Add remesh modifier (dual contouring).

This patch adds a new remeshing modifier. The algorithm is based on
the paper "Dual Contouring of Hermite Data", and the implementation
was contributed to Blender by Dr. Tao Ju.

The contributed code is in intern/dualcon, and was modified to compile
under gcc and work on 64-bit systems. Files not needed for Blender
were removed and a small C wrapper was added in order to interface it
with Blender. The rest of the patch is just standard modifier stuff.

Reviewed by Sergey, code review link:
http://codereview.appspot.com/5491053/

The remesh icon was contributed by Zafio:
http://blenderartists.org/forum/showthread.php?240751-Request-for-modifier-icon/page2.
Thanks to everyone in that thread for the icon proposals and
discussion.

Documentation and examples on the Blender wiki:
http://wiki.blender.org/index.php/User:Nicholasbishop/RemeshModifier

In case the history is needed for anything, check the remesh-modifier
branch of this git repository:
https://gitorious.org/~nicholasbishop/blenderprojects/nicholasbishop-blender

1 files changed, 214 insertions, 0 deletions

diff --git a/source/blender/modifiers/intern/MOD_remesh.c b/source/blender/modifiers/intern/MOD_remesh.c
new file mode 100644
index 00000000000..a58c0416163
--- /dev/null
+++ b/source/blender/modifiers/intern/MOD_remesh.c
@@ -0,0 +1,214 @@
+/*
+* $Id$
+*
+* ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*
+* The Original Code is Copyright (C) 2011 by Nicholas Bishop.
+*
+* ***** END GPL LICENSE BLOCK *****
+*
+*/
+
+/** \file blender/modifiers/intern/MOD_remesh.c
+ *  \ingroup modifiers
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math_vector.h"
+#include "BLI_utildefines.h"
+
+#include "BKE_cdderivedmesh.h"
+#include "BKE_DerivedMesh.h"
+#include "BKE_mesh.h"
+
+#include "DNA_meshdata_types.h"
+#include "DNA_modifier_types.h"
+#include "DNA_object_types.h"
+
+#include "MOD_modifiertypes.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dualcon.h"
+
+static void initData(ModifierData *md)
+{
+	RemeshModifierData *rmd = (RemeshModifierData*) md;
+
+	rmd->scale = 0.9;
+	rmd->depth = 4;
+	rmd->hermite_num = 1;
+	rmd->flag = MOD_REMESH_FLOOD_FILL;
+	rmd->mode = MOD_REMESH_SHARP_FEATURES;
+	rmd->threshold = 1;
+}
+
+static void copyData(ModifierData *md, ModifierData *target)
+{
+	RemeshModifierData *rmd = (RemeshModifierData*) md;
+	RemeshModifierData *trmd = (RemeshModifierData*) target;
+
+	trmd->threshold = rmd->threshold;
+	trmd->scale = rmd->scale;
+	trmd->hermite_num = rmd->hermite_num;
+	trmd->depth = rmd->depth;
+	trmd->flag = rmd->flag;
+	trmd->mode = rmd->mode;
+}
+
+void init_dualcon_mesh(DualConInput *mesh, DerivedMesh *dm)
+{
+	memset(mesh, 0, sizeof(DualConInput));
+
+	mesh->co = (void*)dm->getVertArray(dm);
+	mesh->co_stride = sizeof(MVert);
+	mesh->totco = dm->getNumVerts(dm);
+
+	mesh->faces = (void*)dm->getFaceArray(dm);
+	mesh->face_stride = sizeof(MFace);
+	mesh->totface = dm->getNumFaces(dm);
+
+	dm->getMinMax(dm, mesh->min, mesh->max);
+}
+
+/* simple structure to hold the output: a CDDM and two counters to
