Racing game

//*****************************************************************************
//
// Racing game
//
// This is a small 2D top-view racing game for ARM-CAN kit.
//
// Copyright (c) 2009 Mikk Leini
//
//*****************************************************************************
 
#include <inc/hw_ints.h>
#include <inc/hw_types.h>
#include <inc/hw_memmap.h>
#include <driverlib/sysctl.h>
#include <driverlib/interrupt.h>
#include <driverlib/gpio.h>
#include <driverlib/adc.h>
#include <grlib/grlib.h>
#include <drivers/general.h>
#include <drivers/nokia6610.h>
#include <drivers/class-d.h>
#include <drivers/buttons.h>
#include <drivers/joystick.h>
#include <drivers/rgb_led.h>
#include <utils/ustdlib.h>
#include <utils/sine.h>
#include "config.h"
#include "types.h"
#include "renderer.h"
#include "track.h"
 
//*****************************************************************************
//
// Global variables.
//
//*****************************************************************************
tCar g_pCar;
 
//*****************************************************************************
//
// Car driving by controls.
//
//*****************************************************************************
void DoCarDriving(tCar *pCar)
{
	long lVelocity;
	long lSteering;
	tBoolean bOnTrack;
 
	//
	// Check if car is on track.
	//
	bOnTrack = TrackPointOnTrack(&pCar->pPosition);
 
	//
	// Get joystick position.
	//
	JoystickGetPosition(&lSteering, &lVelocity);
 
	//
	// Do acceleration/deacceleration.
	//
	if(lVelocity > pCar->lVelocity)
	{
		pCar->lVelocity += (bOnTrack ? 3 : 1);
	}
	else if(lVelocity < pCar->lVelocity)
	{
		pCar->lVelocity -= (bOnTrack ? 3 : 1);
	}
 
	//
	// Limit velocity off the track.
	//
	if(!bOnTrack)
	{
		if(pCar->lVelocity > 50)
		{
			pCar->lVelocity = 50;
		}
		if(pCar->lVelocity < -30)
		{
			pCar->lVelocity = -30;
		}
	}
 
	//
	// Handle steering.
	//
	pCar->lSteering = lSteering / (bOnTrack ? 1 : 2);
 
	//
	// Calculate car orientation.
	//
	pCar->ulAngle -= pCar->lSteering * 
		(pCar->lVelocity > 0 ? pCar->lVelocity : -pCar->lVelocity) *
		0x4000;
 
	//
	// Calculate car position.
	//	
	pCar->pPosition.sX -= (pCar->lVelocity * cosine(pCar->ulAngle)) >> 16;
	pCar->pPosition.sY -= (pCar->lVelocity *   sine(pCar->ulAngle)) >> 16;
 
	//
	// Car on finish line?
	//
	if(TrackPointOnFinishLine(&pCar->pPosition))
	{
		if(!pCar->bOnFinishLine)
		{			
			pCar->bOnFinishLine = true;
			ClockReset();
		}
	}
	else
	{
		pCar->bOnFinishLine = false;
	}
 
	//
	// Calculate time.
	//
	pCar->ulLapTime = ClockGetMilliseconds();
}
 
//*****************************************************************************
//
// Car preparing.
//
//*****************************************************************************
void PrepareCar(void)
{
	g_pCar.pPosition.sX = 0;
	g_pCar.pPosition.sY = 0;
	g_pCar.ulAngle = 0x40000000;
	g_pCar.ulColor = ClrBlue;
}
 
//*****************************************************************************
//
// Main function.
//
//*****************************************************************************
int main(void)
{
	//
    // Set the clocking to run from the PLL at 50MHz
    //
    SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |
		SYSCTL_XTAL_8MHZ);
 
	//
	// Device general configuration.
	//
	DeviceConfigure();
 
	//
	// Initialize buttons.
	//
	ButtonsInit(BUTTON_ONBOARD | BUTTON_UIBOARD_UP | BUTTON_UIBOARD_DOWN);
 
	//
	// Initialize joystick.
	//
	JoystickInit();	
 
	//
	// Initialize RGB LED.
	//
	RGBLEDInit();
 
	//
	// Initialize renderer.
	//
	RendererInit();
 
	//
    // Enable processor interrupts.
    //
    IntMasterEnable();	
 
	//
	// Generate track.
	//
	TrackGenerate();	
 
	//
	// Prepare car.
	//
	PrepareCar();
 
    //
    // Loop forever.
    //
    while (true)
  	{
		//
		// Handle user input.
		//
		DoCarDriving(&g_pCar);
 
		//
		// Set viewpoint to the car position.
		//		
		RendererSetViewPoint(&g_pCar.pPosition);
 
		//
		// Render screen.
		//		
		RendererRender();
    }
}