Changed spotlight emission profile texture from 'cosine of angle' ind…

…exing to just 'angle'.

For better angular resolution next to the center of the beam.

inc/refresh/refresh.h

@@ -122,16 +122,18 @@ typedef struct dlight_s {
         dlight_spot_emission_profile emission_profile;
         // Spotlight direction
         vec3_t  direction;
-        // Cosine of angle of spotlight cone width (no emission beyond that)
-        float   cos_total_width;
         union {
             // Options for DLIGHT_SPOT_EMISSION_PROFILE_FALLOFF
             struct {
+                // Cosine of angle of spotlight cone width (no emission beyond that)
+                float   cos_total_width;
                 // Cosine of angle of start of falloff (full emission below that)
                 float   cos_falloff_start;
             };
             // Options for DLIGHT_SPOT_EMISSION_PROFILE_AXIS_ANGLE_TEXTURE
             struct {
+                // Angle of spotlight cone width (no emission beyond that), in radians
+                float   total_width;
                 // Emission profile texture, indexed by 'angle / total_width'
                 qhandle_t texture;
             };

scripts/ies_to_texture.py

@@ -123,8 +123,7 @@ def get_floats(num):
 angle_function = scipy.interpolate.interp1d(ies_file.vert_angles, ies_file.light_values[0], kind='cubic')
 output_values = numpy.zeros(res)
 for x in range(0, res):
-    cos_angle = x / (res - 1)
-    angle = math.degrees(math.acos(cos_angle))
+    angle = (x / (res - 1)) * 90
     if angle <= max_angle:
         interp = angle_function(angle)
     else:

src/client/view.c

@@ -189,7 +189,7 @@ void V_AddSpotLightTexEmission(vec3_t org, vec3_t dir, float intensity, float r,
         return;
 
     dl->spot.emission_profile = DLIGHT_SPOT_EMISSION_PROFILE_AXIS_ANGLE_TEXTURE;
-    dl->spot.cos_total_width = cosf(DEG2RAD(width_angle));
+    dl->spot.total_width = DEG2RAD(width_angle);
     dl->spot.texture = emission_tex;
 }
 

src/refresh/vkpt/main.c

@@ -1666,7 +1666,7 @@ static void add_dlight_spot(const dlight_t* light, DynLightData* dynlight_data)
 		break;
 	case DLIGHT_SPOT_EMISSION_PROFILE_AXIS_ANGLE_TEXTURE:
 		dynlight_data->type |= DYNLIGHT_SPOT_EMISSION_PROFILE_AXIS_ANGLE_TEXTURE << 16;
-		dynlight_data->spot_data = floatToHalf(light->spot.cos_total_width) | (light->spot.texture << 16);
+		dynlight_data->spot_data = floatToHalf(light->spot.total_width) | (light->spot.texture << 16);
 		break;
 	}
 }

src/refresh/vkpt/shader/light_lists.h

@@ -348,11 +348,13 @@ compute_dynlight_spot(uint light_idx, uint spot_style, vec3 light_center, vec3 p
 		}
 	} else if(spot_style == DYNLIGHT_SPOT_EMISSION_PROFILE_AXIS_ANGLE_TEXTURE) {
 		const uint spot_data = global_ubo.dyn_light_data[light_idx].spot_data;
-		const float cosTotalWidth = unpackHalf2x16(spot_data).x;
+		const float theta = acos(cosTheta);
+		const float totalWidth = unpackHalf2x16(spot_data).x;
 		const uint texture_num = spot_data >> 16;
 
 		if (cosTheta >= 0) {
-			float tc = clamp((cosTheta - cosTotalWidth) / (1 - cosTotalWidth), 0, 1);
+			// Use the angle directly as texture coordinate for better angular resolution next to the center of the beam
+			float tc = clamp(theta / totalWidth, 0, 1);
 			falloff = global_texture(texture_num, vec2(tc, 0)).r;
 		} else
 			falloff = 0;