#include "OgreTerrainContentGenerator.h"


namespace Ogre {

/*************************************************/
/*         RayQueryExecutor implementation       */
/*************************************************/

//-----------------------------------------------------------------------
RayQueryExecutor::RayQueryExecutor(SceneManager *sm)
{
	mRaySceneQuery = sm->createRayQuery(Ray());
}
//-----------------------------------------------------------------------
RayQueryExecutor::~RayQueryExecutor()
{
	OGRE_DELETE(mRaySceneQuery);
}
//-----------------------------------------------------------------------
bool RayQueryExecutor::executeRayQuery(Vector3 *result, const Vector3 &pos, 
									   const Vector3 &dir)
{
	return executeRayQuery(result, Ray(pos, dir));
}
//-----------------------------------------------------------------------
bool RayQueryExecutor::executeRayQuery(Vector3 *result, const Ray &ray)
{
    mRaySceneQuery->setRay(ray);

    // Perform the scene query
    RaySceneQueryResult &queryResult = mRaySceneQuery->execute();
    RaySceneQueryResult::iterator it = queryResult.begin();

	if (it != queryResult.end() && it->worldFragment)
	{
		SceneQuery::WorldFragment* wf = it->worldFragment;

		*result = wf->singleIntersection; 
		return true;
	}

	return false;
}

/*******************************************************/
/*     TerrainContentGenerator implementation          */
/*******************************************************/

//-----------------------------------------------------------------------
TerrainContentGenerator::TerrainContentGenerator(SceneManager *sm):
SceneContentGenerator(sm), mOffset(0)
{
	mMinPos = Vector3(0.0f, MAX_HEIGHT, 0.0f);
	mMaxPos = Vector3(3000.0f, MAX_HEIGHT, 3000.0f);

	mMinAngle = Vector3(0.0f, 0.0f, 0.0f);
	mMaxAngle = Vector3(360.0f, 0.0f, 0.0f);

	mRayQueryExecutor = new RayQueryExecutor(sm);
}
//-----------------------------------------------------------------------
TerrainContentGenerator::~TerrainContentGenerator()
{
	delete mRayQueryExecutor;
}
//-----------------------------------------------------------------------
SceneNode *TerrainContentGenerator::GenerateSceneObject(const Vector3 &position, 
					 const Vector3 &rotation, const String& objName, const bool clampToTerrain)
{	
	if (clampToTerrain)
		return GenerateSceneObject(position, rotation, objName);
	
	return SceneContentGenerator::GenerateSceneObject(position, rotation, objName);
}
//-----------------------------------------------------------------------
SceneNode *TerrainContentGenerator::GenerateSceneObject(const Vector3 &position, 
					 const Vector3 &rotation, const String& objName)
{
	Vector3 queryResult;
	// set y to max height so we are sure to be over terrain
	Vector3 pos(position.x, MAX_HEIGHT, position.z);

	if (mRayQueryExecutor->executeRayQuery(&queryResult, position, Vector3::NEGATIVE_UNIT_Y))
	{
		// reject if height is too high
		if (queryResult.y < mMaxPos.y)
		{
			// add offset so object is over terrain
			queryResult.y += mOffset;

			return SceneContentGenerator::GenerateSceneObject(queryResult, rotation, objName);
		}
	}
	
	return NULL;
}
//-----------------------------------------------------------------------
void TerrainContentGenerator::SetOffset(Real offset)
{
	mOffset = offset;
}

} // namespace Ogre