/*
* $Id$
*
* ***** 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, 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.
*
*/ 

/* TODO maybe BIF_gl.h should include string.h? */
#include <string.h>
#include "BIF_gl.h"

#include "BKE_cdderivedmesh.h"
#include "BKE_customdata.h"
#include "BKE_DerivedMesh.h"
#include "BKE_displist.h"
#include "BKE_global.h"
#include "BKE_mesh.h"
#include "BKE_utildefines.h"

#include "BLI_arithb.h"
#include "BLI_blenlib.h"
#include "BLI_edgehash.h"
#include "BLI_editVert.h"
#include "BLI_ghash.h"

#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_fluidsim.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "MEM_guardedalloc.h"

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

#include <string.h>
#include <limits.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;
} 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_getNumFaces(DerivedMesh *dm)
{
	return dm->numFaceData;
}

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_getFace(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_copyFaceArray(DerivedMesh *dm, MFace *face_r)
{
	CDDerivedMesh *cddm = (CDDerivedMesh *)dm;
	memcpy(face_r, cddm->mface, sizeof(*face_r) * dm->numFaceData);
}

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;

	VECCOPY(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++)
		VECCOPY(cos_r[i], mv->co);
}

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

	no_r[0] = no[0]/32767.f;
	no_r[1] = no[1]/32767.f;
	no_r[2] = no[2]/32767.f;
}

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

	glBegin(GL_POINTS);
	for(i = 0; i < dm->numVertData; i++, mv++)
		glVertex3fv(mv->co);
	glEnd();
}

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

	if(mf) {
		glBegin(GL_LINES);
		for(i = 0; i < dm->numFaceData; 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();
	}
}

static void cdDM_drawEdges(DerivedMesh *dm, int drawLooseEdges)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mvert = cddm->mvert;
	MEdge *medge = cddm->medge;
	int i;
		
	glBegin(GL_LINES);
	for(i = 0; i < dm->numEdgeData; i++, medge++) {
		if((medge->flag&ME_EDGEDRAW)
		   && (drawLooseEdges || !(medge->flag&ME_LOOSEEDGE))) {
			glVertex3fv(mvert[medge->v1].co);
			glVertex3fv(mvert[medge->v2].co);
		}
	}
	glEnd();
}

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

	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();
}

static void cdDM_drawFacesSolid(DerivedMesh *dm, int (*setMaterial)(int, void *attribs))
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mvert = cddm->mvert;
	MFace *mface = cddm->mface;
	float *nors= dm->getFaceDataArray(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);	\
}

	glBegin(glmode = GL_QUADS);
	for(a = 0; a < dm->numFaceData; 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) {
						CalcNormFloat4(mvert[mface->v1].co, mvert[mface->v2].co,
									   mvert[mface->v3].co, mvert[mface->v4].co,
									   nor);
					} else {
						CalcNormFloat(mvert[mface->v1].co, mvert[mface->v2].co,
									  mvert[mface->v3].co, nor);
					}
					glNormal3fv(nor);
				}
			}

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

		if(nors) nors += 3;
	}
	glEnd();

	glShadeModel(GL_FLAT);
#undef PASSVERT
}

static void cdDM_drawFacesColored(DerivedMesh *dm, int useTwoSided, unsigned char *col1, unsigned char *col2)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	int a, glmode;
	unsigned char *cp1, *cp2;
	MVert *mvert = cddm->mvert;
	MFace *mface = cddm->mface;

	cp1 = col1;
	if(col2) {
		cp2 = col2;
	} else {
		cp2 = NULL;
		useTwoSided = 0;
	}

