/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software  Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2006 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Ben Batt <benbatt@gmail.com>
 *
 * ***** END GPL LICENSE BLOCK *****
 *
 * Implementation of CDDerivedMesh.
 *
 * BKE_cdderivedmesh.h contains the function prototypes for this file.
 *
 */

/** \file blender/blenkernel/intern/cdderivedmesh.c
 *  \ingroup bke
 */

#include "GL/glew.h"

#include "BKE_cdderivedmesh.h"
#include "BKE_global.h"
#include "BKE_mesh.h"
#include "BKE_paint.h"
#include "BKE_utildefines.h"
#include "BKE_tessmesh.h"

#include "BLI_scanfill.h"
#include "BLI_math.h"
#include "BLI_blenlib.h"
#include "BLI_edgehash.h"
#include "BLI_math.h"
#include "BLI_pbvh.h"
#include "BLI_array.h"
#include "BLI_smallhash.h"
#include "BLI_utildefines.h"

#include "BKE_cdderivedmesh.h"
#include "BKE_global.h"
#include "BKE_mesh.h"
#include "BKE_paint.h"


#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"
#include "DNA_curve_types.h" /* for Curve */

#include "MEM_guardedalloc.h"

#include "GPU_buffers.h"
#include "GPU_draw.h"
#include "GPU_extensions.h"
#include "GPU_material.h"

#include <string.h>
#include <limits.h>
#include <math.h>

typedef struct {
	DerivedMesh dm;

	/* these point to data in the DerivedMesh custom data layers,
	   they are only here for efficiency and convenience **/
	MVert *mvert;
	MEdge *medge;
	MFace *mface;
	MLoop *mloop;
	MPoly *mpoly;

	/* Cached */
	struct PBVH *pbvh;
	int pbvh_draw;

	/* Mesh connectivity */
	struct ListBase *fmap;
	struct IndexNode *fmap_mem;

	struct ListBase *pmap;
	struct IndexNode *pmap_mem;
} CDDerivedMesh;

/**************** DerivedMesh interface functions ****************/
static int cdDM_getNumVerts(DerivedMesh *dm)
{
	return dm->numVertData;
}

static int cdDM_getNumEdges(DerivedMesh *dm)
{
	return dm->numEdgeData;
}

static int cdDM_getNumTessFaces(DerivedMesh *dm)
{
	/* uncomment and add a breakpoint on the printf()
	 * to help debug tessfaces issues since BMESH merge. */
#if 0
	if (dm->numTessFaceData == 0 && dm->numPolyData != 0) {
		printf("%s: has no faces!, call DM_ensure_tessface() if you need them\n");
	}
#endif
	return dm->numTessFaceData;
}

static int cdDM_getNumLoops(DerivedMesh *dm)
{
	return dm->numLoopData;
}

static int cdDM_getNumPolys(DerivedMesh *dm)
{
	return dm->numPolyData;
}

static void cdDM_getVert(DerivedMesh *dm, int index, MVert *vert_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	*vert_r = cddm->mvert[index];
}

static void cdDM_getEdge(DerivedMesh *dm, int index, MEdge *edge_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	*edge_r = cddm->medge[index];
}

static void cdDM_getTessFace(DerivedMesh *dm, int index, MFace *face_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	*face_r = cddm->mface[index];
}

static void cdDM_copyVertArray(DerivedMesh *dm, MVert *vert_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(vert_r, cddm->mvert, sizeof(*vert_r) * dm->numVertData);
}

static void cdDM_copyEdgeArray(DerivedMesh *dm, MEdge *edge_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(edge_r, cddm->medge, sizeof(*edge_r) * dm->numEdgeData);
}

static void cdDM_copyTessFaceArray(DerivedMesh *dm, MFace *face_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(face_r, cddm->mface, sizeof(*face_r) * dm->numTessFaceData);
}

static void cdDM_copyLoopArray(DerivedMesh *dm, MLoop *loop_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(loop_r, cddm->mloop, sizeof(*loop_r) * dm->numLoopData);
}

static void cdDM_copyPolyArray(DerivedMesh *dm, MPoly *poly_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(poly_r, cddm->mpoly, sizeof(*poly_r) * dm->numPolyData);
}

static void cdDM_getMinMax(DerivedMesh *dm, float min_r[3], float max_r[3])
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	int i;

	if (dm->numVertData) {
		for (i=0; i<dm->numVertData; i++) {
			DO_MINMAX(cddm->mvert[i].co, min_r, max_r);
		}
	} else {
		min_r[0] = min_r[1] = min_r[2] = max_r[0] = max_r[1] = max_r[2] = 0.0;
	}
}

static void cdDM_getVertCo(DerivedMesh *dm, int index, float co_r[3])
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;

	copy_v3_v3(co_r, cddm->mvert[index].co);
}

static void cdDM_getVertCos(DerivedMesh *dm, float (*cos_r)[3])
{
	MVert *mv = CDDM_get_verts(dm);
	int i;

	for(i = 0; i < dm->numVertData; i++, mv++)
		copy_v3_v3(cos_r[i], mv->co);
}

static void cdDM_getVertNo(DerivedMesh *dm, int index, float no_r[3])
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	normal_short_to_float_v3(no_r, cddm->mvert[index].no);
}

static ListBase *cdDM_getPolyMap(Object *ob, DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;

	if(!cddm->pmap && ob->type == OB_MESH) {
		Mesh *me= ob->data;

		create_vert_poly_map(&cddm->pmap, &cddm->pmap_mem,
		                     me->mpoly, me->mloop,
		                     me->totvert, me->totpoly, me->totloop);
	}

	return cddm->pmap;
}

static int can_pbvh_draw(Object *ob, DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	Mesh *me= ob->data;
	int deformed= 0;

	/* active modifiers means extra deformation, which can't be handled correct
	   on bith of PBVH and sculpt "layer" levels, so use PBVH only for internal brush
	   stuff and show final DerivedMesh so user would see actual object shape */
	deformed|= ob->sculpt->modifiers_active;

	/* as in case with modifiers, we can't synchronize deformation made against
	   PBVH and non-locked keyblock, so also use PBVH only for brushes and
	   final DM to give final result to user */
	deformed|= ob->sculpt->kb && (ob->shapeflag&OB_SHAPE_LOCK) == 0;

	if(deformed)
		return 0;

	return cddm->mvert == me->mvert || ob->sculpt->kb;
}

static struct PBVH *cdDM_getPBVH(Object *ob, DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;

	if(!ob) {
		cddm->pbvh= NULL;
		return NULL;
	}

	if(!ob->sculpt)
		return NULL;
	if(ob->sculpt->pbvh) {
		cddm->pbvh= ob->sculpt->pbvh;
		cddm->pbvh_draw = can_pbvh_draw(ob, dm);
	}

	/* always build pbvh from original mesh, and only use it for drawing if
	   this derivedmesh is just original mesh. it's the multires subsurf dm
	   that this is actually for, to support a pbvh on a modified mesh */
	if(!cddm->pbvh && ob->type == OB_MESH) {
		SculptSession *ss= ob->sculpt;
		Mesh *me= ob->data;
		cddm->pbvh = BLI_pbvh_new();
		cddm->pbvh_draw = can_pbvh_draw(ob, dm);
		BLI_assert(!(me->mface == NULL && me->mpoly != NULL)); /* BMESH ONLY complain if mpoly is valid but not mface */
		BLI_pbvh_build_mesh(cddm->pbvh, me->mface, me->mvert,
		                    me->totface, me->totvert);

		if(ss->modifiers_active && ob->derivedDeform) {
			DerivedMesh *deformdm= ob->derivedDeform;
			float (*vertCos)[3];
			int totvert;

			totvert= deformdm->getNumVerts(deformdm);
			vertCos= MEM_callocN(3*totvert*sizeof(float), "cdDM_getPBVH vertCos");
			deformdm->getVertCos(deformdm, vertCos);
			BLI_pbvh_apply_vertCos(cddm->pbvh, vertCos);
			MEM_freeN(vertCos);
		}
	}

	return cddm->pbvh;
}

/* update vertex normals so that drawing smooth faces works during sculpt
   TODO: proper fix is to support the pbvh in all drawing modes */
static void cdDM_update_normals_from_pbvh(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	float (*face_nors)[3];

	if(!cddm->pbvh || !cddm->pbvh_draw || !dm->numTessFaceData)
		return;

	face_nors = CustomData_get_layer(&dm->faceData, CD_NORMAL);

	BLI_pbvh_update(cddm->pbvh, PBVH_UpdateNormals, face_nors);
}

static void cdDM_drawVerts(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	int i;

	if( GPU_buffer_legacy(dm) ) {
		glBegin(GL_POINTS);
		for(i = 0; i < dm->numVertData; i++, mv++)
			glVertex3fv(mv->co);
		glEnd();
	}
	else {	/* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		GPU_vertex_setup(dm);
		if( !GPU_buffer_legacy(dm) ) {
			if(dm->drawObject->tot_triangle_point)
				glDrawArrays(GL_POINTS,0, dm->drawObject->tot_triangle_point);
			else
				glDrawArrays(GL_POINTS,0, dm->drawObject->tot_loose_point);
		}
		GPU_buffer_unbind();
	}
}

static void cdDM_drawUVEdges(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MFace *mf = cddm->mface;
	MTFace *tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
	int i;

	if(mf) {
		if( GPU_buffer_legacy(dm) ) {
			glBegin(GL_LINES);
			for(i = 0; i < dm->numTessFaceData; i++, mf++, tf++) {
				if(!(mf->flag&ME_HIDE)) {
					glVertex2fv(tf->uv[0]);
					glVertex2fv(tf->uv[1]);

					glVertex2fv(tf->uv[1]);
					glVertex2fv(tf->uv[2]);

					if(!mf->v4) {
						glVertex2fv(tf->uv[2]);
						glVertex2fv(tf->uv[0]);
					} else {
						glVertex2fv(tf->uv[2]);
						glVertex2fv(tf->uv[3]);

						glVertex2fv(tf->uv[3]);
						glVertex2fv(tf->uv[0]);
					}
				}
			}
			glEnd();
		}
		else {
			int prevstart = 0;
			int prevdraw = 1;
			int draw = 1;
			int curpos = 0;

			GPU_uvedge_setup(dm);
			if( !GPU_buffer_legacy(dm) ) {
				for(i = 0; i < dm->numTessFaceData; i++, mf++) {
					if(!(mf->flag&ME_HIDE)) {
						draw = 1;
					} 
					else {
						draw = 0;
					}
					if( prevdraw != draw ) {
						if( prevdraw > 0 && (curpos-prevstart) > 0) {
							glDrawArrays(GL_LINES,prevstart,curpos-prevstart);
						}
						prevstart = curpos;
					}
					if( mf->v4 ) {
						curpos += 8;
					}
					else {
						curpos += 6;
					}
					prevdraw = draw;
				}
				if( prevdraw > 0 && (curpos-prevstart) > 0 ) {
					glDrawArrays(GL_LINES,prevstart,curpos-prevstart);
				}
			}
			GPU_buffer_unbind();
		}
	}
}

static void cdDM_drawEdges(DerivedMesh *dm, int drawLooseEdges, int drawAllEdges)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mvert = cddm->mvert;
	MEdge *medge = cddm->medge;
	int i;
	
	if( GPU_buffer_legacy(dm) ) {
		DEBUG_VBO( "Using legacy code. cdDM_drawEdges\n" );
		glBegin(GL_LINES);
		for(i = 0; i < dm->numEdgeData; i++, medge++) {
			if((drawAllEdges || (medge->flag&ME_EDGEDRAW))
			   && (drawLooseEdges || !(medge->flag&ME_LOOSEEDGE))) {
				glVertex3fv(mvert[medge->v1].co);
				glVertex3fv(mvert[medge->v2].co);
			}
		}
		glEnd();
	}
	else {	/* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		int prevstart = 0;
		int prevdraw = 1;
		int draw = 1;

