Sync shaders from vkdoom

src/lightmapper/glsl/trace_levelmesh.glsl.h

@@ -1,6 +1,6 @@
 static const char* trace_levelmesh_glsl = R"glsl(
 
-vec4 BeerLambertSimple(vec4 medium, vec4 ray_color);
+vec3 BeerLambertSimple(vec3 medium, float depth, vec3 ray_color);
 
 SurfaceInfo GetSurface(int primitiveIndex)
 {
@@ -16,7 +16,7 @@ vec2 GetSurfaceUV(int primitiveIndex, vec3 primitiveWeights)
 		vertices[elements[index + 0]].uv * primitiveWeights.z;
 }
 
-vec4 BlendTexture(SurfaceInfo surface, vec2 uv, vec4 rayColor)
+vec3 PassRayThroughSurface(SurfaceInfo surface, vec2 uv, vec3 rayColor)
 {
 	if (surface.TextureIndex == 0)
 	{
@@ -25,7 +25,16 @@ vec4 BlendTexture(SurfaceInfo surface, vec2 uv, vec4 rayColor)
 	else
 	{
 		vec4 color = texture(textures[surface.TextureIndex], uv);
-		return BeerLambertSimple(vec4(1.0 - color.rgb, color.a * surface.Alpha), rayColor);
+
+		// To do: currently we do not know the material/renderstyle of the surface.
+		//
+		// This means we can't apply translucency and we can't do something like BeerLambertSimple.
+		// In order to improve this SurfaceInfo needs additional info.
+		//
+		// return BeerLambertSimple(1.0 - color.rgb, color.a * surface.Alpha, rayColor);
+
+		// Assume the renderstyle is basic alpha blend for now.
+		return rayColor * (1.0 - color.a * surface.Alpha);
 	}
 }
 
@@ -36,11 +45,9 @@ void TransformRay(uint portalIndex, inout vec3 origin, inout vec3 dir)
 	dir = (transformationMatrix * vec4(dir, 0.0)).xyz;
 }
 
-vec4 BeerLambertSimple(vec4 medium, vec4 ray_color) // based on Beer-Lambert law
+vec3 BeerLambertSimple(vec3 medium, float depth, vec3 ray_color) // based on Beer-Lambert law
 {
-	float z = medium.w;
-	ray_color.rgb *= exp(-medium.rgb * vec3(z));
-	return ray_color;
+	return ray_color * exp(-medium * depth);
 }
 
 )glsl";

src/lightmapper/glsl/trace_light.glsl.h

@@ -2,7 +2,7 @@ static const char* trace_light_glsl = R"glsl(
 
 #include <shaders/lightmap/montecarlo.glsl>
 
-vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor);
+vec3 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec3 rayColor);
 
 vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, float extraDistance)
 {
@@ -26,7 +26,7 @@ vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, float extraDistance)
 		float attenuation = distAttenuation * angleAttenuation * spotAttenuation;
 		if (attenuation > 0.0)
 		{
-			vec4 rayColor = vec4(light.Color.rgb * (attenuation * light.Intensity), 1.0);
+			vec3 rayColor = light.Color.rgb * (attenuation * light.Intensity);
 
 #if defined(USE_SOFTSHADOWS)
 
@@ -41,11 +41,11 @@ vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, float extraDistance)
 				vec2 gridoffset = getVogelDiskSample(i, step_count, gl_FragCoord.x + gl_FragCoord.y * 13.37) * lightsize;
 				vec3 pos = light.Origin + xdir * gridoffset.x + ydir * gridoffset.y;
 
-				incoming.rgb += TracePointLightRay(origin, pos, minDistance, rayColor).rgb / float(step_count);
+				incoming += TracePointLightRay(origin, pos, minDistance, rayColor) / float(step_count);
 			}
 			
 #else
-			incoming.rgb += TracePointLightRay(origin, light.Origin, minDistance, rayColor).rgb;
+			incoming += TracePointLightRay(origin, light.Origin, minDistance, rayColor);
 #endif
 		}
 	}
@@ -53,7 +53,7 @@ vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, float extraDistance)
 	return incoming;
 }
 
-vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor)
+vec3 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec3 rayColor)
 {
 	vec3 dir = normalize(lightpos - origin);
 	float tmax = distance(origin, lightpos);
@@ -62,18 +62,18 @@ vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor)
 	{
 		TraceResult result = TraceFirstHit(origin, tmin, dir, tmax);
 
