void Demo4Object::DoUpdate( int iCurrentTime )
{
m_iPreviousScreenX = m_iCurrentScreenX;
m_iPreviousScreenY = m_iCurrentScreenY;
/********** EXTRA ********/
// Iterate through the objects
// We are looking for one which is too close to us
DisplayableObject* pObject;
for ( int iObjectId = 0 ;
(pObject = m_pMainEngine->GetDisplayableObject( iObjectId )
) != NULL ;
iObjectId++ )
{
if ( pObject == this ) // This is us, skip it
continue;
// If you need to cast to the sub-class type, you must use dynamic_cast, see lecture 19
// We are just using base class parts
int iXDiff = pObject->GetXCentre() - m_iCurrentScreenX;
int iYDiff = pObject->GetYCentre() - m_iCurrentScreenY;
// Estimate the size - by re-calculating it
int iTick = iCurrentTime/20; // 1 per 20ms
int iFrame = iTick % 30;
int iSize = 10 + iFrame;
if ( iFrame > 15 )
iSize = 10 + (30-iFrame);
int iSizeOther = iSize; // Assume both the same size
// Pythagorus' theorum:
if ( ((iXDiff*iXDiff)+(iYDiff*iYDiff))
< ((iSizeOther+iSize)*(iSizeOther+iSize)) )
{
// Move us to 1,1 and set direction right
m_iMapX = 1+rand()%13;
m_iMapY = 1+(rand()%2)*8;
m_iDir = 1; // Face right
m_oMover.Setup(
m_iMapX *50 + 25 + 25, //m_iCurrentScreenX,
m_iMapY *50 + 25 + 40, //m_iCurrentScreenY,
m_iMapX *50 + 25 + 25,
m_iMapY *50 + 25 + 40,
iCurrentTime,
iCurrentTime+400+rand()%200 );
// Ask the mover where the object should be
m_oMover.Calculate( iCurrentTime );
m_iCurrentScreenX = m_oMover.GetX();
m_iCurrentScreenY = m_oMover.GetY();
// Ensure that the object gets redrawn on the display, if something changed
RedrawObjects();
return;
}
}
/********** END EXTRA ********/
// If movement has finished
if ( m_oMover.HasMovementFinished(iCurrentTime) )
{
Demo4TileManager& tm = m_pMainEngine->GetTileManager();
// Handle any tile that we just moved onto
switch ( tm.GetValue( m_iMapX, m_iMapY ) )
{
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
tm.UpdateTile( m_pMainEngine, m_iMapX, m_iMapY,
tm.GetValue( m_iMapX, m_iMapY ) + 1 );
break;
case 8:
tm.UpdateTile( m_pMainEngine, m_iMapX, m_iMapY, 0 );
break;
}
// Set off a new movement
switch( rand() % 10 )
{
case 0: // Increase dir by 1
m_iDir = ( m_iDir + 1 )%4;
break;
case 1: // Reduce dir by 1
m_iDir = ( m_iDir + 3 )%4;
break;
}
// Allow some control over the object by the player
if ( m_pMainEngine->IsKeyPressed( SDLK_UP ) )
m_iDir = 0;
if ( m_pMainEngine->IsKeyPressed( SDLK_RIGHT ) )
m_iDir = 1;
if ( m_pMainEngine->IsKeyPressed( SDLK_DOWN ) )
m_iDir = 2;
if ( m_pMainEngine->IsKeyPressed( SDLK_LEFT ) )
m_iDir = 3;
switch ( tm.GetValue(
m_iMapX + GetXDiffForDirection(m_iDir),
m_iMapY + GetYDiffForDirection(m_iDir) ) )
{
case 0: // Passageway
case 2: // Pellet
case 3: // Pellet
case 4: // Pellet
case 5: // Pellet
case 6: // Pellet
case 7: // Pellet
case 8: // Pellet
// Allow move - set up new movement now
m_iMapX += GetXDiffForDirection(m_iDir);
m_iMapY += GetYDiffForDirection(m_iDir);
m_oMover.Setup(
m_iCurrentScreenX,
m_iCurrentScreenY,
m_iMapX *50 + 25 + 25,
m_iMapY *50 + 25 + 40,
iCurrentTime,
iCurrentTime+400+rand()%200 );
break;
case 1: // Wall