	/* there's a conflict here... twosided colors versus culling...? */
	/* defined by history, only texture faces have culling option */
	/* we need that as mesh option builtin, next to double sided lighting */
	if(col1 && col2)
		glEnable(GL_CULL_FACE);
	
	glShadeModel(GL_SMOOTH);
	glBegin(glmode = GL_QUADS);
	for(a = 0; a < dm->numFaceData; a++, mface++, cp1 += 16) {
		int new_glmode = mface->v4?GL_QUADS:GL_TRIANGLES;

		if(new_glmode != glmode) {
			glEnd();
			glBegin(glmode = new_glmode);
		}
			
		glColor3ub(cp1[0], cp1[1], cp1[2]);
		glVertex3fv(mvert[mface->v1].co);
		glColor3ub(cp1[4], cp1[5], cp1[6]);
		glVertex3fv(mvert[mface->v2].co);
		glColor3ub(cp1[8], cp1[9], cp1[10]);
		glVertex3fv(mvert[mface->v3].co);
		if(mface->v4) {
			glColor3ub(cp1[12], cp1[13], cp1[14]);
			glVertex3fv(mvert[mface->v4].co);
		}
			
		if(useTwoSided) {
			glColor3ub(cp2[8], cp2[9], cp2[10]);
			glVertex3fv(mvert[mface->v3].co );
			glColor3ub(cp2[4], cp2[5], cp2[6]);
			glVertex3fv(mvert[mface->v2].co );
			glColor3ub(cp2[0], cp2[1], cp2[2]);
			glVertex3fv(mvert[mface->v1].co );
			if(mface->v4) {
				glColor3ub(cp2[12], cp2[13], cp2[14]);
				glVertex3fv(mvert[mface->v4].co );
			}
		}
		if(col2) cp2 += 16;
	}
	glEnd();

	glShadeModel(GL_FLAT);
	glDisable(GL_CULL_FACE);
}

static void cdDM_drawFacesTex_common(DerivedMesh *dm,
               int (*drawParams)(MTFace *tface, MCol *mcol, int matnr),
               int (*drawParamsMapped)(void *userData, int index),
               void *userData) 
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	MFace *mf = cddm->mface;
	MCol *mcol = dm->getFaceDataArray(dm, CD_MCOL);
	float *nors= dm->getFaceDataArray(dm, CD_NORMAL);
	MTFace *tf = DM_get_face_data_layer(dm, CD_MTFACE);
	int i, orig, *index = DM_get_face_data_layer(dm, CD_ORIGINDEX);

	for(i = 0; i < dm->numFaceData; i++, mf++) {
		MVert *mvert;
		int flag;
		unsigned char *cp = NULL;

		if(drawParams) {
			flag = drawParams(tf? &tf[i]: NULL, mcol? &mcol[i*4]: NULL, mf->mat_nr);
		}
		else {
			if(index) {
				orig = *index++;
				if(orig == ORIGINDEX_NONE)		{ if(nors) nors += 3; continue; }
				if(drawParamsMapped) flag = drawParamsMapped(userData, orig);
				else	{ if(nors) nors += 3; continue; }
			}
			else
				if(drawParamsMapped) flag = drawParamsMapped(userData, i);
				else	{ if(nors) nors += 3; continue; }
		}
		
		if(flag != 0) { /* if the flag is 0 it means the face is hidden or invisible */
			if (flag==1 && mcol)
				cp= (unsigned char*) &mcol[i*4];

			if(!(mf->flag&ME_SMOOTH)) {
				if (nors) {
					glNormal3fv(nors);
				}
				else {
					/* TODO make this better (cache facenormals as layer?) */
					float nor[3];
					if(mf->v4) {
						CalcNormFloat4(mv[mf->v1].co, mv[mf->v2].co,
									   mv[mf->v3].co, mv[mf->v4].co,
									   nor);
					} else {
						CalcNormFloat(mv[mf->v1].co, mv[mf->v2].co,
									  mv[mf->v3].co, nor);
					}
					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;
	}
}

static void cdDM_drawFacesTex(DerivedMesh *dm, int (*setDrawOptions)(MTFace *tface, MCol *mcol, int matnr))
{
	cdDM_drawFacesTex_common(dm, setDrawOptions, NULL, NULL);
}

static void cdDM_drawMappedFaces(DerivedMesh *dm, int (*setDrawOptions)(void *userData, int index, int *drawSmooth_r), void *userData, int useColors)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*) dm;
	MVert *mv = cddm->mvert;
	MFace *mf = cddm->mface;
	MCol *mc = DM_get_face_data_layer(dm, CD_MCOL);
	float *nors= dm->getFaceDataArray(dm, CD_NORMAL);
	int i, orig, *index = DM_get_face_data_layer(dm, CD_ORIGINDEX);

