From 5c5e3bdcbab3de777069409740c832c2bec09736 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Mon, 3 Apr 2017 19:11:38 +0200
Subject: [PATCH] - change fuzzing to not do any offsetting but keep the
 shading pattern produced by it

---
 src/swrenderer/drawers/r_draw.cpp      | 17 +++++++++++++
 src/swrenderer/drawers/r_draw_pal.cpp  | 32 +++++++++++++++++++++++--
 src/swrenderer/drawers/r_draw_rgba.cpp | 33 +++++++++++++++++++++++++-
 3 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/src/swrenderer/drawers/r_draw.cpp b/src/swrenderer/drawers/r_draw.cpp
index 1f7b2d560..65958db04 100644
--- a/src/swrenderer/drawers/r_draw.cpp
+++ b/src/swrenderer/drawers/r_draw.cpp
@@ -131,10 +131,27 @@ namespace swrenderer
 			1, 1,-1, 1, 1,-1, 1 
 		};
 
+#ifdef ORIGINAL_FUZZ
 		for (int i = 0; i < FUZZTABLE; i++)
 		{
 			fuzzoffset[i] = fuzzinit[i] * fuzzoff;
 		}
+#else
+		int8_t fuzzcount[FUZZTABLE + 1];
+		for (int i = 0; i < FUZZTABLE + 1; i++) fuzzcount[i] = 0;
+		fuzzcount[0] = 1;
+		for (int i = 1; i < FUZZTABLE; i++)
+			fuzzcount[i] = fuzzcount[i + fuzzinit[i]] + 1;
+
+		for (int i = 0; i < FUZZTABLE; i++)
+		{
+			float shade = 1.0f - 6.0f / NUMCOLORMAPS;
+			float resultshade = 1.0;
+			for (int j = 0; j < fuzzcount[i]; j++)
+				resultshade *= shade;
+			fuzzoffset[i] = clamp((int)((1.0f - resultshade) * NUMCOLORMAPS + 0.5f), 0, NUMCOLORMAPS - 1);
+		}
+#endif
 	}
 
 	void R_InitParticleTexture()
diff --git a/src/swrenderer/drawers/r_draw_pal.cpp b/src/swrenderer/drawers/r_draw_pal.cpp
index 3f75a30ac..574fa2a8c 100644
--- a/src/swrenderer/drawers/r_draw_pal.cpp
+++ b/src/swrenderer/drawers/r_draw_pal.cpp
@@ -1858,8 +1858,6 @@ namespace swrenderer
 		if (count <= 0)
 			return;
 
-		uint8_t *map = &NormalLight.Maps[6 * 256];
-
 		int pitch = _pitch;
 		uint8_t *dest = thread->dest_for_thread(yl, pitch, yl * pitch + _x + _destorg);
 
@@ -1867,6 +1865,35 @@ namespace swrenderer
 		int fuzzstep = thread->num_cores;
 		int fuzz = (_fuzzpos + thread->skipped_by_thread(yl)) % FUZZTABLE;
 
+#ifndef ORIGINAL_FUZZ
+
+		uint8_t *map = NormalLight.Maps;
+
+		while (count > 0)
+		{
+			int available = (FUZZTABLE - fuzz);
+			int next_wrap = available / fuzzstep;
+			if (available % fuzzstep != 0)
+				next_wrap++;
+
+			int cnt = MIN(count, next_wrap);
+			count -= cnt;
+			do
+			{
+				int offset = fuzzoffset[fuzz] << 8;
+
+				*dest = map[offset + *dest];
+				dest += pitch;
+				fuzz += fuzzstep;
+			} while (--cnt);
+
+			fuzz %= FUZZTABLE;
+		}
+
+#else
+
+		uint8_t *map = &NormalLight.Maps[6 * 256];
+
 		yl += thread->skipped_by_thread(yl);
 
 		// Handle the case where we would go out of bounds at the top:
@@ -1920,6 +1947,7 @@ namespace swrenderer
 
 			*dest = map[*srcdest];
 		}
+#endif
 	}
 
 	/////////////////////////////////////////////////////////////////////////
diff --git a/src/swrenderer/drawers/r_draw_rgba.cpp b/src/swrenderer/drawers/r_draw_rgba.cpp
index 3dbd38f46..3592744d9 100644
--- a/src/swrenderer/drawers/r_draw_rgba.cpp
+++ b/src/swrenderer/drawers/r_draw_rgba.cpp
@@ -255,11 +255,41 @@ namespace swrenderer
 			return;
 
 		uint32_t *dest = thread->dest_for_thread(yl, _pitch, _pitch * yl + _x + (uint32_t*)_destorg);
-
 		int pitch = _pitch * thread->num_cores;
+
 		int fuzzstep = thread->num_cores;
 		int fuzz = (_fuzzpos + thread->skipped_by_thread(yl)) % FUZZTABLE;
 
+#ifndef ORIGINAL_FUZZ
+
+		while (count > 0)
+		{
+			int available = (FUZZTABLE - fuzz);
+			int next_wrap = available / fuzzstep;
+			if (available % fuzzstep != 0)
+				next_wrap++;
+
+			int cnt = MIN(count, next_wrap);
+			count -= cnt;
+			do
+			{
+				int alpha = 32 - fuzzoffset[fuzz];
+
+				uint32_t bg = *dest;
+				uint32_t red = (RPART(bg) * alpha) >> 5;
+				uint32_t green = (GPART(bg) * alpha) >> 5;
+				uint32_t blue = (BPART(bg) * alpha) >> 5;
+
+				*dest = 0xff000000 | (red << 16) | (green << 8) | blue;
+				dest += pitch;
+				fuzz += fuzzstep;
+			} while (--cnt);
+
+			fuzz %= FUZZTABLE;
+		}
+
+#else
+
 		yl += thread->skipped_by_thread(yl);
 
 		// Handle the case where we would go out of bounds at the top:
@@ -331,6 +361,7 @@ namespace swrenderer
 
 			*dest = 0xff000000 | (red << 16) | (green << 8) | blue;
 		}
+#endif
 	}
 
 	FString DrawFuzzColumnRGBACommand::DebugInfo()