- enabled the linear shadowmap filter.

Although this doesn't look as good as the PCF version it is a lot less calculation intensive and therefore more suitable for weaker hardware.
It also tends to bleed through walls a lot less.

src/gl/shaders/gl_shader.cpp

@@ -68,6 +68,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 			int uViewHeight;		// Software fuzz scaling
 			float uClipHeight;
 			float uClipHeightDirection;
+			int uShadowmapFilter;
 		};
 	)";
 	

src/hwrenderer/scene/hw_drawinfo.cpp

@@ -280,5 +280,6 @@ void HWViewpointUniforms::SetDefaults()
 	mGlobVis = (float)R_GetGlobVis(r_viewwindow, r_visibility) / 32.f;
 	mPalLightLevels = static_cast<int>(gl_bandedswlight) | (static_cast<int>(gl_fogmode) << 8);
 	mClipLine.X = -10000000.0f;
+	mShadowmapFilter = gl_shadowmap_filter;
 
 }

src/hwrenderer/scene/hw_viewpointuniforms.h

@@ -16,6 +16,7 @@ struct HWViewpointUniforms
 	int mViewHeight = 0;
 	float mClipHeight = 0.f;
 	float mClipHeightDirection = 0.f;
+	int mShadowmapFilter = 1;
 
 	void CalcDependencies()
 	{

src/hwrenderer/utility/hw_cvars.cpp

@@ -132,3 +132,5 @@ CUSTOM_CVAR(Int, gl_fuzztype, 0, CVAR_ARCHIVE)
 {
 	if (self < 0 || self > 8) self = 0;
 }
+
+CVAR(Bool, gl_shadowmap_filter, 1, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)

src/hwrenderer/utility/hw_cvars.h

@@ -69,3 +69,5 @@ EXTERN_CVAR(Bool, gl_billboard_faces_camera)
 EXTERN_CVAR(Bool, gl_billboard_particles)
 EXTERN_CVAR(Int, gl_enhanced_nv_stealth)
 EXTERN_CVAR(Int, gl_fuzztype)
+
+EXTERN_CVAR(Bool, gl_shadowmap_filter)

wadsrc/static/shaders/glsl/main.fp

@@ -218,9 +218,6 @@ float sampleShadowmapLinear(vec2 dir, float v)
 #define PCF_FILTER_STEP_COUNT 3
 #define PCF_COUNT (PCF_FILTER_STEP_COUNT * 2 + 1)
 
-// #define USE_LINEAR_SHADOW_FILTER
-#define USE_PCF_SHADOW_FILTER 1
-
 float shadowmapAttenuation(vec4 lightpos, float shadowIndex)
 {
 	if (shadowIndex >= 1024.0)
@@ -235,23 +232,27 @@ float shadowmapAttenuation(vec4 lightpos, float shadowIndex)
 
 	vec2 dir = ray / length;
 
-#if defined(USE_LINEAR_SHADOW_FILTER)
-	ray -= dir * 6.0; // Shadow acne margin
-	return sampleShadowmapLinear(ray, v);
-#elif defined(USE_PCF_SHADOW_FILTER)
-	ray -= dir * 2.0; // Shadow acne margin
-	dir = dir * min(length / 50.0, 1.0); // avoid sampling behind light
-
-	vec2 normal = vec2(-dir.y, dir.x);
-	vec2 bias = dir * 10.0;
-
-	float sum = 0.0;
-	for (float x = -PCF_FILTER_STEP_COUNT; x <= PCF_FILTER_STEP_COUNT; x++)
+	if (uShadowmapFilter == 0)
 	{
-		sum += sampleShadowmap(ray + normal * x - bias * abs(x), v);
+		ray -= dir * 2.0; // Shadow acne margin
+		return sampleShadowmapLinear(ray, v);
 	}
-	return sum / PCF_COUNT;
-#else // nearest shadow filter
+	else
+	{
+		ray -= dir * 2.0; // Shadow acne margin
+		dir = dir * min(length / 50.0, 1.0); // avoid sampling behind light
+
+		vec2 normal = vec2(-dir.y, dir.x);
+		vec2 bias = dir * 10.0;
+
+		float sum = 0.0;
+		for (float x = -PCF_FILTER_STEP_COUNT; x <= PCF_FILTER_STEP_COUNT; x++)
+		{
+			sum += sampleShadowmap(ray + normal * x - bias * abs(x), v);
+		}
+		return sum / PCF_COUNT;
+	}
+#if 0 // nearest shadow filter (not used)
 	ray -= dir * 6.0; // Shadow acne margin
 	return sampleShadowmap(ray, v);
 #endif