	for(i = 0; i < dm->numFaceData; i++, mf++) {
		int drawSmooth = (mf->flag & ME_SMOOTH);

		if(index) {
			orig = *index++;
			if(setDrawOptions && orig == ORIGINDEX_NONE)
				{ if(nors) nors += 3; continue; }
		}
		else
			orig = i;

		if(!setDrawOptions || setDrawOptions(userData, orig, &drawSmooth)) {
			unsigned char *cp = NULL;

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

			glShadeModel(drawSmooth?GL_SMOOTH:GL_FLAT);
			glBegin(mf->v4?GL_QUADS:GL_TRIANGLES);

			if (!drawSmooth) {
				if (nors) {
					glNormal3fv(nors);
				}
				else {
					/* TODO make this better (cache facenormals as layer?) */
					float nor[3];
					if(mf->v4) {
						CalcNormFloat4(mv[mf->v1].co, mv[mf->v2].co,
									   mv[mf->v3].co, mv[mf->v4].co,
									   nor);
					} else {
						CalcNormFloat(mv[mf->v1].co, mv[mf->v2].co,
									  mv[mf->v3].co, nor);
					}
					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;
	}
}

static void cdDM_drawMappedFacesTex(DerivedMesh *dm, int (*setDrawOptions)(void *userData, int index), void *userData)
{
	cdDM_drawFacesTex_common(dm, NULL, setDrawOptions, userData);
}

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

	matnr = -1;
	smoothnormal = 0;
	dodraw = 0;
	transp = GPU_get_material_blend_mode();
	orig_transp = transp;

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

	glShadeModel(GL_SMOOTH);
	glBegin(GL_QUADS);

	for(a = 0; a < dm->numFaceData; a++, mface++) {
		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[a];

			if(orig == ORIGINDEX_NONE)
				continue;
			else if(!setDrawOptions(userData, orig))
				continue;
		}

		if(tf) {
			new_transp = tf[a].transp;

			if(new_transp != transp) {
				glEnd();

				if(new_transp == GPU_BLEND_SOLID && orig_transp != GPU_BLEND_SOLID)
					GPU_set_material_blend_mode(orig_transp);
				else
					GPU_set_material_blend_mode(new_transp);
				transp = new_transp;

				glBegin(GL_QUADS);
			}
		}

		smoothnormal = (mface->flag & ME_SMOOTH);

		if(!smoothnormal) {
			if(nors) {
				glNormal3fv(nors[a]);
			}
			else {
				/* TODO ideally a normal layer should always be available */
				float nor[3];
				if(mface->v4) {
					CalcNormFloat4(mvert[mface->v1].co, mvert[mface->v2].co,
								   mvert[mface->v3].co, mvert[mface->v4].co,
								   nor);
				} else {
					CalcNormFloat(mvert[mface->v1].co, mvert[mface->v2].co,
								  mvert[mface->v3].co, nor);
				}
				glNormal3fv(nor);
			}
		}

#define PASSVERT(index, vert) {													\
	if(attribs.totorco)															\
		glVertexAttrib3fvARB(attribs.orco.glIndex, attribs.orco.array[index]);	\
	for(b = 0; b < attribs.tottface; b++) {										\
		MTFace *tf = &attribs.tface[b].array[a];								\
		glVertexAttrib2fvARB(attribs.tface[b].glIndex, tf->uv[vert]);			\
	}																			\
	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);					\
	}																			\
	if(attribs.tottang) {														\
		float *tang = attribs.tang.array[a*4 + vert];							\
		glVertexAttrib3fvARB(attribs.tang.glIndex, tang);						\
	}																			\
	if(smoothnormal)															\
		glNormal3sv(mvert[index].no);											\
	glVertex3fv(mvert[index].co);												\
}

		PASSVERT(mface->v1, 0);
		PASSVERT(mface->v2, 1);
		PASSVERT(mface->v3, 2);
		if(mface->v4)
			PASSVERT(mface->v4, 3)
		else
			PASSVERT(mface->v3, 2)

