text: /*
  * $Id: MOD_warp.c 40581 2011-09-26 18:51:10Z campbellbarton $
  *
  * ***** 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.
  *
  * Contributor(s): Campbell Barton
  *
  * ***** END GPL LICENSE BLOCK *****
  *
  */
  
  /** \file blender/modifiers/intern/MOD_warp.c
   *  \ingroup modifiers
   */
  
  #include <string.h>
  
  #include "MEM_guardedalloc.h"
  
  #include "BLI_math.h"
  #include "BLI_utildefines.h"
  #include "BLI_string.h"
  
  #include "BKE_cdderivedmesh.h"
  #include "BKE_modifier.h"
  #include "BKE_deform.h"
  #include "BKE_texture.h"
  #include "BKE_colortools.h"
  
  #include "DNA_object_types.h"
  #include "DNA_meshdata_types.h"
  
  #include "depsgraph_private.h"
  
  #include "RE_shader_ext.h"
  
  #include "MOD_util.h"
  
  
  static void initData(ModifierData *md)
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  
  	wmd->curfalloff = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  	wmd->texture = NULL;
  	wmd->strength = 1.0f;
  	wmd->falloff_radius = 1.0f;
  	wmd->falloff_type = eWarp_Falloff_Smooth;
  	wmd->flag = 0;
  }
  
  static void copyData(ModifierData *md, ModifierData *target)
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  	WarpModifierData *twmd = (WarpModifierData*) target;
  
  	twmd->object_from = wmd->object_from;
  	twmd->object_to = wmd->object_to;
  
  	twmd->strength = wmd->strength;
  	twmd->falloff_radius = wmd->falloff_radius;
  	twmd->falloff_type = wmd->falloff_type;
  	BLI_strncpy(twmd->defgrp_name, wmd->defgrp_name, sizeof(twmd->defgrp_name));
  	twmd->curfalloff = curvemapping_copy(wmd->curfalloff);
  
  	/* map info */
  	twmd->texture = wmd->texture;
  	twmd->map_object = wmd->map_object;
  	BLI_strncpy(twmd->uvlayer_name, wmd->uvlayer_name, sizeof(twmd->uvlayer_name));
  	twmd->texmapping= wmd->texmapping;
  }
  
  static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *md)
  {
  	WarpModifierData *wmd = (WarpModifierData *)md;
  	CustomDataMask dataMask = 0;
  
  	/* ask for vertexgroups if we need them */
  	if(wmd->defgrp_name[0]) dataMask |= (CD_MASK_MDEFORMVERT);
  	dataMask |= (CD_MASK_MDEFORMVERT);
  
  	/* ask for UV coordinates if we need them */
  	if(wmd->texmapping == MOD_DISP_MAP_UV) dataMask |= (1 << CD_MTFACE);
  
  	return dataMask;
  }
  
  static int dependsOnTime(ModifierData *md)
  {
  	WarpModifierData *wmd = (WarpModifierData *)md;
  
  	if(wmd->texture) {
  		return BKE_texture_dependsOnTime(wmd->texture);
  	}
  	else {
  		return 0;
  	}
  }
  
  static void freeData(ModifierData *md)
  {
  	WarpModifierData *wmd = (WarpModifierData *) md;
  	curvemapping_free(wmd->curfalloff);
  }
  
  
  static int isDisabled(ModifierData *md, int UNUSED(userRenderParams))
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  
  	return !(wmd->object_from && wmd->object_to);
  }
  
  static void foreachObjectLink(ModifierData *md, Object *ob, ObjectWalkFunc walk, void *userData)
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  
  	walk(userData, ob, &wmd->object_from);
  	walk(userData, ob, &wmd->object_to);
  	walk(userData, ob, &wmd->map_object);
  }
  
  static void foreachIDLink(ModifierData *md, Object *ob, IDWalkFunc walk, void *userData)
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  
  	walk(userData, ob, (ID **)&wmd->texture);
  
  	walk(userData, ob, (ID **)&wmd->object_from);
  	walk(userData, ob, (ID **)&wmd->object_to);
  	walk(userData, ob, (ID **)&wmd->map_object);
  }
  
  static void foreachTexLink(ModifierData *md, Object *ob, TexWalkFunc walk, void *userData)
  {
  	walk(userData, ob, md, "texture");
  }
  
