Add the optional LightOnly of FreeSpotLight

docs/opengl46-renderer.md

@@ -180,6 +180,9 @@ scales can also be changed in the **Light clusters** debug window.
   shines always). Their colour, power, cone and the optional `Radius:`/`SoftFalloff:`/`CastShadows:` are those of the light
   point (brightness `gfx.lights.freespot.intensity`, the self-illumination threshold doesn't matter), and they fade in the
   daylight as the cab lamp does. The dimming of the cab lamp applies only to the lamp under the top.
+- **`LightOnly: true`** (an optional entry of any `FreeSpotLight`, after `HotspotAngle:` with the others; in e3d the flag 0x8
+  after the radius) makes the light point only a light: it lights its surroundings, but its glowing point and its glare,
+  seen from afar, aren't drawn. For lights hidden in fittings, the backlight of a desk and the like.
 
 The lamps of models and compartments fade in from the light level at which scenery lamps switch on (`ls_Dark`) to full
 darkness; in daylight they are not gathered at all. The cab lamp and the lamps of scenery models nearest to the camera cast

model/Model3d.cpp

@@ -227,6 +227,7 @@ inline void readMatrix(cParser &parser, float4x4 &matrix)
 static constexpr std::uint32_t E3D_LIGHT_SHADESELF{0x1};
 static constexpr std::uint32_t E3D_LIGHT_NOSHADOWS{0x2};
 static constexpr std::uint32_t E3D_LIGHT_SOFTFALLOFF{0x4};
+static constexpr std::uint32_t E3D_LIGHT_LIGHTONLY{0x8};
 
 // a light point whose cone takes the whole sphere (FalloffAngle 360) is a point light: it shines and is seen all around
 static void point_light_cones(float &Falloff, float &Hotspot)
@@ -377,7 +378,7 @@ std::pair<int, int> TSubModel::Load(cParser &parser, bool dynamic)
 		    >> discard >> fCosHotspotAngle; // kąt liczony dla średnicy, a nie promienia
 		// opcjonalne parametry, każdy to nazwa i wartość, w dowolnej kolejności: natężenie światła w procentach (hotspotpower:),
 		// promień kuli świecącej (radius:), cienie od własnego modelu (shadeself:), rzucanie cieni (castshadows:), spadek natężenia
-		// jak przy soft falloff blendera (softfalloff:). trzeba pobrać do kolejki 2 tokeny; jeśli to nie żaden z nich, zostają w
+		// jak przy soft falloff blendera (softfalloff:), samo oświetlenie bez punktu i poświaty (lightonly:). trzeba pobrać do kolejki 2 tokeny; jeśli to nie żaden z nich, zostają w
 		// kolejce dla odczytu zasięgu widoczności, który przywraca autoclear
 		while (true)
 		{
@@ -421,6 +422,10 @@ std::pair<int, int> TSubModel::Load(cParser &parser, bool dynamic)
 			{
 				parser >> discard >> bSoftFalloff;
 			}
+			else if (key == "lightonly:")
+			{
+				parser >> discard >> bLightOnly;
+			}
 			else
 			{
 				parser.autoclear(false);
@@ -1976,7 +1981,7 @@ void TSubModel::serialize(std::ostream &s, std::vector<TSubModel *> &models, std
 	sn_utils::ls_float32(s, fHotspotPower);
 	// the optional parameters of light points. the zeros of the fill of older files are their defaults
 	sn_utils::ls_float32(s, fLightRadius);
-	sn_utils::ls_uint32(s, (bShadeSelf ? E3D_LIGHT_SHADESELF : 0u) | (bCastShadows ? 0u : E3D_LIGHT_NOSHADOWS) | (bSoftFalloff ? E3D_LIGHT_SOFTFALLOFF : 0u));
+	sn_utils::ls_uint32(s, (bShadeSelf ? E3D_LIGHT_SHADESELF : 0u) | (bCastShadows ? 0u : E3D_LIGHT_NOSHADOWS) | (bSoftFalloff ? E3D_LIGHT_SOFTFALLOFF : 0u) | (bLightOnly ? E3D_LIGHT_LIGHTONLY : 0u));
 
 	// fill empty space
 	size_t fill = end - s.tellp();
@@ -2164,6 +2169,7 @@ void TSubModel::deserialize(std::istream &s)
 	bShadeSelf = (lightflags & E3D_LIGHT_SHADESELF) != 0;
 	bCastShadows = (lightflags & E3D_LIGHT_NOSHADOWS) == 0;
 	bSoftFalloff = (lightflags & E3D_LIGHT_SOFTFALLOFF) != 0;
+	bLightOnly = (lightflags & E3D_LIGHT_LIGHTONLY) != 0;
 
 	// necessary rotations were already done during t3d->e3d conversion
 	m_rotation_init_done = true;

model/Model3d.h

@@ -132,6 +132,7 @@ public:
 	bool bShadeSelf { false }; // cienie światła rzuca także model, do którego ono należy (shadeself:)
 	bool bCastShadows { true }; // światło rzuca cienie (castshadows:)
 	bool bSoftFalloff { false }; // natężenie maleje jak 1 / (d^2 + r^2), jak przy soft falloff blendera, zamiast świecenia z powierzchni kuli (softfalloff:)
+	bool bLightOnly { false }; // tylko oświetlenie: bez świecącego punktu i poświaty, widocznych z daleka (lightonly:)
     float fCosViewAngle { 0.0f }; // cos kata pod jakim sie teraz patrzy
 
 	bool m_rotation_init_done = false;

rendering/common/scenewalk.cpp

@@ -3073,8 +3073,9 @@ void scene_walk::Render_Alpha(TSubModel *Submodel)
 				}
 			}
 		}
-		else if (Submodel->eType == TP_FREESPOTLIGHT)
+		else if ((Submodel->eType == TP_FREESPOTLIGHT) && (false == Submodel->bLightOnly))
 		{
+			// the point of the light and its glare; a light point marked lightonly: only lights its surroundings (gfx::local_lights)
 			// NOTE: we're forced here to redo view angle calculations etc, because this data isn't instanced but stored along with the single mesh
 			// TODO: separate instance data from reusable geometry
 			auto const &modelview = OpenGLMatrices.data(GL_MODELVIEW);