#undef PASSVERT
	}
	glEnd();

	glShadeModel(GL_FLAT);
}

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

static void cdDM_drawMappedEdges(DerivedMesh *dm, int (*setDrawOptions)(void *userData, int index), 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)) {
			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;
	MFace *mf = cddm->mface;
	int i, orig, *index = DM_get_face_data_layer(dm, CD_ORIGINDEX);

	for(i = 0; i < dm->numFaceData; i++, mf++) {
		float cent[3];
		float no[3];

		if (index) {
			orig = *index++;
			if(orig == ORIGINDEX_NONE) continue;
		}
		else
			orig = i;

		VECCOPY(cent, mv[mf->v1].co);
		VecAddf(cent, cent, mv[mf->v2].co);
		VecAddf(cent, cent, mv[mf->v3].co);

		if (mf->v4) {
			CalcNormFloat4(mv[mf->v1].co, mv[mf->v2].co,
			               mv[mf->v3].co, mv[mf->v4].co, no);
			VecAddf(cent, cent, mv[mf->v4].co);
			VecMulf(cent, 0.25f);
		} else {
			CalcNormFloat(mv[mf->v1].co, mv[mf->v2].co,
			              mv[mf->v3].co, no);
			VecMulf(cent, 0.33333333333f);
		}

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

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

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

/**************** 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->getNumFaces = cdDM_getNumFaces;
	dm->getNumEdges = cdDM_getNumEdges;

	dm->getVert = cdDM_getVert;
	dm->getEdge = cdDM_getEdge;
	dm->getFace = cdDM_getFace;
	dm->copyVertArray = cdDM_copyVertArray;
	dm->copyEdgeArray = cdDM_copyEdgeArray;
	dm->copyFaceArray = cdDM_copyFaceArray;
	dm->getVertData = DM_get_vert_data;
	dm->getEdgeData = DM_get_edge_data;
	dm->getFaceData = DM_get_face_data;
	dm->getVertDataArray = DM_get_vert_data_layer;
	dm->getEdgeDataArray = DM_get_edge_data_layer;
	dm->getFaceDataArray = DM_get_face_data_layer;

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

	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->drawFacesColored = cdDM_drawFacesColored;
	dm->drawFacesTex = cdDM_drawFacesTex;
	dm->drawFacesGLSL = cdDM_drawFacesGLSL;
	dm->drawMappedFaces = cdDM_drawMappedFaces;
	dm->drawMappedFacesTex = cdDM_drawMappedFacesTex;
	dm->drawMappedFacesGLSL = cdDM_drawMappedFacesGLSL;

	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 numFaces)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_new dm");
	DerivedMesh *dm = &cddm->dm;

	DM_init(dm, numVerts, numEdges, numFaces);

	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, numFaces);

	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, numFaces);

	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);

	return dm;
}

DerivedMesh *CDDM_from_mesh(Mesh *mesh, Object *ob)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_from_mesh dm");
	DerivedMesh *dm = &cddm->dm;
	int i, *index, alloctype;

	/* this does a referenced copy, the only new layers being ORIGINDEX,
	 * with an exception for fluidsim */

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

	CustomData_add_layer(&dm->vertData, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totvert);
	CustomData_add_layer(&dm->edgeData, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totedge);
	CustomData_add_layer(&dm->faceData, CD_ORIGINDEX, CD_CALLOC, NULL, mesh->totface);

	dm->deformedOnly = 1;

	alloctype= CD_REFERENCE;

	CustomData_merge(&mesh->vdata, &dm->vertData, CD_MASK_MESH, alloctype,
	                 mesh->totvert);
	CustomData_merge(&mesh->edata, &dm->edgeData, CD_MASK_MESH, alloctype,
	                 mesh->totedge);
	CustomData_merge(&mesh->fdata, &dm->faceData, CD_MASK_MESH, alloctype,
	                 mesh->totface);

