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var aR, bR, ergR: TRect;
begin
  aRect := Rect(100,100,200,200);
  bRect := Rect(10,10,120,120);
  IntersectRect(ergRect,aRect,bRect);//=> ergRect(100,100,120,120)                    

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function TFormMain.LineCollision(x1: Integer; y1: Integer; x2: Integer;
                                 y2: Integer; x3: Integer; y3: Integer;
                                 x4: Integer; y4: Integer) : Boolean;
var m1,m2,b1,b2,resultX: Real;
begin
result:=FALSE;
  m1:=(y2-y1)/(x2-x1);
  m2:=(y4-y3)/(x4-x3);
  b1:=y1-m1*x1;
  b2:=y3-m2*x3;
  resultX:=(b1-b2)/(m2-m1);
  ShowMessage(FloatToStr(resultX));
if not(resultX=0) then
  begin
    result:=TRUE;
  end;
end;                    

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procedure TFormMain.MoveBall(pCollisionObject: array of TPanel);
var tempObject,CollisionRect,BallAlt: TRect;
    I,: Integer;
begin
//-----------------------------save old Parameters----------------------------//
BallAlt.Top:=Ball.Top;
BallAlt.Bottom:=Ball.Bottom;
BallAlt.Left:=Ball.Left;
BallAlt.Right:=Ball.Right;
oldXCor:=XCor;
oldYCor:=YCor;
//----------------------------------------------------------------------------//
//--------------------Move Ball Check for Wall Collision(x)-------------------//
  sball.left:=sball.left+XCor;
  Ball.Left:=SBall.Left;
  Ball.Right:=SBall.Left+SBall.Width;
    if sball.left < (PLinks.Left+PLinks.Width) then
      begin
      sball.left := (PLinks.Left+PLinks.Width);
      Xcor := -Xcor;
      end;
    if sball.left > PRechts.Left - sball.width then
      begin
      sball.left := (PRechts.Left - sball.width);
      XCor := -XCor;
      end;
//----------------------------------------------------------------------------//
//--------------------Move Ball Check for Wall Collision(y)-------------------//
  sball.top := sball.top+YCor;
  Ball.Top:=SBall.Top;
  Ball.Bottom:=SBall.Top+SBall.Height;
    if sball.top < (POben.Top+POben.Height) then
      begin
      sball.Top := (POben.Top+POben.Height);
      YCor := -YCor;
      end;
    if sball.top > (self.height - sball.height) then
      begin
      sball.top := (self.height - sball.height);
      YCor := -YCor;
      end;
//----------------------------------------------------------------------------//
//-----------------------------Collision Ball Stick---------------------------//
    if IntersectRect(Collision,Ball,Stick) then
      begin
        sball.top := (PStick.top - sball.height);
        YCor:= -YCor;
        XCor:= XCor-1;
      end;
//----------------------------------------------------------------------------//
//------------------------Collision Ball Brick--------------------------------//
for I := 0 to High(pCollisionObject) - 1 do
  begin
    tempObject.Left:=pCollisionObject[I].Left;
    tempObject.Right:=pCollisionObject[I].Left+pCollisionObject[I].Width;
    tempObject.Top:=pCollisionObject[I].Top;
    tempObject.Bottom:=pCollisionObject[I].Top+pCollisionObject[I].Height;
    if IntersectRect(CollisionRect,tempObject,Ball) then
      begin
        TMover.Enabled:=False;
        case Richtung of
          0: begin
               //Ball läuft nach Unten Rechts
             if LineCollision(BallAlt.Left,BallAlt.Top,Ball.Left,Ball.Top,
                              pCollisionObject[I].Left,pCollisionObject[I].Top,
                              pCollisionObject[I].Left+pCollisionObject[I].Width,
                              pCollisionObject[I].Top)=TRUE then
               begin
                 SBall.Top:=(pCollisionObject[I].Top-SBall.Height);
                 YCor:= -YCor;
               end
             else
               begin
                 SBall.Left:=(pCollisionObject[I].Left-SBall.Width);
                 XCor:= -XCor;
               end;
             end;
          1: begin
               //Ball läuft nach Oben Rechts
             if LineCollision(BallAlt.Left,BallAlt.Top,Ball.Left,Ball.Top,
                              pCollisionObject[I].Left,
                              pCollisionObject[I].Top+pCollisionObject[I].Height,
                              pCollisionObject[I].Left+pCollisionObject[I].Width,
