/*
   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_RENDERER_H )
#define INCLUDED_RENDERER_H

#include "irender.h"
#include "renderable.h"
#include "iselection.h"
#include "cullable.h"
#include "scenelib.h"
#include "math/frustum.h"
#include <vector>

inline Cullable *Instance_getCullable(scene::Instance &instance)
{
    return InstanceTypeCast<Cullable>::cast(instance);
}

inline Renderable *Instance_getRenderable(scene::Instance &instance)
{
    return InstanceTypeCast<Renderable>::cast(instance);
}

inline VolumeIntersectionValue
Cullable_testVisible(scene::Instance &instance, const VolumeTest &volume, VolumeIntersectionValue parentVisible)
{
    if (parentVisible == c_volumePartial) {
        Cullable *cullable = Instance_getCullable(instance);
        if (cullable != 0) {
            return cullable->intersectVolume(volume, instance.localToWorld());
        }
    }
    return parentVisible;
}

template<typename _Walker>
class CullingWalker {
    const VolumeTest &m_volume;
    const _Walker &m_walker;
public:
    CullingWalker(const VolumeTest &volume, const _Walker &walker)
            : m_volume(volume), m_walker(walker)
    {
    }

    bool pre(const scene::Path &path, scene::Instance &instance, VolumeIntersectionValue parentVisible) const
    {
        VolumeIntersectionValue visible = Cullable_testVisible(instance, m_volume, parentVisible);
        if (visible != c_volumeOutside) {
            return m_walker.pre(path, instance);
        }
        return true;
    }

    void post(const scene::Path &path, scene::Instance &instance, VolumeIntersectionValue parentVisible) const
    {
        return m_walker.post(path, instance);
    }
};

template<typename Walker_>
class ForEachVisible : public scene::Graph::Walker {
    const VolumeTest &m_volume;
    const Walker_ &m_walker;
    mutable std::vector<VolumeIntersectionValue> m_state;
public:
    ForEachVisible(const VolumeTest &volume, const Walker_ &walker)
            : m_volume(volume), m_walker(walker)
    {
        m_state.push_back(c_volumePartial);
    }

    bool pre(const scene::Path &path, scene::Instance &instance) const
    {
        VolumeIntersectionValue visible = (path.top().get().visible()) ? m_state.back() : c_volumeOutside;

        if (visible == c_volumePartial) {
            visible = m_volume.TestAABB(instance.worldAABB());
        }

        m_state.push_back(visible);

        if (visible == c_volumeOutside) {
            return false;
        } else {
            return m_walker.pre(path, instance, m_state.back());
        }
    }

    void post(const scene::Path &path, scene::Instance &instance) const
    {
        if (m_state.back() != c_volumeOutside) {
            m_walker.post(path, instance, m_state.back());
        }

        m_state.pop_back();
    }
};

template<typename Functor>
inline void Scene_forEachVisible(scene::Graph &graph, const VolumeTest &volume, const Functor &functor)
{
    graph.traverse(ForEachVisible<CullingWalker<Functor> >(volume, CullingWalker<Functor>(volume, functor)));
}

class RenderHighlighted {
    Renderer &m_renderer;
    const VolumeTest &m_volume;
public:
    RenderHighlighted(Renderer &renderer, const VolumeTest &volume)
            : m_renderer(renderer), m_volume(volume)
    {
    }

    void render(const Renderable &renderable) const
    {
        switch (m_renderer.getStyle()) {
            case Renderer::eFullMaterials:
                renderable.renderSolid(m_renderer, m_volume);
                break;
            case Renderer::eWireframeOnly:
                renderable.renderWireframe(m_renderer, m_volume);
                break;
        }
    }

    typedef ConstMemberCaller<RenderHighlighted, void(const Renderable &), &RenderHighlighted::render> RenderCaller;

    bool pre(const scene::Path &path, scene::Instance &instance, VolumeIntersectionValue parentVisible) const
    {
        m_renderer.PushState();

        if (Cullable_testVisible(instance, m_volume, parentVisible) != c_volumeOutside) {
            Renderable *renderable = Instance_getRenderable(instance);
            if (renderable) {
                renderable->viewChanged();
            }

            Selectable *selectable = Instance_getSelectable(instance);
            if (selectable != 0 && selectable->isSelected()) {
                if (GlobalSelectionSystem().Mode() != SelectionSystem::eComponent) {
                    m_renderer.Highlight(Renderer::eFace);
                } else if (renderable) {
                    renderable->renderComponents(m_renderer, m_volume);
                }
                m_renderer.Highlight(Renderer::ePrimitive);
            }

            if (renderable) {
                render(*renderable);
            }
        }

        return true;
    }

    void post(const scene::Path &path, scene::Instance &instance, VolumeIntersectionValue parentVisible) const
    {
        m_renderer.PopState();
    }
};

inline void Scene_Render(Renderer &renderer, const VolumeTest &volume)
{
    GlobalSceneGraph().traverse(ForEachVisible<RenderHighlighted>(volume, RenderHighlighted(renderer, volume)));
    GlobalShaderCache().forEachRenderable(RenderHighlighted::RenderCaller(RenderHighlighted(renderer, volume)));
}

#endif