display the number of tri's in object mode status, often requested feature from users who model for realtime/game-engine output,

the total number of faces wasn't so useful and could be especially misleading with ngons.

source/blender/blenkernel/BKE_displist.h

@@ -83,7 +83,7 @@ void BKE_displist_elem_free(DispList *dl);
 DispList *BKE_displist_find_or_create(struct ListBase *lb, int type);
 DispList *BKE_displist_find(struct ListBase *lb, int type);
 void BKE_displist_normals_add(struct ListBase *lb);
-void BKE_displist_count(struct ListBase *lb, int *totvert, int *totface);
+void BKE_displist_count(struct ListBase *lb, int *totvert, int *totface, int *tottri);
 void BKE_displist_free(struct ListBase *lb);
 int BKE_displist_has_faces(struct ListBase *lb);
 

source/blender/blenkernel/intern/displist.c

@@ -225,29 +225,48 @@ void BKE_displist_normals_add(ListBase *lb)
 	}
 }
 
-void BKE_displist_count(ListBase *lb, int *totvert, int *totface)
+void BKE_displist_count(ListBase *lb, int *totvert, int *totface, int *tottri)
 {
 	DispList *dl;
 
-	dl = lb->first;
-	while (dl) {
+	for (dl = lb->first; dl; dl = dl->next) {
+		int vert_tot = 0;
+		int face_tot = 0;
+		int tri_tot = 0;
+
 		switch (dl->type) {
 			case DL_SURF:
-				*totvert += dl->nr * dl->parts;
-				*totface += (dl->nr - 1) * (dl->parts - 1);
+			{
+				vert_tot = dl->nr * dl->parts;
+				face_tot = (dl->nr - 1) * (dl->parts - 1);
+				tri_tot  = face_tot * 2;
 				break;
+			}
 			case DL_INDEX3:
-			case DL_INDEX4:
-				*totvert += dl->nr;
-				*totface += dl->parts;
+			{
+				vert_tot = dl->nr;
+				face_tot = dl->parts;
+				tri_tot  = face_tot;
 				break;
+			}
+			case DL_INDEX4:
+			{
+				vert_tot = dl->nr;
+				face_tot = dl->parts;
+				tri_tot  = face_tot * 2;
+				break;
+			}
 			case DL_POLY:
 			case DL_SEGM:
-				*totvert += dl->nr * dl->parts;
+			{
+				vert_tot = dl->nr * dl->parts;
 				break;
+			}
 		}
 
-		dl = dl->next;
+		*totvert += vert_tot;
+		*totface += face_tot;
+		*tottri  += tri_tot;
 	}
 }
 

source/blender/blenlib/BLI_math_geom.h

@@ -262,6 +262,8 @@ void axis_dominant_v3(int *axis_a, int *axis_b, const float axis[3]);
 MINLINE int max_axis_v3(const float vec[3]);
 MINLINE int min_axis_v3(const float vec[3]);
 
+MINLINE int poly_to_tri_count(const int poly_count, const int corner_count);
+
 #ifdef __cplusplus
 }
 #endif

source/blender/blenlib/intern/math_geom_inline.c

@@ -158,4 +158,24 @@ MINLINE int min_axis_v3(const float vec[3])
 	       ((y < z) ? 1 : 2));
 }
 
+/**
+ * Simple method to find how many tri's we need when we already know the corner+poly count.
+ *
+ * Formula is:
+ *
+ *   tri = ((corner_count / poly_count) - 2) * poly_count;
+ *
+ * Use doubles since this is used for allocating and we
+ * don't want float precision to give incorrect results.
+ *
+ * \param poly_count The number of ngon's/tris (1-2 sided faces will give incorrect results)
+ * \param corner_count - also known as loops in BMesh/DNA
+ */
+MINLINE int poly_to_tri_count(const int poly_count, const int corner_count)
+{
+	const double poly_count_d   = (double)poly_count;
+	const double corner_count_d = (double)corner_count;
+	return (int)((((corner_count_d / poly_count_d) - 2.0) * poly_count_d) + 0.5);
+}
+
 #endif /* __MATH_GEOM_INLINE_C__ */

source/blender/editors/space_info/info_stats.c

@@ -39,6 +39,7 @@
 #include "DNA_scene_types.h"
 
