// Dark GDK - The Game Creators - www.thegamecreators.com

// include Dark GDK header file
#include "DarkGDK.h"

// global variables - used for the camera
float g_fSpeed        = 0.1f;		// speed at which camera moves
float g_fTurn         = 0.03f;		// turn speed for mouse look
float g_fOldCamAngleX = 0.0f;		// to store original x angle
float g_fOldCamAngleY = 0.0f;		// to store original y angle
float g_fCameraAngleX = 0.0f;		// to sotre new x angle
float g_fCameraAngleY = 0.0f;		// to store new y angle

// forward declaration for functions
void userInput ( void );			// handles user input
void showFPS   ( void );			// show frame rate

void DarkGDK ( void )
{
	// entry point for the application

	dbSetDir ( "media\\" );

	// initial application set up
	dbSyncOn         ( );				// turn sync on
	dbSyncRate       ( 60 );			// set sync rate to 60
	dbBackdropOff    ( );				// switch backdrop off - no need to clear screen
	dbSetCameraRange ( 0.5f, 30000 );	// set the camera range

	// load images for the terrain
	dbLoadImage ( "media\\texture.jpg", 1 );	// diffuse texture
	dbLoadImage ( "media\\detail.jpg",  2 );	// detail texture
	
	// create the terrain
	dbSetupTerrain        ( );										// set up terrain library
	dbMakeObjectTerrain   ( 1 );									// make a new terrain
	dbSetTerrainHeightMap ( 1, "media\\map.bmp" );					// set the terrain height map
	dbSetTerrainScale     ( 1, 3, 0.6f, 3 );						// set the scale
	dbSetTerrainSplit     ( 1, 16 );								// set the split value
	dbSetTerrainTiling    ( 1, 4 );									// set the detail tiling
	dbSetTerrainLight     ( 1, 1.0f, -0.25f, 0.0f, 1, 1, 0.78f, 0.5f );	// set the light
	dbSetTerrainTexture   ( 1, 1, 2 );								// set the textures
	dbBuildTerrain        ( 1 );									// build the terrain

	// create our skybox
	dbLoadObject       ( "media\\skybox2.x", 200 );		// load the skybox model
	dbSetObjectLight   ( 200, 0 );						// turn lighting off
	dbSetObjectTexture ( 200, 3, 1 );					// set texture properties
	dbPositionObject   ( 200, 1000, 2000, 4000 );		// position the skybox
	dbScaleObject      ( 200, 30000, 30000, 30000 );	// and finally scale
	
	// set starting camera position
	dbPositionCamera ( 385, 23, 100 );

	// loop round until escape key is pressed
	while ( LoopGDK ( ) )
	{
		if ( dbEscapeKey ( ) )
			return;

		// show the frame rate and handle user input
		showFPS   ( );
		userInput ( );

		// update the terrain
		dbUpdateTerrain ( );

		// render everything
		dbSync ( );
	}
}

void showFPS ( void )
{
	char szFPS [ 256 ] = "";
	strcpy ( szFPS, "fps = " );
	strcat ( szFPS, dbStr ( dbScreenFPS ( ) ) );
	dbText ( dbScreenWidth ( ) - 20 - dbTextWidth ( szFPS ), dbScreenHeight ( ) - 40, szFPS );
}

void userInput ( void )
{
	dbControlCameraUsingArrowKeys ( 0, g_fSpeed, g_fTurn );

	g_fOldCamAngleY = g_fCameraAngleY;
	g_fOldCamAngleX = g_fCameraAngleX;

	g_fCameraAngleY = dbWrapValue ( g_fCameraAngleY + dbMouseMoveX ( ) * 0.4f );
	g_fCameraAngleX = dbWrapValue ( g_fCameraAngleX + dbMouseMoveY ( ) * 0.4f );

	dbYRotateCamera ( dbCurveAngle ( g_fCameraAngleY, g_fOldCamAngleY, 24 ) );
	dbXRotateCamera ( dbCurveAngle ( g_fCameraAngleX, g_fOldCamAngleX, 24 ) );

	char* szKey = dbInKey ( );

	if ( strcmp ( szKey, "+" ) == 0 )
	{
		if ( g_fSpeed < 1000 )
			g_fSpeed = g_fSpeed + 0.01f;
	}

	if ( strcmp ( szKey, "-" ) == 0 )
	{
		if ( g_fSpeed > 0.02f )
			g_fSpeed = g_fSpeed - 0.01f;
	}

	float fHeight = dbGetTerrainGroundHeight ( 1, dbCameraPositionX ( ), dbCameraPositionZ ( ) );

	dbPositionCamera ( dbCameraPositionX ( ), fHeight + 3.0f, dbCameraPositionZ ( ) );
}