		GPU_edge_setup(dm);
		if( !GPU_buffer_legacy(dm) ) {
			for(i = 0; i < dm->numEdgeData; i++, medge++) {
				if((drawAllEdges || (medge->flag&ME_EDGEDRAW))
				   && (drawLooseEdges || !(medge->flag&ME_LOOSEEDGE))) {
					draw = 1;
				} 
				else {
					draw = 0;
				}
				if( prevdraw != draw ) {
					if( prevdraw > 0 && (i-prevstart) > 0 ) {
						GPU_buffer_draw_elements( dm->drawObject->edges, GL_LINES, prevstart*2, (i-prevstart)*2  );
					}
					prevstart = i;
				}
				prevdraw = draw;
			}
			if( prevdraw > 0 && (i-prevstart) > 0 ) {
				GPU_buffer_draw_elements( dm->drawObject->edges, GL_LINES, prevstart*2, (i-prevstart)*2  );
			}
		}
		GPU_buffer_unbind();
	}
}

static void cdDM_drawLooseEdges(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mvert = cddm->mvert;
	MEdge *medge = cddm->medge;
	int i;

	if( GPU_buffer_legacy(dm) ) {
		DEBUG_VBO( "Using legacy code. cdDM_drawLooseEdges\n" );
		glBegin(GL_LINES);
		for(i = 0; i < dm->numEdgeData; i++, medge++) {
			if(medge->flag&ME_LOOSEEDGE) {
				glVertex3fv(mvert[medge->v1].co);
				glVertex3fv(mvert[medge->v2].co);
			}
		}
		glEnd();
	}
	else {	/* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		int prevstart = 0;
		int prevdraw = 1;
		int draw = 1;

		GPU_edge_setup(dm);
		if( !GPU_buffer_legacy(dm) ) {
			for(i = 0; i < dm->numEdgeData; i++, medge++) {
				if(medge->flag&ME_LOOSEEDGE) {
					draw = 1;
				} 
				else {
					draw = 0;
				}
				if( prevdraw != draw ) {
					if( prevdraw > 0 && (i-prevstart) > 0) {
						GPU_buffer_draw_elements( dm->drawObject->edges, GL_LINES, prevstart*2, (i-prevstart)*2  );
					}
					prevstart = i;
				}
				prevdraw = draw;
			}
			if( prevdraw > 0 && (i-prevstart) > 0 ) {
				GPU_buffer_draw_elements( dm->drawObject->edges, GL_LINES, prevstart*2, (i-prevstart)*2  );
			}
		}
		GPU_buffer_unbind();
	}
}

static void cdDM_drawFacesSolid(DerivedMesh *dm,
				float (*partial_redraw_planes)[4],
				int UNUSED(fast), DMSetMaterial setMaterial)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mvert = cddm->mvert;
	MFace *mface = cddm->mface;
	float *nors= dm->getTessFaceDataArray(dm, CD_NORMAL);
	int a, glmode = -1, shademodel = -1, matnr = -1, drawCurrentMat = 1;

#define PASSVERT(index) {						\
	if(shademodel == GL_SMOOTH) {				\
		short *no = mvert[index].no;			\
		glNormal3sv(no);						\
	}											\
	glVertex3fv(mvert[index].co);	\
}

	if(cddm->pbvh && cddm->pbvh_draw) {
		if(dm->numTessFaceData) {
			float (*face_nors)[3] = CustomData_get_layer(&dm->faceData, CD_NORMAL);

			BLI_pbvh_draw(cddm->pbvh, partial_redraw_planes, face_nors, setMaterial);
			glShadeModel(GL_FLAT);
		}

		return;
	}

	if( GPU_buffer_legacy(dm) ) {
		DEBUG_VBO( "Using legacy code. cdDM_drawFacesSolid\n" );
		glBegin(glmode = GL_QUADS);
		for(a = 0; a < dm->numTessFaceData; a++, mface++) {
			int new_glmode, new_matnr, new_shademodel;

			new_glmode = mface->v4?GL_QUADS:GL_TRIANGLES;
			new_matnr = mface->mat_nr + 1;
			new_shademodel = (mface->flag & ME_SMOOTH)?GL_SMOOTH:GL_FLAT;
			
			if(new_glmode != glmode || new_matnr != matnr
			   || new_shademodel != shademodel) {
				glEnd();

				drawCurrentMat = setMaterial(matnr = new_matnr, NULL);

				glShadeModel(shademodel = new_shademodel);
				glBegin(glmode = new_glmode);
			} 
			
			if(drawCurrentMat) {
				if(shademodel == GL_FLAT) {
					if (nors) {
						glNormal3fv(nors);
					}
					else {
						/* TODO make this better (cache facenormals as layer?) */
						float nor[3];
						if(mface->v4) {
							normal_quad_v3( nor,mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co, mvert[mface->v4].co);
						} else {
							normal_tri_v3( nor,mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co);
						}
						glNormal3fv(nor);
					}
				}

				PASSVERT(mface->v1);
				PASSVERT(mface->v2);
				PASSVERT(mface->v3);
				if(mface->v4) {
					PASSVERT(mface->v4);
				}
			}

			if(nors) nors += 3;
		}
		glEnd();
	}
	else {	/* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		GPU_vertex_setup( dm );
		GPU_normal_setup( dm );
		if( !GPU_buffer_legacy(dm) ) {
			glShadeModel(GL_SMOOTH);
			for( a = 0; a < dm->drawObject->totmaterial; a++ ) {
				if( setMaterial(dm->drawObject->materials[a].mat_nr+1, NULL) )
					glDrawArrays(GL_TRIANGLES, dm->drawObject->materials[a].start,
						     dm->drawObject->materials[a].totpoint);
			}
		}
		GPU_buffer_unbind( );
	}

#undef PASSVERT
	glShadeModel(GL_FLAT);
}

static void cdDM_drawFacesTex_common(DerivedMesh *dm,
			   DMSetDrawOptionsTex drawParams,
			   DMSetDrawOptions drawParamsMapped,
			   DMCompareDrawOptions compareDrawOptions,
			   void *userData) 
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	MFace *mf = DM_get_tessface_data_layer(dm, CD_MFACE);
	MCol *realcol = dm->getTessFaceDataArray(dm, CD_TEXTURE_MCOL);
	float *nors= dm->getTessFaceDataArray(dm, CD_NORMAL);
	MTFace *tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
	int i, j, orig, *index = DM_get_tessface_data_layer(dm, CD_ORIGINDEX);
	int startFace = 0 /*, lastFlag = 0xdeadbeef */ /* UNUSED */;
	MCol *mcol = dm->getTessFaceDataArray(dm, CD_WEIGHT_MCOL);
	if(!mcol)
		mcol = dm->getTessFaceDataArray(dm, CD_MCOL);

	cdDM_update_normals_from_pbvh(dm);

	if( GPU_buffer_legacy(dm) ) {
		DEBUG_VBO( "Using legacy code. cdDM_drawFacesTex_common\n" );
		for(i = 0; i < dm->numTessFaceData; i++, mf++) {
			MVert *mvert;
			DMDrawOption draw_option;
			unsigned char *cp = NULL;

			if(drawParams) {
				draw_option = drawParams(tf? &tf[i]: NULL, (mcol != NULL), mf->mat_nr);
			}
			else {
				if(index) {
					orig = *index++;
					if(orig == ORIGINDEX_NONE)		{ if(nors) nors += 3; continue; }
					if(drawParamsMapped) draw_option = drawParamsMapped(userData, orig);
					else	{ if(nors) nors += 3; continue; }
				}
				else
					if(drawParamsMapped) draw_option = drawParamsMapped(userData, i);
					else	{ if(nors) nors += 3; continue; }
			}
			
			if(draw_option != DM_DRAW_OPTION_SKIP) {
				if (draw_option != DM_DRAW_OPTION_NO_MCOL && mcol)
					cp= (unsigned char*) &mcol[i*4];

				if(!(mf->flag&ME_SMOOTH)) {
					if (nors) {
						glNormal3fv(nors);
					}
					else {
						float nor[3];
						if(mf->v4) {
							normal_quad_v3( nor,mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co, mv[mf->v4].co);
						} else {
							normal_tri_v3( nor,mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co);
						}
						glNormal3fv(nor);
					}
				}

				glBegin(mf->v4?GL_QUADS:GL_TRIANGLES);
				if(tf) glTexCoord2fv(tf[i].uv[0]);
				if(cp) glColor3ub(cp[3], cp[2], cp[1]);
				mvert = &mv[mf->v1];
				if(mf->flag&ME_SMOOTH) glNormal3sv(mvert->no);
				glVertex3fv(mvert->co);
					
				if(tf) glTexCoord2fv(tf[i].uv[1]);
				if(cp) glColor3ub(cp[7], cp[6], cp[5]);
				mvert = &mv[mf->v2];
				if(mf->flag&ME_SMOOTH) glNormal3sv(mvert->no);
				glVertex3fv(mvert->co);

				if(tf) glTexCoord2fv(tf[i].uv[2]);
				if(cp) glColor3ub(cp[11], cp[10], cp[9]);
				mvert = &mv[mf->v3];
				if(mf->flag&ME_SMOOTH) glNormal3sv(mvert->no);
				glVertex3fv(mvert->co);

				if(mf->v4) {
					if(tf) glTexCoord2fv(tf[i].uv[3]);
					if(cp) glColor3ub(cp[15], cp[14], cp[13]);
					mvert = &mv[mf->v4];
					if(mf->flag&ME_SMOOTH) glNormal3sv(mvert->no);
					glVertex3fv(mvert->co);
				}
				glEnd();
			}
			
			if(nors) nors += 3;
		}
	} else { /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		MCol *col = realcol;
		if(!col)
			col = mcol;

		GPU_vertex_setup( dm );
		GPU_normal_setup( dm );
		GPU_uv_setup( dm );
		if( col != NULL ) {
			/*if( realcol && dm->drawObject->colType == CD_TEXTURE_MCOL ) {
				col = 0;
			} else if( mcol && dm->drawObject->colType == CD_MCOL ) {
				col = 0;
			}
			
			if( col != 0 ) {*/
				unsigned char *colors = MEM_mallocN(dm->getNumTessFaces(dm)*4*3*sizeof(unsigned char), "cdDM_drawFacesTex_common");
				for( i=0; i < dm->getNumTessFaces(dm); i++ ) {
					for( j=0; j < 4; j++ ) {
						/* bgr -> rgb is intentional (and stupid), but how its stored internally */
						colors[i*12+j*3] = col[i*4+j].b;
						colors[i*12+j*3+1] = col[i*4+j].g;
						colors[i*12+j*3+2] = col[i*4+j].r;
					}
				}
				GPU_color3_upload(dm,colors);
				MEM_freeN(colors);
				if(realcol)
					dm->drawObject->colType = CD_TEXTURE_MCOL;
				else if(mcol)
					dm->drawObject->colType = CD_MCOL;
			//}
			GPU_color_setup( dm );
		}

		if( !GPU_buffer_legacy(dm) ) {
			int tottri = dm->drawObject->tot_triangle_point/3;
			int next_actualFace= dm->drawObject->triangle_to_mface[0];

			glShadeModel( GL_SMOOTH );
			/* lastFlag = 0; */ /* UNUSED */
			for(i = 0; i < tottri; i++) {
				int actualFace = next_actualFace;
				DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
				int flush = 0;

				if(i != tottri-1)
					next_actualFace= dm->drawObject->triangle_to_mface[i+1];

				if(drawParams) {
					draw_option = drawParams(tf? &tf[actualFace]: NULL, (mcol != NULL), mf[actualFace].mat_nr);
				}
				else {
					if(index) {
						orig = index[actualFace];
						if(orig == ORIGINDEX_NONE) continue;
						if(drawParamsMapped)
							draw_option = drawParamsMapped(userData, orig);
					}
					else
						if(drawParamsMapped)
							draw_option = drawParamsMapped(userData, actualFace);
				}

