vmap/radiant/view.h

/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   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_VIEW_H )
#define INCLUDED_VIEW_H

#include "globaldefs.h"
#include "cullable.h"
#include "math/frustum.h"


#if GDEF_DEBUG
#define DEBUG_CULLING
#endif


#if defined( DEBUG_CULLING )

extern int g_count_dots;
extern int g_count_planes;
extern int g_count_oriented_planes;
extern int g_count_bboxs;
extern int g_count_oriented_bboxs;

#endif

inline void debug_count_dot()
{
#if defined( DEBUG_CULLING )
    ++g_count_dots;
#endif
}

inline void debug_count_plane()
{
#if defined( DEBUG_CULLING )
    ++g_count_planes;
#endif
}

inline void debug_count_oriented_plane()
{
#if defined( DEBUG_CULLING )
    ++g_count_oriented_planes;
#endif
}

inline void debug_count_bbox()
{
#if defined( DEBUG_CULLING )
    ++g_count_bboxs;
#endif
}

inline void debug_count_oriented_bbox()
{
#if defined( DEBUG_CULLING )
    ++g_count_oriented_bboxs;
#endif
}


/// \brief View-volume culling and transformations.
class View : public VolumeTest {
/// modelview matrix
    Matrix4 m_modelview;
/// projection matrix
    Matrix4 m_projection;
/// device-to-screen transform
    Matrix4 m_viewport;

    Matrix4 m_scissor;

/// combined modelview and projection matrix
    Matrix4 m_viewproj;
/// camera position in world space
    Vector4 m_viewer;
/// view frustum in world space
    Frustum m_frustum;

    bool m_fill;

    void construct()
    {
        m_viewproj = matrix4_multiplied_by_matrix4(matrix4_multiplied_by_matrix4(m_scissor, m_projection), m_modelview);

        m_frustum = frustum_from_viewproj(m_viewproj);
        m_viewer = viewer_from_viewproj(m_viewproj);
    }

public:
    View(bool fill = false) :
            m_modelview(g_matrix4_identity),
            m_projection(g_matrix4_identity),
            m_scissor(g_matrix4_identity),
            m_fill(fill)
    {
    }

    void Construct(const Matrix4 &projection, const Matrix4 &modelview, std::size_t width, std::size_t height)
    {
        // modelview
        m_modelview = modelview;

        // projection
        m_projection = projection;

        // viewport
        m_viewport = g_matrix4_identity;
        m_viewport[0] = float(width / 2);
        m_viewport[5] = float(height / 2);
        if (fabs(m_projection[11]) > 0.0000001) {
            m_viewport[10] = m_projection[0] * m_viewport[0];
        } else {
            m_viewport[10] = 1 / m_projection[10];
        }

        construct();
    }

    void EnableScissor(float min_x, float max_x, float min_y, float max_y)
    {
        m_scissor = g_matrix4_identity;
        m_scissor[0] = static_cast<float>((max_x - min_x) * 0.5 );
        m_scissor[5] = static_cast<float>((max_y - min_y) * 0.5 );
        m_scissor[12] = static_cast<float>((min_x + max_x) * 0.5 );
        m_scissor[13] = static_cast<float>((min_y + max_y) * 0.5 );
        matrix4_full_invert(m_scissor);

        construct();
    }

    void DisableScissor()
    {
        m_scissor = g_matrix4_identity;

        construct();
    }

    bool TestPoint(const Vector3 &point) const
    {
        return viewproj_test_point(m_viewproj, point);
    }

    bool TestLine(const Segment &segment) const
    {
        return frustum_test_line(m_frustum, segment);
    }

    bool TestPlane(const Plane3 &plane) const
    {
        debug_count_plane();
        return viewer_test_plane(m_viewer, plane);
    }

    bool TestPlane(const Plane3 &plane, const Matrix4 &localToWorld) const
    {
        debug_count_oriented_plane();
        return viewer_test_transformed_plane(m_viewer, plane, localToWorld);
    }

    VolumeIntersectionValue TestAABB(const AABB &aabb) const
    {
        debug_count_bbox();
        return frustum_test_aabb(m_frustum, aabb);
    }

    VolumeIntersectionValue TestAABB(const AABB &aabb, const Matrix4 &localToWorld) const
    {
        debug_count_oriented_bbox();
        return frustum_intersects_transformed_aabb(m_frustum, aabb, localToWorld);
    }

    const Matrix4 &GetViewMatrix() const
    {
        return m_viewproj;
    }

    const Matrix4 &GetViewport() const
    {
        return m_viewport;
    };

    const Matrix4 &GetModelview() const
    {
        return m_modelview;
    }

    const Matrix4 &GetProjection() const
    {
        return m_projection;
    }

    bool fill() const
    {
        return m_fill;
    }

    const Vector3 &getViewer() const
    {
        return vector4_to_vector3(m_viewer);
    }
};

#endif