+   keep track of the current elements */
+typedef struct {
+	DerivedMesh *dm;
+	int curvert, curface;
+} DualConOutput;
+
+/* allocate and initialize a DualConOutput */
+void *dualcon_alloc_output(int totvert, int totquad)
+{
+	DualConOutput *output;
+
+	if(!(output = MEM_callocN(sizeof(DualConOutput),
+							  "DualConOutput")))
+		return NULL;
+	
+	output->dm = CDDM_new(totvert, 0, totquad);
+	return output;
+}
+
+void dualcon_add_vert(void *output_v, const float co[3])
+{
+	DualConOutput *output = output_v;
+	DerivedMesh *dm = output->dm;
+	
+	assert(output->curvert < dm->getNumVerts(dm));
+	
+	copy_v3_v3(CDDM_get_verts(dm)[output->curvert].co, co);
+	output->curvert++;
+}
+
+void dualcon_add_quad(void *output_v, const int vert_indices[4])
+{
+	DualConOutput *output = output_v;
+	DerivedMesh *dm = output->dm;
+	MFace *mface;
+	
+	assert(output->curface < dm->getNumFaces(dm));
+
+	mface = &CDDM_get_faces(dm)[output->curface];
+	mface->v1 = vert_indices[0];
+	mface->v2 = vert_indices[1];
+	mface->v3 = vert_indices[2];
+	mface->v4 = vert_indices[3];
+	
+	if(test_index_face(mface, NULL, 0, 4))
+		output->curface++;
+}
+
+static DerivedMesh *applyModifier(ModifierData *md,
+								  Object *UNUSED(ob),
+								  DerivedMesh *dm,
+								  int UNUSED(useRenderParams),
+								  int UNUSED(isFinalCalc))
+{
+	RemeshModifierData *rmd;
+	DualConOutput *output;
+	DualConInput input;
+	DerivedMesh *result;
+	DualConFlags flags = 0;
+	DualConMode mode;
+
+	rmd = (RemeshModifierData*)md;
+
+	init_dualcon_mesh(&input, dm);
+
+	if(rmd->flag & MOD_REMESH_FLOOD_FILL)
+		flags |= DUALCON_FLOOD_FILL;
+
+	switch(rmd->mode) {
+	case MOD_REMESH_CENTROID:
+		mode = DUALCON_CENTROID;
+		break;
+	case MOD_REMESH_MASS_POINT:
+		mode = DUALCON_MASS_POINT;
+		break;
+	case MOD_REMESH_SHARP_FEATURES:
+		mode = DUALCON_SHARP_FEATURES;
+		break;
+	}
+	
+	output = dualcon(&input,
+					 dualcon_alloc_output,
+					 dualcon_add_vert,
+					 dualcon_add_quad,
+					 flags,
+					 mode,
+					 rmd->threshold,
+					 rmd->hermite_num,
+					 rmd->scale,
+					 rmd->depth);
+	result = output->dm;
+	CDDM_lower_num_faces(result, output->curface);
+	MEM_freeN(output);
+
+	CDDM_calc_edges(result);
+	CDDM_calc_normals(result);
+
+	return result;
+}
+
+ModifierTypeInfo modifierType_Remesh = {
+	/* name */              "Remesh",
+	/* structName */        "RemeshModifierData",
+	/* structSize */        sizeof(RemeshModifierData),
+	/* type */              eModifierTypeType_Nonconstructive,
+	/* flags */             eModifierTypeFlag_AcceptsMesh |	eModifierTypeFlag_SupportsEditmode,
+	/* copyData */          copyData,
+	/* deformVerts */       NULL,
+	/* deformMatrices */    NULL,
+	/* deformVertsEM */     NULL,
+	/* deformMatricesEM */  NULL,
+	/* applyModifier */     applyModifier,
+	/* applyModifierEM */   NULL,
+	/* initData */          initData,
+	/* requiredDataMask */  NULL,
+	/* freeData */          NULL,
+	/* isDisabled */        NULL,
+	/* updateDepgraph */    NULL,
+	/* dependsOnTime */     NULL,
+	/* dependsOnNormals */	NULL,
+	/* foreachObjectLink */ NULL,
+	/* foreachIDLink */     NULL,
+};