[MFC] How to make a ball bounce off from an object?

[hkboy1019]

How would i make the ball bounce off from the object (bitmap) in MFC? (look at the picture below)
How would i set the boundaries and stuff?
Does anyone have the code?
I really really need help....i need to complete my project soon.

just in case you want to know, the bitmap size is 40 x 40.
don't know if it matters though.
and remember, i want the ball to bounce off from all four sides of the bitmap, and it would just repeat this process over and over.

[hkboy1019]

bump

[MrViggy]

Assuming you have objects for ( a ) the ball, and ( b ) the obstacles; all you need to do is check that the two are not intersecting after you've moved them.

Some pseudo code:

- Check ball bounds for obstacle intersection
-  If something intersects, check which side of ball
  -  Change ball direction based on side hit
- Move ball

While this is a simple solution; I don't have any actual code offhand...

Viggy

[TDM]

The attachment in this thread might provide some insight.

TDM

[kirants]

Hey !! That thread was started by the same person

[MrViggy]

HAHAHAHAHAHAHA! That's funny! I didn't realize that!!!



Viggy

[patricksky]

The project file contain the program of bouncing ball. This require DirectX SDK to compile. But you can run the executable inside the release folder. And i written this program just for fun

The program segment you may interest is

void CBallDlg::OnTimer(UINT nIDEvent) 
{
	
	if(nIDEvent==1){
		if(curX+circleWidth>=windowRect.right){
			offsetx=-offsetx;
			m_pEdgeSound->Play();
		}
		if(curX<=0){
			offsetx=-offsetx;
			m_pEdgeSound->Play();
		}
		if(curY+circleWidth>=windowRect.bottom){
			offsety=-offsety;
			m_pEdgeSound->Play();
		}
		if(curY<=0){
			offsety=-offsety;
			m_pEdgeSound->Play();
		}
		
		if(curY+circleWidth==curBarRect.top||curY==curBarRect.bottom){
			if(curX>=curBarRect.left&&curX<=curBarRect.right){
				offsety=-offsety;
				m_pBarSound->Play();
			}
		}
		curX+=offsetx;
		curY+=offsety;
		//curX=rand()%windowRect.right;
		//curY=rand()%windowRect.bottom;
		m_pMemDC->FillSolidRect(&windowRect,RGB(0,0,0));
		m_pMemDC->Ellipse(curX,curY,curX+circleWidth,curY+circleWidth);
		m_pMemDC->FillSolidRect(&curBarRect,RGB(0,255,0));
		sprintf(mess,"X: %d\nY: %d",curX,curY);
		//m_status.SetWindowText("X:\nY:");
		m_status.SetWindowText(mess);
		Invalidate(NULL);
	}
	CDialog::OnTimer(nIDEvent);
}

[hkboy1019]

Originally posted by MrViggy
HAHAHAHAHAHAHA! That's funny! I didn't realize that!!!



Viggy

yeah, i started that thread.
i solved that problem (in the other thread)...so now i could click anywhere in the four areas and the ball will move to different directions!

[hkboy1019]

Originally posted by patricksky
The project file contain the program of bouncing ball. This require DirectX SDK to compile. But you can run the executable inside the release folder. And i written this program just for fun

The program segment you may interest is

void CBallDlg::OnTimer(UINT nIDEvent) 
{
	
	if(nIDEvent==1){
		if(curX+circleWidth>=windowRect.right){
			offsetx=-offsetx;
			m_pEdgeSound->Play();
		}
		if(curX<=0){
			offsetx=-offsetx;
			m_pEdgeSound->Play();
		}
		if(curY+circleWidth>=windowRect.bottom){
			offsety=-offsety;
			m_pEdgeSound->Play();
		}
		if(curY<=0){
			offsety=-offsety;
			m_pEdgeSound->Play();
		}
		
		if(curY+circleWidth==curBarRect.top||curY==curBarRect.bottom){
			if(curX>=curBarRect.left&&curX<=curBarRect.right){
				offsety=-offsety;
				m_pBarSound->Play();
			}
		}
		curX+=offsetx;
		curY+=offsety;
		//curX=rand()%windowRect.right;
		//curY=rand()%windowRect.bottom;
		m_pMemDC->FillSolidRect(&windowRect,RGB(0,0,0));
		m_pMemDC->Ellipse(curX,curY,curX+circleWidth,curY+circleWidth);
		m_pMemDC->FillSolidRect(&curBarRect,RGB(0,255,0));
		sprintf(mess,"X: %d\nY: %d",curX,curY);
		//m_status.SetWindowText("X:\nY:");
		m_status.SetWindowText(mess);
		Invalidate(NULL);
	}
	CDialog::OnTimer(nIDEvent);
}

oh thank you for the code....i'll try it.
i am from hong kong too wor.