I will take a look at this and try to put together some cool things that can be done with it.

In the meantime, check it out for yourself: http://www.xihsolutions.net/dotmsn/

Visual Basics .NET

 
If Object1.IntersectsWith(Object2) Then
'do whatever
End If
 

Object1 and Object2 can be anything from labels or shapes. This code can be placed in a timer to continuously check if there's a intersection occurring and act accordingly.

Java
In Java, the code is almost the exact same.

 
  if (Object1.intersects(Object2.getBounds())){
//do stuff
 }
 

The use is the same and only executes the if statement if they are touching.

And that's it, hope it helps.

If you have any more suggestions, don't hesitate to contact me

So I will go over line by line what each thing does in the full article.

Here is the full loadLevel function from the LightsOn clone posted yesterday:

 
    Public Sub loadLevel(ByVal level As Integer)
        Dim oFile As System.IO.File
        Dim oRead As System.IO.StreamReader
        Dim LineIn As String
        Dim currentcolumn As Integer
        If System.IO.File.Exists(CurDir() & "\levels\" & level.ToString & ".txt") Then
            oRead = oFile.OpenText(CurDir() & "\levels\" & level.ToString & ".txt")
            While oRead.Peek <> -1
                LineIn = oRead.ReadLine()
                For i As Integer = 0 To (LineIn.Length - 1) Step 1
                    If LineIn.ElementAt(i) = "|" Then
                        buttons(i, currentcolumn).Text = "|"
                        buttons(i, currentcolumn).ForeColor = Color.Blue
                        buttons(i, currentcolumn).BackColor = Color.Blue
                    Else
                        buttons(i, currentcolumn).Text = "-"
                        buttons(i, currentcolumn).ForeColor = Color.Red
                        buttons(i, currentcolumn).BackColor = Color.Red
                    End If
                Next
                currentcolumn = currentcolumn + 1
            End While
            oRead.Close()
        Else
            MsgBox("Level " & level.ToString & " does not exist!")
        End If
    End Sub
 

The function takes the integer value of the level to load. This is used in finding the level .txt file (level & ".txt")

The first two variables declared are for the streamreader, this allows the loading of files. There is also another variable that can be declared for the writing of txt files, can be used to make a level editor. But that wont be looked at.

LineIn is the string that holds the current line that has been read for later processing. The integer currentcolumn holds the current column the txt file loading is on (can be a max of 7).

Right away it checks to make sure the file located in the current directory\levels\levelnumber.txt exists. This is to prevent errors from trying to load a text file that dosn't exist.

The entire text file is loaded into the StreamReader that was previously declared as oRead. A while loop is started that loops while there is still more columns left. Right after the loop is started, the string LineIn is set to the entire string found at that current line in the text file.

Now its for the fun part, the part that generates the level based on what it loads.

A For loop is started from 0 to the size of the line minus 1. Remember, everything in programming starts at 0, not a 1. If we were to start the for loop at a 1, the first button in each column would be ignored!

A if statement is used to check the ElementAt the i index. ElementAt returns the value at the index.

For example, if there is a string that says:
Dim mystring as string
mystring = "BncApps"

And this was done:
MessageBox.Show(mystring.ElementAt(2))

A message box would appear saying "c"

So if the element at the current loop index is a |, then it sets the tiles to blue, meaning they are on. Notice how currentcolumn isn't incremented at all within the for loop. If the element at that position is not a |, then it assumes its a dash (-) and sets them to red, or off.

After the for loop exits, currentcolumn is incremented by one.

Once the while loop finishes, it closes the StreamReader. A else statement is set for the first if statement that was in place (the one that made sure the file existed) to give a message box if the level does not exist.

Well that's everything, hope it helps!

This is how a level file would look:

|||||||
||-||||
|--||||
|||--||
|||-|||
|||||||
|||||||

Where | are the blue ones and the dashes (-) are the ones that must be turned into blue. Levels can be created anyway, aslong as they are 7x7. There is 7 levels included, all I have been able to finish except level 7 (can any of you try to beat it?)

If you create any levels and would like to share them, please use the contact me form and they will be posted!

As always, its Open Source.
Download the binary and source here: LightsOn (741) - 192.62 kB
Or
Download from Ziddu and support BncApps

This can be futher extended with more commands such as a way to jump to a certain part of the code. This is not in the project, but if requested a new version will be released.

