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

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

// **** Global variables and structures
#define TIM_TEXT      (0x80090000)
#define TIM_BALL      (0x80094000)

// **** Global variables and structures
u_long      GameRunning = true;                       // flag used to quit
float       CurrentDepth = 0;

typedef struct
  {
  GsSPRITE  Sred;
  GsSPRITE  Sblue;
  long      x;
  long      y;
  float     depth;
  } sprite3D;

sprite3D    mySprite[9];
sprite3D    Ball[5];

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

void Set3DspriteInfo(sprite3D *tSprite, u_long tAddress, long tX, long tY, float tDepth);
void Draw3Dsprite(sprite3D *tSprite, u_long tPriority);

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

  InitialiseScreen();
  InitialiseJoyPad();

  LoadTIMData(TIM_TEXT);
  LoadTIMData(TIM_BALL);
  for (tTemp=0; tTemp<9; tTemp++)
    {
    Set3DspriteInfo(&mySprite[tTemp], TIM_TEXT, 320, tTemp*22+30, tTemp*2 - 9);
    mySprite[tTemp].Sred.rotate = mySprite[tTemp].Sblue.rotate = ONE * (tTemp-4);
    }
  for (tTemp=0; tTemp<5; tTemp++)
    {
    Set3DspriteInfo(&Ball[tTemp], TIM_BALL, 320 - (tTemp-2)*96, 118, 0);
    }

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

    UpdateWorld();
    RenderWorld();
    }

  ResetGraph(3);
  }

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

// **** Update everything in the world before drawing
void UpdateWorld()
  {
  long tTemp;
  FntPrint(FntOne, "Speed          - %d/280\n", VerticalSync);
  FntPrint(FntOne, "Up / Down      - alter depth\n");
  FntPrint(FntOne, "Start + Select - quit\n");

  for (tTemp=0; tTemp<9; tTemp++)
    {
    mySprite[tTemp].depth = CurrentDepth * (tTemp - 4);
    }
  for (tTemp=0; tTemp<5; tTemp++)
    {
    Ball[tTemp].depth = CurrentDepth * (tTemp - 2) * 2;
    }
  }

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

  RenderPrepare();

  for (tTemp=0; tTemp<10; tTemp++)
    if (tTemp!=4) Draw3Dsprite(&mySprite[tTemp], 0);

  for (tTemp=0; tTemp<5; tTemp++)
    Draw3Dsprite(&Ball[tTemp], 0);

  RenderFinish();
  }

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

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

  if ((PAD& PADup) && (CurrentDepth < 5.00)) CurrentDepth += 0.1;
  if ((PAD& PADdown) && (CurrentDepth > -5.00)) CurrentDepth -= 0.1;

  if (PAD& PADcross)
    {
    while (PAD!=0)
      {
      PAD = ReadJoyPad();
      }
    }
  }

// **** Initialise a 3d sprite
void Set3DspriteInfo(sprite3D *tSprite, u_long tAddress, long tX, long tY, float tDepth)
  {
  SetSpriteInfo(&tSprite->Sred, tAddress, tX, tY);
  SetSpriteInfo(&tSprite->Sblue, tAddress, tX, tY);
  tSprite->depth = tDepth;

  tSprite->Sred.r = 47;
  tSprite->Sred.g = tSprite->Sred.b = 0;
  tSprite->Sblue.r = 0;
  tSprite->Sblue.g = 0;
  tSprite->Sblue.b = 97;

  tSprite->Sred.attribute = tSprite->Sblue.attribute += (1<<30) + (1<<28);
  }

// **** Draw a 3D sprite
void Draw3Dsprite(sprite3D *tSprite, u_long tPriority)
  {
  float tOriginalPosition = tSprite->Sred.x;

  tSprite->Sred.x -= tSprite->depth;
  tSprite->Sblue.x += tSprite->depth;
  tSprite->Sred.scalex = ONE*2 - tSprite->depth * 80;
  tSprite->Sred.scaley = ONE - tSprite->depth * 40;
  tSprite->Sblue.scalex = ONE*2 - tSprite->depth * 80;
  tSprite->Sblue.scaley = ONE - tSprite->depth * 40;

  DrawSprite(&tSprite->Sred, tPriority);
  DrawSprite(&tSprite->Sblue, tPriority);

  tSprite->Sred.x = tOriginalPosition;
  tSprite->Sblue.x = tOriginalPosition;
  }