subd_ring.cpp

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/*
 * Copyright 2006, NVIDIA Corporation Ignacio Castano <icastano@nvidia.com>
 * 
 * Modifications copyright (c) 2011, Blender Foundation.
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "subd_face.h"
#include "subd_ring.h"
#include "subd_stencil.h"
#include "subd_vert.h"

#include "util_algorithm.h"
#include "util_debug.h"
#include "util_math.h"

CCL_NAMESPACE_BEGIN

/* Utility for sorting verts by index */

class vertex_compare
{
public:
    const vector<int>& index;
    vertex_compare(const vector<int>& index_) : index(index_) {}
    bool operator()(int a, int b) const { return index[a] < index[b]; }
};

/* Subd Face Ring */

SubdFaceRing::SubdFaceRing(SubdFace *face, SubdEdge *firstEdge)
{
    m_face = face;
    m_firstEdge = firstEdge;
    m_num_edges = face->num_edges();

    assert(m_num_edges == 3 || m_num_edges == 4);

    initVerts();
}

int SubdFaceRing::num_verts()
{
    return m_verts.size();
}

SubdVert *SubdFaceRing::vertexAt(int i)
{
    return m_verts[i];
}

int SubdFaceRing::vert_index(SubdVert *vertex)
{
    int count = this->num_verts();

    for(int i = 0; i < count; i++)
        if(m_verts[i] == vertex)
            return i;
    
    assert(0);
    return 0;
}

void SubdFaceRing::evaluate_stencils(float3 *P, StencilMask *mask, int num)
{
    /* first we sort verts by id. this way verts will always be added
       in the same order to ensure the exact same float ops happen for control
       points of other patches, so we get water-tight patches */
    int num_verts = m_verts.size();

    vector<int> vmap(num_verts);
    vector<int> vertid(num_verts);

    for(int v = 0; v < num_verts; v++) {
        vmap[v] = v;
        vertid[v] = m_verts[v]->id;
    }

    sort(vmap.begin(), vmap.end(), vertex_compare(vertid));

    /* then evaluate the stencils */
    for(int j = 0; j < num; j++) {
        float3 p = make_float3(0.0f, 0.0f, 0.0f);

        for(int i = 0; i < num_verts; i++) {
            int idx = vmap[i];
            p += m_verts[idx]->co * mask[j][idx];
        }

        P[j] = p;
    }
}

bool SubdFaceRing::is_triangle()
{
    return m_num_edges == 3;
}

bool SubdFaceRing::is_quad()
{
    return m_num_edges == 4;
}

int SubdFaceRing::num_edges()
{
    return m_num_edges;
}

bool SubdFaceRing::is_regular(SubdFace *face)
{
    if(!is_quad(face))
        return false;

    for(SubdFace::EdgeIterator it(face->edges()); !it.isDone(); it.advance()) {
        SubdEdge *edge = it.current();

        /* regular faces don't have boundary edges */
        if(edge->is_boundary())
            return false;

        /* regular faces only have ordinary verts */
        if(edge->vert->valence() != 4)
            return false;

        /* regular faces are only adjacent to quads */
        for(SubdVert::EdgeIterator eit(edge); !eit.isDone(); eit.advance())
            if(eit.current()->face == NULL || eit.current()->face->num_edges() != 4)
                return false;
    }

    return true;
}

bool SubdFaceRing::is_triangle(SubdFace *face)
{
    return face->num_edges() == 3;
}
bool SubdFaceRing::is_quad(SubdFace *face)
{
    return face->num_edges() == 4;
}

bool SubdFaceRing::is_boundary(SubdFace *face)
{
    /* note that face->is_boundary() returns a different result. That function
       returns true when any of the *edges* are on the boundary. however, this
       function returns true if any of the face *verts* are on the boundary.  */

    for(SubdFace::EdgeIterator it(face->edges()); !it.isDone(); it.advance()) {
        SubdEdge *edge = it.current();

        if(edge->vert->is_boundary())
            return true;
    }

    return false;
}

void SubdFaceRing::initVerts()
{
    m_verts.reserve(16);

    /* add face verts */
    for(SubdFace::EdgeIterator it(m_firstEdge); !it.isDone(); it.advance()) {
        SubdEdge *edge = it.current();
        m_verts.push_back(edge->from());
    }
    
    // @@ Add support for non manifold surfaces!
    // The fix: 
    // - not all colocals should point to the same edge.
    // - multiple colocals could belong to different boundaries, make sure they point to the right one.

    // @@ When the face neighborhood wraps that could result in overlapping stencils. 

    // Add surronding verts.
    for(SubdFace::EdgeIterator it(m_firstEdge); !it.isDone(); it.advance()) {
        SubdEdge *firstEdge = it.current();
    
        int i = 0;

        /* traverse edges around vertex */
        for(SubdVert::ReverseEdgeIterator eit(firstEdge); !eit.isDone(); eit.advance(), i++) {
            SubdEdge *edge = eit.current();

            assert(edge->from()->co == firstEdge->from()->co);

            add_vert(edge->to());

            if(edge->face != NULL)
                add_vert(edge->next->to());
        }

        assert(i == firstEdge->from()->valence());
    }
}


void SubdFaceRing::add_vert(SubdVert *vertex)
{
    /* avoid having duplicate verts */
    if(!has_vert(vertex))
        m_verts.push_back(vertex);
}

bool SubdFaceRing::has_vert(SubdVert *vertex)
{
    int num_verts = m_verts.size();

    for(int i = 0; i < num_verts; i++)
        if(m_verts[i]->co == vertex->co)
            return true;

    return false;
}

CCL_NAMESPACE_END