worldspawn/radiant/winding.h

/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined( INCLUDED_WINDING_H )
#define INCLUDED_WINDING_H

#include "debugging/debugging.h"

#include <vector>

#include "math/vector.h"
#include "container/array.h"

enum ProjectionAxis {
    eProjectionAxisX = 0,
    eProjectionAxisY = 1,
    eProjectionAxisZ = 2,
};

const float ProjectionAxisEpsilon = static_cast<float>( 0.0001 );

inline bool projectionaxis_better(float axis, float other)
{
    return fabs(axis) > fabs(other) + ProjectionAxisEpsilon;
}

/// \brief Texture axis precedence: Z > X > Y
inline ProjectionAxis projectionaxis_for_normal(const Vector3 &normal)
{
    return (projectionaxis_better(normal[eProjectionAxisY], normal[eProjectionAxisX]))
           ? (projectionaxis_better(normal[eProjectionAxisY], normal[eProjectionAxisZ]))
             ? eProjectionAxisY
             : eProjectionAxisZ
           : (projectionaxis_better(normal[eProjectionAxisX], normal[eProjectionAxisZ]))
             ? eProjectionAxisX
             : eProjectionAxisZ;
}


struct indexremap_t {
    indexremap_t(std::size_t _x, std::size_t _y, std::size_t _z)
            : x(_x), y(_y), z(_z)
    {
    }

    std::size_t x, y, z;
};

inline indexremap_t indexremap_for_projectionaxis(const ProjectionAxis axis)
{
    switch (axis) {
        case eProjectionAxisX:
            return indexremap_t(1, 2, 0);
        case eProjectionAxisY:
            return indexremap_t(2, 0, 1);
        default:
            return indexremap_t(0, 1, 2);
    }
}

enum PlaneClassification {
    ePlaneFront = 0,
    ePlaneBack = 1,
    ePlaneOn = 2,
};

#define MAX_POINTS_ON_WINDING 64
const std::size_t c_brush_maxFaces = 1024;


class WindingVertex {
public:
    Vector3 vertex;
    Vector2 texcoord;
    Vector3 tangent;
    Vector3 bitangent;
    std::size_t adjacent;
};


struct Winding {
    typedef Array<WindingVertex> container_type;

    std::size_t numpoints;
    container_type points;

    typedef container_type::iterator iterator;
    typedef container_type::const_iterator const_iterator;

    Winding() : numpoints(0)
    {
    }

    Winding(std::size_t size) : numpoints(0), points(size)
    {
    }

    void resize(std::size_t size)
    {
        points.resize(size);
        numpoints = 0;
    }

    iterator begin()
    {
        return points.begin();
    }

    const_iterator begin() const
    {
        return points.begin();
    }

    iterator end()
    {
        return points.begin() + numpoints;
    }

    const_iterator end() const
    {
        return points.begin() + numpoints;
    }

    WindingVertex &operator[](std::size_t index)
    {
        ASSERT_MESSAGE(index < points.size(), "winding: index out of bounds");
        return points[index];
    }

    const WindingVertex &operator[](std::size_t index) const
    {
        ASSERT_MESSAGE(index < points.size(), "winding: index out of bounds");
        return points[index];
    }

    void push_back(const WindingVertex &point)
    {
        points[numpoints] = point;
        ++numpoints;
    }

    void erase(iterator point)
    {
        for (iterator i = point + 1; i != end(); point = i, ++i) {
            *point = *i;
        }
        --numpoints;
    }
};

typedef BasicVector3<double> DoubleVector3;

class DoubleLine {
public:
    DoubleVector3 origin;
    DoubleVector3 direction;
};

class FixedWindingVertex {
public:
    DoubleVector3 vertex;
    DoubleLine edge;
    std::size_t adjacent;

    FixedWindingVertex(const DoubleVector3 &vertex_, const DoubleLine &edge_, std::size_t adjacent_)
            : vertex(vertex_), edge(edge_), adjacent(adjacent_)
    {
    }
};

struct FixedWinding {
    typedef std::vector<FixedWindingVertex> Points;
    Points points;

