Basic 2D Game Template
Posted: Wed Nov 03, 2010 3:11 am
Here's a basic template that should help on creating a 2D game. It's has a grid that can be enabled by pressing the "G" key. I found this a pretty simple way of setting up graphics without using a separate editor. But if this method is not for you, you can always remove the grid code. I commented on as much as I could, so it should be easy to follow. 
Code: Select all
;Screen settings which can be also useful for sprites.
#ScreenWidth = 1024
#ScreenHeight = 768
#ScreenDepth = 32
#GameTitle = "New Game"
;Temporary grid settings for editing.
#GridSize = 512
#GridTile = 32
#GridMarker = 128
#LevelWidth = 2048 ;Can also make #LevelWidth1, #LevelWidth2, and so on for different level lengths. Although the grid is set for #LevelWidth but could be edited.
;Initializing the game requirements and checking for errors.
If InitSprite() = 0
MessageRequester("Error!", "Sprite system can not be initialized.", 0)
End
EndIf
If InitSprite3D() = 0
MessageRequester("Error!", "Sprite3D system can not be initialized.", 0)
End
EndIf
If InitKeyboard() = 0
MessageRequester("Error!", "Keyboard can not be initialized.", 0)
End
EndIf
If InitMouse() = 0
MessageRequester("Error!", "Mouse can not be initialized.", 0)
End
EndIf
If InitJoystick() = 0 ;Generic auto joystick initializing.
Gamepad = 0
Else
Gamepad = 1
EndIf
UsePNGImageDecoder() ;For nice looking graphics, 32bit png images with alpha channel. But not required.
If OpenScreen(#ScreenWidth, #ScreenHeight, #ScreenDepth, #GameTitle, #PB_Screen_SmartSynchronization)
;-Draw Grid
;Temporary grid for editing. Remove grid code when done editing the game.
CreateSprite(99999, #GridSize, #ScreenHeight, #PB_Sprite_AlphaBlending | #PB_Sprite_Texture)
StartDrawing(SpriteOutput(99999))
DrawingMode(#PB_2DDrawing_Default)
LW = 4
For GridWidth = 0 To #GridSize Step #GridTile
If LW = 4
Line(GridWidth, 0, 1, #ScreenHeight , RGBA(255, 0, 0, 0))
LW = 1
Else
Line(GridWidth, 0, 1, #ScreenHeight , RGBA(255, 255, 255, 0))
LW +1
EndIf
Next GridWidth
For GridHeight = 0 To #ScreenHeight Step #GridTile
If LH = 4
Line(0, GridHeight, #ScreenHeight, 1 , RGB(255, 0, 0))
LH = 1
Else
Line(0, GridHeight, #ScreenHeight, 1 , RGB(255, 255, 255))
LH +1
EndIf
Next GridHeight
StopDrawing()
TransparentSpriteColor(99999, RGB(0, 0, 0))
Else
;Displays an error if the users pc can not use the resolution and/or color depth requirement.
MessageRequester("Error!", "Unable to open screen at " + Str(#ScreenWidth) + "x" + Str(#ScreenHeight) + " with " + Str(#ScreenDepth) + "bit color.", 0)
End
EndIf
Grid = 0 ;Editing grid is disabled until the "G" key is pushed/released.
GridX = 0 ;Starting position of our scrolling grid.
Level = 0 ;Game starts at the "Start Screen".
LoadGraphics = 1 ;Loads needed graphics.
Repeat
ExamineKeyboard()
FlipBuffers()
ClearScreen(0)
;-Start Screen
If Level = 0 ;The "Start Screen".
If LoadGraphics = 1
;CatchSprite(0, ?Pic0, #PB_Sprite_AlphaBlending | #PB_Sprite_Texture) ;Load some graphics.
LoadGraphics = 0
EndIf
;DisplayTransparentSprite(1, 10, 10) ;Display our "Start Screen" graphics.
If KeyboardPushed(#PB_Key_Return) ;Or you mouse click on the "Start" button.
;FreeImage() ;Free the graphics. May need a For/Next loop to free multiple images.
Level = 1 ;While a new game would start at level 1, it would be even better if you create a saved game setting and loaded it.
LoadGraphics = 1
EndIf
If KeyboardReleased(#PB_Key_Escape) ;Closes the game.
;FreeImage() ;Free the graphics. May need a For/Next loop to free multiple images.
End
EndIf
EndIf
;-Level 1
If Level = 1
;Same as the "Start Screen" pretty much.
If KeyboardReleased(#PB_Key_Escape) ;Goes back to the "Start Screen".
;FreeImage() ;Free the graphics. May need a For/Next loop to free multiple images.
Level = 0
EndIf
EndIf
;-Display Grid
;Temporary grid for editing. Should be drawn last or over sprites. Remove grid code when done editing the game.
If KeyboardReleased(#PB_Key_G)
If Grid = 1
Grid = 0
Else
Grid = 1
EndIf
EndIf
If Grid = 1
For GridTile = 0 To #LevelWidth Step #GridSize
DisplayTransparentSprite(99999, GridX +GridTile, 0)
Next GridTile
StartDrawing(ScreenOutput())
DrawingMode(#PB_2DDrawing_Default)
For GridText = 0 To #LevelWidth Step #GridMarker
DrawText(GridX +GridText, 0, Str(GridText), RGB(255, 255, 255))
Next GridText
StopDrawing()
StartDrawing(ScreenOutput())
DrawingMode(#PB_2DDrawing_Default)
For GridText = #GridMarker To #ScreenHeight Step #GridMarker
DrawText(0, GridText, Str(GridText), RGB(255, 255, 255))
Next GridText
StopDrawing()
EndIf
;-Keyboard
If Not KeyboardPushed(#PB_Key_Left) ;Make sure the "Left Cursor" key isn't still being held down.
If KeyboardPushed(#PB_Key_Right)
If Grid = 1
If GridX > -#LevelWidth + #ScreenWidth
GridX -5
EndIf
EndIf
;More scrolling variables go here.
EndIf
EndIf
If Not KeyboardPushed(#PB_Key_Right) ;Make sure the "Right Cursor" key isn't still being held down.
If KeyboardPushed(#PB_Key_Left)
If Grid = 1
If GridX < 0
GridX +5
EndIf
EndIf
;More scrolling variables go here.
EndIf
EndIf
;-Joystick
If Gamepad = 1 ;If a joystick is detected it will be available.
ExamineJoystick(0)
If JoystickAxisX(0) = 1 ;Right
If Grid = 1
If GridX > -#LevelWidth + #ScreenWidth
GridX -5
EndIf
EndIf
;More scrolling variables go here.
EndIf
If JoystickAxisX(0) = -1 ;Left
If Grid = 1
If GridX < 0
GridX +5
EndIf
EndIf
;More scrolling variables go here.
EndIf
EndIf
Delay(1) ;Save the cpu from maxing out.
ForEver
;Include the graphics in the executable.
DataSection
;Pic0: IncludeBinary "image 0.png"
;Pic1: IncludeBinary "image 1.png"
;Pic2: IncludeBinary "image 2.png"
EndDataSection