path: root/source/blender/modifiers/intern/MOD_simpledeform.c

/*
 * ***** 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) 2005 by the Blender Foundation.
 * All rights reserved.
 *
 * Contributor(s): Daniel Dunbar
 *                 Ton Roosendaal,
 *                 Ben Batt,
 *                 Brecht Van Lommel,
 *                 Campbell Barton
 *
 * ***** END GPL LICENSE BLOCK *****
 *
 */

/** \file blender/modifiers/intern/MOD_simpledeform.c
 *  \ingroup modifiers
 */

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

#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "BKE_editmesh.h"
#include "BKE_mesh.h"
#include "BKE_library.h"
#include "BKE_library_query.h"
#include "BKE_modifier.h"
#include "BKE_deform.h"

#include "MOD_util.h"

#include "bmesh.h"

#define BEND_EPS 0.000001f

/* Re-maps the indicies for X Y Z by shifting them up and wrapping, such that
 * X = Y, Y = Z, Z = X (for X axis), and X = Z, Y = X, Z = Y (for Y axis). This
 * exists because the deformations (excluding bend) are based on the Z axis.
 * Having this helps avoid long, drawn out switches. */
static const uint axis_map_table[3][3] = {
	{1, 2, 0},
	{2, 0, 1},
	{0, 1, 2},
};

BLI_INLINE void copy_v3_v3_map(float a[3], const float b[3], const uint map[3])
{
	a[0] = b[map[0]];
	a[1] = b[map[1]];
	a[2] = b[map[2]];
}

BLI_INLINE void copy_v3_v3_unmap(float a[3], const float b[3], const uint map[3])
{
	a[map[0]] = b[0];
	a[map[1]] = b[1];
	a[map[2]] = b[2];
}

/* Clamps/Limits the given coordinate to:  limits[0] <= co[axis] <= limits[1]
 * The amount of clamp is saved on dcut */
static void axis_limit(const int axis, const float limits[2], float co[3], float dcut[3])
{
	float val = co[axis];
	if (limits[0] > val) val = limits[0];
	if (limits[1] < val) val = limits[1];

	dcut[axis] = co[axis] - val;
	co[axis] = val;
}

static void simpleDeform_taper(const float factor, const int UNUSED(axis), const float dcut[3], float r_co[3])
{
	float x = r_co[0], y = r_co[1], z = r_co[2];
	float scale = z * factor;

	r_co[0] = x + x * scale;
	r_co[1] = y + y * scale;
	r_co[2] = z;

	add_v3_v3(r_co, dcut);
}

static void simpleDeform_stretch(const float factor, const int UNUSED(axis), const float dcut[3], float r_co[3])
{
	float x = r_co[0], y = r_co[1], z = r_co[2];
	float scale;

	scale = (z * z * factor - factor + 1.0f);

	r_co[0] = x * scale;
	r_co[1] = y * scale;
	r_co[2] = z * (1.0f + factor);

	add_v3_v3(r_co, dcut);
}

static void simpleDeform_twist(const float factor, const int UNUSED(axis), const float *dcut, float r_co[3])
{
	float x = r_co[0], y = r_co[1], z = r_co[2];
	float theta, sint, cost;

	theta = z * factor;
	sint  = sinf(theta);
	cost  = cosf(theta);

	r_co[0] = x * cost - y * sint;
	r_co[1] = x * sint + y * cost;
	r_co[2] = z;

	add_v3_v3(r_co, dcut);
}

static void simpleDeform_bend(const float factor, const int axis, const float dcut[3], float r_co[3])
{
	float x = r_co[0], y = r_co[1], z = r_co[2];
	float theta, sint, cost;

	BLI_assert(!(fabsf(factor) < BEND_EPS));

	switch (axis) {
		case 0:
			ATTR_FALLTHROUGH;
		case 1:
			theta = z * factor;
			break;
		default:
			theta = x * factor;
	}
	sint = sinf(theta);
	cost = cosf(theta);

	switch (axis) {
		case 0:
			r_co[0] =  x;
			r_co[1] =  (y - 1.0f / factor) * cost + 1.0f / factor;
			r_co[2] = -(y - 1.0f / factor) * sint;
			{
				r_co[0] += dcut[0];
				r_co[1] += sint * dcut[2];
				r_co[2] += cost * dcut[2];
			}
			break;
		case 1:
			r_co[0] =  (x - 1.0f / factor) * cost + 1.0f / factor;
			r_co[1] =  y;
			r_co[2] = -(x - 1.0f / factor) * sint;
			{
				r_co[0] += sint * dcut[2];
				r_co[1] += dcut[1];
				r_co[2] += cost * dcut[2];
			}
			break;
		default:
			r_co[0] = -(y - 1.0f / factor) * sint;
			r_co[1] =  (y - 1.0f / factor) * cost + 1.0f / factor;
			r_co[2] = z;
			{
				r_co[0] += cost * dcut[0];
				r_co[1] += sint * dcut[0];
				r_co[2] += dcut[2];
			}
	}