Download the binary and source: MouseMacro (698)
Download from Ziddu.com and support BncApps!

Since this is a big project, only registered users will be able to download it. It will not take you any longer than 2 minutes to be registered. When registered you will also be able to post comments!

Download Binary and Source (Registered members only): Slot Machine (654) -
Don't want to register? Click here to download the Binary and Source from Ziddu and support BncApps at the same time!

There are two methods, mouse down and mouse up. Mouse down handles clicking on the form, and basically doing things while the mouse button is being held down. Mouse up does the opposite, handles doing things when the mouse is not being clicked, or detecting where it was unclicked.

Here is the mouse down event:

Private Sub Form1_Mousedown(ByVal sender As System.Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
If e.Button = MouseButtons.Left Then
'do stuff
End If
End Sub

With this you can do various things. Instead of MouseButtons.Left you can also use MouseButtons.Right and MouseButtons.Middle. Also, you can determine where the mouse was clicked by using e.X and e.Y.

For example, add this line of code into your mouseDown method and click on the form:

If e.Button = MouseButtons.Left Then
MessageBox.Show("Left mouse button clicked at: " & e.X & ", " & e.Y)
Else If e.Button = Mousebuttons.Middle Then
MessageBox.Show("Middle mouse button clicked at: " & e.X & ", " & e.Y)
Else If e.Button = Mousebuttons.Right Then
MessageBox.Show("Right mouse button clicked at: " & e.X & ", " & e.Y)
End If


Easy enough? MouseUp is the exact same thing...

Private Sub Form1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp
If e.Button = MouseButtons.Left Then

End If
End Sub


This allows you to do all the same functions.

What can it be used for? Well when the mouse is clicked, you can set a boolean to true, and when its released you can set it back to false. Then you can have a Timer to check when the mouse is being held down and do something. In the project file from my previous post, VB.NET - Handling shape movements and collision, it is used for growth of the shapes. When the "helddown" boolean is true, the size of the current rectangle is continuously increased by 1 until the mouse is released.

Thats all for that!

In the previous post(Found here) I talked about creating shape objects at random positions and drawing them on the form. This tutorial will go over making them all move, and handling collisions. I made a Visual Basics project as a way to test "gravity." You click around the form and it will create a square at that position, they instantly bein to fall. Once they hit the ground (the bottom of the form) they stop moving, if they hit others that are touching the ground (double clicking in the air will not work) they will stack up and stop moving.

The project binary and full source code will be available at the end of this post.
Note: This was made in Visual Studio 2008, if you try on previous versions you may have problems! You can download Visual Studio 2008 for FREE on Microsoft's website!

Notice how most of these are arrays of 500, just like the Rectangle array. Each rectangle will have its own slot in each of these arrays.

Add this to your form_load, this reduces the flicker when the form refreshes:

Me.DoubleBuffered = True

And add this to your form_load:

drawnRectangles = 1
unlockAll()
intersectUnlock()
connectsUnlock()
unlockSquares()

This is basically to call methods that will set all the boolean variables to false, useful for instantiating them and each time we decide to clear the form.

Here is the full code for the methods:

Sub unlockAll()
For i As Integer = 1 To 500 Step 1
rectangleLock(i) = False
Next
End Sub

Sub unlockSquares()
For i As Integer = 1 To 500 Step 1
squareLocked(i) = False
Next
End Sub


The next thing to add is the mousedown event:

Private Sub Form1_Mousedown(ByVal sender As System.Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
If e.Button = MouseButtons.Left Then
drawRectangle(drawnRectangles, e.X, e.Y)
drawnRectangles = drawnRectangles + 1
If drawnRectangles = 500 Then
drawnRectangles = 1
unlockAll()
intersectUnlock()
connectsUnlock()
End If
End If
End Sub

What this basically does is get the x and y position of where the mouse was clicked, pass the integer value drawnRectangles, x, and y to drawRectangle. Within drawRectangle it adds it to the array (as mentioned in the previous post) It then increases drawnRectagngles by 1, and if drawnRectangles is 500 (the size of the array) it will reset it down to 1 and clear the form of all squares by calling all the unlock functions.

Add a timer, call it tmrRefresh, set its interval to 1 and enable it right away. All the code this timer needs is:

Me.Refresh()

This will refresh the form and clear all the other shapes for them to be redrawn. After we add the movement section, try disabling this timer and see what happens!

