SpiderBasic

Posted: **Mon Apr 27, 2015 9:23 pm**

Is it possible to detect when a graphic (or sound) has been loaded ? I need to get the size of a graphic, and of course, it is currently possible for the image loading command to finish after the getting the size for the graphic, which is, of course, not desired.

I have tried a while loop until either a good or bad load is reported, but that just locks everything up.

I dont synchronous loading as I want to be able to load things at any time, and not just at a fixed point.

Posted: **Thu May 07, 2015 6:25 am**

You need to use a callback with BindEvent() to know when the image is loadedas shown below:

Code: Select all

  Procedure Loaded(Type, Filename$, ObjectId)

    ; Display the image in a new window
    OpenWindow(#PB_Any, 10, 10, 300, 300, "Image", #PB_Window_SizeGadget)
      ImageGadget(#PB_Any, 0, 0, ImageWidth(ObjectId), ImageHeight(ObjectId), ImageID(ObjectId))
    
  EndProcedure
  
  Procedure LoadingError(Type, Filename$, ObjectId)
    Debug Filename$ + ": loading error"
  EndProcedure
  
  ; Register the loading event before calling any resource load command
  BindEvent(#PB_Event_Loading, @Loaded())
  BindEvent(#PB_Event_LoadingError, @LoadingError())
  
  LoadImage(0, "Data/SpiderBasicLogo.png")

Posted: **Fri May 08, 2015 9:22 pm**

Thanks for that. What I might do is look into setting different events for sprites, sounds etc

Posted: **Fri May 08, 2015 10:27 pm**

MrTAToad wrote:Thanks for that. What I might do is look into setting different events for sprites, sounds etc

You can get Type and ObjectID in Procedure Loaded()
Type = 3 for Sprite
Type = 2 for sound
Type = 1 for Image
Fred, it would be fine to write all type possible in doc.

And some constants are missed in the doc for BindEvent() :
#PB_Event_Loading
#PB_Event_LoadingError
#PB_Event_RenderFrame

Code: Select all

Procedure Loaded(Type, Filename$, ObjectId)
  Debug "Type = " + Type + " ObjectID = " + ObjectId
EndProcedure

Procedure LoadingError(Type, Filename$, ObjectId)
  Debug Filename$ + ": loading error"
EndProcedure

; Register the loading event before calling any resource load command
BindEvent(#PB_Event_Loading, @Loaded())
BindEvent(#PB_Event_LoadingError, @LoadingError())

LoadImage(5, "Data/SpiderBasicLogo.png")
LoadSprite(10, "Data/SpiderBasicLogo.png")

run this code and you get :

Type = 1 ObjectID = 5
Type = 3 ObjectID = 10

Posted: **Sun May 10, 2015 8:32 pm**

I have found that trying to get a sprites size inside the loading event sometimes fails (with a value undefined), ie the loading hasn't finished before the sprite size request.

Posted: **Wed May 13, 2015 1:32 pm**

I have updated the doc to reflect this.

Posted: **Thu May 21, 2015 2:18 pm**

It seems that the loading event is called at the start of the loading process, rather than at the end (as the documentation states), as I have noticed that sometimes a graphics width (called in the loading event) can be read and at other times its "undefined" (as though the graphic hasn't loaded by the time the procedure is called).

Posted: **Fri May 22, 2015 6:42 am**

If you can illustrate this in a small snippet, it will be perfect for us to take a look.

Posted: **Fri May 22, 2015 7:35 pm**

This is the loading event :

Code: Select all

Procedure Loading(type, fileName.s,objectID)			
	Define *Element.__loadingList
	Define spr.__sprite
	
	*Element.__loadingList= LastElement(loadingList())
	If *Element<>0
		Select *Element\type
			Case	#AREA_SPRITES
											sprites(*Element\id)\id=*Element\id
											sprites(*Element\id)\width=SpriteWidth(sprites(*Element\id)\id)
											sprites(*Element\id)\height=SpriteHeight(sprites(*Element\id)\id)
											
											SETSPRITEANIM(*Element\id,sprites(*Element\id)\width,sprites(*Element\id)\height)
											
											Debug "Sprite Width : "
											Debug sprites(*Element\id)\width
											
											Debug "Sprite Height : "
											Debug sprites(*Element\id)\height
											
		EndSelect
									
		; Delete loading item
		LastElement(loadingList())
		DeleteElement(loadingList())
	EndIf
	;__loadGood+1
	; EndIf
EndProcedure

and the routine to start the loading (and setup the array so the event knows what to do with the data) :

Code: Select all

Procedure LOADANIM(fileName.s,index,width,height)
	Define tempFilename.s
	Define g.i
	Define *Element.__loadingList
    
	If index<0 Or index>=#MAX_SPRITES
		SETERROR(#CMP_INVALID_INDEX)
		ProcedureReturn #False
	Else	
			ExpandSprites(index)
			
			If Len(fileName)>0
				*Element = AddElement(loadingList())
  			If *Element<>0
  				*Element\type=#AREA_SPRITES
  				*Element\id=index
  				If width<0 And height<0
  					*Element\info1=#False
  				Else
  					*Element\info2=#True
  				EndIf
  				
  				*Element\info2=width
  				*Element\info3=height
    		EndIf
								
				tempFileName=#SPRITEPATH+fileName
				LoadSprite(index,tempFileName,#PB_Sprite_AlphaBlending | #PB_Sprite_PixelCollision)		
				
				ProcedureReturn #True
			EndIf
		EndIf
EndProcedure

Sometimes the loading returns the sprite size :

https://onedrive.live.com/redir?resid=3 ... hoto%2cpng

and sometimes not :

https://onedrive.live.com/redir?resid=3 ... hoto%2cpng

SpiderBasic

Waiting for loading to finish

Waiting for loading to finish

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