    FixedWinding()
    {
        points.reserve(MAX_POINTS_ON_WINDING);
    }

    FixedWindingVertex &front()
    {
        return points.front();
    }

    const FixedWindingVertex &front() const
    {
        return points.front();
    }

    FixedWindingVertex &back()
    {
        return points.back();
    }

    const FixedWindingVertex &back() const
    {
        return points.back();
    }

    void clear()
    {
        points.clear();
    }

    void push_back(const FixedWindingVertex &point)
    {
        points.push_back(point);
    }

    std::size_t size() const
    {
        return points.size();
    }

    FixedWindingVertex &operator[](std::size_t index)
    {
        //ASSERT_MESSAGE(index < MAX_POINTS_ON_WINDING, "winding: index out of bounds");
        return points[index];
    }

    const FixedWindingVertex &operator[](std::size_t index) const
    {
        //ASSERT_MESSAGE(index < MAX_POINTS_ON_WINDING, "winding: index out of bounds");
        return points[index];
    }

};


inline void Winding_forFixedWinding(Winding &winding, const FixedWinding &fixed)
{
    winding.resize(fixed.size());
    winding.numpoints = fixed.size();
    for (std::size_t i = 0; i < fixed.size(); ++i) {
        winding[i].vertex[0] = static_cast<float>( fixed[i].vertex[0] );
        winding[i].vertex[1] = static_cast<float>( fixed[i].vertex[1] );
        winding[i].vertex[2] = static_cast<float>( fixed[i].vertex[2] );
        winding[i].adjacent = fixed[i].adjacent;
    }
}

inline std::size_t Winding_wrap(const Winding &winding, std::size_t i)
{
    ASSERT_MESSAGE(winding.numpoints != 0, "Winding_wrap: empty winding");
    return i % winding.numpoints;
}

inline std::size_t Winding_next(const Winding &winding, std::size_t i)
{
    return Winding_wrap(winding, ++i);
}


class Plane3;

void Winding_createInfinite(FixedWinding &w, const Plane3 &plane, double infinity);

const double ON_EPSILON = 1.0 / (1 << 8);

/// \brief Returns true if edge (\p x, \p y) is smaller than the epsilon used to classify winding points against a plane.
inline bool Edge_isDegenerate(const Vector3 &x, const Vector3 &y)
{
    return vector3_length_squared(y - x) < (ON_EPSILON * ON_EPSILON);
}

void Winding_Clip(const FixedWinding &winding, const Plane3 &plane, const Plane3 &clipPlane, std::size_t adjacent,
                  FixedWinding &clipped);

struct brushsplit_t {
    brushsplit_t()
    {
        counts[0] = 0;
        counts[1] = 0;
        counts[2] = 0;
    }

    brushsplit_t &operator+=(const brushsplit_t &other)
    {
        counts[0] += other.counts[0];
        counts[1] += other.counts[1];
        counts[2] += other.counts[2];
        return *this;
    }

    std::size_t counts[3];
};

brushsplit_t Winding_ClassifyPlane(const Winding &w, const Plane3 &plane);

bool Winding_PlanesConcave(const Winding &w1, const Winding &w2, const Plane3 &plane1, const Plane3 &plane2);

bool Winding_TestPlane(const Winding &w, const Plane3 &plane, bool flipped);

std::size_t Winding_FindAdjacent(const Winding &w, std::size_t face);

std::size_t Winding_Opposite(const Winding &w, const std::size_t index, const std::size_t other);

std::size_t Winding_Opposite(const Winding &w, std::size_t index);

void Winding_Centroid(const Winding &w, const Plane3 &plane, Vector3 &centroid);


inline void Winding_printConnectivity(Winding &winding)
{
    for (Winding::iterator i = winding.begin(); i != winding.end(); ++i) {
        std::size_t vertexIndex = std::distance(winding.begin(), i);
        globalOutputStream() << "vertex: " << Unsigned(vertexIndex) << " adjacent: " << Unsigned((*i).adjacent) << "\n";
    }
}

#endif