	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);

	index = CustomData_get_layer(&dm->vertData, CD_ORIGINDEX);
	for(i = 0; i < mesh->totvert; ++i, ++index)
		*index = i;

	index = CustomData_get_layer(&dm->edgeData, CD_ORIGINDEX);
	for(i = 0; i < mesh->totedge; ++i, ++index)
		*index = i;

	index = CustomData_get_layer(&dm->faceData, CD_ORIGINDEX);
	for(i = 0; i < mesh->totface; ++i, ++index)
		*index = i;
	
	/* works in conjunction with hack during modifier calc, where active mcol
	   layer with weight paint colors is temporarily added */
	if ((G.f & G_WEIGHTPAINT) &&
		(ob && ob==(G.scene->basact?G.scene->basact->object:NULL)))
		CustomData_duplicate_referenced_layer(&dm->faceData, CD_MCOL);

	return dm;
}

DerivedMesh *CDDM_from_editmesh(EditMesh *em, Mesh *me)
{
	DerivedMesh *dm = CDDM_new(BLI_countlist(&em->verts),
	                           BLI_countlist(&em->edges),
	                           BLI_countlist(&em->faces));
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	EditVert *eve;
	EditEdge *eed;
	EditFace *efa;
	MVert *mvert = cddm->mvert;
	MEdge *medge = cddm->medge;
	MFace *mface = cddm->mface;
	int i, *index;

	dm->deformedOnly = 1;

	CustomData_merge(&em->vdata, &dm->vertData, CD_MASK_DERIVEDMESH,
	                 CD_CALLOC, dm->numVertData);
	/* CustomData_merge(&em->edata, &dm->edgeData, CD_MASK_DERIVEDMESH,
	                 CD_CALLOC, dm->numEdgeData); */
	CustomData_merge(&em->fdata, &dm->faceData, CD_MASK_DERIVEDMESH,
	                 CD_CALLOC, dm->numFaceData);

	/* set eve->hash to vert index */
	for(i = 0, eve = em->verts.first; eve; eve = eve->next, ++i)
		eve->tmp.l = i;

	/* Need to be able to mark loose edges */
	for(eed = em->edges.first; eed; eed = eed->next) {
		eed->f2 = 0;
	}
	for(efa = em->faces.first; efa; efa = efa->next) {
		efa->e1->f2 = 1;
		efa->e2->f2 = 1;
		efa->e3->f2 = 1;
		if(efa->e4) efa->e4->f2 = 1;
	}

	index = dm->getVertDataArray(dm, CD_ORIGINDEX);
	for(i = 0, eve = em->verts.first; i < dm->numVertData;
	    i++, eve = eve->next, index++) {
		MVert *mv = &mvert[i];

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

		mv->no[0] = eve->no[0] * 32767.0;
		mv->no[1] = eve->no[1] * 32767.0;
		mv->no[2] = eve->no[2] * 32767.0;
		mv->bweight = (unsigned char) (eve->bweight * 255.0f);

		mv->mat_nr = 0;
		mv->flag = 0;

		*index = i;

		CustomData_from_em_block(&em->vdata, &dm->vertData, eve->data, i);
	}

	index = dm->getEdgeDataArray(dm, CD_ORIGINDEX);
	for(i = 0, eed = em->edges.first; i < dm->numEdgeData;
	    i++, eed = eed->next, index++) {
		MEdge *med = &medge[i];

		med->v1 = eed->v1->tmp.l;
		med->v2 = eed->v2->tmp.l;
		med->crease = (unsigned char) (eed->crease * 255.0f);
		med->bweight = (unsigned char) (eed->bweight * 255.0f);
		med->flag = ME_EDGEDRAW|ME_EDGERENDER;
		
		if(eed->seam) med->flag |= ME_SEAM;
		if(eed->sharp) med->flag |= ME_SHARP;
		if(!eed->f2) med->flag |= ME_LOOSEEDGE;

		*index = i;