-		// We hit nothing. Point light is visible.
+		// Stop if we hit nothing - the point light is visible.
 		if (result.primitiveIndex == -1)
 			return rayColor;
 
 		SurfaceInfo surface = GetSurface(result.primitiveIndex);
 
-		// Blend with surface texture
-		rayColor = BlendTexture(surface, GetSurfaceUV(result.primitiveIndex, result.primitiveWeights), rayColor);
+		// Pass through surface texture
+		rayColor = PassRayThroughSurface(surface, GetSurfaceUV(result.primitiveIndex, result.primitiveWeights), rayColor);
 
 		// Stop if there is no light left
 		if (rayColor.r + rayColor.g + rayColor.b <= 0.0)
-			return vec4(0.0);
+			return vec3(0.0);
 
 		// Move to surface hit point
 		origin += dir * result.t;
@@ -82,7 +82,7 @@ vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor)
 		// Move through the portal, if any
 		TransformRay(surface.PortalIndex, origin, dir);
 	}
-	return vec4(0.0);
+	return vec3(0.0);
 }
 
 )glsl";

src/lightmapper/glsl/trace_sunlight.glsl.h

@@ -2,7 +2,7 @@ static const char* trace_sunlight_glsl = R"glsl(
 
 #include <shaders/lightmap/montecarlo.glsl>
 
-vec4 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec4 rayColor);
+vec3 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec3 rayColor);
 
 vec3 TraceSunLight(vec3 origin, vec3 normal)
 {
@@ -14,7 +14,7 @@ vec3 TraceSunLight(vec3 origin, vec3 normal)
 	vec3 incoming = vec3(0.0);
 	const float dist = 65536.0;
 
-	vec4 rayColor = vec4(SunColor.rgb * SunIntensity, 1.0);
+	vec3 rayColor = SunColor.rgb * SunIntensity;
 
 #if defined(USE_SOFTSHADOWS)
 
@@ -30,27 +30,27 @@ vec3 TraceSunLight(vec3 origin, vec3 normal)
 	{
 		vec2 gridoffset = getVogelDiskSample(i, step_count, gl_FragCoord.x + gl_FragCoord.y * 13.37) * lightsize;
 		vec3 pos = target + xdir * gridoffset.x + ydir * gridoffset.y;
-		incoming.rgb += TraceSunRay(origin, minDistance, normalize(pos - origin), dist, rayColor).rgb / float(step_count);
+		incoming += TraceSunRay(origin, minDistance, normalize(pos - origin), dist, rayColor) / float(step_count);
 	}
 			
 #else
 
-	incoming.rgb = TraceSunRay(origin, minDistance, SunDir, dist, rayColor).rgb;
+	incoming = TraceSunRay(origin, minDistance, SunDir, dist, rayColor);
 
 #endif
 
 	return incoming * angleAttenuation;
 }
 
-vec4 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec4 rayColor)
+vec3 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec3 rayColor)
 {
 	for (int i = 0; i < 3; i++)
 	{
 		TraceResult result = TraceFirstHit(origin, tmin, dir, tmax);
 
-		// We hit nothing. We have to hit a sky surface to hit the sky.
+		// Stop if we hit nothing. We have to hit a sky surface to hit the sky.
 		if (result.primitiveIndex == -1)
-			return vec4(0.0);
+			return vec3(0.0);
 
 		SurfaceInfo surface = GetSurface(result.primitiveIndex);
 
@@ -58,23 +58,23 @@ vec4 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec4 rayColor)
 		if (surface.Sky > 0.0)
 			return rayColor;
 
-		// Blend with surface texture
-		rayColor = BlendTexture(surface, GetSurfaceUV(result.primitiveIndex, result.primitiveWeights), rayColor);
+		// Pass through surface texture
+		rayColor = PassRayThroughSurface(surface, GetSurfaceUV(result.primitiveIndex, result.primitiveWeights), rayColor);
 
 		// Stop if there is no light left
 		if (rayColor.r + rayColor.g + rayColor.b <= 0.0)
-			return vec4(0.0);
+			return vec3(0.0);
 
 		// Move to surface hit point
 		origin += dir * result.t;
 		tmax -= result.t;
 		if (tmax <= tmin)
-			return vec4(0.0);
+			return vec3(0.0);
 
 		// Move through the portal, if any
 		TransformRay(surface.PortalIndex, origin, dir);
 	}
-	return vec4(0.0);
+	return vec3(0.0);
 }
 
 )glsl";