GetImagePitch
Pitch = GetImagePitch(ImageIndex)
 
Parameters:

    ImageIndex = The Index of the Image you wish to query
Returns:

    Pitch = The width in bytes of a row of pixels in this image
 

      The GetImagePitch function returns the Pitch of a selected image. The pitch is the number of bytes that a single row of pixels uses. This information is used to calculate the Y coordinate when manually rendering pixels to a surface.




FACTS:


     * The GetImagePtr(), () & GetImageDepth() functions are used to manually read/write pixels to/from PlayBASIC images.

     * The image must be locked before you manually access it ! See (LockBuffer)




Mini Tutorial:


      This example creates four images then manually Pokes pixels to each of them.


  
  
  Cls RGB(0,0,255)
  
; create four images in each in a different video format
  w=128
  h=256
  CreateFXImageEx 1,w,h,15          ; 15bit version
  CreateFXImageEx 2,w,h,16          ; 16bit version
  CreateFXImageEx 3,w,h,24          ; 24bit version
  CreateFXImageEx 4,w,h,32          ; 32bit version
  
  
  
; Draw them to the screen
  Xpos=60
  Ypos=50
  For i=1 To 4
     FillImage(i)
     Text Xpos,Ypos,   "Address:"+Str$(GetImagePtr(i))
     Text Xpos,Ypos+20,"  Pitch:"+Str$(GetImagePitch(i))
     Text Xpos,Ypos+40,"  Depth:"+Str$(GetImageDepth(i))
     
     DrawImage i,Xpos,Ypos+60,false
     Xpos=Xpos+w+40
  Next
  
  
; show the screen and wait for user to press a key
  Sync
  WaitKey
  
  
  
  
  
Function FillImage(ThisImage)
  
  RenderToImage ThisImage
  
  LockBuffer
  
  Address     =GetImagePtr(ThisImage)
  Pitch          =GetImagePitch(ThisIMage)
  Depth          =GetImageDepth(ThisImage)
  
  Colour=0
  For ylp=0 To GetImageHeight(ThisImage)-1
     Colour2=colour
     For xlp=0 To GetImageWidth(ThisImage)-1
        PokePixel(Address,Pitch,Depth,Xlp,Ylp,Colour2)
        Colour2=Colour2+1
     Next
     Colour=RgbAlphaAdd(Colour,$020101)
  Next
  UnLockBuffer
  RenderToScreen
  
EndFunction
  
  
;*=------------------------------------------------------=*
;          >> Generic Poke Pixel Routine  <<
;*=-----------------------------------------------------=*
  
Psub PokePixel(Address,Pitch,Depth,Xpos,Ypos,Colour)
  If Address<>0
     Select Depth
         Case 15          ; 16bit RGB 555 format
             
             R=LSL16((RgbR(colour) & $f8),7)
             G=LSL16((RgbG(colour) & $f8),2)
             B=LSR16((RgbB(colour) & $f8),3)
             PokeWord Address+(ypos*pitch)+(xpos*2), R | G | B
             
         Case 16
             R=LSL16((RgbR(colour) & $f8),8)
             G=LSL16((RgbG(colour) & $fc),3)
             B=LSR16((RgbB(colour) & $f8),3)
             PokeWord Address+(ypos*pitch)+(xpos*2), R | G | B
             
             
         Case 24          ; 24bit RGB's
             R=RgbR(colour)
             G=RgbG(colour)
             B=RgbB(colour)
             
             Address=Address+(Ypos*pitch)+(xpos*3)
             PokeByte Address,R
             PokeByte Address+1,G
             PokeByte Address+2,B
             
         Case 32          ; 32bit RGB either XRGB (-888) format or (ARGB 8888) format
             PokeInt Address+(Ypos*Pitch)+(Xpos*4),COlour
             
     EndSelect
  EndIf
EndPsub
  
  
  
  
  

 
Related Info: Byte | CreateImage | DeleteImage | DrawImage | GetFreeImage | GetImageDepth | GetImagePtr | LoadImage | NewImage | Pointer | PrepareFXimage | RenderToImage :
 


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