///////////////////////////////////////////////////////////////////////////////
//
//      ##  ######
//       ######  ###
//  ## ###############        Shark 3D Engine (www.shark3d.com)
//   ########## # # #
//    ########                Copyright (c) 1996-2006 Spinor GmbH.
//   ######### # # #          All rights reserved.
//  ##   ##########
//      ##
//
///////////////////////////////////////////////////////////////////////////////

//@cpp

#ifndef S3D_ENG_SPECIALSHADER_OPTICS_UTIL_H
#define S3D_ENG_SPECIALSHADER_OPTICS_UTIL_H

#include "../../interf/eng_gfxstruct.h"
#include "../../interf/eng_shader.h"

///////////////////////////////////////////////////////////////////////////////

//@
class gtp_ShaderOpticsUtil
{
public:
    static bool CalcViewNormalDist(
            s3d_CUtilVec3f &ViewNormal, float &ViewDist,
            s3d_CUtilTranslQuatf_cr ViewTransf);
    static bool CalcChildCamFull(
            s3d_CEngGfxCam &ChildCam, 
            void *Exclude,
            int MaxRecursion, float Coeff, float Precision,
            bool UseCompactFrustum, s3d_CEngShaderScope *Scope,
            s3d_CUtilTranslQuatf_cr ViewTransf,
            s3d_CUtilVec3f_cr ViewNormal, float ViewDist);
    static bool CalcChildRange(
            s3d_CUtilVec3f &SubNeg, s3d_CUtilVec3f &SubPos,
            s3d_CUtilTranslQuatf_cr ViewTransf,
            s3d_CUtilVec3f_cr BoundCen, s3d_CUtilVec3f_cr BoundExt,
            s3d_CEngShaderScope *Scope);
    static void SnapChildRange(
            s3d_CUtilVec3f &SubNeg, s3d_CUtilVec3f &SubPos,
            int SnapWidth, int SnapHeight);
    static void ApplyRangeToChildCam(
            s3d_CEngGfxCam &ChildCam, s3d_CUtilMat4x4f &BaseProj,
            s3d_CUtilVec3f_cr SubNeg, s3d_CUtilVec3f_cr SubPos);

    static int RoundToPowerOfTwoDown(int x);
    static int RoundToPowerOfTwoUp(int x);
};

///////////////////////////////////////////////////////////////////////////////

#endif