 #include "BLI_utildefines.h"
+#include "BLI_math.h"
 
 #include "BKE_anim.h"
 #include "BKE_blender.h"
@@ -62,7 +63,7 @@ typedef struct SceneStats {
 	int totbone, totbonesel;
 	int totobj,  totobjsel;
 	int totlamp, totlampsel; 
-	int tottri, totmesh, totcurve;
+	int tottri, totmesh;
 
 	char infostr[512];
 } SceneStats;
@@ -74,7 +75,7 @@ static void stats_object(Object *ob, int sel, int totob, SceneStats *stats)
 		{
 			/* we assume derivedmesh is already built, this strictly does stats now. */
 			DerivedMesh *dm = ob->derivedFinal;
-			int totvert, totedge, totface;
+			int totvert, totedge, totface, totloop;
 
 			stats->totmesh += totob;
 
@@ -82,10 +83,12 @@ static void stats_object(Object *ob, int sel, int totob, SceneStats *stats)
 				totvert = dm->getNumVerts(dm);
 				totedge = dm->getNumEdges(dm);
 				totface = dm->getNumPolys(dm);
+				totloop = dm->getNumLoops(dm);
 
 				stats->totvert += totvert * totob;
 				stats->totedge += totedge * totob;
 				stats->totface += totface * totob;
+				stats->tottri  += poly_to_tri_count(totface, totloop) * totob;
 
 				if (sel) {
 					stats->totvertsel += totvert;
@@ -103,40 +106,23 @@ static void stats_object(Object *ob, int sel, int totob, SceneStats *stats)
 		case OB_SURF:
 		case OB_CURVE:
 		case OB_FONT:
-		{
-			int tot = 0, totf = 0;
-
-			stats->totcurve += totob;
-
-			if (ob->disp.first)
-				BKE_displist_count(&ob->disp, &tot, &totf);
-
-			tot *= totob;
-			totf *= totob;
-
-			stats->totvert += tot;
-			stats->totface += totf;
-
-			if (sel) {
-				stats->totvertsel += tot;
-				stats->totfacesel += totf;
-			}
-			break;
-		}
 		case OB_MBALL:
 		{
-			int tot = 0, totf = 0;
+			int totv = 0, totf = 0, tottri = 0;
 
-			BKE_displist_count(&ob->disp, &tot, &totf);
+			if (ob->disp.first)
+				BKE_displist_count(&ob->disp, &totv, &totf, &tottri);
 
-			tot *= totob;
-			totf *= totob;
+			totv   *= totob;
+			totf   *= totob;
+			tottri *= totob;
 
-			stats->totvert += tot;
+			stats->totvert += totv;
 			stats->totface += totf;
+			stats->tottri  += tottri;
 
 			if (sel) {
-				stats->totvertsel += tot;
+				stats->totvertsel += totv;
 				stats->totfacesel += totf;
 			}
 			break;
@@ -389,8 +375,8 @@ static void stats_string(Scene *scene)
 		             stats->totbonesel, stats->totbone, memstr);
 	}
 	else {
-		s += sprintf(s, "Verts:%d | Faces:%d | Objects:%d/%d | Lamps:%d/%d%s",
-		             stats->totvert, stats->totface, stats->totobjsel, stats->totobj, stats->totlampsel, stats->totlamp, memstr);
+		s += sprintf(s, "Verts:%d | Faces:%d| Tris:%d | Objects:%d/%d | Lamps:%d/%d%s",
+		             stats->totvert, stats->totface, stats->tottri, stats->totobjsel, stats->totobj, stats->totlampsel, stats->totlamp, memstr);
 	}
 
 	if (ob)