return to breakout

well I have decided to finish my breakout game using opengl and c++. I am still stuck on how to get the ball to bounce off the brick and get it to disappear. Then when it is removed I want the ball to pass through the space where the brick was. Please don't give me a lot of code. Also I am using magic numbers for now. Here is just a little bit of code.

if(x>=3.0f && x<=5.0f && y>=3.5f && y<=4.0f)
	{
	ystep = -ystep;
	g_bBlock[4].m_bActive_three=false;	
	}

well this code checks for a brick and then switches the ball's velocity and then turns off the brick. but it still bounces off where the brick was. I know I have asked this question before but I would like a fresh perspective. I am doing my best to finish this project.

simply check that the brick is still valid when your comparing to hit it, like so:

if(x>=3.0f && x<=5.0f && y>=3.5f && y<=4.0f && g_bBlock[4].m_bActive_three==true) { 
   ystep = -ystep; 
   g_bBlock[4].m_bActive_three=false; 
}

your naming convention is a bit odd(_three?)

edit: also, just to toss this out their for thought: what happens when your ball impacts the block along the side's rather than top or bottom?

As Endurion pointed out just use the bool in the condition for collision.

if(g_bBlock[4].m_bActive_three==true)
{
if(x>=3.0f && x<=5.0f && y>=3.5f && y<=4.0f)
{
ystep = -ystep;
g_bBlock[4].m_bActive_three=false;
}
}

But trust me, there are much more efficient ways of detecting collision and removing the blocks. The one you are using is probably the easiest but not accurate in many cases.

I would agree with Endurion and Sam Sandeep. Sounds like you are calculating collision even if the brick is "turned off". I would also like to add why are you keeping the brick in memory at all? If it is "destroyed" once the ball makes impact why don't you just completely remove it from memory? Remove it from the active collection, free up memory don't have to waste time calculating for collision on it (even if it is turned off).

Sometimes I feel like Phil is trolling us, and he just chuckles when we post a lot of code to help him.

Then I think maybe he's just struggling very hard and just can't "get it". It happens. At least he's trying hard (if he's not trolling)

I graduated from college with a b.s. in c.s. in 2005.

Which college?

Phil, what did you not understand about this code I posted?

It gives a general idea of how to encapsulate brick's and the ball into it's own structure, and shows how to handle collisions and rendering.

Start with the structures:

 
struct TBrick {
  int XPosition;
  int YPosition;
  int XSize;
  int YSize;
  uint32_t Color;
  uint32_t ActiveState;  // 0 is deactive; If it takes multiple hits to kill a brick, it can start greater than 1
};
 
struct TBall {
  int XPosition;
  int YPosition;
  int XSize;
  int YSize;
  int XSpeed;
  int YSpeed;
};

#define BRICK_COLUMNS 20 // how many bricks in a column
#define BRICK_ROWS 10 // how many bricks ina  row
#define BRICK_START_X 60 // Where the bricks start on the x-axis
#define BRICK_START_Y 40 // Where the bricks start on the y-axis
#define BRICK_WIDTH 30 // brick width in pixels
#define BRICK_HEIGHT 15 // brickheight in pixels

 

// make this a global array
TBrick BrickArray[BRICK_COLUMNS][BRICK_ROWS];
 
// Initialize the Brick Array somewhere at the start of your code
for (int x = 0; x < BRICK_COLUMNS; x++) {
  for (int y = 0; y < BRICK_ROWS; y++) {
    BrickArray[x][y].XSize = BRICK_WIDTH;
    BrickArray[x][y].YSize = BRICK_HEIGHT;
    BrickArray[x][y].XLocation = BRICK_START_X + x*BRICK_WIDTH;
    BrickArray[x][y].YLocation = BRICK_START_Y + y*BRICK_HEIGHT;
    BrickArray[x][y].Color = 0xFFFFFFFF; // white
    BrickArray[x][y].ActiveState = 1; // 1 hit to turn off brick
  }
}

yeah!! thanks for all the help, I finally solved the collision problem with the ball and bricks.

Show us your solution. I've heard you say that before, but you come back and ask the question again.

well here it is

if(	g_bBlock[4].m_bActive_three==true)	
	{
	if(x>=3.0f && x<=5.0f && y>=3.5f && y<=4.0f)
	{
	ystep = -ystep;
	bricks[2][4]=true;
	g_bBlock[4].m_bActive_three=false;	
	}
	}

Sigh.

...

Just...Sigh.

I give up. Good luck to you.