/***********************************************************************
    filename:   CEGUIIrrlichtGeometryBuffer.cpp
    created:    Tue Mar 3 2009
    author:     Paul D Turner (parts based on original code by Thomas Suter)
*************************************************************************/
/***************************************************************************
 *   Copyright (C) 2004 - 2009 Paul D Turner & The CEGUI Development Team
 *
 *   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 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.
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "CEGUIIrrlichtGeometryBuffer.h"
#include "CEGUIRenderEffect.h"
#include "CEGUIIrrlichtTexture.h"
#include "CEGUIVertex.h"

// Start of CEGUI namespace section
namespace CEGUI
{
//----------------------------------------------------------------------------//
IrrlichtGeometryBuffer::IrrlichtGeometryBuffer(irr::video::IVideoDriver& driver):
    d_driver(driver),
    d_activeTexture(0),
    d_translation(0, 0, 0),
    d_rotation(0, 0, 0),
    d_pivot(0, 0, 0),
    d_effect(0),
    d_matrixValid(false),
    d_xViewDir(driver.getDriverType() != irr::video::EDT_OPENGL ? 1.0f : -1.0f),
    d_texelOffset(driver.getDriverType() != irr::video::EDT_OPENGL ? -0.5f : 0.0f)
{
    d_material.BackfaceCulling = false;
    d_material.Lighting = false;
    d_material.ZBuffer = 0;
    d_material.ZWriteEnable = false;
    #if CEGUI_IRR_SDK_VERSION >= 16
        d_material.MaterialType = irr::video::EMT_ONETEXTURE_BLEND;
        d_material.MaterialTypeParam = irr::video::pack_texureBlendFunc(
                irr::video::EBF_SRC_ALPHA,
                irr::video::EBF_ONE_MINUS_SRC_ALPHA,
                irr::video::EMFN_MODULATE_1X,
                irr::video::EAS_NONE);
    #else
        d_material.MaterialType = irr::video::EMT_TRANSPARENT_ALPHA_CHANNEL;
        d_material.MaterialTypeParam = 0;
    #endif
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::draw() const
{
    // Set up clipping for this buffer
    //
    // NB: This is done via viewport & projection manipulation because Irrlicht
    // does not expose scissoring facilities of underlying APIs.  This has the
    // unfortunate side effect of being much more expensive to set up.
    const irr::core::rect<irr::s32> target_vp(d_driver.getViewPort());
    const irr::core::matrix4 proj
        (d_driver.getTransform(irr::video::ETS_PROJECTION));

    const Size csz(d_clipRect.getSize());
    const Size tsz(static_cast<float>(target_vp.getWidth()),
                   static_cast<float>(target_vp.getHeight()));

    // set modified projection 'scissor' matix that negates scale and
    // translation that would be done by setting the viewport to the clip area.
    irr::core::matrix4 scsr(irr::core::matrix4::EM4CONST_IDENTITY);
    scsr(0, 0) = tsz.d_width / csz.d_width;
    scsr(1, 1) = tsz.d_height / csz.d_height;
    scsr(3, 0) = d_xViewDir * (tsz.d_width + 2.0f *
                   (target_vp.UpperLeftCorner.X -
                     (d_clipRect.d_left + csz.d_width * 0.5f))) / csz.d_width;
    scsr(3, 1) = -(tsz.d_height + 2.0f *
                   (target_vp.UpperLeftCorner.Y -
                     (d_clipRect.d_top + csz.d_height * 0.5f))) / csz.d_height;
    scsr *= proj;
    d_driver.setTransform(irr::video::ETS_PROJECTION, scsr);

    // set new viewport for the clipping area
    const irr::core::rect<irr::s32> vp(
            static_cast<irr::s32>(d_clipRect.d_left),
            static_cast<irr::s32>(d_clipRect.d_top),
            static_cast<irr::s32>(d_clipRect.d_right),
            static_cast<irr::s32>(d_clipRect.d_bottom));
    d_driver.setViewPort(vp);

    if (!d_matrixValid)
        updateMatrix();

    d_driver.setTransform(irr::video::ETS_WORLD, d_matrix);

    const int pass_count = d_effect ? d_effect->getPassCount() : 1;
    for (int pass = 0; pass < pass_count; ++pass)
    {
        // set up RenderEffect
        if (d_effect)
            d_effect->performPreRenderFunctions(pass);