}


/* simple deform modifier */
static void SimpleDeformModifier_do(
        SimpleDeformModifierData *smd, struct Object *ob, struct Mesh *mesh,
        float (*vertexCos)[3], int numVerts)
{
	const float base_limit[2] = {0.0f, 0.0f};
	int i;
	float smd_limit[2], smd_factor;
	SpaceTransform *transf = NULL, tmp_transf;
	void (*simpleDeform_callback)(const float factor, const int axis, const float dcut[3], float co[3]) = NULL;  /* Mode callback */
	int vgroup;
	MDeformVert *dvert;

	/* This is historically the lock axis, _not_ the deform axis as the name would imply */
	const int deform_axis = smd->deform_axis;
	int lock_axis = smd->axis;
	if (smd->mode == MOD_SIMPLEDEFORM_MODE_BEND) { /* Bend mode shouln't have any lock axis */
		lock_axis = 0;
	}
	else {
		/* Don't lock axis if it is the chosen deform axis, as this flattens
		 * the geometry */
		if (deform_axis == 0) {
			lock_axis &= ~MOD_SIMPLEDEFORM_LOCK_AXIS_X;
		}
		if (deform_axis == 1) {
			lock_axis &= ~MOD_SIMPLEDEFORM_LOCK_AXIS_Y;
		}
		if (deform_axis == 2) {
			lock_axis &= ~MOD_SIMPLEDEFORM_LOCK_AXIS_Z;
		}
	}


	/* Safe-check */
	if (smd->origin == ob) smd->origin = NULL;  /* No self references */

	if (smd->limit[0] < 0.0f) smd->limit[0] = 0.0f;
	if (smd->limit[0] > 1.0f) smd->limit[0] = 1.0f;

	smd->limit[0] = min_ff(smd->limit[0], smd->limit[1]);  /* Upper limit >= than lower limit */

	/* Calculate matrixs do convert between coordinate spaces */
	if (smd->origin) {
		transf = &tmp_transf;
		BLI_SPACE_TRANSFORM_SETUP(transf, ob, smd->origin);
	}

	/* Update limits if needed */
	int limit_axis = deform_axis;
	if (smd->mode == MOD_SIMPLEDEFORM_MODE_BEND) {
		/* Bend is a special case. */
		switch (deform_axis) {
			case 0:
				ATTR_FALLTHROUGH;
			case 1:
				limit_axis = 2;
				break;
			default:
				limit_axis = 0;
		}
	}

	{
		float lower =  FLT_MAX;
		float upper = -FLT_MAX;

		for (i = 0; i < numVerts; i++) {
			float tmp[3];
			copy_v3_v3(tmp, vertexCos[i]);

			if (transf) {
				BLI_space_transform_apply(transf, tmp);
			}

			lower = min_ff(lower, tmp[limit_axis]);
			upper = max_ff(upper, tmp[limit_axis]);
		}


		/* SMD values are normalized to the BV, calculate the absolut values */
		smd_limit[1] = lower + (upper - lower) * smd->limit[1];
		smd_limit[0] = lower + (upper - lower) * smd->limit[0];

		smd_factor   = smd->factor / max_ff(FLT_EPSILON, smd_limit[1] - smd_limit[0]);
	}

	switch (smd->mode) {
		case MOD_SIMPLEDEFORM_MODE_TWIST:   simpleDeform_callback = simpleDeform_twist;     break;
		case MOD_SIMPLEDEFORM_MODE_BEND:    simpleDeform_callback = simpleDeform_bend;      break;
		case MOD_SIMPLEDEFORM_MODE_TAPER:   simpleDeform_callback = simpleDeform_taper;     break;
		case MOD_SIMPLEDEFORM_MODE_STRETCH: simpleDeform_callback = simpleDeform_stretch;   break;
		default:
			return; /* No simpledeform mode? */
	}

	if (smd->mode == MOD_SIMPLEDEFORM_MODE_BEND) {
		if (fabsf(smd_factor) < BEND_EPS) {
			return;
		}
	}

	modifier_get_vgroup_mesh(ob, mesh, smd->vgroup_name, &dvert, &vgroup);
	const bool invert_vgroup = (smd->flag & MOD_SIMPLEDEFORM_FLAG_INVERT_VGROUP) != 0;
	const uint *axis_map = axis_map_table[(smd->mode != MOD_SIMPLEDEFORM_MODE_BEND) ? deform_axis : 2];

	for (i = 0; i < numVerts; i++) {
		float weight = defvert_array_find_weight_safe(dvert, i, vgroup);

		if (invert_vgroup) {
			weight = 1.0f - weight;
		}

		if (weight != 0.0f) {
			float co[3], dcut[3] = {0.0f, 0.0f, 0.0f};

			if (transf) {
				BLI_space_transform_apply(transf, vertexCos[i]);
			}

			copy_v3_v3(co, vertexCos[i]);

