is vision blocking
+				if (col == end && inBlocking && (int)Math.ceil((row - 0.5) * rSlope - 0.499) != end){
+					break;
+				}
 				
 				fov[cell] = true;