				/* flush buffer if current triangle isn't drawable or it's last triangle */
				flush= (draw_option == DM_DRAW_OPTION_SKIP) || (i == tottri - 1);

				if(!flush && compareDrawOptions) {
					/* also compare draw options and flush buffer if they're different
					   need for face selection highlight in edit mode */
					flush|= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
				}

				if(flush) {
					int first= startFace*3;
					/* Add one to the length if we're drawing at the end of the array */
					int count= (i-startFace+(draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0))*3;

					if(count) {
						if (col)
							GPU_color_switch(1);
						else
							GPU_color_switch(0);

						glDrawArrays(GL_TRIANGLES, first, count);
					}

					startFace = i + 1;
				}
			}
		}

		GPU_buffer_unbind();
		glShadeModel( GL_FLAT );
	}
}

static void cdDM_drawFacesTex(DerivedMesh *dm,
			   DMSetDrawOptionsTex setDrawOptions,
			   DMCompareDrawOptions compareDrawOptions,
			   void *userData)
{
	cdDM_drawFacesTex_common(dm, setDrawOptions, NULL, compareDrawOptions, userData);
}

static void cdDM_drawMappedFaces(DerivedMesh *dm,
			DMSetDrawOptions setDrawOptions,
			DMSetMaterial setMaterial,
			DMCompareDrawOptions compareDrawOptions,
			void *userData, DMDrawFlag flag)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	MFace *mf = cddm->mface;
	MCol *mc;
	float *nors= DM_get_tessface_data_layer(dm, CD_NORMAL);
	int useColors = flag & DM_DRAW_USE_COLORS;
	int i, orig, *index = DM_get_tessface_data_layer(dm, CD_ORIGINDEX);

	mc = DM_get_tessface_data_layer(dm, CD_ID_MCOL);
	if(!mc)
		mc = DM_get_tessface_data_layer(dm, CD_WEIGHT_MCOL);
	if(!mc)
		mc = DM_get_tessface_data_layer(dm, CD_MCOL);

	cdDM_update_normals_from_pbvh(dm);

	/* back-buffer always uses legacy since VBO's would need the
	 * color array temporarily overwritten for drawing, then reset. */
	if( GPU_buffer_legacy(dm) || G.f & G_BACKBUFSEL) {
		DEBUG_VBO( "Using legacy code. cdDM_drawMappedFaces\n" );
		for(i = 0; i < dm->numTessFaceData; i++, mf++) {
			int drawSmooth = (flag & DM_DRAW_ALWAYS_SMOOTH) ? 1 : (mf->flag & ME_SMOOTH);
			DMDrawOption draw_option= DM_DRAW_OPTION_NORMAL;

			orig= (index==NULL) ? i : *index++;
			
			if(orig == ORIGINDEX_NONE)
				draw_option= setMaterial(mf->mat_nr + 1, NULL);
			else if (setDrawOptions != NULL)
				draw_option= setDrawOptions(userData, orig);

			if(draw_option != DM_DRAW_OPTION_SKIP) {
				unsigned char *cp = NULL;

				if(useColors && mc)
					cp = (unsigned char *)&mc[i * 4];

				/* no need to set shading mode to flat because
				*  normals are already used to change shading */
				glShadeModel(GL_SMOOTH);
				glBegin(mf->v4?GL_QUADS:GL_TRIANGLES);

				if (!drawSmooth) {
					if (nors) {
						glNormal3fv(nors);
					}
					else {
						float nor[3];
						if(mf->v4) {
							normal_quad_v3( nor,mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co, mv[mf->v4].co);
						} else {
							normal_tri_v3( nor,mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co);
						}
						glNormal3fv(nor);
					}

					if(cp) glColor3ub(cp[3], cp[2], cp[1]);
					glVertex3fv(mv[mf->v1].co);
					if(cp) glColor3ub(cp[7], cp[6], cp[5]);
					glVertex3fv(mv[mf->v2].co);
					if(cp) glColor3ub(cp[11], cp[10], cp[9]);
					glVertex3fv(mv[mf->v3].co);
					if(mf->v4) {
						if(cp) glColor3ub(cp[15], cp[14], cp[13]);
						glVertex3fv(mv[mf->v4].co);
					}
				} else {
					if(cp) glColor3ub(cp[3], cp[2], cp[1]);
					glNormal3sv(mv[mf->v1].no);
					glVertex3fv(mv[mf->v1].co);
					if(cp) glColor3ub(cp[7], cp[6], cp[5]);
					glNormal3sv(mv[mf->v2].no);
					glVertex3fv(mv[mf->v2].co);
					if(cp) glColor3ub(cp[11], cp[10], cp[9]);
					glNormal3sv(mv[mf->v3].no);
					glVertex3fv(mv[mf->v3].co);
					if(mf->v4) {
						if(cp) glColor3ub(cp[15], cp[14], cp[13]);
						glNormal3sv(mv[mf->v4].no);
						glVertex3fv(mv[mf->v4].co);
					}
				}

				glEnd();
			}
			
			if (nors) nors += 3;
		}
	}
	else { /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
		int prevstart = 0;
		GPU_vertex_setup(dm);
		GPU_normal_setup(dm);
		if( useColors && mc )
			GPU_color_setup(dm);
		if( !GPU_buffer_legacy(dm) ) {
			int tottri = dm->drawObject->tot_triangle_point/3;
			glShadeModel(GL_SMOOTH);
			
			if(tottri == 0) {
				/* avoid buffer problems in following code */
			}
			if(setDrawOptions == NULL) {
				/* just draw the entire face array */
				glDrawArrays(GL_TRIANGLES, 0, (tottri) * 3);
			}
			else {
				/* we need to check if the next material changes */
				int next_actualFace= dm->drawObject->triangle_to_mface[0];
				
				for( i = 0; i < tottri; i++ ) {
					//int actualFace = dm->drawObject->triangle_to_mface[i];
					int actualFace = next_actualFace;
					MFace *mface= mf + actualFace;
					/*int drawSmooth= (flag & DM_DRAW_ALWAYS_SMOOTH) ? 1 : (mface->flag & ME_SMOOTH);*/ /* UNUSED */
					DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
					int flush = 0;

					if(i != tottri-1)
						next_actualFace= dm->drawObject->triangle_to_mface[i+1];

					orig= (index==NULL) ? actualFace : index[actualFace];

					if(orig == ORIGINDEX_NONE)
						draw_option= setMaterial(mface->mat_nr + 1, NULL);
					else if (setDrawOptions != NULL)
						draw_option= setDrawOptions(userData, orig);
	
					/* Goal is to draw as long of a contiguous triangle
					   array as possible, so draw when we hit either an
					   invisible triangle or at the end of the array */

					/* flush buffer if current triangle isn't drawable or it's last triangle... */
					flush= (draw_option == DM_DRAW_OPTION_SKIP) || (i == tottri - 1);

					/* ... or when material setting is dissferent  */
					flush|= mf[actualFace].mat_nr != mf[next_actualFace].mat_nr;

					if(!flush && compareDrawOptions) {
						flush|= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
					}

					if(flush) {
						int first= prevstart*3;
						/* Add one to the length if we're drawing at the end of the array */
						int count= (i-prevstart+(draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0))*3;

						if(count)
							glDrawArrays(GL_TRIANGLES, first, count);

						prevstart = i + 1;
					}
				}
			}

			glShadeModel(GL_FLAT);
		}
		GPU_buffer_unbind();
	}
}

static void cdDM_drawMappedFacesTex(DerivedMesh *dm,
			   DMSetDrawOptions setDrawOptions,
			   DMCompareDrawOptions compareDrawOptions,
			   void *userData)
{
	cdDM_drawFacesTex_common(dm, NULL, setDrawOptions, compareDrawOptions, userData);
}

static void cddm_draw_attrib_vertex(DMVertexAttribs *attribs, MVert *mvert, int a, int index, int vert, int smoothnormal)
{
	int b;

	/* orco texture coordinates */
	if(attribs->totorco) {
		if(attribs->orco.glTexco)
			glTexCoord3fv(attribs->orco.array[index]);
		else
			glVertexAttrib3fvARB(attribs->orco.glIndex, attribs->orco.array[index]);
	}

	/* uv texture coordinates */
	for(b = 0; b < attribs->tottface; b++) {
		MTFace *tf = &attribs->tface[b].array[a];

		if(attribs->tface[b].glTexco)
			glTexCoord2fv(tf->uv[vert]);
		else
			glVertexAttrib2fvARB(attribs->tface[b].glIndex, tf->uv[vert]);
	}

	/* vertex colors */
	for(b = 0; b < attribs->totmcol; b++) {
		MCol *cp = &attribs->mcol[b].array[a*4 + vert];
		GLubyte col[4];
		col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
		glVertexAttrib4ubvARB(attribs->mcol[b].glIndex, col);
	}

	/* tangent for normal mapping */
	if(attribs->tottang) {
		float *tang = attribs->tang.array[a*4 + vert];
		glVertexAttrib4fvARB(attribs->tang.glIndex, tang);
	}

	/* vertex normal */
	if(smoothnormal)
		glNormal3sv(mvert[index].no);
	
	/* vertex coordinate */
	glVertex3fv(mvert[index].co);
}

static void cdDM_drawMappedFacesGLSL(DerivedMesh *dm,
			   DMSetMaterial setMaterial,
			   DMSetDrawOptions setDrawOptions,
			   void *userData)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	GPUVertexAttribs gattribs;
	DMVertexAttribs attribs;
	MVert *mvert = cddm->mvert;
	MFace *mface = cddm->mface;
	/* MTFace *tf = dm->getTessFaceDataArray(dm, CD_MTFACE); */ /* UNUSED */
	float (*nors)[3] = dm->getTessFaceDataArray(dm, CD_NORMAL);
	int a, b, dodraw, matnr, new_matnr;
	int orig, *index = dm->getTessFaceDataArray(dm, CD_ORIGINDEX);

	cdDM_update_normals_from_pbvh(dm);

	matnr = -1;
	dodraw = 0;

	glShadeModel(GL_SMOOTH);

	if( GPU_buffer_legacy(dm) || setDrawOptions != NULL ) {
		DEBUG_VBO( "Using legacy code. cdDM_drawMappedFacesGLSL\n" );
		memset(&attribs, 0, sizeof(attribs));

		glBegin(GL_QUADS);

		for(a = 0; a < dm->numTessFaceData; a++, mface++) {
			const int smoothnormal = (mface->flag & ME_SMOOTH);
			new_matnr = mface->mat_nr + 1;

			if(new_matnr != matnr) {
				glEnd();

				dodraw = setMaterial(matnr = new_matnr, &gattribs);
				if(dodraw)
					DM_vertex_attributes_from_gpu(dm, &gattribs, &attribs);

				glBegin(GL_QUADS);
			}

			if(!dodraw) {
				continue;
			}
			else if(setDrawOptions) {
				orig = (index)? index[a]: a;

				if(orig == ORIGINDEX_NONE) {
					/* since the material is set by setMaterial(), faces with no
					 * origin can be assumed to be generated by a modifier */ 
					
					/* continue */
				}
				else if(setDrawOptions(userData, orig) == DM_DRAW_OPTION_SKIP)
					continue;
			}

			if(!smoothnormal) {
				if(nors) {
					glNormal3fv(nors[a]);
				}
				else {
					/* TODO ideally a normal layer should always be available */
					float nor[3];
					if(mface->v4) {
						normal_quad_v3( nor,mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co, mvert[mface->v4].co);
					} else {
						normal_tri_v3( nor,mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co);
					}
					glNormal3fv(nor);
				}
			}

			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v1, 0, smoothnormal);
			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v2, 1, smoothnormal);
			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v3, 2, smoothnormal);

			if(mface->v4)
				cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v4, 3, smoothnormal);
			else
				cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v3, 2, smoothnormal);
		}
		glEnd();
	}
	else {
		GPUBuffer *buffer = NULL;
		char *varray = NULL;
		int numdata = 0, elementsize = 0, offset;
		int start = 0, numfaces = 0 /* , prevdraw = 0 */ /* UNUSED */, curface = 0;
		int i;

		MFace *mf = mface;
		GPUAttrib datatypes[GPU_MAX_ATTRIB]; /* TODO, messing up when switching materials many times - [#21056]*/
		memset(&attribs, 0, sizeof(attribs));

		GPU_vertex_setup(dm);
		GPU_normal_setup(dm);

		if( !GPU_buffer_legacy(dm) ) {
			for( i = 0; i < dm->drawObject->tot_triangle_point/3; i++ ) {

				a = dm->drawObject->triangle_to_mface[i];

				mface = mf + a;
				new_matnr = mface->mat_nr + 1;

				if(new_matnr != matnr ) {
					numfaces = curface - start;
					if( numfaces > 0 ) {

						if( dodraw ) {

							if( numdata != 0 ) {

								GPU_buffer_unlock(buffer);