                              pCollisionObject[I].Top+pCollisionObject[I].Height)
                              =TRUE then
               begin
                 SBall.Top:=(pCollisionObject[I].Top+SBall.Height);
                 YCor:= -YCor;
               end
             else
               begin
                 SBall.Left:=(pCollisionObject[I].Left-SBall.Width);
                 XCor:= -XCor;
               end;
             end;
          2: begin
              //Ball läuft nach Oben Links
             if LineCollision(BallAlt.Left,BallAlt.Top,Ball.Left,Ball.Top,
                              pCollisionObject[I].Left,
                              pCollisionObject[I].Top+pCollisionObject[I].Height,
                              pCollisionObject[I].Left+pCollisionObject[I].Width,
                              pCollisionObject[I].Top+pCollisionObject[I].Height)
                              =TRUE then
               begin
                 SBall.Top:=(pCollisionObject[I].Top+SBall.Height);
                 YCor:= -YCor;
               end
             else
               begin
                 SBall.Left:=(pCollisionObject[I].Left+SBall.Width);
                 XCor:= -XCor;
               end;
             end;
          3: begin
              //Ball läuft nach Unten Links
             if LineCollision(BallAlt.Left,BallAlt.Top,Ball.Left,Ball.Top,
                              pCollisionObject[I].Left,pCollisionObject[I].Top,
                              pCollisionObject[I].Left+pCollisionObject[I].Width,
                              pCollisionObject[I].Top)=TRUE then
               begin
                 SBall.Top:=(pCollisionObject[I].Top-SBall.Height);
                 YCor:= -YCor;
               end
             else
               begin
                 SBall.Left:=(pCollisionObject[I].Left+SBall.Width);
                 XCor:= -XCor;
               end;
             end;
        end;
        TMover.Enabled:=TRUE;
      end;
  end;
//----------------------------------------------------------------------------//
//-------------------------Ball doesn't hit Stick-----------------------------//
    if Sball.Top > PStick.Top then
      begin
        SBall.Visible:=False;
        TMover.Enabled:=False;
        MessageDLG('Game Over!',mtWarning,[mbOk],0);
        SpawnBall;
      end;
//----------------------------------------------------------------------------//
//------------------------Save (?)new(?) Direction----------------------------//
if ((BallAlt.Left-Ball.Left)<0) then
  begin
    //links
    if ((BallAlt.Top-Ball.Top)<0) then
      begin
        //schräg unten links
        Richtung:=3;
      end
    else
      begin
        if ((BallAlt.Top-Ball.Top)>0) then
          begin
            //schräg oben links
            Richtung:=2;
          end;
      end;
  end
else
  begin
    if ((BallAlt.Left-Ball.Left)>0) then
      begin
        //rechts
        if ((BallAlt.Top-Ball.Top)<0) then
          begin
            //schräg unten rechts
            Richtung:=0;
          end
        else
          begin
            if ((BallAlt.Top-Ball.Top)>0) then
              begin
                //schräg oben rechts
                Richtung:=1;
              end;
          end;
      end;
  end;
//----------------------------------------------------------------------------//
end;                    

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function TFormMain.LineCollision(x1: Integer; y1: Integer; x2: Integer;
                                 y2: Integer; x3: Integer; y3: Integer;
                                 x4: Integer; y4: Integer) : Boolean;
var m1,m2,b1,b2,resultX: Real;
begin
//ShowMessage('x1:'+IntToStr(x1)+'y1:'+IntToStr(y1)+'x2:'+IntToStr(x2)+'y2:'+
//            IntToStr(y2)+'x3:'+IntToStr(x3)+'y3:'+IntToStr(y3)+'x4:'+
//            IntToStr(x4)+'y4:'+IntToStr(y4));
result:=FALSE;
  m1:=(y2-y1)/(x2-x1);
//ShowMessage(FloatToStr(m1));
  m2:=(y4-y3)/(x4-x3);
//ShowMessage(FloatToStr(m2));
  b1:=y1-m1*x1;
//ShowMessage(FloatToStr(b1));
  b2:=y3-m2*x3;
//ShowMessage(FloatToStr(b2));
  resultX:=(b1-b2)/(m2-m1);
//ShowMessage(FloatToStr(resultX));
if not(resultX=0) then
  begin
    result:=TRUE;
  end;
end;