light: implement minlighting for bmodels

Collect the appropriate keys from the models at load time and pass them
into the minlighting function (if > world minlight).

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

changelog.txt

@@ -14,6 +14,7 @@
 * 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
+* light: implemented minlighting for brush models
 
 2013-02-25 TyrUtils v0.5
 

include/light/light.h

@@ -38,7 +38,13 @@ void LoadNodes(char *file);
 qboolean TestLine(const vec3_t start, const vec3_t stop);
 qboolean TestSky(const vec3_t start, const vec3_t dirn);
 
-void LightFace(int surfnum, const vec3_t faceoffset);
+typedef struct {
+    int minlight;
+    vec3_t mincolor;
+    vec3_t offset;
+} modelinfo_t;
+
+void LightFace(int surfnum, const modelinfo_t *modelinfo);
 void LightLeaf(dleaf_t * leaf);
 
 void MakeTnodes(void);

light.txt

@@ -82,6 +82,19 @@ ENTITY PARAMETERS
 	sunlight. RGB component values are between -255 and 255. Negative
 	values will cause colour subtraction from light cast by other entities.
 
+    MODEL PARAMETERS
+
+	The following parameters can be used on any entity with a brush model.
+
+	"_minlight" "n"
+
+	Set the minimum light level for any surface of the brush model.
+
+	"_mincolor" "r g b"
+
+	Specify red(r), green(g) and blue(b) components for the colour of the
+	minlight. RGB component values are between 0 and 255.
+
     LIGHT PARAMETERS
 
 	Light parameters can be used in any entity with a classname starting

light/light.c

@@ -39,7 +39,7 @@ byte *lit_filebase;		// start of litfile data
 static byte *lit_file_p;	// start of free space after litfile data
 static byte *lit_file_end;	// end of space for litfile data
 
-static vec3_t *modeloffset;
+static modelinfo_t *modelinfo;
 
 int oversample = 1;
 qboolean compress_ents;
@@ -94,21 +94,21 @@ LightThread(void *junk)
 	if (i == nummodels)
 	    Error("%s: no model has face %d", __func__, facenum);
 
-	LightFace(facenum, modeloffset[i]);
+	LightFace(facenum, &modelinfo[i]);
     }
 
     return NULL;
 }
 
 static void
-FindModelOffsets(void)
+FindModelInfo(void)
 {
     int i;
     entity_t *entity;
     char modelname[20];
-    const char *classname;
+    const char *attribute;
 
-    memset(modeloffset, 0, sizeof(*modeloffset) * nummodels);
+    memset(modelinfo, 0, sizeof(*modelinfo) * nummodels);
     for (i = 1; i < nummodels; i++) {
 	snprintf(modelname, sizeof(modelname), "*%d", i);
 	entity = FindEntityWithKeyPair("model", modelname);
@@ -116,9 +116,25 @@ FindModelOffsets(void)
 	    Error("%s: Couldn't find entity for model %s.\n", __func__,
 		  modelname);
 
-	classname = ValueForKey(entity, "classname");
-	if (!strncmp(classname, "rotate_", 7))
-	    GetVectorForKey(entity, "origin", modeloffset[i]);
+	/* Set up the offset for rotate_* entities */
+	attribute = ValueForKey(entity, "classname");
+	if (!strncmp(attribute, "rotate_", 7))
+	    GetVectorForKey(entity, "origin", modelinfo[i].offset);
+
+	/* Grab the bmodel minlight values, if any */
+	attribute = ValueForKey(entity, "_minlight");
+	if (attribute[0])
+	    modelinfo[i].minlight = atoi(attribute);
+	GetVectorForKey(entity, "_mincolor", modelinfo[i].mincolor);
+	if (!VectorCompare(modelinfo[i].mincolor, vec3_origin)) {
+	    if (!colored) {
+		colored = true;
+		logprint("Colored light entities detected: "
+			 ".lit output enabled.\n");
+	    }
+	} else {
+	    VectorCopy(vec3_white, modelinfo[i].mincolor);
+	}
     }
 }
 
@@ -239,10 +255,10 @@ main(int argc, const char **argv)
 
     LoadEntities();
     MakeTnodes();
-    modeloffset = malloc(nummodels * sizeof(*modeloffset));
-    FindModelOffsets();
+    modelinfo = malloc(nummodels * sizeof(*modelinfo));
+    FindModelInfo();
     LightWorld();
-    free(modeloffset);
+    free(modelinfo);
 
     WriteEntitiesToString();
     WriteBSPFile(source, bsp_version);

light/ltface.c

@@ -825,7 +825,7 @@ NegativeColors(int light, vec3_t dest, const vec3_t src)
  * ============
  */
 void
-LightFace(int surfnum, const vec3_t faceoffset)
+LightFace(int surfnum, const modelinfo_t *modelinfo)
 {
     const entity_t *entity;
     dface_t *face;
@@ -864,7 +864,7 @@ LightFace(int surfnum, const vec3_t faceoffset)
     VectorCopy(dplanes[face->planenum].normal, l.facenormal);
     l.facedist = dplanes[face->planenum].dist;
     VectorScale(l.facenormal, l.facedist, point);
-    VectorAdd(point, faceoffset, point);
+    VectorAdd(point, modelinfo->offset, point);
     l.facedist = DotProduct(point, l.facenormal);
 
     if (face->side) {
@@ -873,7 +873,7 @@ LightFace(int surfnum, const vec3_t faceoffset)
     }
 
     CalcFaceVectors(&l);
-    CalcFaceExtents(&l, faceoffset);
+    CalcFaceExtents(&l, modelinfo->offset);
     CalcPoints(&l);
 
     lightmapwidth = l.texsize[0] + 1;
@@ -935,8 +935,11 @@ LightFace(int surfnum, const vec3_t faceoffset)
 	    SkyLightFace(&l, sunlight_color);
     }
 
-    /* Minimum lighting */
-    FixMinlight(&l, worldminlight, minlight_color);
+    /* Minimum lighting - Use the greater of global or model minlight. */
+    if (modelinfo->minlight > worldminlight)
+	FixMinlight(&l, modelinfo->minlight, modelinfo->mincolor);
+    else
+	FixMinlight(&l, worldminlight, minlight_color);
 
     if (nominlimit) {
 	/* cast only negative lights */