								GPU_interleaved_attrib_setup(buffer,datatypes,numdata);
							}

							glDrawArrays(GL_TRIANGLES,start*3,numfaces*3);

							if( numdata != 0 ) {

								GPU_buffer_free(buffer);

								buffer = NULL;
							}

						}
					}
					numdata = 0;
					start = curface;
					/* prevdraw = dodraw; */ /* UNUSED */
					dodraw = setMaterial(matnr = new_matnr, &gattribs);
					if(dodraw) {
						DM_vertex_attributes_from_gpu(dm, &gattribs, &attribs);

						if(attribs.totorco) {
							datatypes[numdata].index = attribs.orco.glIndex;
							datatypes[numdata].size = 3;
							datatypes[numdata].type = GL_FLOAT;
							numdata++;
						}
						for(b = 0; b < attribs.tottface; b++) {
							datatypes[numdata].index = attribs.tface[b].glIndex;
							datatypes[numdata].size = 2;
							datatypes[numdata].type = GL_FLOAT;
							numdata++;
						}	
						for(b = 0; b < attribs.totmcol; b++) {
							datatypes[numdata].index = attribs.mcol[b].glIndex;
							datatypes[numdata].size = 4;
							datatypes[numdata].type = GL_UNSIGNED_BYTE;
							numdata++;
						}	
						if(attribs.tottang) {
							datatypes[numdata].index = attribs.tang.glIndex;
							datatypes[numdata].size = 4;
							datatypes[numdata].type = GL_FLOAT;
							numdata++;
						}
						if( numdata != 0 ) {
							elementsize = GPU_attrib_element_size( datatypes, numdata );
							buffer = GPU_buffer_alloc( elementsize*dm->drawObject->tot_triangle_point);
							if( buffer == NULL ) {
								GPU_buffer_unbind();
								dm->drawObject->legacy = 1;
								return;
							}
							varray = GPU_buffer_lock_stream(buffer);
							if( varray == NULL ) {
								GPU_buffer_unbind();
								GPU_buffer_free(buffer);
								dm->drawObject->legacy = 1;
								return;
							}
						}
						else {
							/* if the buffer was set, dont use it again.
							 * prevdraw was assumed true but didnt run so set to false - [#21036] */
							/* prevdraw= 0; */ /* UNUSED */
							buffer= NULL;
						}
					}
				}

				if(dodraw && numdata != 0 ) {
					offset = 0;
					if(attribs.totorco) {
						copy_v3_v3((float *)&varray[elementsize*curface*3],(float *)attribs.orco.array[mface->v1]);
						copy_v3_v3((float *)&varray[elementsize*curface*3+elementsize],(float *)attribs.orco.array[mface->v2]);
						copy_v3_v3((float *)&varray[elementsize*curface*3+elementsize*2],(float *)attribs.orco.array[mface->v3]);
						offset += sizeof(float)*3;
					}
					for(b = 0; b < attribs.tottface; b++) {
						MTFace *tf = &attribs.tface[b].array[a];
						copy_v2_v2((float *)&varray[elementsize*curface*3+offset],tf->uv[0]);
						copy_v2_v2((float *)&varray[elementsize*curface*3+offset+elementsize],tf->uv[1]);

						copy_v2_v2((float *)&varray[elementsize*curface*3+offset+elementsize*2],tf->uv[2]);
						offset += sizeof(float)*2;
					}
					for(b = 0; b < attribs.totmcol; b++) {
						MCol *cp = &attribs.mcol[b].array[a*4 + 0];
						GLubyte col[4];
						col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
						copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset], (char *)col);
						cp = &attribs.mcol[b].array[a*4 + 1];
						col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
						copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset+elementsize], (char *)col);
						cp = &attribs.mcol[b].array[a*4 + 2];
						col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
						copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset+elementsize*2], (char *)col);
						offset += sizeof(unsigned char)*4;
					}	
					if(attribs.tottang) {
						float *tang = attribs.tang.array[a*4 + 0];
						copy_v4_v4((float *)&varray[elementsize*curface*3+offset], tang);
						tang = attribs.tang.array[a*4 + 1];
						copy_v4_v4((float *)&varray[elementsize*curface*3+offset+elementsize], tang);
						tang = attribs.tang.array[a*4 + 2];
						copy_v4_v4((float *)&varray[elementsize*curface*3+offset+elementsize*2], tang);
						offset += sizeof(float)*4;
					}
					(void)offset;
				}
				curface++;
				if(mface->v4) {
					if(dodraw && numdata != 0 ) {
						offset = 0;
						if(attribs.totorco) {
							copy_v3_v3((float *)&varray[elementsize*curface*3],(float *)attribs.orco.array[mface->v3]);
							copy_v3_v3((float *)&varray[elementsize*curface*3+elementsize],(float *)attribs.orco.array[mface->v4]);
							copy_v3_v3((float *)&varray[elementsize*curface*3+elementsize*2],(float *)attribs.orco.array[mface->v1]);
							offset += sizeof(float)*3;
						}
						for(b = 0; b < attribs.tottface; b++) {
							MTFace *tf = &attribs.tface[b].array[a];
							copy_v2_v2((float *)&varray[elementsize*curface*3+offset],tf->uv[2]);
							copy_v2_v2((float *)&varray[elementsize*curface*3+offset+elementsize],tf->uv[3]);
							copy_v2_v2((float *)&varray[elementsize*curface*3+offset+elementsize*2],tf->uv[0]);
							offset += sizeof(float)*2;
						}
						for(b = 0; b < attribs.totmcol; b++) {
							MCol *cp = &attribs.mcol[b].array[a*4 + 2];
							GLubyte col[4];
							col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
							copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset], (char *)col);
							cp = &attribs.mcol[b].array[a*4 + 3];
							col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
							copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset+elementsize], (char *)col);
							cp = &attribs.mcol[b].array[a*4 + 0];
							col[0]= cp->b; col[1]= cp->g; col[2]= cp->r; col[3]= cp->a;
							copy_v4_v4_char((char *)&varray[elementsize*curface*3+offset+elementsize*2], (char *)col);
							offset += sizeof(unsigned char)*4;
						}	
						if(attribs.tottang) {
							float *tang = attribs.tang.array[a*4 + 2];
							copy_v4_v4((float *)&varray[elementsize*curface*3+offset], tang);
							tang = attribs.tang.array[a*4 + 3];
							copy_v4_v4((float *)&varray[elementsize*curface*3+offset+elementsize], tang);
							tang = attribs.tang.array[a*4 + 0];
							copy_v4_v4((float *)&varray[elementsize*curface*3+offset+elementsize*2], tang);
							offset += sizeof(float)*4;
						}
						(void)offset;
					}
					curface++;
					i++;
				}
			}
			numfaces = curface - start;
			if( numfaces > 0 ) {
				if( dodraw ) {
					if( numdata != 0 ) {
						GPU_buffer_unlock(buffer);
						GPU_interleaved_attrib_setup(buffer,datatypes,numdata);
					}
					glDrawArrays(GL_TRIANGLES,start*3,(curface-start)*3);
				}
			}
			GPU_buffer_unbind();
		}
		GPU_buffer_free(buffer);
	}

	glShadeModel(GL_FLAT);
}

static void cdDM_drawFacesGLSL(DerivedMesh *dm, DMSetMaterial setMaterial)
{
	dm->drawMappedFacesGLSL(dm, setMaterial, NULL, NULL);
}

static void cdDM_drawMappedFacesMat(DerivedMesh *dm,
	void (*setMaterial)(void *userData, int, void *attribs),
	int (*setFace)(void *userData, int index), void *userData)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	GPUVertexAttribs gattribs;
	DMVertexAttribs attribs;
	MVert *mvert = cddm->mvert;
	MFace *mf = cddm->mface;
	float (*nors)[3] = dm->getTessFaceDataArray(dm, CD_NORMAL);
	int a, matnr, new_matnr;
	int orig, *index = dm->getTessFaceDataArray(dm, CD_ORIGINDEX);

	cdDM_update_normals_from_pbvh(dm);

	matnr = -1;

	glShadeModel(GL_SMOOTH);

	memset(&attribs, 0, sizeof(attribs));

	glBegin(GL_QUADS);

	for(a = 0; a < dm->numTessFaceData; a++, mf++) {
		const int smoothnormal = (mf->flag & ME_SMOOTH);

		/* material */
		new_matnr = mf->mat_nr + 1;

		if(new_matnr != matnr) {
			glEnd();

			setMaterial(userData, matnr = new_matnr, &gattribs);
			DM_vertex_attributes_from_gpu(dm, &gattribs, &attribs);

			glBegin(GL_QUADS);
		}

		/* skipping faces */
		if(setFace) {
			orig = (index)? index[a]: a;

			if(orig != ORIGINDEX_NONE && !setFace(userData, orig))
				continue;
		}

		/* smooth normal */
		if(!smoothnormal) {
			if(nors) {
				glNormal3fv(nors[a]);
			}
			else {
				/* TODO ideally a normal layer should always be available */
				float nor[3];

				if(mf->v4)
					normal_quad_v3( nor,mvert[mf->v1].co, mvert[mf->v2].co, mvert[mf->v3].co, mvert[mf->v4].co);
				else
					normal_tri_v3( nor,mvert[mf->v1].co, mvert[mf->v2].co, mvert[mf->v3].co);

				glNormal3fv(nor);
			}
		}

		/* vertices */
		cddm_draw_attrib_vertex(&attribs, mvert, a, mf->v1, 0, smoothnormal);
		cddm_draw_attrib_vertex(&attribs, mvert, a, mf->v2, 1, smoothnormal);
		cddm_draw_attrib_vertex(&attribs, mvert, a, mf->v3, 2, smoothnormal);

		if(mf->v4)
			cddm_draw_attrib_vertex(&attribs, mvert, a, mf->v4, 3, smoothnormal);
		else
			cddm_draw_attrib_vertex(&attribs, mvert, a, mf->v3, 2, smoothnormal);
	}
	glEnd();

	glShadeModel(GL_FLAT);
}

static void cdDM_drawMappedEdges(DerivedMesh *dm, DMSetDrawOptions setDrawOptions, void *userData)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *vert = cddm->mvert;
	MEdge *edge = cddm->medge;
	int i, orig, *index = DM_get_edge_data_layer(dm, CD_ORIGINDEX);

	glBegin(GL_LINES);
	for(i = 0; i < dm->numEdgeData; i++, edge++) {
		if(index) {
			orig = *index++;
			if(setDrawOptions && orig == ORIGINDEX_NONE) continue;
		}
		else
			orig = i;

		if(!setDrawOptions || (setDrawOptions(userData, orig) != DM_DRAW_OPTION_SKIP)) {
			glVertex3fv(vert[edge->v1].co);
			glVertex3fv(vert[edge->v2].co);
		}
	}
	glEnd();
}

static void cdDM_foreachMappedVert(
						   DerivedMesh *dm,
						   void (*func)(void *userData, int index, float *co,
										float *no_f, short *no_s),
						   void *userData)
{
	MVert *mv = CDDM_get_verts(dm);
	int i, orig, *index = DM_get_vert_data_layer(dm, CD_ORIGINDEX);

	for(i = 0; i < dm->numVertData; i++, mv++) {
		if(index) {
			orig = *index++;
			if(orig == ORIGINDEX_NONE) continue;
			func(userData, orig, mv->co, NULL, mv->no);
		}
		else
			func(userData, i, mv->co, NULL, mv->no);
	}
}

static void cdDM_foreachMappedEdge(
						   DerivedMesh *dm,
						   void (*func)(void *userData, int index,
										float *v0co, float *v1co),
						   void *userData)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	MEdge *med = cddm->medge;
	int i, orig, *index = DM_get_edge_data_layer(dm, CD_ORIGINDEX);

	for(i = 0; i < dm->numEdgeData; i++, med++) {
		if (index) {
			orig = *index++;
			if(orig == ORIGINDEX_NONE) continue;
			func(userData, orig, mv[med->v1].co, mv[med->v2].co);
		}
		else
			func(userData, i, mv[med->v1].co, mv[med->v2].co);
	}
}

static void cdDM_foreachMappedFaceCenter(
						   DerivedMesh *dm,
						   void (*func)(void *userData, int index,
										float *cent, float *no),
						   void *userData)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	MVert *mv = cddm->mvert;
	MPoly *mf = cddm->mpoly;
	MLoop *ml = cddm->mloop;
	int i, j, orig, *index;

	index = CustomData_get_layer(&dm->polyData, CD_ORIGINDEX);
	mf = cddm->mpoly;
	for(i = 0; i < dm->numPolyData; i++, mf++) {
		float cent[3];
		float no[3];

		if (index) {
			orig = *index++;
			if(orig == ORIGINDEX_NONE) continue;
		}
		else
			orig = i;
		
		ml = &cddm->mloop[mf->loopstart];
		cent[0] = cent[1] = cent[2] = 0.0f;
		for (j=0; j<mf->totloop; j++, ml++) {
			add_v3_v3v3(cent, cent, mv[ml->v].co);
		}
		mul_v3_fl(cent, 1.0f / (float)j);

		ml = &cddm->mloop[mf->loopstart];
		if (j > 3) {
			normal_quad_v3(no, mv[ml->v].co, mv[(ml+1)->v].co,
				       mv[(ml+2)->v].co, mv[(ml+3)->v].co);
		} else {
			normal_tri_v3(no, mv[ml->v].co, mv[(ml+1)->v].co, mv[(ml+2)->v].co);
		}

		func(userData, orig, cent, no);
	}

}

void CDDM_recalc_tessellation_ex(DerivedMesh *dm, const int do_face_nor_cpy)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	dm->numTessFaceData = mesh_recalcTessellation(&dm->faceData, &dm->loopData, &dm->polyData,
	                                             cddm->mvert,
	                                             dm->numTessFaceData, dm->numLoopData, dm->numPolyData,
	                                             do_face_nor_cpy);

	if (!CustomData_get_layer(&dm->faceData, CD_ORIGINDEX)) {
		int *polyIndex = CustomData_get_layer(&dm->faceData, CD_POLYINDEX);
		CustomData_add_layer(&dm->faceData, CD_ORIGINDEX, CD_REFERENCE, polyIndex, dm->numTessFaceData);
	}

	cddm->mface = CustomData_get_layer(&dm->faceData, CD_MFACE);

