ecmascript:

function set_Color(Col)
{
    croneDiffuseColor= new  SFColor( Col.r * .7
                                   , Col.g * .7
                                   , Col.b * .7
                                   );
    croneEmissiveColor= new SFColor( Col.r * .3
                                   , Col.g * .3
                                   , Col.b * .3
                                   );
}

        

      
ecmascript:

function sin0(x)
{
return Math.sin(x * 6.28318530717959); // We don't use 2*Math.PI in the hope it will increase performance.
}

function cos0(x)
{
return Math.cos(x * 6.28318530717959); // We don't use 2*Math.PI in the hope it will increase performance.
}

function initialize()
{
    var Heights= new MFFloat;
    Heights.length= Grid.xDimension * Grid.zDimension;

    var ZFrom= -Grid.zDimension*Grid.zSpacing/2;
    var ZTo=    Grid.zDimension*Grid.zSpacing/2 - Grid.zSpacing * .1;
    var ZStep=  Grid.zSpacing;
    var XFrom= -Grid.xDimension*Grid.xSpacing/2;
    var XTo=    Grid.xDimension*Grid.xSpacing/2 - Grid.xSpacing * .1;
    var XStep=  Grid.xSpacing;

//        ZFrom+= Grid.zSpacing;
//        ZTo-=   Grid.zSpacing;
//        XFrom+= Grid.xSpacing;
//        XTo-=   Grid.xSpacing;

    var Idx= 0;

//        Idx+= 1 + Grid.xDimension * 1;

    for(var Z= ZFrom; Z<=ZTo; Z+= ZStep)
    {
        for(var X= XFrom; X<=XTo; X+= XStep)
        {
            var s= 9;

            var H= .7*( cos0(Z*s / 30) + cos0(X*s / 35 + X*X*s*s / 34) + sin0(X*Z*s / 40));
            H+= cos0(Math.sqrt(X*X + Z*Z) / 300) * 15;
            Heights[Idx++]= H;
        }
//            Idx+= 2;
    }

    Grid.height= Heights;
}

    

      
ecmascript:

function initialize()
{
    Trees= TreeGroup.children;

    for(var C= 0; C<Trees.length; C++ )
        Trees[C].position= AddGroundHeight(Trees[C].position);
}

// receives an SFVec3f of a position over ground, evaluates the ground height at that 
// position and adds it to the y value of the vector.

function AddGroundHeight(Vec)
{
    var PosOnGrid= Vec.subtract(GroundTrans.translation);

    var FloatIdxX= PosOnGrid.x / GroundGrid.xSpacing;
    var FloatIdxZ= PosOnGrid.z / GroundGrid.zSpacing;

    var FracX= FloatIdxX - Math.floor(FloatIdxX);
    var FracZ= FloatIdxZ - Math.floor(FloatIdxZ);


    // We do linear interpolation in the square we have.

    var IdxLowerX= Math.floor(FloatIdxX);
    var IdxLowerZ= Math.floor(FloatIdxZ);
    var IdxHigherX= IdxLowerX + 1;
    var IdxHigherZ= IdxLowerZ + 1;

    if(IdxLowerX  < 0) IdxLowerX= 0;
    if(IdxLowerZ  < 0) IdxLowerZ= 0;
    if(IdxHigherX < 0) IdxHigherX= 0;
    if(IdxHigherZ < 0) IdxHigherZ= 0;
    if(IdxLowerX  >= GroundGrid.xDimension) IdxLowerX=  GroundGrid.xDimension - 1;
    if(IdxHigherX >= GroundGrid.xDimension) IdxHigherX= GroundGrid.xDimension - 1;
    if(IdxLowerZ  >= GroundGrid.zDimension) IdxLowerZ=  GroundGrid.zDimension - 1;
    if(IdxHigherZ >= GroundGrid.zDimension) IdxHigherZ= GroundGrid.zDimension - 1;

    var LowerXHeight=  GetGroundGridHeightAt(IdxLowerX,  IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxLowerX,  IdxHigherZ) * FracZ;
    var HigherXHeight= GetGroundGridHeightAt(IdxHigherX, IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxHigherX, IdxHigherZ) * FracZ;

    var Height= LowerXHeight * (1 - FracX) + HigherXHeight * FracX;

    return new SFVec3f(Vec.x, Vec.y + Height, Vec.z);
}

function GetGroundGridHeightAt(IdxX, IdxZ)
{
    return GroundGrid.height[IdxX + IdxZ * GroundGrid.xDimension];
}

