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58 lines
2.2 KiB
Markdown
58 lines
2.2 KiB
Markdown
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The [_RGBA32](_RGBA32) function returns the 32-bit *RGBA* color value with the specified red, green, blue and alpha component intensities.
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## Syntax
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> color32value~& = [_RGBA32](_RGBA32)(red&, green&, blue&, alpha&)
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## Description
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* The value returned is a 32-bit [_UNSIGNED](_UNSIGNED) [LONG](LONG) color value.
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* **Return variable types must be [_UNSIGNED](_UNSIGNED) [LONG](LONG) or resulting color may lose the [_BLUE](_BLUE) value.**
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* red& specifies the red component intensity from 0 to 255.
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* green& specifies the green component intensity from 0 to 255.
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* blue& specifies the blue component intensity from 0 to 255.
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* alpha& specifies the [_ALPHA](_ALPHA) component transparency value from 0 (fully transparent) to 255 (opaque).
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* Alpha or intensity values outside of the valid range of 0 to 255 are clipped.
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* Returns [LONG](LONG) 32-bit hexadecimal values from **&H00000000** to **&HFFFFFFFF** with varying [_ALPHA](_ALPHA) transparency.
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* When [LONG](LONG) values are [PUT](PUT) to file, the ARGB values become BGRA. Use [LEFT$](LEFT$)([MKL$](MKL$)(color32value~&), 3) to place 3 colors.
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* **NOTE: Default 32-bit backgrounds are clear black or [_RGBA](_RGBA)(0, 0, 0, 0). Use [CLS](CLS) to make the black opaque.**
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## Example(s)
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Changing the [ALPHA](ALPHA) value to fade an image in and out using a 32 bit PNG image.
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```vb
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SCREEN _NEWIMAGE(600, 400, 32)
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img& = _LOADIMAGE("qb64_trans.png") 'use any 24/32 bit image
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'Turn off auto display
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_DISPLAY
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' Fade in
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FOR i% = 255 TO 0 STEP -5
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_LIMIT 20 'control fade speed
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_PUTIMAGE (0, 0)-(600, 400), img&
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LINE (0, 0)-(600, 400), _RGBA(0, 0, 0, i%), BF 'decrease black box transparency
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_DISPLAY
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NEXT
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' Fade out
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FOR i% = 0 TO 255 STEP 5
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_LIMIT 20 'control fade speed
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_PUTIMAGE (0, 0)-(600, 400), img&
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LINE (0, 0)-(600, 400), _RGBA(0, 0, 0, i%), BF 'increase black box transparency
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_DISPLAY
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NEXT
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END
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```
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## See Also
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* [_RGB32](_RGB32), [_RGBA](_RGBA), [_RGB](_RGB)
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* [_RED32](_RED32), [_GREEN32](_GREEN32), [_BLUE32](_BLUE32)
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* [HEX$ 32 Bit Values](HEX$-32-Bit-Values), [POINT](POINT)
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* [SAVEIMAGE](SAVEIMAGE)
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* [Hexadecimal Color Values](http://www.w3schools.com/html/html_colornames.asp)
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