[GL] Fix skinned NiMesh rendering from 11f2980

POSITION_BP semantic was being ignored for the check that the mesh had vertices.  This was causing skinned meshes using POSITION_BP to no longer render.

src/data/niftypes.h

@@ -2052,15 +2052,19 @@ typedef enum
 
 typedef enum {
 	HAS_NONE = 0,
-	HAS_POSITION = 1 << E_POSITION,
-	HAS_NORMAL = 1 << E_NORMAL,
-	HAS_BINORMAL = 1 << E_BINORMAL,
-	HAS_TANGENT = 1 << E_TANGENT,
-	HAS_TEXCOORD = 1 << E_TEXCOORD,
-	HAS_BLENDWEIGHT = 1 << E_BLENDWEIGHT,
+	HAS_POSITION     = 1 << E_POSITION,
+	HAS_NORMAL       = 1 << E_NORMAL,
+	HAS_BINORMAL     = 1 << E_BINORMAL,
+	HAS_TANGENT      = 1 << E_TANGENT,
+	HAS_TEXCOORD     = 1 << E_TEXCOORD,
+	HAS_BLENDWEIGHT  = 1 << E_BLENDWEIGHT,
 	HAS_BLENDINDICES = 1 << E_BLENDINDICES,
-	HAS_COLOR = 1 << E_COLOR,
-	HAS_INDEX = 1 << E_INDEX
+	HAS_COLOR        = 1 << E_COLOR,
+	HAS_INDEX        = 1 << E_INDEX,
+	HAS_POSITION_BP  = 1 << E_POSITION_BP,
+	HAS_NORMAL_BP    = 1 << E_NORMAL_BP,
+	HAS_BINORMAL_BP  = 1 << E_BINORMAL_BP,
+	HAS_TANGENT_BP   = 1 << E_TANGENT_BP,
 } SemanticFlags;
 
 #define SEM(string) {#string, E_##string},

src/gl/glmesh.cpp

@@ -381,7 +381,7 @@ void Mesh::transform()
 			}
 
 			// This NiMesh does not have vertices, abort
-			if ( !(semFlags & NiMesh::HAS_POSITION) )
+			if ( !(semFlags & NiMesh::HAS_POSITION || semFlags & NiMesh::HAS_POSITION_BP) )
 				return;
 
 			// The number of triangle indices across the submeshes for this NiMesh