_BLEND

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The _BLEND statement turns on 32 bit alpha blending for an image or screen mode and is on by default.


Syntax

_BLEND [imageHandle&]

Parameters

  • imageHandle& refers to an image in memory. If not specified, the current destination page (See _DEST) is affected.


Description

  • Alpha blending is on by default when loading a .PNG image to a 32-bit surface.
  • Normally it is used to turn blending on after a previous _DONTBLEND call.
  • _BLEND can only be used on 32-bit surfaces, otherwise it will produce the error Illegal Function Call.
  • Note: _DONTBLEND is faster than the default _BLEND unless you really need to use it in 32 bit.
  • 32 bit screen surface backgrounds (black) have zero _ALPHA so that they are transparent when placed over other surfaces.


Examples

Example:

SCREEN _NEWIMAGE(640, 480, 32) 'CLS , _RGB(128, 128, 128) 'change background color for other results _DONTBLEND bg& = POINT(0, 0) PRINT _RED(bg&), _GREEN(bg&), _BLUE(bg&), _ALPHA(bg&) LINE (100, 100)-(200, 200), _RGBA32(255, 128, 0, 128), BF LINE (440, 100)-(540, 200), _RGBA32(0, 0, 255, 64), BF K$ = INPUT$(1) _BLEND LINE (270, 300)-(370, 400), _RGBA32(255, 128, 0, 128), BF m& = POINT(303, 302) PRINT _RED(m&), _GREEN(m&), _BLUE(m&), _ALPHA(m&) K$ = INPUT$(1) LINE (270, 300)-(370, 400), _RGBA32(0, 0, 255, 64), BF m& = POINT(303, 302) PRINT _RED(m&), _GREEN(m&), _BLUE(m&), _ALPHA(m&)


 

_RGBA(255,128,0,128)

   onto

     _RGBA(0,0,255,64)

 

results in

  _RGBA(95,48,64,128)

 


See also



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