From eac98ac2263b2625f43614c3f3454b24907d3748 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Tue, 14 Feb 2017 06:37:06 +0100
Subject: [PATCH] Calculate sprite dynamic light contribution and pass it along
 to the sprite drawer

---
 src/swrenderer/things/r_sprite.cpp       | 50 ++++++++++++++++++++++++
 src/swrenderer/things/r_sprite.h         |  2 +
 src/swrenderer/viewport/r_spritedrawer.h |  5 +++
 3 files changed, 57 insertions(+)

diff --git a/src/swrenderer/things/r_sprite.cpp b/src/swrenderer/things/r_sprite.cpp
index 1da377c7df..652bfcef27 100644
--- a/src/swrenderer/things/r_sprite.cpp
+++ b/src/swrenderer/things/r_sprite.cpp
@@ -56,6 +56,7 @@
 #include "swrenderer/viewport/r_viewport.h"
 #include "swrenderer/r_memory.h"
 #include "swrenderer/r_renderthread.h"
+#include "gl/dynlights/gl_dynlight.h"
 
 EXTERN_CVAR(Bool, r_fullbrightignoresectorcolor)
 
@@ -225,6 +226,54 @@ namespace swrenderer
 
 		bool fullbright = !vis->foggy && ((renderflags & RF_FULLBRIGHT) || (thing->flags5 & MF5_BRIGHT));
 		bool fadeToBlack = (vis->RenderStyle.Flags & STYLEF_FadeToBlack) != 0;
+		
+		if (r_dynlights)
+		{
+			float lit_red = 0;
+			float lit_green = 0;
+			float lit_blue = 0;
+			auto node = vis->sector->lighthead;
+			while (node != nullptr)
+			{
+				ADynamicLight *light = node->lightsource;
+				if (light->visibletoplayer && !(light->flags2&MF2_DORMANT) && (!(light->flags4&MF4_DONTLIGHTSELF) || light->target != thing))
+				{
+					double lightX = light->X() - ViewPos.X;
+					double lightY = light->Y() - ViewPos.Y;
+					double lightZ = light->Z() - ViewPos.Z;
+
+					float lx = (float)(lightX * ViewSin - lightY * ViewCos) - pos.X;
+					float ly = (float)(lightX * ViewTanCos + lightY * ViewTanSin) - pos.Y;
+					float lz = (float)lightZ - pos.Z;
+					
+					bool is_point_light = (node->lightsource->flags4 & MF4_ATTENUATE) != 0;
+					float LdotL = lx * lx + ly * ly + lz * lz;
+					float NdotL = is_point_light ? -ly : 0.0f;
+					
+					float radius = node->lightsource->GetRadius();
+					if (radius * radius >= LdotL && NdotL > 0.0f)
+					{
+						uint32_t red = light->GetRed();
+						uint32_t green = light->GetGreen();
+						uint32_t blue = light->GetBlue();
+						float distance = sqrt(LdotL);
+						float attenuation = distance / radius * NdotL;
+						lit_red += red * attenuation;
+						lit_red += green * attenuation;
+						lit_red += blue * attenuation;
+					}
+				}
+				node = node->nextLight;
+			}
+			lit_red = MIN(lit_red, 255.0f);
+			lit_green = MIN(lit_green, 255.0f);
+			lit_blue = MIN(lit_blue, 255.0f);
+			vis->dynlightcolor = (((uint32_t)lit_red) << 16) | (((uint32_t)lit_green) << 8) | ((uint32_t)lit_blue);
+		}
+		else
+		{
+			vis->dynlightcolor = 0;
+		}
 
 		vis->Light.SetColormap(LightVisibility::Instance()->SpriteGlobVis() / MAX(tz, MINZ), spriteshade, basecolormap, fullbright, invertcolormap, fadeToBlack);
 
@@ -250,6 +299,7 @@ namespace swrenderer
 
 		SpriteDrawerArgs drawerargs;
 		drawerargs.SetLight(vis->Light.BaseColormap, 0, vis->Light.ColormapNum << FRACBITS);
+		drawerargs.SetDynamicLight(dynlightcolor);
 
 		FDynamicColormap *basecolormap = static_cast<FDynamicColormap*>(vis->Light.BaseColormap);
 
diff --git a/src/swrenderer/things/r_sprite.h b/src/swrenderer/things/r_sprite.h
index 776af54fa8..678c909090 100644
--- a/src/swrenderer/things/r_sprite.h
+++ b/src/swrenderer/things/r_sprite.h
@@ -32,5 +32,7 @@ namespace swrenderer
 
 		uint32_t Translation = 0;
 		uint32_t FillColor = 0;
+		
+		uint32_t dynlightcolor = 0;
 	};
 }
diff --git a/src/swrenderer/viewport/r_spritedrawer.h b/src/swrenderer/viewport/r_spritedrawer.h
index fc5053e6e0..bca4664aa1 100644
--- a/src/swrenderer/viewport/r_spritedrawer.h
+++ b/src/swrenderer/viewport/r_spritedrawer.h
@@ -21,6 +21,7 @@ namespace swrenderer
 		void SetDest(int x, int y);
 		void SetCount(int count) { dc_count = count; }
 		void SetSolidColor(int color) { dc_color = color; }
+		void SetDynamicLight(uint32_t color) { dynlightcolor = color; }
 
 		void DrawMaskedColumn(RenderThread *thread, int x, fixed_t iscale, FTexture *texture, fixed_t column, double spryscale, double sprtopscreen, bool sprflipvert, const short *mfloorclip, const short *mceilingclip, bool unmasked = false);
 		void FillColumn(RenderThread *thread);
@@ -50,6 +51,8 @@ namespace swrenderer
 		uint32_t *DestBlend() const { return dc_destblend; }
 		fixed_t SrcAlpha() const { return dc_srcalpha; }
 		fixed_t DestAlpha() const { return dc_destalpha; }
+		
+		uint32_t DynamicLight() const { return dynlightcolor; }
 
 	private:
 		bool SetBlendFunc(int op, fixed_t fglevel, fixed_t bglevel, int flags);
@@ -81,6 +84,8 @@ namespace swrenderer
 		int dc_color = 0;
 		uint32_t dc_srccolor = 0;
 		uint32_t dc_srccolor_bgra = 0;
+		
+		uint32_t dynlightcolor = 0;
 
 		typedef void(SWPixelFormatDrawers::*SpriteDrawerFunc)(const SpriteDrawerArgs &args);
 		SpriteDrawerFunc colfunc;