	/* Tessellation recreated faceData, and the active layer indices need to get re-propagated
	   from loops and polys to faces */
	CustomData_bmesh_update_active_layers(&dm->faceData, &dm->polyData, &dm->loopData);
}

void CDDM_recalc_tessellation(DerivedMesh *dm)
{
	CDDM_recalc_tessellation_ex(dm, TRUE);
}

static void cdDM_free_internal(CDDerivedMesh *cddm)
{
	if(cddm->fmap) MEM_freeN(cddm->fmap);
	if(cddm->fmap_mem) MEM_freeN(cddm->fmap_mem);

	if(cddm->pmap) MEM_freeN(cddm->pmap);
	if(cddm->pmap_mem) MEM_freeN(cddm->pmap_mem);
}

static void cdDM_release(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	if (DM_release(dm)) {
		cdDM_free_internal(cddm);
		MEM_freeN(cddm);
	}
}

int CDDM_Check(DerivedMesh *dm)
{
	return dm && dm->getMinMax == cdDM_getMinMax;
}

/**************** CDDM interface functions ****************/
static CDDerivedMesh *cdDM_create(const char *desc)
{
	CDDerivedMesh *cddm;
	DerivedMesh *dm;

	cddm = MEM_callocN(sizeof(*cddm), desc);
	dm = &cddm->dm;

	dm->getMinMax = cdDM_getMinMax;

	dm->getNumVerts = cdDM_getNumVerts;
	dm->getNumEdges = cdDM_getNumEdges;
	dm->getNumTessFaces = cdDM_getNumTessFaces;
	dm->getNumLoops = cdDM_getNumLoops;
	dm->getNumPolys = cdDM_getNumPolys;

	dm->getVert = cdDM_getVert;
	dm->getEdge = cdDM_getEdge;
	dm->getTessFace = cdDM_getTessFace;

	dm->copyVertArray = cdDM_copyVertArray;
	dm->copyEdgeArray = cdDM_copyEdgeArray;
	dm->copyTessFaceArray = cdDM_copyTessFaceArray;
	dm->copyLoopArray = cdDM_copyLoopArray;
	dm->copyPolyArray = cdDM_copyPolyArray;

	dm->getVertData = DM_get_vert_data;
	dm->getEdgeData = DM_get_edge_data;
	dm->getTessFaceData = DM_get_tessface_data;
	dm->getVertDataArray = DM_get_vert_data_layer;
	dm->getEdgeDataArray = DM_get_edge_data_layer;
	dm->getTessFaceDataArray = DM_get_tessface_data_layer;

	dm->calcNormals = CDDM_calc_normals_mapping;
	dm->recalcTessellation = CDDM_recalc_tessellation;

	dm->getVertCos = cdDM_getVertCos;
	dm->getVertCo = cdDM_getVertCo;
	dm->getVertNo = cdDM_getVertNo;

	dm->getPBVH = cdDM_getPBVH;
	dm->getPolyMap = cdDM_getPolyMap;

	dm->drawVerts = cdDM_drawVerts;

	dm->drawUVEdges = cdDM_drawUVEdges;
	dm->drawEdges = cdDM_drawEdges;
	dm->drawLooseEdges = cdDM_drawLooseEdges;
	dm->drawMappedEdges = cdDM_drawMappedEdges;

	dm->drawFacesSolid = cdDM_drawFacesSolid;
	dm->drawFacesTex = cdDM_drawFacesTex;
	dm->drawFacesGLSL = cdDM_drawFacesGLSL;
	dm->drawMappedFaces = cdDM_drawMappedFaces;
	dm->drawMappedFacesTex = cdDM_drawMappedFacesTex;
	dm->drawMappedFacesGLSL = cdDM_drawMappedFacesGLSL;
	dm->drawMappedFacesMat = cdDM_drawMappedFacesMat;

	dm->foreachMappedVert = cdDM_foreachMappedVert;
	dm->foreachMappedEdge = cdDM_foreachMappedEdge;
	dm->foreachMappedFaceCenter = cdDM_foreachMappedFaceCenter;

	dm->release = cdDM_release;

	return cddm;
}

DerivedMesh *CDDM_new(int numVerts, int numEdges, int numTessFaces, int numLoops, int numPolys)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_new dm");
	DerivedMesh *dm = &cddm->dm;

	DM_init(dm, DM_TYPE_CDDM, numVerts, numEdges, numTessFaces, numLoops, numPolys);

	CustomData_add_layer(&dm->vertData, CD_ORIGINDEX, CD_CALLOC, NULL, numVerts);
	CustomData_add_layer(&dm->edgeData, CD_ORIGINDEX, CD_CALLOC, NULL, numEdges);
	CustomData_add_layer(&dm->faceData, CD_ORIGINDEX, CD_CALLOC, NULL, numTessFaces);
	CustomData_add_layer(&dm->faceData, CD_POLYINDEX, CD_CALLOC, NULL, numTessFaces);
	CustomData_add_layer(&dm->polyData, CD_ORIGINDEX, CD_CALLOC, NULL, numPolys);

	CustomData_add_layer(&dm->vertData, CD_MVERT, CD_CALLOC, NULL, numVerts);
	CustomData_add_layer(&dm->edgeData, CD_MEDGE, CD_CALLOC, NULL, numEdges);
	CustomData_add_layer(&dm->faceData, CD_MFACE, CD_CALLOC, NULL, numTessFaces);
	CustomData_add_layer(&dm->loopData, CD_MLOOP, CD_CALLOC, NULL, numLoops);
	CustomData_add_layer(&dm->polyData, CD_MPOLY, CD_CALLOC, NULL, numPolys);

	cddm->mvert = CustomData_get_layer(&dm->vertData, CD_MVERT);
	cddm->medge = CustomData_get_layer(&dm->edgeData, CD_MEDGE);
	cddm->mface = CustomData_get_layer(&dm->faceData, CD_MFACE);
	cddm->mloop = CustomData_get_layer(&dm->loopData, CD_MLOOP);
	cddm->mpoly = CustomData_get_layer(&dm->polyData, CD_MPOLY);

	return dm;
}

DerivedMesh *CDDM_from_mesh(Mesh *mesh, Object *UNUSED(ob))
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_from_mesh dm");
	DerivedMesh *dm = &cddm->dm;
	CustomDataMask mask = CD_MASK_MESH & (~CD_MASK_MDISPS);
	int alloctype;
	int *polyindex = NULL;

	/* this does a referenced copy, with an exception for fluidsim */

	DM_init(dm, DM_TYPE_CDDM, mesh->totvert, mesh->totedge, mesh->totface,
	            mesh->totloop, mesh->totpoly);

	dm->deformedOnly = 1;

	alloctype= CD_REFERENCE;

	CustomData_merge(&mesh->vdata, &dm->vertData, mask, alloctype,
					 mesh->totvert);
	CustomData_merge(&mesh->edata, &dm->edgeData, mask, alloctype,
					 mesh->totedge);
	CustomData_merge(&mesh->fdata, &dm->faceData, mask|CD_MASK_POLYINDEX, alloctype,
					 mesh->totface);
	CustomData_merge(&mesh->ldata, &dm->loopData, mask, alloctype,
	                 mesh->totloop);
	CustomData_merge(&mesh->pdata, &dm->polyData, mask, alloctype,
	                 mesh->totpoly);

	cddm->mvert = CustomData_get_layer(&dm->vertData, CD_MVERT);
	cddm->medge = CustomData_get_layer(&dm->edgeData, CD_MEDGE);
	cddm->mloop = CustomData_get_layer(&dm->loopData, CD_MLOOP);
	cddm->mpoly = CustomData_get_layer(&dm->polyData, CD_MPOLY);
	cddm->mface = CustomData_get_layer(&dm->faceData, CD_MFACE);

	/* commented since even when CD_POLYINDEX was first added this line fails
	 * on the default cube, (after editmode toggle too) - campbell */
#if 0
	BLI_assert(CustomData_has_layer(&cddm->dm.faceData, CD_POLYINDEX));
#endif

	polyindex = CustomData_get_layer(&dm->faceData, CD_POLYINDEX);
	if (!CustomData_has_layer(&cddm->dm.faceData, CD_ORIGINDEX)) {
		CustomData_add_layer(&dm->faceData, CD_ORIGINDEX, CD_REFERENCE, polyindex, mesh->totface);
	}

	return dm;
}

DerivedMesh *CDDM_from_curve(Object *ob)
{
	return CDDM_from_curve_customDB(ob, &ob->disp);
}

DerivedMesh *CDDM_from_curve_customDB(Object *ob, ListBase *dispbase)
{
	DerivedMesh *dm;
	CDDerivedMesh *cddm;
	MVert *allvert;
	MEdge *alledge;
	MLoop *allloop;
	MPoly *allpoly;
	int totvert, totedge, totloop, totpoly;

	if (nurbs_to_mdata_customdb(ob, dispbase, &allvert, &totvert, &alledge,
		&totedge, &allloop, &allpoly, &totloop, &totpoly) != 0) {
		/* Error initializing mdata. This often happens when curve is empty */
		return CDDM_new(0, 0, 0, 0, 0);
	}

	dm = CDDM_new(totvert, totedge, 0, totloop, totpoly);
	dm->deformedOnly = 1;

	cddm = (CDDerivedMesh*)dm;

	memcpy(cddm->mvert, allvert, totvert*sizeof(MVert));
	memcpy(cddm->medge, alledge, totedge*sizeof(MEdge));
	memcpy(cddm->mloop, allloop, totloop*sizeof(MLoop));
	memcpy(cddm->mpoly, allpoly, totpoly*sizeof(MPoly));

	MEM_freeN(allvert);
	MEM_freeN(alledge);
	MEM_freeN(allloop);
	MEM_freeN(allpoly);

	CDDM_calc_edges(dm);

	return dm;
}

static void loops_to_customdata_corners(BMesh *bm, CustomData *facedata,
					  int cdindex, BMLoop *l3[3],
					  int numCol, int numTex)
{
	BMLoop *l;
	BMFace *f = l3[0]->f;
	MTFace *texface;
	MTexPoly *texpoly;
	MCol *mcol;
	MLoopCol *mloopcol;
	MLoopUV *mloopuv;
	int i, j, hasWCol = CustomData_has_layer(&bm->ldata, CD_WEIGHT_MLOOPCOL);

	for (i=0; i < numTex; i++) {
		texface = CustomData_get_n(facedata, CD_MTFACE, cdindex, i);
		texpoly = CustomData_bmesh_get_n(&bm->pdata, f->head.data, CD_MTEXPOLY, i);
		