  static void updateDepgraph(ModifierData *md, DagForest *forest, struct Scene *UNUSED(scene),
                             Object *UNUSED(ob), DagNode *obNode)
  {
  	WarpModifierData *wmd = (WarpModifierData*) md;
  
  	if(wmd->object_from && wmd->object_to) {
  		DagNode *fromNode = dag_get_node(forest, wmd->object_from);
  		DagNode *toNode = dag_get_node(forest, wmd->object_to);
  
  		dag_add_relation(forest, fromNode, obNode, DAG_RL_DATA_DATA | DAG_RL_OB_DATA, "Warp Modifier1");
  		dag_add_relation(forest, toNode, obNode, DAG_RL_DATA_DATA | DAG_RL_OB_DATA, "Warp Modifier2");
  	}
  
  	if((wmd->texmapping == MOD_DISP_MAP_OBJECT) && wmd->map_object) {
  		DagNode *curNode = dag_get_node(forest, wmd->map_object);
  		dag_add_relation(forest, curNode, obNode, DAG_RL_DATA_DATA | DAG_RL_OB_DATA, "Warp Modifier3");
  	}
  }
  
  static void warpModifier_do(WarpModifierData *wmd, Object *ob,
                              DerivedMesh *dm, float (*vertexCos)[3], int numVerts)
  {
  	float obinv[4][4];
  	float mat_from[4][4];
  	float mat_from_inv[4][4];
  	float mat_to[4][4];
  	float mat_unit[4][4];
  	float mat_final[4][4];
  
  	float tmat[4][4];
  
  	float strength = wmd->strength;
  	float fac = 1.0f, weight;
  	int i;
  	int defgrp_index;
  	MDeformVert *dvert, *dv= NULL;
  
  	float (*tex_co)[3]= NULL;
  
  	if(!(wmd->object_from && wmd->object_to))
  		return;
  
  	modifier_get_vgroup(ob, dm, wmd->defgrp_name, &dvert, &defgrp_index);
  
  	if(wmd->curfalloff==NULL) /* should never happen, but bad lib linking could cause it */
  		wmd->curfalloff = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  
  	invert_m4_m4(obinv, ob->obmat);
  
  	mul_m4_m4m4(mat_from, wmd->object_from->obmat, obinv);
  	mul_m4_m4m4(mat_to, wmd->object_to->obmat, obinv);
  
  	invert_m4_m4(tmat, mat_from); // swap?
  	mul_m4_m4m4(mat_final, mat_to, tmat);
  
  	invert_m4_m4(mat_from_inv, mat_from);
  
  	unit_m4(mat_unit);
  
  	if(strength < 0.0f) {
  		float loc[3];
  		strength = -strength;
  
  		/* inverted location is not useful, just use the negative */
  		copy_v3_v3(loc, mat_final[3]);
  		invert_m4(mat_final);
  		negate_v3_v3(mat_final[3], loc);
  
  	}
  	weight= strength;
  
  	if(wmd->texture) {
  		tex_co = MEM_mallocN(sizeof(*tex_co) * numVerts, "warpModifier_do tex_co");
  		get_texture_coords((MappingInfoModifierData *)wmd, ob, dm, vertexCos, tex_co, numVerts);
  	}
  
  	for(i = 0; i < numVerts; i++) {
  		float *co = vertexCos[i];
  
  		if(wmd->falloff_type==eWarp_Falloff_None ||
  		        ((fac=len_v3v3(co, mat_from[3])) < wmd->falloff_radius && (fac=(wmd->falloff_radius-fac)/wmd->falloff_radius)) ) {
  
  			/* skip if no vert group found */
  			if(dvert && defgrp_index >= 0) {
  				dv = &dvert[i];
  
  				if(dv) {
  					weight = defvert_find_weight(dv, defgrp_index) * strength;
  					if(weight <= 0.0f) /* Should never occure... */
  						continue;
  				}
  			}
  
