light: implement the _softangle key for spotlights

Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>

changelog.txt

@@ -9,6 +9,7 @@
 * light: lit files now automatically generated when coloured lights detected
 * light: implemented 4x4 oversampling with -extra4 command line
 * light: implemented the -gate option to help speed processing (default 0.001)
+* light: implemented the "_softangle" key for spotlights
 
 2013-02-25 TyrUtils v0.5
 

include/light/entities.h

@@ -56,6 +56,8 @@ typedef struct entity_s {
     vec3_t spotvec;
     float spotangle;
     float spotfalloff;
+    float spotangle2;
+    float spotfalloff2;
 
     int style;
     int light;

light.txt

@@ -135,6 +135,13 @@ ENTITY PARAMETERS
 
 	Specifies the angle in degrees for a spotlight cone. Default 40.
 
+	"_softangle" "n"
+
+	Specifies the angle in degrees for an inner spotlight cone (must be
+	less than the "angle" cone. Creates a softer transition between the
+	full brightness of the inner cone to the edge of the outer cone.
+	Default 0 (disabled).
+
 	"targetname" "name"
 
 	Turns the light into a switchable light, toggled by another entity

light/entities.c

@@ -126,8 +126,15 @@ SetupSpotlights(void)
 	    entity->spotlight = true;
 	}
 	if (entity->spotlight) {
-	    vec_t angle = entity->spotangle ? entity->spotangle : 40;
+	    vec_t angle, angle2;
+
+	    angle = (entity->spotangle > 0) ? entity->spotangle : 40;
 	    entity->spotfalloff = -cos(angle / 2 * Q_PI / 180);
+
+	    angle2 = entity->spotangle2;
+	    if (angle2 <= 0 || angle2 > angle)
+		angle2 = angle;
+	    entity->spotfalloff2 = -cos(angle2 / 2 * Q_PI / 180);
 	}
     }
 }
@@ -302,11 +309,12 @@ LoadEntities(void)
 		entity->light = atof(com_token);
 	    else if (!strcmp(key, "style")) {
 		entity->style = atof(com_token);
-		if ((unsigned)entity->style > 254)
-		    Error("Bad light style %i (must be 0-254)",
-			  entity->style);
+		if (entity->style < 0 || entity->style > 254)
+		    Error("Bad light style %i (must be 0-254)", entity->style);
 	    } else if (!strcmp(key, "angle"))
 		entity->spotangle = atof(com_token);
+	    else if (!strcmp(key, "_softangle"))
+		entity->spotangle2 = atof(com_token);
 	    else if (!strcmp(key, "wait"))
 		entity->atten = atof(com_token);
 	    else if (!strcmp(key, "delay"))

light/ltface.c

@@ -477,7 +477,7 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
 		const vec3_t faceoffset, const vec3_t colors)
 {
     vec_t dist;
-    vec_t angle;
+    vec_t angle, spotscale;
     vec_t add;
     const vec_t *surf;
     qboolean newmap, hit;
@@ -540,10 +540,17 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
 	/* Check spotlight cone */
 	VectorScale(ray, 1.0 / dist, ray);
 	angle = DotProduct(ray, l->facenormal);
+	spotscale = 1;
 	if (light->spotlight) {
 	    vec_t falloff = DotProduct(light->spotvec, ray);
 	    if (falloff > light->spotfalloff)
 		continue;
+	    if (falloff > light->spotfalloff2) {
+		/* Interpolate between the two spotlight falloffs */
+		spotscale = falloff - light->spotfalloff2;
+		spotscale /= light->spotfalloff - light->spotfalloff2;
+		spotscale = 1.0 - spotscale;
+	    }
 	}
 
 	/* Test for line of sight */
@@ -551,7 +558,7 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
 	    continue;
 
 	angle = (1.0 - scalecos) + scalecos * angle;
-	add = GetLightValue(light, dist) * angle;
+	add = GetLightValue(light, dist) * angle * spotscale;
 	lightsamp[c] += add;
 	if (colored)
 	    VectorMA(colorsamp[c], add / 255, colors, colorsamp[c]);