Editor.TerrainBuilder

//=============================================================================
// TerrainBuilder: Builds a 3D cube brush, with a tessellated bottom.
//=============================================================================
class TerrainBuilder
    extends BrushBuilder;

var() float Height, Width, Breadth;
var() int WidthSegments, DepthSegments;     // How many breaks to have in each direction
var() name GroupName;

function BuildTerrain( int Direction, float dx, float dy, float dz, int WidthSeg, int DepthSeg )
{
    local int n,nbottom,ntop,i,j,k,x,y;
    local float WidthStep, DepthStep;

    //
    // TOP
    //

    n = GetVertexCount();

    // Create vertices
    for( i=-1; i<2; i+=2 )
        for( j=-1; j<2; j+=2 )
            for( k=-1; k<2; k+=2 )
                Vertex3f( i*dx/2, j*dy/2, k*dz/2 );

    // Create the top
    Poly4i(Direction,n+3,n+1,n+5,n+7, 'sky');

    //
    // BOTTOM
    //

    nbottom = GetVertexCount();

    // Create vertices
    WidthStep = dx / WidthSeg;
    DepthStep = dy / DepthSeg;

    for( x = 0 ; x < WidthSeg + 1 ; x++ )
        for( y = 0 ; y < DepthSeg + 1 ; y++ )
            Vertex3f( (WidthStep * x) - dx/2, (DepthStep * y) - dy/2, -(dz/2) );

    ntop = GetVertexCount();

    for( x = 0 ; x < WidthSeg + 1 ; x++ )
        for( y = 0 ; y < DepthSeg + 1 ; y++ )
            Vertex3f( (WidthStep * x) - dx/2, (DepthStep * y) - dy/2, dz/2 );

    // Create the bottom as a mesh of triangles
    for( x = 0 ; x < WidthSeg ; x++ )
        for( y = 0 ; y < DepthSeg ; y++ )
        {
            Poly3i(-Direction,
                (nbottom+y)     + ((DepthSeg+1) * x),
                (nbottom+y)     + ((DepthSeg+1) * (x+1)),
                ((nbottom+1)+y) + ((DepthSeg+1) * (x+1)),
                'ground');
            Poly3i(-Direction,
                (nbottom+y)     + ((DepthSeg+1) * x),
                ((nbottom+1)+y) + ((DepthSeg+1) * (x+1)),
                ((nbottom+1)+y) + ((DepthSeg+1) * x),
                'ground');
        }

    //
    // SIDES
    //
    // The bottom poly of each side is basically a triangle fan.
    //
    for( x = 0 ; x < WidthSeg ; x++ )
    {
        Poly4i(-Direction,
            nbottom + DepthSeg + ((DepthSeg+1) * x),
            nbottom + DepthSeg + ((DepthSeg+1) * (x + 1)),
            ntop + DepthSeg + ((DepthSeg+1) * (x + 1)),
            ntop + DepthSeg + ((DepthSeg+1) * x),
            'sky' );
        Poly4i(-Direction,
            nbottom + ((DepthSeg+1) * (x + 1)),
            nbottom + ((DepthSeg+1) * x),
            ntop + ((DepthSeg+1) * x),
            ntop + ((DepthSeg+1) * (x + 1)),
            'sky' );
    }
    for( y = 0 ; y < DepthSeg ; y++ )
    {
        Poly4i(-Direction,
            nbottom + y,
            nbottom + (y + 1),
            ntop + (y + 1),
            ntop + y,
            'sky' );
        Poly4i(-Direction,
            nbottom + ((DepthSeg+1) * WidthSeg) + (y + 1),
            nbottom + ((DepthSeg+1) * WidthSeg) + y,
            ntop + ((DepthSeg+1) * WidthSeg) + y,
            ntop + ((DepthSeg+1) * WidthSeg) + (y + 1),
            'sky' );
    }
}

event bool Build()
{
    if( Height<=0 || Width<=0 || Breadth<=0 || WidthSegments<=0 || DepthSegments<=0 )
        return BadParameters();

    BeginBrush( false, GroupName );
    BuildTerrain( +1, Breadth, Width, Height, WidthSegments, DepthSegments );
    return EndBrush();
}

defaultproperties
{
     Height=256.000000
     Width=256.000000
     Breadth=512.000000
     WidthSegments=4
     DepthSegments=2
     GroupName="Terrain"
     BitmapFilename="BBTerrain"
     ToolTip="BSP Based Terrain"
}