			/* Apply axis limits, and axis mappings */
			if (lock_axis & MOD_SIMPLEDEFORM_LOCK_AXIS_X) {
				axis_limit(0, base_limit, co, dcut);
			}
			if (lock_axis & MOD_SIMPLEDEFORM_LOCK_AXIS_Y) {
				axis_limit(1, base_limit, co, dcut);
			}
			if (lock_axis & MOD_SIMPLEDEFORM_LOCK_AXIS_Z) {
				axis_limit(2, base_limit, co, dcut);
			}
			axis_limit(limit_axis, smd_limit, co, dcut);

			/* apply the deform to a mapped copy of the vertex, and then re-map it back. */
			float co_remap[3];
			float dcut_remap[3];
			copy_v3_v3_map(co_remap, co, axis_map);
			copy_v3_v3_map(dcut_remap, dcut, axis_map);
			simpleDeform_callback(smd_factor, deform_axis, dcut_remap, co_remap);  /* apply deform */
			copy_v3_v3_unmap(co, co_remap, axis_map);

			interp_v3_v3v3(vertexCos[i], vertexCos[i], co, weight);  /* Use vertex weight has coef of linear interpolation */

			if (transf) {
				BLI_space_transform_invert(transf, vertexCos[i]);
			}
		}
	}
}


/* SimpleDeform */
static void initData(ModifierData *md)
{
	SimpleDeformModifierData *smd = (SimpleDeformModifierData *) md;

	smd->mode = MOD_SIMPLEDEFORM_MODE_TWIST;
	smd->axis = 0;
	smd->deform_axis = 0;

	smd->origin   =  NULL;
	smd->factor   =  DEG2RADF(45.0f);
	smd->limit[0] =  0.0f;
	smd->limit[1] =  1.0f;
}

static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *md)
{
	SimpleDeformModifierData *smd = (SimpleDeformModifierData *)md;
	CustomDataMask dataMask = 0;

	/* ask for vertexgroups if we need them */
	if (smd->vgroup_name[0])
		dataMask |= CD_MASK_MDEFORMVERT;

	return dataMask;
}

static void foreachObjectLink(
        ModifierData *md, Object *ob,
        ObjectWalkFunc walk, void *userData)
{
	SimpleDeformModifierData *smd  = (SimpleDeformModifierData *)md;
	walk(userData, ob, &smd->origin, IDWALK_CB_NOP);
}

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
	SimpleDeformModifierData *smd  = (SimpleDeformModifierData *)md;
	if (smd->origin != NULL) {
		DEG_add_object_relation(ctx->node, smd->origin, DEG_OB_COMP_TRANSFORM, "SimpleDeform Modifier");
	}
}

static void deformVerts(
        ModifierData *md, const ModifierEvalContext *ctx,
        struct Mesh *mesh,
        float (*vertexCos)[3],
        int numVerts)
{
	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);

	SimpleDeformModifier_do((SimpleDeformModifierData *)md, ctx->object, mesh_src, vertexCos, numVerts);

	if (mesh_src != mesh) {
		BKE_id_free(NULL, mesh_src);
	}
}

static void deformVertsEM(
        ModifierData *md, const ModifierEvalContext *ctx,
        struct BMEditMesh *editData,
        struct Mesh *mesh,
        float (*vertexCos)[3],
        int numVerts)
{
	Mesh *mesh_src = get_mesh(ctx->object, editData, mesh, NULL, false, false);

	SimpleDeformModifier_do((SimpleDeformModifierData *)md, ctx->object, mesh_src, vertexCos, numVerts);

	if (mesh_src != mesh) {
		BKE_id_free(NULL, mesh_src);
	}
}


ModifierTypeInfo modifierType_SimpleDeform = {
	/* name */              "SimpleDeform",
	/* structName */        "SimpleDeformModifierData",
	/* structSize */        sizeof(SimpleDeformModifierData),
	/* type */              eModifierTypeType_OnlyDeform,

	/* flags */             eModifierTypeFlag_AcceptsMesh |
	                        eModifierTypeFlag_AcceptsCVs |
	                        eModifierTypeFlag_AcceptsLattice |
	                        eModifierTypeFlag_SupportsEditmode |
	                        eModifierTypeFlag_EnableInEditmode,

	/* copyData */          modifier_copyData_generic,

	/* deformVerts_DM */    NULL,
	/* deformMatrices_DM */ NULL,
	/* deformVertsEM_DM */  NULL,
	/* deformMatricesEM_DM*/NULL,
	/* applyModifier_DM */  NULL,
	/* applyModifierEM_DM */NULL,

	/* deformVerts */       deformVerts,
	/* deformMatrices */    NULL,
	/* deformVertsEM */     deformVertsEM,
	/* deformMatricesEM */  NULL,
	/* applyModifier */     NULL,
	/* applyModifierEM */   NULL,

	/* initData */          initData,
	/* requiredDataMask */  requiredDataMask,
	/* freeData */          NULL,
	/* isDisabled */        NULL,
	/* updateDepsgraph */   updateDepsgraph,
	/* dependsOnTime */     NULL,
	/* dependsOnNormals */	NULL,
	/* foreachObjectLink */ foreachObjectLink,
	/* foreachIDLink */     NULL,
	/* foreachTexLink */    NULL,
};