  
  			/* closely match PROP_SMOOTH and similar */
  			switch(wmd->falloff_type) {
  			case eWarp_Falloff_None:
  				fac = 1.0f;
  				break;
  			case eWarp_Falloff_Curve:
  				fac = curvemapping_evaluateF(wmd->curfalloff, 0, fac);
  				break;
  			case eWarp_Falloff_Sharp:
  				fac = fac*fac;
  				break;
  			case eWarp_Falloff_Smooth:
  				fac = 3.0f*fac*fac - 2.0f*fac*fac*fac;
  				break;
  			case eWarp_Falloff_Root:
  				fac = (float)sqrt(fac);
  				break;
  			case eWarp_Falloff_Linear:
  				/* pass */
  				break;
  			case eWarp_Falloff_Const:
  				fac = 1.0f;
  				break;
  			case eWarp_Falloff_Sphere:
  				fac = (float)sqrt(2*fac - fac * fac);
  				break;
  			}
  
  			fac *= weight;
  
  			if(tex_co) {
  				TexResult texres;
  				texres.nor = NULL;
  				get_texture_value(wmd->texture, tex_co[i], &texres);
  				fac *= texres.tin;
  			}
  
  			/* into the 'from' objects space */
  			mul_m4_v3(mat_from_inv, co);
  
  			if(fac >= 1.0f) {
  				mul_m4_v3(mat_final, co);
  			}
  			else if(fac > 0.0f) {
  				if(wmd->flag & MOD_WARP_VOLUME_PRESERVE) {
  					/* interpolate the matrix for nicer locations */
  					blend_m4_m4m4(tmat, mat_unit, mat_final, fac);
  					mul_m4_v3(tmat, co);
  				}
  				else {
  					float tvec[3];
  					mul_v3_m4v3(tvec, mat_final, co);
  					interp_v3_v3v3(co, co, tvec, fac);
  				}
  			}
  
  			/* out of the 'from' objects space */
  			mul_m4_v3(mat_from, co);
  		}
  	}
  
  	if(tex_co)
  		MEM_freeN(tex_co);
  
  }
  
  static int warp_needs_dm(WarpModifierData *wmd)
  {
  	return wmd->texture || wmd->defgrp_name[0];
  }
  
  static void deformVerts(ModifierData *md, Object *ob, DerivedMesh *derivedData,
                          float (*vertexCos)[3], int numVerts, int UNUSED(useRenderParams), int UNUSED(isFinalCalc))
  {
  	DerivedMesh *dm= NULL;
  	int use_dm= warp_needs_dm((WarpModifierData *)md);
  
  	if(use_dm) {
  		dm= get_cddm(ob, NULL, derivedData, vertexCos);
  	}
  
  	warpModifier_do((WarpModifierData *)md, ob, dm, vertexCos, numVerts);
  
  	if(use_dm) {
  		if(dm != derivedData) dm->release(dm);
  	}
  }
  
  static void deformVertsEM(ModifierData *md, Object *ob, struct EditMesh *editData,
                            DerivedMesh *derivedData, float (*vertexCos)[3], int numVerts)
  {
  	DerivedMesh *dm = derivedData;
  	int use_dm= warp_needs_dm((WarpModifierData *)md);
  
  	if(use_dm) {
  		if(!derivedData)
  			dm = CDDM_from_editmesh(editData, ob->data);
  	}
  
  	deformVerts(md, ob, dm, vertexCos, numVerts, 0, 0);
  
  	if(use_dm) {
  		if(!derivedData) dm->release(dm);
  	}
  }
  
  
  ModifierTypeInfo modifierType_Warp = {
  	/* name */              "Warp",
  	/* structName */        "WarpModifierData",
  	/* structSize */        sizeof(WarpModifierData),
  	/* type */              eModifierTypeType_OnlyDeform,
  	/* flags */             eModifierTypeFlag_AcceptsCVs
  							| eModifierTypeFlag_SupportsEditmode,
  	/* copyData */          copyData,
  	/* deformVerts */       deformVerts,
  	/* deformMatrices */    NULL,
  	/* deformVertsEM */     deformVertsEM,
  	/* deformMatricesEM */  NULL,
  	/* applyModifier */     0,
  	/* applyModifierEM */   0,
  	/* initData */          initData,
  	/* requiredDataMask */  requiredDataMask,
  	/* freeData */          freeData,
  	/* isDisabled */        isDisabled,
  	/* updateDepgraph */    updateDepgraph,
  	/* dependsOnTime */     dependsOnTime,
  	/* dependsOnNormals */	NULL,
  	/* foreachObjectLink */ foreachObjectLink,
  	/* foreachIDLink */     foreachIDLink,
  	/* foreachTexLink */    foreachTexLink,
  };
  