/// <summary>
/// Setup constructor
/// </summary>
/// <param name="camera">Camera, used to determine patch error</param>
/// <param name="generator">Object used to generate the patch vertices</param>
/// <param name="patch">Terrain patch</param>
/// <param name="calculatePatchError">If true, the maximum error between the patch geometry and the terrain model is calculated</param>
private unsafe TerrainPatchBuildItem( IProjectionCamera camera, ITerrainPatchGenerator generator, ITerrainPatch patch, bool calculatePatchError )
{
m_Camera = camera;
m_Generator = generator;
m_Patch = patch;
m_CalculatePatchError = calculatePatchError;
}
/// <summary>
/// Patches are defined in a local space. This determines the planet-space parameters of a patch
/// </summary>
public void SetPatchPlanetParameters( ITerrainPatch patch )
{
float radius = SpherePlanet.PlanetModel.Radius.ToRenderUnits;
Point3 edge = patch.LocalOrigin + ( patch.LocalUAxis / 2 );
Point3 centre = edge + ( patch.LocalVAxis / 2 );
Point3 plEdge = ( edge.ToVector3( ).MakeNormal( ) * radius ).ToPoint3( );
Point3 plCentre = ( centre.ToVector3( ).MakeNormal( ) * radius ).ToPoint3( );
patch.SetPlanetParameters( plCentre, plCentre.DistanceTo( plEdge ) );
}
/// <summary>
/// Generates vertices for a patch. Calculates maximum error between this patch and next higher detail patch
/// </summary>
/// <param name="patch">Patch</param>
/// <param name="res">Patch resolution</param>
/// <param name="firstVertex">Patch vertices</param>
/// <param name="error">Maximum error value between this patch and higher level patch</param>
public unsafe void GenerateTerrainPatchVertices( ITerrainPatch patch, int res, TerrainVertex* firstVertex, out float error )
{
SetPatchPlanetParameters( patch );
SafeTerrainGenerator.GenerateVertices( patch.LocalOrigin, patch.LocalUStep, patch.LocalVStep, res, res, patch.Uv, patch.UvResolution, firstVertex, out error );
}
/// <summary>
/// Allocates a terrain patch build item from an internal pool
/// </summary>
public static TerrainPatchBuildItem Allocate( IProjectionCamera camera, ITerrainPatchGenerator generator, ITerrainPatch patch, bool calculatePatchError )
{
if ( s_BuildItems.Count == 0 )
{
return new TerrainPatchBuildItem( camera, generator, patch, calculatePatchError );
}
TerrainPatchBuildItem item = s_BuildItems[ 0 ];
s_BuildItems.RemoveAt( 0 );
item.m_Camera = camera;
item.m_Generator = generator;
item.m_Patch = patch;
item.m_CalculatePatchError = calculatePatchError;
return item;
}