store shadow map index in the light actor instead of a separate TMap

This frees another file of a direct renderer dependency and generally also should be faster

src/g_shared/a_dynlight.h

@@ -229,5 +229,7 @@ public:
 	LightFlags lightflags;
 	DAngle SpotInnerAngle = 10.0;
 	DAngle SpotOuterAngle = 25.0;
+    
+    int mShadowmapIndex = 1024;
 
 };

src/gl/dynlights/gl_dynlight1.cpp

@@ -52,7 +52,6 @@
 CVAR (Bool, gl_lights_checkside, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
 CVAR (Bool, gl_light_sprites, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
 CVAR (Bool, gl_light_particles, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
-CVAR (Bool, gl_light_shadowmap, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
 
 CVAR(Int, gl_attenuate, -1, 0);	// This is mainly a debug option.
 
@@ -117,10 +116,10 @@ void gl_AddLightToList(int group, ADynamicLight * light, FDynLightData &ldata)
 		i = 1;
 	}
 
-	// Store attenuate flag in the sign bit of the float.
+	float shadowIndex = light->mShadowmapIndex + 1.0f;
-	float shadowIndex = GLRenderer->mShadowMap.ShadowMapIndex(light) + 1.0f;
 	bool attenuate;
 
+    // Store attenuate flag in the sign bit of the float.
 	if (gl_attenuate == -1) attenuate = !!(light->lightflags & LF_ATTENUATE);
 	else attenuate = !!gl_attenuate;
 

src/gl/dynlights/gl_shadowmap.cpp

@@ -42,12 +42,7 @@
 	the fragment shader (main.fp) needs to sample from row 20. That is, the V texture coordinate needs
 	to be 20.5/1024.
 
-	mLightToShadowmap is a hash map storing which line each ADynamicLight is assigned to. The public
+    The texel row for each light is split into four parts. One for each direction, like a cube texture,
-	ShadowMapIndex function allows the main rendering to find the index and upload that along with the
-	normal light data. From there, the main.fp shader can sample from the shadow map texture, which
-	is currently always bound to texture unit 16.
-
-	The texel row for each light is split into four parts. One for each direction, like a cube texture,
 	but then only in 2D where this reduces itself to a square. When main.fp samples from the shadow map
 	it first decides in which direction the fragment is (relative to the light), like cubemap sampling does
 	for 3D, but once again just for the 2D case.
@@ -97,6 +92,20 @@ CUSTOM_CVAR(Int, gl_shadowmap_quality, 512, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 	}
 }
 
+CUSTOM_CVAR (Bool, gl_light_shadowmap, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
+{
+    if (!self)
+    {
+        // Unset any residual shadow map indices in the light actors.
+        TThinkerIterator<ADynamicLight> it(STAT_DLIGHT);
+        while (auto light = it.Next())
+        {
+            light->mShadowmapIndex = 1024;
+        }
+    }
+}
+
+
 void FShadowMap::Update()
 {
 	UpdateCycles.Reset();
@@ -152,42 +161,32 @@ bool FShadowMap::IsEnabled() const
 	return gl_light_shadowmap && !!(gl.flags & RFL_SHADER_STORAGE_BUFFER);
 }
 
-int FShadowMap::ShadowMapIndex(ADynamicLight *light)
-{
-	if (IsEnabled())
-	{
-		auto val = mLightToShadowmap.CheckKey(light);
-		if (val != nullptr) return *val;
-	}
-	return 1024;
-}
-
 void FShadowMap::UploadLights()
 {
 	if (mLights.Size() != 1024 * 4) mLights.Resize(1024 * 4);
 	int lightindex = 0;
-	mLightToShadowmap.Clear(mLightToShadowmap.CountUsed() * 2); // To do: allow clearing a TMap while building up a reserve
 
 	// Todo: this should go through the blockmap in a spiral pattern around the player so that closer lights are preferred.
 	TThinkerIterator<ADynamicLight> it(STAT_DLIGHT);
 	while (auto light = it.Next())
 	{
 		LightsProcessed++;
-		if (light->shadowmapped)
+		if (light->shadowmapped && lightindex < 1024 * 4)
 		{
 			LightsShadowmapped++;
 
-			mLightToShadowmap[light] = lightindex >> 2;
+			light->mShadowmapIndex = lightindex >> 2;
 
 			mLights[lightindex] = light->X();
 			mLights[lightindex+1] = light->Y();
 			mLights[lightindex+2] = light->Z();
 			mLights[lightindex+3] = light->GetRadius();
 			lightindex += 4;
-
-			if (lightindex == 1024*4) // Only 1024 lights for now
-				break;
 		}
+        else
+        {
+            light->mShadowmapIndex = 1024;
+        }
 
 	}
 

src/gl/dynlights/gl_shadowmap.h

@@ -20,9 +20,6 @@ public:
 	// Update shadow map texture
 	void Update();
 
-	// Return the assigned shadow map index for a given light
-	int ShadowMapIndex(ADynamicLight *light);
-
 	// Test if a world position is in shadow relative to the specified light and returns false if it is
 	bool ShadowTest(ADynamicLight *light, const DVector3 &pos);
 
@@ -42,9 +39,6 @@ private:
 	// Working buffer for creating the list of lights. Stored here to avoid allocating memory each frame
 	TArray<float> mLights;
 
-	// The assigned shadow map index for each light
-	TMap<ADynamicLight*, int> mLightToShadowmap;
-
 	// OpenGL storage buffers for the AABB tree
 	int mNodesBuffer = 0;
 	int mLinesBuffer = 0;