		ME_MTEXFACE_CPY(texface, texpoly);
	
		for (j=0; j<3; j++) {
			l = l3[j];
			mloopuv = CustomData_bmesh_get_n(&bm->ldata, l->head.data, CD_MLOOPUV, i);
			copy_v2_v2(texface->uv[j], mloopuv->uv);
		}
	}

	for (i=0; i < numCol; i++) {
		mcol = CustomData_get_n(facedata, CD_MCOL, cdindex, i);
		
		for (j=0; j<3; j++) {
			l = l3[j];
			mloopcol = CustomData_bmesh_get_n(&bm->ldata, l->head.data, CD_MLOOPCOL, i);
			mcol[j].r = mloopcol->r;
			mcol[j].g = mloopcol->g;
			mcol[j].b = mloopcol->b;
			mcol[j].a = mloopcol->a;
		}
	}

	if (hasWCol) {
		mcol = CustomData_get(facedata, cdindex, CD_WEIGHT_MCOL);

		for (j=0; j<3; j++) {
			l = l3[j];
			mloopcol = CustomData_bmesh_get(&bm->ldata, l->head.data, CD_WEIGHT_MLOOPCOL);
			mcol[j].r = mloopcol->r;
			mcol[j].g = mloopcol->g;
			mcol[j].b = mloopcol->b;
			mcol[j].a = mloopcol->a;
		}
	}
}

DerivedMesh *CDDM_from_BMEditMesh(BMEditMesh *em, Mesh *UNUSED(me), int use_mdisps, int use_tessface)
{
	BMesh *bm = em->bm;

	DerivedMesh *dm = CDDM_new(bm->totvert,
	                           bm->totedge,
	                           use_tessface ? em->tottri : 0,
	                           bm->totloop,
	                           bm->totface);

	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	BMIter iter, liter;
	BMVert *eve;
	BMEdge *eed;
	BMFace *efa;
	MVert *mvert = cddm->mvert;
	MEdge *medge = cddm->medge;
	MFace *mface = cddm->mface;
	MLoop *mloop = cddm->mloop;
	MPoly *mpoly = cddm->mpoly;
	int numCol = CustomData_number_of_layers(&bm->ldata, CD_MLOOPCOL);
	int numTex = CustomData_number_of_layers(&bm->pdata, CD_MTEXPOLY);
	int *index, add_orig;
	int has_crease, has_edge_bweight, has_vert_bweight;
	CustomDataMask mask;
	unsigned int i, j;
	
	has_edge_bweight = CustomData_has_layer(&bm->edata, CD_BWEIGHT);
	has_vert_bweight = CustomData_has_layer(&bm->vdata, CD_BWEIGHT);
	has_crease = CustomData_has_layer(&bm->edata, CD_CREASE);
	
	dm->deformedOnly = 1;
	
	/*don't add origindex layer if one already exists*/
	add_orig = !CustomData_has_layer(&bm->pdata, CD_ORIGINDEX);

	mask = use_mdisps ? CD_MASK_DERIVEDMESH|CD_MASK_MDISPS : CD_MASK_DERIVEDMESH;
	
	/*don't process shapekeys, we only feed them through the modifier stack as needed,
	  e.g. for applying modifiers or the like*/
	mask &= ~CD_MASK_SHAPEKEY;
	CustomData_merge(&bm->vdata, &dm->vertData, mask,
	                 CD_CALLOC, dm->numVertData);
	CustomData_merge(&bm->edata, &dm->edgeData, mask,
	                 CD_CALLOC, dm->numEdgeData);
	CustomData_merge(&bm->ldata, &dm->loopData, mask,
	                 CD_CALLOC, dm->numLoopData);
	CustomData_merge(&bm->pdata, &dm->polyData, mask,
	                 CD_CALLOC, dm->numPolyData);
	
	/*add tessellation mface layers*/
	if (use_tessface) {
		CustomData_from_bmeshpoly(&dm->faceData, &dm->polyData, &dm->loopData, em->tottri);
	}

	index = dm->getVertDataArray(dm, CD_ORIGINDEX);

	eve = BM_iter_new(&iter, bm, BM_VERTS_OF_MESH, NULL);
	for (i=0; eve; eve=BM_iter_step(&iter), i++, index++) {
		MVert *mv = &mvert[i];

		copy_v3_v3(mv->co, eve->co);

		BM_elem_index_set(eve, i); /* set_inline */

		normal_float_to_short_v3(mv->no, eve->no);

		mv->flag = BM_vert_flag_to_mflag(eve);

		if (has_vert_bweight)
			mv->bweight = (unsigned char)(BM_elem_float_data_get(&bm->vdata, eve, CD_BWEIGHT)*255.0f);

		if (add_orig) *index = i;

		CustomData_from_bmesh_block(&bm->vdata, &dm->vertData, eve->head.data, i);
	}
	bm->elem_index_dirty &= ~BM_VERT;

	index = dm->getEdgeDataArray(dm, CD_ORIGINDEX);
	eed = BM_iter_new(&iter, bm, BM_EDGES_OF_MESH, NULL);
	for (i=0; eed; eed=BM_iter_step(&iter), i++, index++) {
		MEdge *med = &medge[i];

		BM_elem_index_set(eed, i); /* set_inline */

		med->v1 = BM_elem_index_get(eed->v1);
		med->v2 = BM_elem_index_get(eed->v2);

		if (has_crease)
			med->crease = (unsigned char)(BM_elem_float_data_get(&bm->edata, eed, CD_CREASE)*255.0f);
		if (has_edge_bweight)
			med->bweight = (unsigned char)(BM_elem_float_data_get(&bm->edata, eed, CD_BWEIGHT)*255.0f);
		
		med->flag = BM_edge_flag_to_mflag(eed);

		CustomData_from_bmesh_block(&bm->edata, &dm->edgeData, eed->head.data, i);
		if (add_orig) *index = i;
	}
	bm->elem_index_dirty &= ~BM_EDGE;

	/* avoid this where possiblem, takes extra memory */
	if (use_tessface) {
		int *polyindex;

		BM_mesh_elem_index_ensure(bm, BM_FACE);

		polyindex = dm->getTessFaceDataArray(dm, CD_POLYINDEX);
		index = dm->getTessFaceDataArray(dm, CD_ORIGINDEX);
		for(i = 0; i < dm->numTessFaceData; i++, index++, polyindex++) {
			MFace *mf = &mface[i];
			BMLoop **l = em->looptris[i];
			efa = l[0]->f;

			mf->v1 = BM_elem_index_get(l[0]->v);
			mf->v2 = BM_elem_index_get(l[1]->v);
			mf->v3 = BM_elem_index_get(l[2]->v);
			mf->v4 = 0;
			mf->mat_nr = efa->mat_nr;
			mf->flag = BM_face_flag_to_mflag(efa);

			*index = add_orig ? BM_elem_index_get(efa) : *(int*)CustomData_bmesh_get(&bm->pdata, efa->head.data, CD_ORIGINDEX);
			*polyindex = BM_elem_index_get(efa);

			loops_to_customdata_corners(bm, &dm->faceData, i, l, numCol, numTex);
			test_index_face(mf, &dm->faceData, i, 3);
		}
	}
	
	index = CustomData_get_layer(&dm->polyData, CD_ORIGINDEX);
	j = 0;
	efa = BM_iter_new(&iter, bm, BM_FACES_OF_MESH, NULL);
	for (i=0; efa; i++, efa=BM_iter_step(&iter), index++) {
		BMLoop *l;
		MPoly *mp = &mpoly[i];

		BM_elem_index_set(efa, i); /* set_inline */

		mp->totloop = efa->len;
		mp->flag = BM_face_flag_to_mflag(efa);
		mp->loopstart = j;
		mp->mat_nr = efa->mat_nr;
		
		BM_ITER(l, &liter, bm, BM_LOOPS_OF_FACE, efa) {
			mloop->v = BM_elem_index_get(l->v);
			mloop->e = BM_elem_index_get(l->e);
			CustomData_from_bmesh_block(&bm->ldata, &dm->loopData, l->head.data, j);

			j++;
			mloop++;
		}

		CustomData_from_bmesh_block(&bm->pdata, &dm->polyData, efa->head.data, i);

		if (add_orig) *index = i;
	}
	bm->elem_index_dirty &= ~BM_FACE;

	return dm;
}

static DerivedMesh *cddm_copy_ex(DerivedMesh *source, int faces_from_tessfaces)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_copy cddm");
	DerivedMesh *dm = &cddm->dm;
	int numVerts = source->numVertData;
	int numEdges = source->numEdgeData;
	int numTessFaces = source->numTessFaceData;
	int numLoops = source->numLoopData;
	int numPolys = source->numPolyData;

	/* ensure these are created if they are made on demand */
	source->getVertDataArray(source, CD_ORIGINDEX);
	source->getEdgeDataArray(source, CD_ORIGINDEX);
	source->getTessFaceDataArray(source, CD_ORIGINDEX);

	/* this initializes dm, and copies all non mvert/medge/mface layers */
	DM_from_template(dm, source, DM_TYPE_CDDM, numVerts, numEdges, numTessFaces,
		numLoops, numPolys);
	dm->deformedOnly = source->deformedOnly;

	CustomData_copy_data(&source->vertData, &dm->vertData, 0, 0, numVerts);
	CustomData_copy_data(&source->edgeData, &dm->edgeData, 0, 0, numEdges);
	CustomData_copy_data(&source->faceData, &dm->faceData, 0, 0, numTessFaces);

	/* now add mvert/medge/mface layers */
	cddm->mvert = source->dupVertArray(source);
	cddm->medge = source->dupEdgeArray(source);
	cddm->mface = source->dupTessFaceArray(source);

	CustomData_add_layer(&dm->vertData, CD_MVERT, CD_ASSIGN, cddm->mvert, numVerts);
	CustomData_add_layer(&dm->edgeData, CD_MEDGE, CD_ASSIGN, cddm->medge, numEdges);
	CustomData_add_layer(&dm->faceData, CD_MFACE, CD_ASSIGN, cddm->mface, numTessFaces);
	
	if (!faces_from_tessfaces)
		DM_DupPolys(source, dm);
	else
		CDDM_tessfaces_to_faces(dm);

	cddm->mloop = CustomData_get_layer(&dm->loopData, CD_MLOOP);
	cddm->mpoly = CustomData_get_layer(&dm->polyData, CD_MPOLY);

	/* any callers that need tessface data can calculate it - campbell */
#if 0
	/* BMESH_TODO: Find out why this is necessary (or else find a way to remove
	   it). If it is necessary, add a comment explaining why. */
	CDDM_recalc_tessellation((DerivedMesh *)cddm);
#endif

	return dm;
}

DerivedMesh *CDDM_copy(DerivedMesh *source)
{
	return cddm_copy_ex(source, 0);
}

DerivedMesh *CDDM_copy_from_tessface(DerivedMesh *source)
{
	return cddm_copy_ex(source, 1);
}

/* note, the CD_ORIGINDEX layers are all 0, so if there is a direct
 * relationship between mesh data this needs to be set by the caller. */
DerivedMesh *CDDM_from_template(DerivedMesh *source,
                                int numVerts, int numEdges, int numTessFaces,
                                int numLoops, int numPolys)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_from_template dest");
	DerivedMesh *dm = &cddm->dm;

	/* ensure these are created if they are made on demand */
	source->getVertDataArray(source, CD_ORIGINDEX);
	source->getEdgeDataArray(source, CD_ORIGINDEX);
	source->getTessFaceDataArray(source, CD_ORIGINDEX);

	/* this does a copy of all non mvert/medge/mface layers */
	DM_from_template(dm, source, DM_TYPE_CDDM, numVerts, numEdges, numTessFaces, numLoops, numPolys);

	/* now add mvert/medge/mface layers */
	CustomData_add_layer(&dm->vertData, CD_MVERT, CD_CALLOC, NULL, numVerts);
	CustomData_add_layer(&dm->edgeData, CD_MEDGE, CD_CALLOC, NULL, numEdges);
	CustomData_add_layer(&dm->faceData, CD_MFACE, CD_CALLOC, NULL, numTessFaces);
	CustomData_add_layer(&dm->loopData, CD_MLOOP, CD_CALLOC, NULL, numLoops);
	CustomData_add_layer(&dm->polyData, CD_MPOLY, CD_CALLOC, NULL, numPolys);

	if(!CustomData_get_layer(&dm->vertData, CD_ORIGINDEX))
		CustomData_add_layer(&dm->vertData, CD_ORIGINDEX, CD_CALLOC, NULL, numVerts);
	if(!CustomData_get_layer(&dm->edgeData, CD_ORIGINDEX))
		CustomData_add_layer(&dm->edgeData, CD_ORIGINDEX, CD_CALLOC, NULL, numEdges);
	if(!CustomData_get_layer(&dm->faceData, CD_ORIGINDEX))
		CustomData_add_layer(&dm->faceData, CD_ORIGINDEX, CD_CALLOC, NULL, numTessFaces);
	if(!CustomData_get_layer(&dm->faceData, CD_POLYINDEX))
		CustomData_add_layer(&dm->faceData, CD_POLYINDEX, CD_CALLOC, NULL, numTessFaces);

	cddm->mvert = CustomData_get_layer(&dm->vertData, CD_MVERT);
	cddm->medge = CustomData_get_layer(&dm->edgeData, CD_MEDGE);
	cddm->mface = CustomData_get_layer(&dm->faceData, CD_MFACE);
	cddm->mloop = CustomData_get_layer(&dm->loopData, CD_MLOOP);
	cddm->mpoly = CustomData_get_layer(&dm->polyData, CD_MPOLY);

	return dm;
}

void CDDM_apply_vert_coords(DerivedMesh *dm, float (*vertCoords)[3])
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	MVert *vert;
	int i;

