'==========================================
' MAIN GAME LOOP
'==========================================
Initialise()
While (running)
start = Clock.ElapsedMilliseconds
'Update game logic based on any events
UpdateEvents()
'Update the position of all game shapes
UpdateShapes()
'Detect any collisons and update game
UpdateCollisions()
'Delay the game To try To maintain even 50 frame per second (fps)
delay = 20-(Clock.ElapsedMilliseconds-start)
GraphicsWindow.Title = delay 'To check For performance issues While testing
If (delay > 0) Then
Program.Delay(delay)
EndIf
EndWhile
'Set up all properties For the gane
Sub Initialise
'Create the GraphicsWindow
gw = 600
gh = 600
GraphicsWindow.Width = gw
GraphicsWindow.Height = gh
GraphicsWindow.Top = 50
GraphicsWindow.Left = (Desktop.Width-gw)/2
'Create game sprites
'player is at the bottom of screen
playerW = 10
playerH = 10
player = Shapes.AddRectangle(2*playerW,2*playerH)
playerX = gw/2
playerY = gh-playerH
playerVelX = 5
'Sprite enemies
'Moving horizontally
numSprite = 10
spriteW = 10
spriteH = 10
For i = 1 To numSprite
sprite[i] = Shapes.AddEllipse(2*spriteW,2*spriteH)
spriteX[i] = 50+Math.GetRandomNumber(gw-100)
spriteY[i] = 50+Math.GetRandomNumber(gh-200)
spriteVelX[i] = Math.GetRandomNumber(10)*(2*Math.GetRandomNumber(2)-3) 'Positive and negative values, but not 0
spriteVelY[i] = 0
spriteActive[i] = "True"
EndFor
'Bullets (also used for bombs)
'Initially hidden and inactive
numBullet = 100
bulletW = 4
bulletH = 10
bulletSpeed = 10
For i = 1 To numBullet
bullet[i] = Shapes.AddEllipse(2*bulletW,2*bulletH)
Shapes.HideShape(bullet[i])
bulletX[i] = 0
bulletY[i] = 0
bulletVelX[i] = 0
bulletVelY[i] = 0
bulletActive[i] = ""
EndFor
Sub UpdateEvents
If (mouseClick) Then
Fire()
mouseClick = "" 'Event handled
EndIf
If (keyPressed["Space"]) Then
Fire()
keyPressed["Space"] = "" 'Event handled
EndIf
If (keyDown["Left"]) Then
playerX = playerX-playerVelX
EndIf
If (keyDown["Right"]) Then
playerX = playerX+playerVelX
EndIf
If (mouseMove) Then
playerX = GraphicsWindow.MouseX
mouseMove = "" 'Event handled
EndIf
Sub UpdateShapes
Shapes.Move(player,playerX-playerW,playerY-playerH)
For i = 1 To numSprite
If (SpriteActive[i]) Then
spriteX[i] = spriteX[i]+spriteVelX[i]
spriteY[i] = spriteY[i]+spriteVelY[i]
If (spriteX[i] < spriteW Or spriteX[i] > gw-spriteW) Then 'Bounce sprites on side walls
spriteVelX[i] = -spriteVelX[i]
EndIf
If (spriteY[i] < spriteH Or spriteY[i] > gh-100-spriteH) Then 'Souldn't happen unless we have spriteVelY <> 0
spriteVelY[i] = -spriteVelY[i]
EndIf
'Randomly drop a bomb
If (Math.GetRandomNumber(100) = 1) Then
For k = 1 To numBullet
If (bulletActive[k] <> "True") Then 'Find a bullet not already being used
bulletActive[k] = "True"
Shapes.ShowShape(bullet[k])
bulletX[k] = spriteX[i]
bulletY[k] = spriteY[i]
bulletVelX[k] = 0
bulletVelY[k] = bulletSpeed
k = numBullet 'End check For available bullet
EndIf
EndFor
EndIf
EndIf
EndFor
For i = 1 To numBullet
If (bulletActive[i]) Then
bulletX[i] = bulletX[i]+bulletVelX[i]
bulletY[i] = bulletY[i]+bulletVelY[i]
If (bulletX[i] < -bulletW Or bulletX[i] > gw+bulletW) Then 'Souldn't happen unless we have bulletVelX <> 0
bulletActive[i] = ""
Shapes.HideShape(bullet[i])
EndIf
If (bulletY[i] < -bulletH Or bulletY[i] > gh+bulletH) Then
bulletActive[i] = ""
Shapes.HideShape(bullet[i])
EndIf
Sub Fire
For k = 1 To numBullet
If (bulletActive[k] <> "True") Then 'Find a bullet not already being used
bulletActive[k] = "True"
Shapes.ShowShape(bullet[k])
bulletX[k] = playerX
bulletY[k] = gh-bulletH
bulletVelX[k] = 0
bulletVelY[k] = -bulletSpeed
k = numBullet 'End check For available bullet
EndIf
EndFor
EndSub
Sub UpdateCollisions
'Simple overlap of bullet and sprite regions
For i = 1 To numBullet
If (bulletActive[i]) Then
If (bulletVelY[i] > 0) Then 'A bomb being dropped down
If (bulletX[i] > playerX-playerW And bulletX[i] < playerX+playerW) Then
If (bulletY[i] > playerY-playerH And bulletY[i] < playerY+playerH) Then
'Collision detected - just remove bullet and do a short delay so we can see it happened
bulletActive[i] = ""
Shapes.HideShape(bullet[i])
Program.Delay(500)
EndIf
EndIf
Else 'A bullet being fired up
For j = 1 To numSprite
If (spriteActive[j]) Then
If (bulletX[i] > spriteX[j]-spriteW And bulletX[i] < spriteX[j]+spriteW) Then
If (bulletY[i] > spriteY[j]-spriteH And bulletY[i] < spriteY[j]+spriteH) Then
'Collision detected - just remove bullet and sprite
bulletActive[i] = ""
Shapes.HideShape(bullet[i])
spriteActive[j] = ""
Shapes.HideShape(sprite[j])
EndIf
EndIf
EndIf
EndFor
EndIf
EndIf
EndFor
EndSub
'==========================================
' EVENT SUBROUTNINES
'mouseClick = "True" when any mouse button is clicked - should be reset To "" after this event is handled
'Use Mouse.IsLeftButtonDown and Mouse.IsLeftButtonDown To check mouse state
'keyPressed = "True" when key is pressed - should be reset To "" after this event is handled
'keyDown[key] = "True" While 'key' is pressed down
'==========================================
Sub OnMouseDown
mouseClick = "True"
EndSub
Sub OnMouseMove
MouseMove = "True"
EndSub
Sub OnKeyDown
key = GraphicsWindow.LastKey
If (keyDown[key] <> "True") Then 'Prevent this event on auto key repeat (requires key To be released first)
keyPressed[key] = "True"
EndIf
keyDown[key] = "True"
EndSub
Sub OnKeyUp
key = GraphicsWindow.LastKey
keyDown[key] = ""
EndSub
Program Listing: NTG546