    

      
ecmascript:

function set_hitCoord(C)
{
    hitCoord= C;

    if(SensIsActive)
    {
        userInput= C.subtract(ActivationCoords).multiply(cScale);
    }
}

function set_activated(a)
{
    SensIsActive= a;
    if(a)
        ActivationCoords= hitCoord;
    else
        userInput= new SFVec2f(0, 0);

}

    

      
ecmascript:

function NonLin(x)
{
    var cAmount= .3;
    var cBmount= 1 - cAmount;
    return (x * x * (x>0? 1:-1)) * cAmount + (x) * cBmount; // TBD: Some exponential function would be better.
}

function userInput(inp)
{
    lastUserInput= inp;

    ProcessMoveInput(inp.y);
    ProcessRotateInput(inp.x);
}

function ProcessMoveInput(inp)
{
    MoveSpeed= NonLin(inp / cInputNominalX) * cNominalMoveSpeed;
}

function ProcessRotateInput(inp)
{
    OriSpeed=  NonLin(inp / cInputNominalY) * cNominalOriSpeed;
}

function Tick(Now)
{
    if(!lastTick)
    {
        lastTick= Now;
        return;
    }

    var DeltaT= Now - lastTick;
    lastTick= Now;

    if(OriSpeed || MoveSpeed)
    {
        ObjectOri= ObjectOri.multiply(new SFRotation(0, 1, 0, -OriSpeed * DeltaT));
        ObjectPos= ObjectPos.add(ObjectOri.multVec(new SFVec3f(0, 0, -MoveSpeed * DeltaT)));

        objectPos_changed= AddGroundHeight(ObjectPos);
        objectOri_changed=                 ObjectOri;
    }
}
// receives an SFVec3f of a position over ground, evaluates the ground height at that 
// position and adds it to the y value of the vector.

function AddGroundHeight(Vec)
{
    var PosOnGrid= Vec.subtract(GroundTrans.translation);

    var FloatIdxX= PosOnGrid.x / GroundGrid.xSpacing;
    var FloatIdxZ= PosOnGrid.z / GroundGrid.zSpacing;

    var FracX= FloatIdxX - Math.floor(FloatIdxX);
    var FracZ= FloatIdxZ - Math.floor(FloatIdxZ);


    // We do linear interpolation in the square we have.

    var IdxLowerX= Math.floor(FloatIdxX);
    var IdxLowerZ= Math.floor(FloatIdxZ);
    var IdxHigherX= IdxLowerX + 1;
    var IdxHigherZ= IdxLowerZ + 1;

    if(IdxLowerX  < 0) IdxLowerX= 0;
    if(IdxLowerZ  < 0) IdxLowerZ= 0;
    if(IdxHigherX < 0) IdxHigherX= 0;
    if(IdxHigherZ < 0) IdxHigherZ= 0;
    if(IdxLowerX  >= GroundGrid.xDimension) IdxLowerX=  GroundGrid.xDimension - 1;
    if(IdxHigherX >= GroundGrid.xDimension) IdxHigherX= GroundGrid.xDimension - 1;
    if(IdxLowerZ  >= GroundGrid.zDimension) IdxLowerZ=  GroundGrid.zDimension - 1;
    if(IdxHigherZ >= GroundGrid.zDimension) IdxHigherZ= GroundGrid.zDimension - 1;

    var LowerXHeight=  GetGroundGridHeightAt(IdxLowerX,  IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxLowerX,  IdxHigherZ) * FracZ;
    var HigherXHeight= GetGroundGridHeightAt(IdxHigherX, IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxHigherX, IdxHigherZ) * FracZ;

    var Height= LowerXHeight * (1 - FracX) + HigherXHeight * FracX;

    return new SFVec3f(Vec.x, Vec.y + Height, Vec.z);
}

function GetGroundGridHeightAt(IdxX, IdxZ)
{
    return GroundGrid.height[IdxX + IdxZ * GroundGrid.xDimension];
}

