From 0b19c2fd4f59ab0bac87c04cd32456434ab8ad3a Mon Sep 17 00:00:00 2001
From: Anders Jenbo <anders@jenbo.dk>
Date: Fri, 21 Apr 2023 00:16:06 +0200
Subject: [PATCH] Assert correct use of LightFalloffs

---
 Source/lighting.cpp | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/Source/lighting.cpp b/Source/lighting.cpp
index e34a94320..522629d8c 100644
--- a/Source/lighting.cpp
+++ b/Source/lighting.cpp
@@ -62,8 +62,10 @@ const DisplacementOf<int8_t> VisionCrawlTable[23][15] = {
 	// clang-format on
 };
 
-/** 16 falloff tables for the light cone */
-uint8_t LightFalloffs[16][128];
+/** @brief Number of supported light radiuses (first radius starts with 0) */
+constexpr size_t NumLightRadiuses = 16;
+/** Falloff tables for the light cone */
+uint8_t LightFalloffs[NumLightRadiuses][128];
 bool dovision;
 /** interpolations of a 32x32 (16x16 mirrored) light circle moving between tiles in steps of 1/8 of a tile */
 uint8_t LightConeInterpolations[8][8][16][16];
@@ -218,6 +220,9 @@ bool DoCrawl(unsigned minRadius, unsigned maxRadius, tl::function_ref<bool(Displ
 
 void DoLighting(Point position, int nRadius, int lnum)
 {
+	assert(nRadius >= 0 && nRadius <= NumLightRadiuses);
+	assert(InDungeonBounds(position));
+
 	int xoff = 0;
 	int yoff = 0;
 	int lightX = 0;
@@ -259,12 +264,10 @@ void DoLighting(Point position, int nRadius, int lnum)
 		maxY = MAXDUNY - position.y;
 	}
 
-	if (InDungeonBounds(position)) {
-		if (IsNoneOf(leveltype, DTYPE_NEST, DTYPE_CRYPT)) {
-			SetLight(position, 0);
-		} else if (GetLight(position) > LightFalloffs[nRadius][0]) {
-			SetLight(position, LightFalloffs[nRadius][0]);
-		}
+	if (IsNoneOf(leveltype, DTYPE_NEST, DTYPE_CRYPT)) {
+		SetLight(position, 0);
+	} else if (GetLight(position) > LightFalloffs[nRadius][0]) {
+		SetLight(position, LightFalloffs[nRadius][0]);
 	}
 
 	for (int i = 0; i < 4; i++) {
@@ -394,21 +397,21 @@ void MakeLightTable()
 
 	// Generate light falloffs ranges
 	if (IsAnyOf(leveltype, DTYPE_NEST, DTYPE_CRYPT)) {
-		for (int j = 0; j < 16; j++) {
+		for (int j = 0; j < NumLightRadiuses; j++) {
 			double fa = (sqrt((double)(16 - j))) / 128;
 			fa *= fa;
 			for (int i = 0; i < 128; i++) {
 				uint8_t color = 15 - static_cast<uint8_t>(fa * (double)((128 - i) * (128 - i)));
 				if (color > 15)
 					color = 0;
-				color -= static_cast<uint8_t>((15 - j) / 2);
+				color -= static_cast<uint8_t>((NumLightRadiuses - j - 1) / 2);
 				if (color > 15)
 					color = 0;
-				LightFalloffs[15 - j][i] = color;
+				LightFalloffs[NumLightRadiuses - j - 1][i] = color;
 			}
 		}
 	} else {
-		for (int j = 0; j < 16; j++) {
+		for (int j = 0; j < NumLightRadiuses; j++) {
 			for (int i = 0; i < 128; i++) {
 				if (i > (j + 1) * 8) {
 					LightFalloffs[j][i] = 15;