m_iDir = rand()%4; // Rotate randomly
break;
}
}
// If making a move then do the move
if ( !m_oMover.HasMovementFinished(iCurrentTime) )
{
// Ask the mover where the object should be
m_oMover.Calculate( iCurrentTime );
m_iCurrentScreenX = m_oMover.GetX();
m_iCurrentScreenY = m_oMover.GetY();
}
// Ensure that the object gets redrawn on the display, if something changed
RedrawObjects();
}
void Nxs13uEnemyObject::DoUpdate(int currentTime)
{
//keep the objects in the playing field
//so the dimensions of the player field is (0,50), (600,50), (0,550), (600,550)
int fieldXmin = 0;
int fieldXmax = 600;
int fieldYmin = 50;
int fieldYmax = 550;
if (id == 3){ //for start page, enemy must be able to travel anywhere
fieldXmin = 0;
fieldXmax = GetEngine()->GetScreenWidth();
fieldYmin = 0;
fieldYmax = GetEngine()->GetScreenHeight();
}
// Alter position for speed - this makes the ball appear to vibrate
// remember that speed is basically pixels travelled per tick
m_iCurrentScreenX += (speedX * rand() % (difficulty + 1));
m_iCurrentScreenY += (speedY * rand() % (difficulty + 1));
// Check for bounce off the edge
if (m_iCurrentScreenX < fieldXmin + radius)
{
m_iCurrentScreenX = fieldXmin + radius;
if (speedX < 0)
speedX = -speedX;
}
if (m_iCurrentScreenX > fieldXmax - radius)
{
m_iCurrentScreenX = fieldXmax - radius;
if (speedX > 0)
speedX = -speedX;
}
if (m_iCurrentScreenY < fieldYmin + radius)
{
m_iCurrentScreenY = fieldYmin + radius;
if (speedY < 0)
speedY = -speedY;
}
if (m_iCurrentScreenY > fieldYmax - radius)
{
m_iCurrentScreenY = fieldYmax - radius;
if (speedY > 0)
speedY = -speedY;
}
// Set current position
m_iCurrentScreenX = (int)(m_iCurrentScreenX + speedX);
m_iCurrentScreenY = (int)(m_iCurrentScreenY + speedY);
//dynamic cast
DisplayableObject* playerObject;
//COLLISIONS
if (id == 2){ //FOR GAME MODE ENEMY (not start-up page enemy)
for (int objectId = 0; (playerObject = m_pMainEngine->GetDisplayableObject(objectId)) != NULL; objectId++)
{
if (playerObject == this) // This is us, skip it
continue;
//get the difference between the player and the enemy
int playerSize = 40;
int xDifference = playerObject->GetXCentre() - m_iCurrentScreenX;
int yDifference = playerObject->GetYCentre() - m_iCurrentScreenY;
// Pythagorus' theorum, if the distance is smaller than the size (radius size of both objects), then it is a collission
if (((xDifference*xDifference) + (yDifference*yDifference)) < ((playerSize + radius)*(playerSize + radius)))
{
//move 70 pixels away from user and go in opposite direction (prevents re-collision)
speedX = -speedX;
speedY = -speedY;
if (speedX < 0 || m_iCurrentScreenX > 530)
m_iCurrentScreenX = m_iCurrentScreenX - 70;
else
m_iCurrentScreenX = m_iCurrentScreenX + 70;
if (speedY < 0 || m_iCurrentScreenY > 480)
m_iCurrentScreenY = m_iCurrentScreenY - 70;
else
m_iCurrentScreenY = m_iCurrentScreenY + 70;
collision = true;
//check which player it collided with - lives are passed back to Nxs13uMain
if (objectId == 0)
player1lives--;
else if (objectId == 1)
player2lives--;
}
// end of collissions
}
}
RedrawObjects();
}
