// ***********************************************************************************
// Programs written by R.Swan - rs108@mdx.ac.uk - www.netyaroze-europe.com/~middex2
// MAIN routine
// ***********************************************************************************

#include <libps.h>
#include "header.h"
#include "stdlib.h"

// **** Global #defines
#define   TIM_HEADING             (0x80090000)
#define   TIM_DOT                 (0x80091000)

// **** Global variables and structures
GsSPRITE  TextSprite;                                 // instance of a sprite

u_long    GameRunning = true;
u_long    JustMoved = 0;

// STRUCTRE HOLDING INFORMATION FOR EACH STAR
typedef struct
  {
  long    x, y;
  long    dx;
  } StarStruct;

// CREATE 300 STRUCTURES, ONE FOR EACH STAR
StarStruct  Stars[300];
// CREATE ONLY ONE INSTANCE OF GSSPRITE FOR ALL THE STARS
GsSPRITE    StarSprite;

// **** Function prototypes
void UpdateWorld();
void RenderWorld();
void ProcessJoyPad();

// ***********************************************************************************
// MAIN FUNCTION
// ***********************************************************************************
void main()
  {
  u_long tTemp;

  InitialiseScreen();
  InitialiseJoyPad();

  LoadTIMData(TIM_HEADING);
  LoadTIMData(TIM_DOT);

  SetSpriteInfo(&TextSprite, TIM_HEADING, 160, 220);
  SetSpriteInfo(&StarSprite, TIM_DOT, 0, 0);
  TextSprite.attribute += (1<<30) + (1<<28);

  // ROUTINE FOR MOVING STARS
  for (tTemp=0; tTemp<300; tTemp++)
    {
    Stars[tTemp].x = (rand() % 320) << 8; // SET THE RANDOM X POSITION
    Stars[tTemp].y = (rand() % 240) << 8; // SET THE RANDOM Y POSITION
    Stars[tTemp].dx = rand() % ((1<<8) * 3) + (1<<7); // SET RANDOM AMOUNT
                                                      // BY WHICH STAR MOVES
    }

  while (GameRunning == true)
    {
    ProcessJoyPad();

    UpdateWorld();
    RenderWorld();
    }

  ResetGraph(3);
  }

// ***********************************************************************************
// Function Definitions
// ***********************************************************************************

// **** Update everything in the world before drawing
void UpdateWorld()
  {
  u_long tTemp;

  FntPrint(FntOne, "Speed          - %d/280\n", VerticalSync);

  // ROUTINE FOR MOVING STARS
  for (tTemp=0; tTemp<300; tTemp++)
    {
    Stars[tTemp].x -= Stars[tTemp].dx; // UPDATE THE X POSITION
    if (Stars[tTemp].x < 0) Stars[tTemp].x += 320<<8; // MOVE TO RIGHT IF
                                                      // THEY GO OFF LEFT
    }
  }

// **** Register everything that needs to be drawn and then draw it
void RenderWorld()
  {
  u_long tTemp;

  RenderPrepare();

  DrawSprite(&TextSprite, 0);

  DrawColouredBox(160-120, 220-13, 160+120, 220+13, 0, 0,
        0, 0, 0,
        0, 0, 0,
        255, 255, 255,
        255, 255, 255);

  // ROUTINE FOR MOVING STARS
  // NOTE THAT I HAVE ONLY THE ONE GSSPRITE, BUT I UDPATE ITS POSITION,
  // DRAW IT, THEN ALTER IT AGAIN, THEN DRAW IT, ETC. THIS IS PERFECTLY
  // LEGAL!
  for (tTemp=0; tTemp<320; tTemp++)
    {
    StarSprite.x = (short) (Stars[tTemp].x >> 8); // SET SPRITES X POSITION
    StarSprite.y = (short) (Stars[tTemp].y >> 8); // SET SPRITES Y POSITION
    DrawSprite(&StarSprite, 1); // DRAW SPRITE
    }


  RenderFinish();
  }

// **** Respond to user input from joypad 1
void ProcessJoyPad()
  {
  u_long PAD = ReadJoyPad();

  if ((PAD& PADselect) && (PAD& PADstart)) GameRunning = false;
  }

// ***********************************************************************************
// MAIN FUNCTION
// ***********************************************************************************