	/* this will just return the pointer if it wasn't a referenced layer */
	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
	cddm->mvert = vert;

	for(i = 0; i < dm->numVertData; ++i, ++vert)
		copy_v3_v3(vert->co, vertCoords[i]);
}

void CDDM_apply_vert_normals(DerivedMesh *dm, short (*vertNormals)[3])
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	MVert *vert;
	int i;

	/* this will just return the pointer if it wasn't a referenced layer */
	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
	cddm->mvert = vert;

	for(i = 0; i < dm->numVertData; ++i, ++vert)
		copy_v3_v3_short(vert->no, vertNormals[i]);
}

void CDDM_calc_normals_mapping(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	float (*face_nors)[3] = NULL;

	/* use this to skip calculating normals on original vert's, this may need to be changed */
	const short only_face_normals = CustomData_is_referenced_layer(&dm->vertData, CD_MVERT);
	
	if(dm->numVertData == 0) return;

	/* now we skip calculating vertex normals for referenced layer,
	 * no need to duplicate verts.
	 * WATCH THIS, bmesh only change!,
	 * need to take care of the side effects here - campbell */
#if 0
	/* we don't want to overwrite any referenced layers */
	cddm->mvert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
#endif


	if (dm->numTessFaceData == 0) {
		/* No tessellation on this mesh yet, need to calculate one.
		 *
		 * Important not to update face normals from polys since it
		 * interfears with assigning the new normal layer in the following code.
		 */
		CDDM_recalc_tessellation_ex(dm, FALSE);
	}
	else {
		/* A tessellation already exists, it should always have a CD_POLYINDEX */
		BLI_assert(CustomData_has_layer(&dm->faceData, CD_POLYINDEX));
		CustomData_free_layers(&dm->faceData, CD_NORMAL, dm->numTessFaceData);
	}


	face_nors = MEM_mallocN(sizeof(float)*3*dm->numTessFaceData, "face_nors");
	
	/* calculate face normals */
	mesh_calc_normals_mapping_ex(cddm->mvert, dm->numVertData, CDDM_get_loops(dm), CDDM_get_polys(dm),
	                             dm->numLoopData, dm->numPolyData, NULL, cddm->mface, dm->numTessFaceData,
	                             CustomData_get_layer(&dm->faceData, CD_POLYINDEX), face_nors,
	                             only_face_normals);
	
	CustomData_add_layer(&dm->faceData, CD_NORMAL, CD_ASSIGN, 
	                     face_nors, dm->numTessFaceData);


}

/* bmesh note: this matches what we have in trunk */
void CDDM_calc_normals(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	float (*poly_nors)[3];

	if(dm->numVertData == 0) return;

	/* we don't want to overwrite any referenced layers */
	cddm->mvert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);

	/* fill in if it exists */
	poly_nors = CustomData_get_layer(&dm->polyData, CD_NORMAL);
	if (!poly_nors) {
		poly_nors = CustomData_add_layer(&dm->polyData, CD_NORMAL, CD_CALLOC, NULL, dm->numPolyData);
	}

	mesh_calc_normals(cddm->mvert, dm->numVertData, CDDM_get_loops(dm), CDDM_get_polys(dm),
	                  dm->numLoopData, dm->numPolyData, poly_nors);
}

void CDDM_calc_normals_tessface(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	float (*face_nors)[3];

	if(dm->numVertData == 0) return;

	/* we don't want to overwrite any referenced layers */
	cddm->mvert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);

	/* fill in if it exists */
	face_nors = CustomData_get_layer(&dm->faceData, CD_NORMAL);
	if (!face_nors) {
		face_nors = CustomData_add_layer(&dm->faceData, CD_NORMAL, CD_CALLOC, NULL, dm->numTessFaceData);
	}

	mesh_calc_normals_tessface(cddm->mvert, dm->numVertData,
							   cddm->mface, dm->numTessFaceData, face_nors);
}

#if 1
/* merge verts
 *
 * vtargetmap is a table that maps vertices to target vertices.  a value of -1
 * indicates a vertex is a target, and is to be kept.
 *
 * this frees dm, and returns a new one.
 *
 * this is a really horribly written function.  ger. - joeedh
 *
 * note, CDDM_recalc_tessellation has to run on the returned DM if you want to access tessfaces.
 */
DerivedMesh *CDDM_merge_verts(DerivedMesh *dm, const int *vtargetmap)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	CDDerivedMesh *cddm2 = NULL;
	MVert *mv, *mvert = NULL;
	BLI_array_declare(mvert);
	MEdge *med, *medge = NULL;
	BLI_array_declare(medge);
	MPoly *mp, *mpoly = NULL;
	BLI_array_declare(mpoly);
	MLoop *ml, *mloop = NULL;
	BLI_array_declare(mloop);
	EdgeHash *ehash = BLI_edgehash_new();
	int *newv = NULL, *newe = NULL, *newl = NULL;
	int *oldv = NULL, *olde = NULL, *oldl = NULL, *oldp = NULL;
	BLI_array_declare(oldv); BLI_array_declare(olde); BLI_array_declare(oldl); BLI_array_declare(oldp);
	int i, j, c, totloop, totpoly;
	
	totloop = dm->numLoopData;
	totpoly = dm->numPolyData;
	
	newv = MEM_callocN(sizeof(int)*dm->numVertData, "newv vtable CDDM_merge_verts");
	newe = MEM_callocN(sizeof(int)*dm->numEdgeData, "newv etable CDDM_merge_verts");
	newl = MEM_callocN(sizeof(int)*totloop, "newv ltable CDDM_merge_verts");
	
	/*fill newl with destination vertex indices*/
	mv = cddm->mvert;
	c = 0;
	for (i=0; i<dm->numVertData; i++, mv++) {
		if (vtargetmap[i] == -1) {
			BLI_array_append(oldv, i);
			newv[i] = c++;
			BLI_array_append(mvert, *mv);
		}
	}
	
	/*now link target vertices to destination indices*/
	for (i=0; i<dm->numVertData; i++) {
		if (vtargetmap[i] != -1) {
			newv[i] = newv[vtargetmap[i]];
		}
	}
	
	/*find-replace merged vertices with target vertices*/	
	ml = cddm->mloop;
	for (i=0; i<totloop; i++, ml++) {
		if (vtargetmap[ml->v] != -1) {
			ml->v = vtargetmap[ml->v];
		}
	}

	/*now go through and fix edges and faces*/
	med = cddm->medge;
	c = 0;
	for (i=0; i<dm->numEdgeData; i++, med++) {
		
		if (LIKELY(med->v1 != med->v2)) {
			const unsigned int v1 = (vtargetmap[med->v1] != -1) ? vtargetmap[med->v1] : med->v1;
			const unsigned int v2 = (vtargetmap[med->v2] != -1) ? vtargetmap[med->v2] : med->v2;
			void **eh_p= BLI_edgehash_lookup_p(ehash, v1, v2);

			if (eh_p) {
				newe[i] = GET_INT_FROM_POINTER(*eh_p);
			}
			else {
				BLI_array_append(olde, i);
				newe[i] = c;
				BLI_array_append(medge, *med);
				BLI_edgehash_insert(ehash, v1, v2, SET_INT_IN_POINTER(c));
				c++;
			}
		}
		else {
			newe[i] = -1;
		}
	}
	
	mp = cddm->mpoly;
	for (i=0; i<totpoly; i++, mp++) {
		MPoly *mp2;
		
		ml = cddm->mloop + mp->loopstart;

		c = 0;
		for (j=0; j<mp->totloop; j++, ml++) {
			med = cddm->medge + ml->e;
			if (LIKELY(med->v1 != med->v2)) {
				newl[j+mp->loopstart] = BLI_array_count(mloop);
				BLI_array_append(oldl, j+mp->loopstart);
				BLI_array_append(mloop, *ml);
				c++;
			}
		}

		if (UNLIKELY(c == 0)) {
			continue;
		}
		
		mp2 = BLI_array_append_r(mpoly, *mp);
		mp2->totloop = c;
		mp2->loopstart = BLI_array_count(mloop) - c;
		
		BLI_array_append(oldp, i);
	}
	
	/*create new cddm*/	
	cddm2 = (CDDerivedMesh*) CDDM_from_template((DerivedMesh*)cddm, BLI_array_count(mvert), BLI_array_count(medge), 0, BLI_array_count(mloop), BLI_array_count(mpoly));
	
	/*update edge indices and copy customdata*/
	med = medge;
	for (i=0; i<cddm2->dm.numEdgeData; i++, med++) {
		if (newv[med->v1] != -1)
			med->v1 = newv[med->v1];
		if (newv[med->v2] != -1)
			med->v2 = newv[med->v2];
		
		CustomData_copy_data(&dm->edgeData, &cddm2->dm.edgeData, olde[i], i, 1);
	}
	
	/*update loop indices and copy customdata*/
	ml = mloop;
	for (i=0; i<cddm2->dm.numLoopData; i++, ml++) {
		if (newe[ml->e] != -1)
			ml->e = newe[ml->e];
		if (newv[ml->v] != -1)
			ml->v = newv[ml->v];
			
		CustomData_copy_data(&dm->loopData, &cddm2->dm.loopData, oldl[i], i, 1);
	}
	
	/*copy vertex customdata*/	
	mv = mvert;
	for (i=0; i<cddm2->dm.numVertData; i++, mv++) {
		CustomData_copy_data(&dm->vertData, &cddm2->dm.vertData, oldv[i], i, 1);
	}
	
	/*copy poly customdata*/
	mp = mpoly;
	for (i=0; i<cddm2->dm.numPolyData; i++, mp++) {
		CustomData_copy_data(&dm->polyData, &cddm2->dm.polyData, oldp[i], i, 1);
	}
	
	/*copy over data.  CustomData_add_layer can do this, need to look it up.*/
	memcpy(cddm2->mvert, mvert, sizeof(MVert)*BLI_array_count(mvert));
	memcpy(cddm2->medge, medge, sizeof(MEdge)*BLI_array_count(medge));
	memcpy(cddm2->mloop, mloop, sizeof(MLoop)*BLI_array_count(mloop));
	memcpy(cddm2->mpoly, mpoly, sizeof(MPoly)*BLI_array_count(mpoly));
	BLI_array_free(mvert); BLI_array_free(medge); BLI_array_free(mloop); BLI_array_free(mpoly);
	
	if (newv) 
		MEM_freeN(newv); 
	if (newe)
		MEM_freeN(newe); 
	if (newl)
		MEM_freeN(newl);
	if (oldv) 
		MEM_freeN(oldv); 
	if (olde) 
		MEM_freeN(olde); 
	if (oldl) 
		MEM_freeN(oldl); 
	if (oldp) 
		MEM_freeN(oldp);
	if (ehash)
		BLI_edgehash_free(ehash, NULL);

