source: downloads/PlugIns/OctreeSceneManager/include/OgreTerrainVertexProgram.h @ 3

/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/

#ifndef __TERRAINVERTEXPROGRAM_H__
#define __TERRAINVERTEXPROGRAM_H__

#include "OgrePrerequisites.h"
#include "OgreCommon.h"
#include "OgreString.h"

namespace Ogre {

    /*
    Static class containing the source to vertex programs used to 
    morph the terrain LOD levels. The programs are generated from 
    the following Cg:
    @code       
    // No fog morphing terrain
    void terrain_vp(
            float4 position : POSITION,
            float2 uv1          : TEXCOORD0,
            float2 uv2          : TEXCOORD1,
            float delta     : BLENDWEIGHT,

            out float4 oPosition : POSITION,
            out float2 oUv1              : TEXCOORD0,
            out float2 oUv2              : TEXCOORD1,
            out float4 colour    : COLOR,
            uniform float4x4 worldViewProj,
            uniform float morphFactor
            )
    {
            // Apply morph
            position.y = position.y + (delta.x * morphFactor);
            // world / view / projection
            oPosition = mul(worldViewProj, position);
            // Main texture coords
            oUv1 = uv1;
            // Detail texture coords
            oUv2 = uv2;
            // Full bright (no lighting)
            colour = float4(1,1,1,1);
    }


    // Linear fogged morphing terrain
    void terrain_vp_linear(
            float4 position : POSITION,
            float2 uv1          : TEXCOORD0,
            float2 uv2          : TEXCOORD1,
            float delta     : BLENDWEIGHT,

            out float4 oPosition : POSITION,
            out float2 oUv1              : TEXCOORD0,
            out float2 oUv2              : TEXCOORD1,
            out float4 colour    : COLOR,
            out float fog                : FOG,
            uniform float4x4 worldViewProj,
            uniform float morphFactor
            )
    {
            // Apply morph
            position.y = position.y + (delta.x * morphFactor);
            // world / view / projection
            oPosition = mul(worldViewProj, position);
            // Main texture coords
            oUv1 = uv1;
            // Detail texture coords
            oUv2 = uv2;
            // Full bright (no lighting)
            colour = float4(1,1,1,1);
            // Fog 
            // f = end - camz / end - start
            // when start / end has been set, fog value is distance
            fog = oPosition.z;
    }


    // Exp fogged morphing terrain
    void terrain_vp_exp(
            float4 position : POSITION,
            float2 uv1          : TEXCOORD0,
            float2 uv2          : TEXCOORD1,
            float delta     : BLENDWEIGHT,

            out float4 oPosition : POSITION,
            out float2 oUv1              : TEXCOORD0,
            out float2 oUv2              : TEXCOORD1,
            out float4 colour    : COLOR,
            out float fog                : FOG,
            uniform float4x4 worldViewProj,
            uniform float morphFactor,
            uniform float fogDensity)
    {
            // Apply morph
            position.y = position.y + (delta.x * morphFactor);
            // world / view / projection
            oPosition = mul(worldViewProj, position);
            // Main texture coords
            oUv1 = uv1;
            // Detail texture coords
            oUv2 = uv2;
            // Full bright (no lighting)
            colour = float4(1,1,1,1);
            // Fog 
            // f = 1 / e ^ (camz x density)
            // note pow = exp(src1 * log(src0)).
            fog = 1 / (exp((oPosition.z * fogDensity) * log(2.718281828)));
    }


    // Exp2 fogged morphing terrain
    void terrain_vp_exp2(
            float4 position : POSITION,
            float2 uv1          : TEXCOORD0,
            float2 uv2          : TEXCOORD1,
            float delta     : BLENDWEIGHT,

            out float4 oPosition : POSITION,
            out float2 oUv1              : TEXCOORD0,
            out float2 oUv2              : TEXCOORD1,
            out float4 colour    : COLOR,
            out float fog                : FOG,
            uniform float4x4 worldViewProj,
            uniform float morphFactor,
            uniform float fogDensity)
    {
            // Apply morph
            position.y = position.y + (delta.x * morphFactor);
            // world / view / projection
            oPosition = mul(worldViewProj, position);
            // Main texture coords
            oUv1 = uv1;
            // Detail texture coords
            oUv2 = uv2;
            // Full bright (no lighting)
            colour = float4(1,1,1,1);
            // Fog 
            // f = 1 / e ^ (camz x density)^2
            // note pow = exp(src1 * log(src0)).
            float src1 = oPosition.z * 0.002;
            fog = 1 / (exp((src1*src1) * log(2.718281828f)));
    }

        // Shadow receiver vertex program
    void terrain_shadow_receiver_vp(
            float4 position : POSITION,
            float2 uv1          : TEXCOORD0,
            float2 uv2          : TEXCOORD1,
            float delta     : BLENDWEIGHT,

            out float4 oPosition : POSITION,
            out float2 oUv1              : TEXCOORD0,
            out float4 colour    : COLOR,
            uniform float4x4 worldViewProj,
                uniform float4x4 world,
            uniform float4x4 textureViewProj,
            uniform float morphFactor
            )
    {
            // Apply morph
            position.y = position.y + (delta.x * morphFactor);
            // world / view / projection
            oPosition = mul(worldViewProj, position);
                
            // Main texture coords
                float4 worldpos = mul(world, position);
            float4 projuv = mul(textureViewProj, worldpos);
                oUv1.xy = projuv.xy / projuv.w;
            // Full bright (no lighting)
            colour = float4(1,1,1,1);
    }

    @endcode
    */
    class TerrainVertexProgram
    {
    private:
        static String mNoFogArbvp1;
        static String mLinearFogArbvp1;
        static String mExpFogArbvp1;
        static String mExp2FogArbvp1;
                static String mShadowReceiverArbvp1;

        static String mNoFogVs_1_1;
        static String mLinearFogVs_1_1;
        static String mExpFogVs_1_1;
        static String mExp2FogVs_1_1;
                static String mShadowReceiverVs_1_1;

    public:
        /// General purpose method to get any of the program sources
        static const String& getProgramSource(FogMode fogMode, 
                        const String syntax, bool shadowReceiver = false);


    };
}

#endif