        // draw the batches
        size_t pos = 0;
        BatchList::const_iterator i = d_batches.begin();
        for ( ; i != d_batches.end(); ++i)
        {
            d_material.setTexture(0, (*i).first);
            d_driver.setMaterial(d_material);
            d_driver.drawIndexedTriangleList(&d_vertices[pos], (*i).second,
                                            &d_indices[pos], (*i).second / 3);
            pos += (*i).second;
        }
    }

    // clean up RenderEffect
    if (d_effect)
        d_effect->performPostRenderFunctions();

    // restore original projection matrix and viewport.
    d_driver.setTransform(irr::video::ETS_PROJECTION, proj);
    d_driver.setViewPort(target_vp);
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setTranslation(const Vector3& v)
{
    d_translation.X = v.d_x;
    d_translation.Y = v.d_y;
    d_translation.Z = v.d_z;
    d_matrixValid = false;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setRotation(const Vector3& r)
{
    d_rotation.X = r.d_x;
    d_rotation.Y = r.d_y;
    d_rotation.Z = r.d_z;
    d_matrixValid = false;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setPivot(const Vector3& p)
{
    d_pivot.X = p.d_x;
    d_pivot.Y = p.d_y;
    d_pivot.Z = p.d_z;
    d_matrixValid = false;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setClippingRegion(const Rect& region)
{
    d_clipRect = region;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::appendVertex(const Vertex& vertex)
{
    appendGeometry(&vertex, 1);
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::appendGeometry(const Vertex* const vbuff,
                                            uint vertex_count)
{
    // see if we should start a new batch
    irr::video::ITexture* t =
        d_activeTexture ? d_activeTexture->getIrrlichtTexture() : 0;

    if (d_batches.empty() || d_batches.back().first != t)
        d_batches.push_back(BatchInfo(t, 0));

    // buffer these vertices
    const irr::u16 idx_start = d_batches.back().second;
    irr::video::S3DVertex v;
    for (uint i = 0; i < vertex_count; ++i)
    {
        const Vertex& vs = vbuff[i];
        v.Pos.X     = vs.position.d_x + d_texelOffset;
        v.Pos.Y     = vs.position.d_y + d_texelOffset;
        v.Pos.Z     = vs.position.d_z;
        v.TCoords.X = vs.tex_coords.d_x;
        v.TCoords.Y = vs.tex_coords.d_y;
        v.Color.set(vs.colour_val.getARGB());
        d_vertices.push_back(v);
        d_indices.push_back(idx_start + i);
    }

    // update size of current batch
    d_batches.back().second += vertex_count;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setActiveTexture(Texture* texture)
{
    d_activeTexture = static_cast<IrrlichtTexture*>(texture);
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::reset()
{
    d_vertices.clear();
    d_indices.clear();
    d_batches.clear();
    d_activeTexture = 0;
}

//----------------------------------------------------------------------------//
Texture* IrrlichtGeometryBuffer::getActiveTexture() const
{
    return d_activeTexture;
}

//----------------------------------------------------------------------------//
uint IrrlichtGeometryBuffer::getVertexCount() const
{
    return d_vertices.size();
}

//----------------------------------------------------------------------------//
uint IrrlichtGeometryBuffer::getBatchCount() const
{
    return d_batches.size();
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::setRenderEffect(RenderEffect* effect)
{
    d_effect = effect;
}

//----------------------------------------------------------------------------//
RenderEffect* IrrlichtGeometryBuffer::getRenderEffect()
{
    return d_effect;
}

//----------------------------------------------------------------------------//
const irr::core::matrix4& IrrlichtGeometryBuffer::getMatrix() const
{
    return d_matrix;
}

//----------------------------------------------------------------------------//
void IrrlichtGeometryBuffer::updateMatrix() const
{
    d_matrix.makeIdentity();
    d_matrix.setTranslation(d_translation + d_pivot);

    irr::core::matrix4 rot;
    rot.setRotationDegrees(d_rotation);
    irr::core::matrix4 ptrans;
    ptrans.setTranslation(-d_pivot);

    d_matrix *= rot;
    d_matrix *= ptrans;

    d_matrixValid = true;
}

//----------------------------------------------------------------------------//

} // End of  CEGUI namespace section