Next is the timer that will force all the shapes downwards, name it tmrMove, in the project file its called Timer1. Give it a interval of 2


For i As Integer = 1 To (drawnRectangles - 1) Step 1
If (myRectangle(i).Top < Me.Height - 50) And rectangleLock(i) = False Then
If intersectLock(i) = False Then '
If (myRectangle(i).Left > 0) Then
myRectangle(i).Location = New Point(myRectangle(i).X, myRectangle(i).Y + 1)
Else
myRectangle(i).Location = New Point(myRectangle(i).X, myRectangle(i).Y + 1)
End If ' end if for the width check
End If
myGraphics.DrawRectangle(pen:=myPen, rect:=myRectangle(i))
myGraphics.FillRectangle(brush:=myBrush, rect:=myRectangle(i))
Else
If intersectLock(i) = False Then
myRectangle(i).Location = New Point(myRectangle(i).X, Me.Height - 50)
End If
rectangleLock(i) = True
connectsToGround(i) = True 'This one has hit the ground
myGraphics.DrawRectangle(pen:=myPen, rect:=myRectangle(i))
myGraphics.FillRectangle(brush:=myBrush, rect:=myRectangle(i))
End If
Next

Steps in the code:
1.The code starts with a loop from 1 to the number of rectangles drawn on the form (remember the variable was increased when we clicked?)

2. Within that it checks if the Top value (basically the y value) is less than the forms height, and rectangleLock at the array spot i, meaning the loop index is false.

3. Right after it checks if the boolean intersectLock is also false
Then it checks to makesure the left (or x value) is greater than 0. This part is mainly used for the "wind" code thats in the project file, to make sure the square is not moved off the form.

4. If all these if statements passed, then it runs the code of setting the rectangles location to a new point, of the rectangles y value, plus 1. This will make it slide down each timer tick.

5. If the rectangle's x value is less than 0, it will only pull it downwards. This is for the "wind" part, which is why it may not sound right. In the project file you will see it makes more sense.

6. The rectangle is then redrawn and refilled

7. The else statement is called for the first if statement (the one that checks if its y value is greater than the forms height). Within this, it checks to see if intersectLock is false, the purpose of this variable is described later. If the Y position of the square did go outside of the form, it resets it to the forms height, subtracted from 50. It then sets intersectLock to true, to prevent it from moving anymore. It will then lock it in and since it touched the ground, it sets that one to true. This is used later for the collision stacking.

8. The rectangles are drawn again and the final end if appears

9. The loop restarts, for the next rectangle.

So movement is out of the way, now for collision and stacking.

Add a new timer, this one will be to handle collisions. Call it tmrCollisions (in the project file its Timer2) and give it a interval of 1, enable it right away.

The code for this timer is much shorter, but more complex:

For i As Integer = 1 To (drawnRectangles - 1) Step 1
For x As Integer = 1 To (drawnRectangles - 1) Step 1
If i <> x Then
If connectsToGround(x) = True Then
If myRectangle(i).IntersectsWith(myRectangle(x)) Then
intersectLock(i) = True
connectsToGround(i) = True 'its connected to one thats touching the ground
End If
End If 'end if for if rectangleLock
End If
Next 'x
Next 'i

The code starts by starting a for loop to the size of the drawn rectangles, then another to the size of the rectangles. A nested for loop within the main for loop. Right away it checks to makesure I is not the same as X, to prevent it from checking a collision with itself (which will always be true). Then it checks if x is connected to the ground, if it is then that means its touching the floor. It then calls the .intersectsWith to check if i intersects with X. If it does, then it intersect locks it, and sets i being connected to the ground, as its connected to one that links to the ground. And thats it for that!

The 2 loops cause something like this:
i and x, i and x+1, i and x+2

x will always be incrementing, once x has finished its loop, i gets incremented, then the x loop starts again, comparing each with each other to check for intersections.

And thats it! You can get the source download below. No screenshot this time as the form is really big to allow the objects space to fall and stack.

Like always, the source is licensed under the GPL license. If you use it with the intent to re distribute it, the source must be released too, as well as a link back to BncApps.

Download: GravityExample (871) - 136.19 kB

Helpful? why not buy me a coffee for my next project?