	/*free old derivedmesh*/
	dm->needsFree = 1;
	dm->release(dm);
	
	return (DerivedMesh*)cddm2;
}
#endif

void CDDM_calc_edges_tessface(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	CustomData edgeData;
	EdgeHashIterator *ehi;
	MFace *mf = cddm->mface;
	MEdge *med;
	EdgeHash *eh = BLI_edgehash_new();
	int i, *index, numEdges, maxFaces = dm->numTessFaceData;

	for (i = 0; i < maxFaces; i++, mf++) {
		if (!BLI_edgehash_haskey(eh, mf->v1, mf->v2))
			BLI_edgehash_insert(eh, mf->v1, mf->v2, NULL);
		if (!BLI_edgehash_haskey(eh, mf->v2, mf->v3))
			BLI_edgehash_insert(eh, mf->v2, mf->v3, NULL);
		
		if (mf->v4) {
			if (!BLI_edgehash_haskey(eh, mf->v3, mf->v4))
				BLI_edgehash_insert(eh, mf->v3, mf->v4, NULL);
			if (!BLI_edgehash_haskey(eh, mf->v4, mf->v1))
				BLI_edgehash_insert(eh, mf->v4, mf->v1, NULL);
		} else {
			if (!BLI_edgehash_haskey(eh, mf->v3, mf->v1))
				BLI_edgehash_insert(eh, mf->v3, mf->v1, NULL);
		}
	}

	numEdges = BLI_edgehash_size(eh);

	/* write new edges into a temporary CustomData */
	memset(&edgeData, 0, sizeof(edgeData));
	CustomData_add_layer(&edgeData, CD_MEDGE, CD_CALLOC, NULL, numEdges);
	CustomData_add_layer(&edgeData, CD_ORIGINDEX, CD_CALLOC, NULL, numEdges);

	ehi = BLI_edgehashIterator_new(eh);
	med = CustomData_get_layer(&edgeData, CD_MEDGE);
	index = CustomData_get_layer(&edgeData, CD_ORIGINDEX);
	for(i = 0; !BLI_edgehashIterator_isDone(ehi);
		BLI_edgehashIterator_step(ehi), ++i, ++med, ++index) {
		BLI_edgehashIterator_getKey(ehi, &med->v1, &med->v2);

		med->flag = ME_EDGEDRAW|ME_EDGERENDER;
		*index = ORIGINDEX_NONE;
	}
	BLI_edgehashIterator_free(ehi);

	/* free old CustomData and assign new one */
	CustomData_free(&dm->edgeData, dm->numEdgeData);
	dm->edgeData = edgeData;
	dm->numEdgeData = numEdges;

	cddm->medge = CustomData_get_layer(&dm->edgeData, CD_MEDGE);

	BLI_edgehash_free(eh, NULL);
}

/* warning, this uses existing edges but CDDM_calc_edges_tessface() doesn't */
void CDDM_calc_edges(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	CustomData edgeData;
	EdgeHashIterator *ehi;
	MPoly *mp = cddm->mpoly;
	MLoop *ml;
	MEdge *med;
	EdgeHash *eh = BLI_edgehash_new();
	int v1, v2;
	int *eindex;
	int i, j, *index, numEdges = cddm->dm.numEdgeData, maxFaces = dm->numPolyData;

	eindex = DM_get_edge_data_layer(dm, CD_ORIGINDEX);

	med = cddm->medge;
	if (med) {
		for (i=0; i < numEdges; i++, med++) {
			BLI_edgehash_insert(eh, med->v1, med->v2, SET_INT_IN_POINTER(i+1));
		}
	}

	for (i=0; i < maxFaces; i++, mp++) {
		ml = cddm->mloop + mp->loopstart;
		for (j=0; j<mp->totloop; j++, ml++) {
			v1 = ml->v;
			v2 = ME_POLY_LOOP_NEXT(cddm->mloop, mp, j)->v;
			if (!BLI_edgehash_haskey(eh, v1, v2)) {
				BLI_edgehash_insert(eh, v1, v2, NULL);
			}
		}
	}

	numEdges = BLI_edgehash_size(eh);

	/* write new edges into a temporary CustomData */
	memset(&edgeData, 0, sizeof(edgeData));
	CustomData_add_layer(&edgeData, CD_MEDGE, CD_CALLOC, NULL, numEdges);
	CustomData_add_layer(&edgeData, CD_ORIGINDEX, CD_CALLOC, NULL, numEdges);

	ehi = BLI_edgehashIterator_new(eh);
	med = CustomData_get_layer(&edgeData, CD_MEDGE);
	index = CustomData_get_layer(&edgeData, CD_ORIGINDEX);
	for(i = 0; !BLI_edgehashIterator_isDone(ehi);
	    BLI_edgehashIterator_step(ehi), ++i, ++med, ++index) {
		BLI_edgehashIterator_getKey(ehi, &med->v1, &med->v2);
		j = GET_INT_FROM_POINTER(BLI_edgehashIterator_getValue(ehi));

		med->flag = ME_EDGEDRAW|ME_EDGERENDER;
		*index = j==0 ? ORIGINDEX_NONE : eindex[j-1];

		BLI_edgehashIterator_setValue(ehi, SET_INT_IN_POINTER(i));
	}
	BLI_edgehashIterator_free(ehi);

	/* free old CustomData and assign new one */
	CustomData_free(&dm->edgeData, dm->numEdgeData);
	dm->edgeData = edgeData;
	dm->numEdgeData = numEdges;

	cddm->medge = CustomData_get_layer(&dm->edgeData, CD_MEDGE);

	mp = cddm->mpoly;
	for (i=0; i < maxFaces; i++, mp++) {
		ml = cddm->mloop + mp->loopstart;
		for (j=0; j<mp->totloop; j++, ml++) {
			v1 = ml->v;
			v2 = ME_POLY_LOOP_NEXT(cddm->mloop, mp, j)->v;
			ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, v1, v2));
		}
	}

	BLI_edgehash_free(eh, NULL);
}

void CDDM_lower_num_verts(DerivedMesh *dm, int numVerts)
{
	if (numVerts < dm->numVertData)
		CustomData_free_elem(&dm->vertData, numVerts, dm->numVertData-numVerts);

	dm->numVertData = numVerts;
}

void CDDM_lower_num_edges(DerivedMesh *dm, int numEdges)
{
	if (numEdges < dm->numEdgeData)
		CustomData_free_elem(&dm->edgeData, numEdges, dm->numEdgeData-numEdges);

	dm->numEdgeData = numEdges;
}

void CDDM_lower_num_tessfaces(DerivedMesh *dm, int numTessFaces)
{
	if (numTessFaces < dm->numTessFaceData)
		CustomData_free_elem(&dm->faceData, numTessFaces, dm->numTessFaceData-numTessFaces);

	dm->numTessFaceData = numTessFaces;
}

void CDDM_lower_num_polys(DerivedMesh *dm, int numPolys)
{
	if (numPolys < dm->numPolyData)
		CustomData_free_elem(&dm->polyData, numPolys, dm->numPolyData-numPolys);

	dm->numPolyData = numPolys;
}

/* mesh element access functions */

MVert *CDDM_get_vert(DerivedMesh *dm, int index)
{
	return &((CDDerivedMesh*)dm)->mvert[index];
}

MEdge *CDDM_get_edge(DerivedMesh *dm, int index)
{
	return &((CDDerivedMesh*)dm)->medge[index];
}

MFace *CDDM_get_tessface(DerivedMesh *dm, int index)
{
	return &((CDDerivedMesh*)dm)->mface[index];
}

MLoop *CDDM_get_loop(DerivedMesh *dm, int index)
{
	return &((CDDerivedMesh*)dm)->mloop[index];
}

MPoly *CDDM_get_poly(DerivedMesh *dm, int index)
{
	return &((CDDerivedMesh*)dm)->mpoly[index];
}

/* array access functions */

MVert *CDDM_get_verts(DerivedMesh *dm)
{
	return ((CDDerivedMesh*)dm)->mvert;
}

MEdge *CDDM_get_edges(DerivedMesh *dm)
{
	return ((CDDerivedMesh*)dm)->medge;
}

MFace *CDDM_get_tessfaces(DerivedMesh *dm)
{
	return ((CDDerivedMesh*)dm)->mface;
}

MLoop *CDDM_get_loops(DerivedMesh *dm)
{
	return ((CDDerivedMesh*)dm)->mloop;
}

MPoly *CDDM_get_polys(DerivedMesh *dm)
{
	return ((CDDerivedMesh*)dm)->mpoly;
}

void CDDM_tessfaces_to_faces(DerivedMesh *dm)
{
	/*converts mfaces to mpolys/mloops*/
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	MFace *mf;
	MEdge *me;
	EdgeHash *eh = BLI_edgehash_new();
	int i, totloop;
	
	/*ensure we have all the edges we need*/
	CDDM_calc_edges_tessface(dm);

	/*build edge hash*/
	me = cddm->medge;
	for (i=0; i<cddm->dm.numEdgeData; i++, me++) {
		BLI_edgehash_insert(eh, me->v1, me->v2, SET_INT_IN_POINTER(i));
	}

	mf = cddm->mface;
	totloop = 0;
	for (i=0; i<cddm->dm.numTessFaceData; i++, mf++) {
		totloop += mf->v4 ? 4 : 3;
	}

	CustomData_free(&cddm->dm.polyData, cddm->dm.numPolyData);
	CustomData_free(&cddm->dm.loopData, cddm->dm.numLoopData);
	
	cddm->dm.numLoopData = totloop;
	cddm->dm.numPolyData = cddm->dm.numTessFaceData;

	if (totloop) {
		MLoop *ml;
		MPoly *mp;
		int l, *polyindex;

		cddm->mloop = MEM_callocN(sizeof(MLoop)*totloop, "cddm->mloop in CDDM_tessfaces_to_faces");
		cddm->mpoly = MEM_callocN(sizeof(MPoly)*cddm->dm.numTessFaceData, "cddm->mpoly in CDDM_tessfaces_to_faces");

		CustomData_add_layer(&cddm->dm.loopData, CD_MLOOP, CD_ASSIGN, cddm->mloop, totloop);
		CustomData_add_layer(&cddm->dm.polyData, CD_MPOLY, CD_ASSIGN, cddm->mpoly, cddm->dm.numPolyData);
		CustomData_merge(&cddm->dm.faceData, &cddm->dm.polyData,
			CD_MASK_ORIGINDEX, CD_DUPLICATE, cddm->dm.numTessFaceData);

		polyindex = CustomData_get_layer(&cddm->dm.faceData, CD_POLYINDEX);

		mf = cddm->mface;
		mp = cddm->mpoly;
		ml = cddm->mloop;
		l = 0;
		for (i=0; i<cddm->dm.numTessFaceData; i++, mf++, mp++) {
			mp->flag = mf->flag;
			mp->loopstart = l;
			mp->mat_nr = mf->mat_nr;
			mp->totloop = mf->v4 ? 4 : 3;

			ml->v = mf->v1;
			ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, mf->v1, mf->v2));
			ml++, l++;

			ml->v = mf->v2;
			ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, mf->v2, mf->v3));
			ml++, l++;

			ml->v = mf->v3;
			ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, mf->v3, mf->v4?mf->v4:mf->v1));
			ml++, l++;

			if (mf->v4) {
				ml->v = mf->v4;
				ml->e =	GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, mf->v4, mf->v1));
				ml++, l++;
			}

			*polyindex = i;
		}
	}

	BLI_edgehash_free(eh, NULL);
}

void CDDM_set_mvert(DerivedMesh *dm, MVert *mvert)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	
	if (!CustomData_has_layer(&dm->vertData, CD_MVERT))
		CustomData_add_layer(&dm->vertData, CD_MVERT, CD_ASSIGN, mvert, dm->numVertData);
				
	cddm->mvert = mvert;
}

void CDDM_set_medge(DerivedMesh *dm, MEdge *medge)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	if (!CustomData_has_layer(&dm->edgeData, CD_MEDGE))
		CustomData_add_layer(&dm->edgeData, CD_MEDGE, CD_ASSIGN, medge, dm->numEdgeData);

	cddm->medge = medge;
}

void CDDM_set_mface(DerivedMesh *dm, MFace *mface)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	if (!CustomData_has_layer(&dm->faceData, CD_MFACE))
		CustomData_add_layer(&dm->faceData, CD_MFACE, CD_ASSIGN, mface, dm->numTessFaceData);

	cddm->mface = mface;
}

void CDDM_set_mloop(DerivedMesh *dm, MLoop *mloop)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	if (!CustomData_has_layer(&dm->loopData, CD_MLOOP))
		CustomData_add_layer(&dm->loopData, CD_MLOOP, CD_ASSIGN, mloop, dm->numLoopData);

	cddm->mloop = mloop;
}

void CDDM_set_mpoly(DerivedMesh *dm, MPoly *mpoly)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;

	if (!CustomData_has_layer(&dm->polyData, CD_MPOLY))
		CustomData_add_layer(&dm->polyData, CD_MPOLY, CD_ASSIGN, mpoly, dm->numPolyData);

	cddm->mpoly = mpoly;
}