    

      
ecmascript:

function set_avatarPos(Pos)
{
    avatarPos= Pos;
    Update();
}

function set_avatarOri(Ori)
{
    avatarOri= Ori;
    Update();
}

function Update()
{
    var viewPos= avatarPos.add(avatarOri.multVec(cCameraOffsetPos));
    var viewOri= cCameraOffsetOri.multiply(avatarOri);

    if( viewPos_changed != viewPos)
        viewPos_changed=   viewPos;

    if( viewOri_changed != viewOri)
        viewOri_changed=   viewOri;
}

    

      
ecmascript:

function set_MonkeyPos(Pos)
{
    MonkeyPos= Pos;
    Update();
}

function set_MonkeyOri(Ori)
{
    MonkeyOri= Ori;
    Update();
}

function Update()
{
    ShadowPos_changed= AddGroundHeight(new SFVec3f(MonkeyPos.x, .4, MonkeyPos.z));

    var ViewDir= MonkeyOri.multVec(new SFVec3f(0, 0, -1));
    ViewDir.y= 0; // make it horizontal.

    var HorzOri= new SFRotation(new SFVec3f(0, 0, -1), ViewDir);
    // now we have a horizontal orientation only.

    // figure out the normal vector of the ground.
    // for this, figure out three points on the ground around the monkey position.

    var cRadius= 2.3;

    var EvGridPointA= AddGroundHeight((new SFVec3f(MonkeyPos.x, 0, MonkeyPos.z)).add(HorzOri.multVec((new SFVec3f(  0, 0, -1  )).multiply(cRadius))));
    var EvGridPointB= AddGroundHeight((new SFVec3f(MonkeyPos.x, 0, MonkeyPos.z)).add(HorzOri.multVec((new SFVec3f( .866, 0, .5)).multiply(cRadius))));
    var EvGridPointC= AddGroundHeight((new SFVec3f(MonkeyPos.x, 0, MonkeyPos.z)).add(HorzOri.multVec((new SFVec3f(-.866, 0, .5)).multiply(cRadius))));

    var Normal= EvGridPointC.subtract(EvGridPointA).cross(EvGridPointB.subtract(EvGridPointA));

    var NormalOri= new SFRotation(new SFVec3f(0, 1, 0), Normal);

    ShadowOri_changed= HorzOri.multiply(NormalOri);
}

// receives an SFVec3f of a position over ground, evaluates the ground height at that 
// position and adds it to the y value of the vector.

function AddGroundHeight(Vec)
{
    var PosOnGrid= Vec.subtract(GroundTrans.translation);

    var FloatIdxX= PosOnGrid.x / GroundGrid.xSpacing;
    var FloatIdxZ= PosOnGrid.z / GroundGrid.zSpacing;

    var FracX= FloatIdxX - Math.floor(FloatIdxX);
    var FracZ= FloatIdxZ - Math.floor(FloatIdxZ);

    // We do linear interpolation in the square we have.

    var IdxLowerX= Math.floor(FloatIdxX);
    var IdxLowerZ= Math.floor(FloatIdxZ);
    var IdxHigherX= IdxLowerX + 1;
    var IdxHigherZ= IdxLowerZ + 1;

    if(IdxLowerX  < 0) IdxLowerX= 0;
    if(IdxLowerZ  < 0) IdxLowerZ= 0;
    if(IdxHigherX < 0) IdxHigherX= 0;
    if(IdxHigherZ < 0) IdxHigherZ= 0;
    if(IdxLowerX  >= GroundGrid.xDimension) IdxLowerX=  GroundGrid.xDimension - 1;
    if(IdxHigherX >= GroundGrid.xDimension) IdxHigherX= GroundGrid.xDimension - 1;
    if(IdxLowerZ  >= GroundGrid.zDimension) IdxLowerZ=  GroundGrid.zDimension - 1;
    if(IdxHigherZ >= GroundGrid.zDimension) IdxHigherZ= GroundGrid.zDimension - 1;

    var LowerXHeight=  GetGroundGridHeightAt(IdxLowerX,  IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxLowerX,  IdxHigherZ) * FracZ;
    var HigherXHeight= GetGroundGridHeightAt(IdxHigherX, IdxLowerZ) * (1 - FracZ) + GetGroundGridHeightAt(IdxHigherX, IdxHigherZ) * FracZ;

    var Height= LowerXHeight * (1 - FracX) + HigherXHeight * FracX;

    return new SFVec3f(Vec.x, Vec.y + Height, Vec.z);
}

function GetGroundGridHeightAt(IdxX, IdxZ)
{
    return GroundGrid.height[IdxX + IdxZ * GroundGrid.xDimension];
}