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51 lines
2.3 KiB
Markdown
51 lines
2.3 KiB
Markdown
The [_RGBA](_RGBA) function returns the closest palette index (legacy SCREEN modes) OR the 32-bit [LONG](LONG) color value (32-bit screens).
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## Syntax
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> colorIndex~& = [_RGBA](_RGBA)(red&, green&, blue&, alpha&[, imageHandle&]**)**
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* The value returned is either the closest color attribute number or a 32-bit [_UNSIGNED](_UNSIGNED) [LONG](LONG) color value.
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* **Return variable types must be [LONG](LONG) or the 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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* The [_ALPHA](_ALPHA) value can be set to make the color transparent (0), opaque (255) or somewhere in between.
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* Parameter values outside of the 0 to 255 range 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$](MKL$)(colorIndex~&), 3) to place 3 colors.
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* If imageHandle& is omitted, the image is assumed to be the current [_DEST](_DEST) or [SCREEN](SCREEN) page.
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* Allows the blending of pixel colors red, green and blue to create any of 16 million 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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Setting a font's background color alpha to clear to overlay a second text color.
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```vb
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scrn& = _NEWIMAGE(400, 400, 32)
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SCREEN scrn&
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fnt& = _LOADFONT("C:\WINDOWS\FONTS\ARIAL.TTF", 26)
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_FONT fnt&
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X% = 20
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Y% = 20
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COLOR _RGB(255, 255, 255), _RGB(0, 0, 0) 'Foreground set to WHITE background to BLACK
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_PRINTSTRING (X%, Y%), "Hello World"
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COLOR _RGB(255, 0, 0), _RGBA(0, 0, 0, 0) 'Foreground set to RED background to TRANSPARENT BLACK
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_PRINTSTRING (X% + 2, Y% + 2), "Hello World"
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END
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```
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*Explanation:* [_PRINTSTRING](_PRINTSTRING) allows text or font colors to be alpha blended in 32 bit screens.
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## See Also
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* [_RGB](_RGB), [_RGB32](_RGB32), [_RGBA32](_RGBA32)
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* [_RED](_RED), [_GREEN](_GREEN), [_BLUE](_BLUE)
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* [_LOADIMAGE](_LOADIMAGE)
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* [_PRINTSTRING](_PRINTSTRING)
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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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