From f07007f8ad08d0edf3c14d9c27ab9132ec347e7f Mon Sep 17 00:00:00 2001
From: Kevin Shanahan <kmshanah@disenchant.net>
Date: Fri, 1 Mar 2013 11:49:46 +1030
Subject: [PATCH] light: setup spotlight paramters once at load time

We were calculating these values for every light and for every surface,
which seems a little excessive... Also made the variable names a bit more
sensible - we had stored a direction vector, not the actual mangle values.

Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
---
 include/light/entities.h | 14 ++++++++------
 light/entities.c         | 29 ++++++++++++++++++++++++++---
 light/ltface.c           | 26 +++-----------------------
 3 files changed, 37 insertions(+), 32 deletions(-)

diff --git a/include/light/entities.h b/include/light/entities.h
index 7009d609..69ad2626 100644
--- a/include/light/entities.h
+++ b/include/light/entities.h
@@ -51,16 +51,18 @@ typedef enum {
 typedef struct entity_s {
     char classname[MAX_ENT_VALUE];
     vec3_t origin;
-    float angle;
 
-    light_formula_t formula;
+    qboolean spotlight;
+    vec3_t spotvec;
+    float spotangle;
+    float spotfalloff;
+
+    int style;
+    int light;
     float atten;
-    vec3_t mangle;
-    qboolean use_mangle;
+    light_formula_t formula;
     vec3_t lightcolor;
 
-    int light;
-    int style;
     char target[MAX_ENT_VALUE];
     char targetname[MAX_ENT_VALUE];
     struct epair_s *epairs;
diff --git a/light/entities.c b/light/entities.c
index 0c9ad511..66e21897 100644
--- a/light/entities.c
+++ b/light/entities.c
@@ -110,6 +110,28 @@ MatchTargets(void)
     }
 }
 
+static void
+SetupSpotlights(void)
+{
+    int i;
+    entity_t *entity;
+
+    for (i = 0, entity = entities; i < num_entities; i++, entity++) {
+	if (strncmp(entity->classname, "light", 5))
+	    continue;
+	if (entity->targetent) {
+	    VectorSubtract(entity->targetent->origin, entity->origin,
+			   entity->spotvec);
+	    VectorNormalize(entity->spotvec);
+	    entity->spotlight = true;
+	}
+	if (entity->spotlight) {
+	    vec_t angle = entity->spotangle ? entity->spotangle : 40;
+	    entity->spotfalloff = -cos(angle / 2 * Q_PI / 180);
+	}
+    }
+}
+
 /* helper function */
 static void
 scan_vec3(vec3_t dest, const char *buf, const char *name)
@@ -249,15 +271,15 @@ LoadEntities(void)
 		    Error("Bad light style %i (must be 0-254)",
 			  entity->style);
 	    } else if (!strcmp(key, "angle"))
-		entity->angle = atof(com_token);
+		entity->spotangle = atof(com_token);
 	    else if (!strcmp(key, "wait"))
 		entity->atten = atof(com_token);
 	    else if (!strcmp(key, "delay"))
 		entity->formula = atoi(com_token);
 	    else if (!strcmp(key, "mangle")) {
 		scan_vec3(vec, com_token, "mangle");
-		vec_from_mangle(entity->mangle, vec);
-		entity->use_mangle = true;
+		vec_from_mangle(entity->spotvec, vec);
+		entity->spotlight = true;
 	    } else if (!strcmp(key, "_color") || !strcmp(key, "color"))
 		scan_vec3(entity->lightcolor, com_token, "color");
 	    else if (!strcmp(key, "_sunlight"))
@@ -311,6 +333,7 @@ LoadEntities(void)
 
     logprint("%d entities read, %d are lights.\n", num_entities, num_lights);
     MatchTargets();
+    SetupSpotlights();
 }
 
 const char *
diff --git a/light/ltface.c b/light/ltface.c
index 4f55fdee..1ac58276 100644
--- a/light/ltface.c
+++ b/light/ltface.c
@@ -517,8 +517,6 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
     int mapnum;
     int c;
     vec3_t rel;
-    vec3_t spotvec;
-    vec_t falloff;
     vec_t *lightsamp;
     vec3_t *colorsamp;
     vec_t newlightmap[SINGLEMAP];
@@ -538,23 +536,6 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
 	return;
     }
 
-    if (light->targetent) {
-	VectorSubtract(light->targetent->origin, light->origin, spotvec);
-	VectorNormalize(spotvec);
-	if (!light->angle)
-	    falloff = -cos(20 * Q_PI / 180);
-	else
-	    falloff = -cos(light->angle / 2 * Q_PI / 180);
-    } else if (light->use_mangle) {
-	VectorCopy(light->mangle, spotvec);
-	if (!light->angle)
-	    falloff = -cos(20 * Q_PI / 180);
-	else
-	    falloff = -cos(light->angle / 2 * Q_PI / 180);
-    } else {
-	falloff = 0;		/* shut up compiler warnings */
-    }
-
     /*
      * Find the lightmap with matching style
      */
@@ -590,11 +571,10 @@ SingleLightFace(const entity_t *light, lightinfo_t * l,
 	VectorSubtract(light->origin, surf, incoming);
 	VectorNormalize(incoming);
 	angle = DotProduct(incoming, l->facenormal);
-	if (light->targetent || light->use_mangle) {
+	if (light->spotlight &&
+	    DotProduct(light->spotvec, incoming) > light->spotfalloff)
 	    /* spotlight cutoff */
-	    if (DotProduct(spotvec, incoming) > falloff)
-		continue;
-	}
+	    continue;
 
 	angle = (1.0 - scalecos) + scalecos * angle;
 	add = scaledLight(CastRay(light->origin, surf), light);