		/* CustomData_from_em_block(&em->edata, &dm->edgeData, eed->data, i); */
	}

	index = dm->getFaceDataArray(dm, CD_ORIGINDEX);
	for(i = 0, efa = em->faces.first; i < dm->numFaceData;
	    i++, efa = efa->next, index++) {
		MFace *mf = &mface[i];

		mf->v1 = efa->v1->tmp.l;
		mf->v2 = efa->v2->tmp.l;
		mf->v3 = efa->v3->tmp.l;
		mf->v4 = efa->v4 ? efa->v4->tmp.l : 0;
		mf->mat_nr = efa->mat_nr;
		mf->flag = efa->flag;

		*index = i;

		CustomData_from_em_block(&em->fdata, &dm->faceData, efa->data, i);
		test_index_face(mf, &dm->faceData, i, efa->v4?4:3);
	}

	return dm;
}

DerivedMesh *CDDM_copy(DerivedMesh *source)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_copy cddm");
	DerivedMesh *dm = &cddm->dm;
	int numVerts = source->numVertData;
	int numEdges = source->numEdgeData;
	int numFaces = source->numFaceData;

	/* this initializes dm, and copies all non mvert/medge/mface layers */
	DM_from_template(dm, source, numVerts, numEdges, numFaces);
	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, numFaces);

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

	return dm;
}

DerivedMesh *CDDM_from_template(DerivedMesh *source,
                                int numVerts, int numEdges, int numFaces)
{
	CDDerivedMesh *cddm = cdDM_create("CDDM_from_template dest");
	DerivedMesh *dm = &cddm->dm;

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

	/* 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, numFaces);

	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);

	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);
	cddm->mvert = vert;

	for(i = 0; i < dm->numVertData; ++i, ++vert)
		VECCOPY(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);
	cddm->mvert = vert;

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

/* adapted from mesh_calc_normals */
void CDDM_calc_normals(DerivedMesh *dm)
{
	CDDerivedMesh *cddm = (CDDerivedMesh*)dm;
	float (*temp_nors)[3];
	float (*face_nors)[3];
	int i;
	int numVerts = dm->numVertData;
	int numFaces = dm->numFaceData;
	MFace *mf;
	MVert *mv;

	if(numVerts == 0) return;

	temp_nors = MEM_callocN(numVerts * sizeof(*temp_nors),
	                        "CDDM_calc_normals temp_nors");

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

	/* make a face normal layer if not present */
	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->numFaceData);

	/* calculate face normals and add to vertex normals */
	mf = CDDM_get_faces(dm);
	for(i = 0; i < numFaces; i++, mf++) {
		float *f_no = face_nors[i];

		if(mf->v4)
			CalcNormFloat4(mv[mf->v1].co, mv[mf->v2].co,
			               mv[mf->v3].co, mv[mf->v4].co, f_no);
		else
			CalcNormFloat(mv[mf->v1].co, mv[mf->v2].co,
			              mv[mf->v3].co, f_no);
		
		VecAddf(temp_nors[mf->v1], temp_nors[mf->v1], f_no);
		VecAddf(temp_nors[mf->v2], temp_nors[mf->v2], f_no);
		VecAddf(temp_nors[mf->v3], temp_nors[mf->v3], f_no);
		if(mf->v4)
			VecAddf(temp_nors[mf->v4], temp_nors[mf->v4], f_no);
	}

	/* normalize vertex normals and assign */
	for(i = 0; i < numVerts; i++, mv++) {
		float *no = temp_nors[i];
		
		if (Normalize(no) == 0.0) {
			VECCOPY(no, mv->co);
			Normalize(no);
		}

		mv->no[0] = (short)(no[0] * 32767.0);
		mv->no[1] = (short)(no[1] * 32767.0);
		mv->no[2] = (short)(no[2] * 32767.0);
	}
	
	MEM_freeN(temp_nors);
}

void CDDM_calc_edges(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->numFaceData;

	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, (int*)&med->v1, (int*)&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->numVertData);
	dm->edgeData = edgeData;
	dm->numEdgeData = numEdges;

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

	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_faces(DerivedMesh *dm, int numFaces)
{
	if (numFaces < dm->numFaceData)
		CustomData_free_elem(&dm->faceData, numFaces, dm->numFaceData-numFaces);

	dm->numFaceData = numFaces;
}

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

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

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

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