3D View: add Backface Culling option, to hide faces when seen from the back side,

found in the Display panel.

Patch by Simon Kirk and Irie Shinsuke, refactored to also work for non-mesh objects
and avoid globals.

1 files changed, 23 insertions, 1 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 780f4a2d86a..a5f3df4257a 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -3610,7 +3610,13 @@ static int draw_mesh_object(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D
 		else if (ob->modifiers.first || obedit->modifiers.first) {}
 		else drawlinked = 1;
 	}
-	
+
+	/* backface culling */
+	if (v3d->flag2 & V3D_BACKFACE_CULLING) {
+		glEnable(GL_CULL_FACE);
+		glCullFace(GL_BACK);
+	}
+
 	if (ob == obedit || drawlinked) {
 		DerivedMesh *finalDM, *cageDM;
 		
@@ -3669,6 +3675,9 @@ static int draw_mesh_object(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D
 			}
 		}
 	}
+
+	if (v3d->flag2 & V3D_BACKFACE_CULLING)
+		glDisable(GL_CULL_FACE);
 	
 	return retval;
 }
@@ -3939,7 +3948,17 @@ static int drawDispList(Scene *scene, View3D *v3d, RegionView3D *rv3d, Base *bas
 	const short solid = (dt > OB_WIRE);
 	int retval = 0;
 
+	/* backface culling */
+	if(v3d->flag2 & V3D_BACKFACE_CULLING) {
+		/* not all displists use same in/out normal direction convention */
+		glEnable(GL_CULL_FACE);
+		glCullFace((ob->type == OB_MBALL) ? GL_BACK : GL_FRONT);
+	}
+
 	if (drawCurveDerivedMesh(scene, v3d, rv3d, base, dt) == 0) {
+		if (v3d->flag2 & V3D_BACKFACE_CULLING)
+			glDisable(GL_CULL_FACE);
+
 		return 0;
 	}
 
@@ -4045,6 +4064,9 @@ static int drawDispList(Scene *scene, View3D *v3d, RegionView3D *rv3d, Base *bas
 			break;
 	}
 	
+	if (v3d->flag2 & V3D_BACKFACE_CULLING)
+		glDisable(GL_CULL_FACE);
+
 	return retval;
 }