Difference between revisions of "RGB"

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#REDIRECT [[Color Components]]
The [[_RGB]] function returns the closest palette attribute index OR the [[LONG]] 32 bit color value in 32 bit screens only.
:colorindex~& = '''_RGB('''{{Parameter|red}}, {{Parameter|green}}, {{Parameter|blue}}[, {{Parameter|image_handle}}]''')'''
* The value returned is either the closest color attribute number or a 32 bit [[_UNSIGNED]] [[LONG]] color value.
* '''Return variable types MUST be [[LONG]] or resulting color may lose the [[_BLUE]] value!'''
* {{Parameter|red&}} specifies the red component intensity from 0 to 255.
* {{Parameter|green&}} specifies the green component intensity from 0 to 255.
* {{Parameter|blue&}} specifies the blue component intensity from 0 to 255.
* Intensity values outside the valid range are clipped.
* Returns [[LONG]] 32 bit hexadecimal values from '''&HFF{{text|00|red}}{{text|00|green}}{{text|00|blue}}''' to '''&HFF{{text|FF|red}}{{text|FF|green}}{{text|FF|blue}}''' with full [[_ALPHA]] only.
* When [[LONG]] values are [[PUT]] to file, the ARGB values become BGRA. Use [[LEFT$]]([[MKL$]](colorvalue&), 3) to place 3 colors.
* If the ''image_handle'' is omitted the image is assumed to be the current [[_DEST|destination]] or [[SCREEN]] page.
* Colors returned are ALWAYS opaque as the transparency value is always 255! Use [[_ALPHA]] or [[_CLEARCOLOR]] to change it.
* '''NOTE: Default 32 bit backgrounds are clear black or [[_RGBA]](0, 0, 0, 0)! Use [[CLS]] to make the black opaque!'''
''Example:'' Converting the color port RGB intensity palette values 0 to 63 to 32 bit hexadecimal values.
{{Cl|SCREEN}} 12
{{Cl|DIM}} hex32$(15)
{{Cl|FOR...NEXT|FOR}} attribute = 1 {{Cl|TO}} 15
  {{Cl|OUT}} {{Cl|&H}}3C7, attribute      'set color attribute to read
  red = {{Cl|INP}}({{Cl|&H}}3C9) * 4      'multiply by 4 to convert intensity to 0 to 255 RGB values
  grn = {{Cl|INP}}({{Cl|&H}}3C9) * 4
  blu = {{Cl|INP}}({{Cl|&H}}3C9) * 4
  hex32$(attribute) = "{{Cl|&H}}" + {{Cl|HEX$}}({{Cl|_RGB32}}(red, grn, blu))  'always returns the 32 bit value
  {{Cl|COLOR}} attribute
  {{Cl|PRINT}} "{{Cl|COLOR}}" + {{Cl|STR$}}({{Cl|_RGB}}(red, grn, blu)) + " = " + hex32$(attribute)  'closest attribute
{{Cl|NEXT}} '' ''
{{OutputStart}}{{text|COLOR 1 <nowiki>=</nowiki> &HFF0000A8|#0000A8}}
{{text|COLOR 2 <nowiki>=</nowiki> &HFF00A800|#00A800}}
{{text|COLOR 3 <nowiki>=</nowiki> &HFF00A8A8|#00A8A8}}
{{text|COLOR 4 <nowiki>=</nowiki> &HFFA80000|#A80000}}
{{text|COLOR 5 <nowiki>=</nowiki> &HFFA800A8|#A800A8}}
{{text|COLOR 6 <nowiki>=</nowiki> &HFFA85400|#A85400}}
{{text|COLOR 7 <nowiki>=</nowiki> &HFFA8A8A8|#A8A8A8}}
{{text|COLOR 8 <nowiki>=</nowiki> &HFF545454|#545454}}
{{text|COLOR 9 <nowiki>=</nowiki> &HFF5454FC|#5454FC}}
{{text|COLOR 10 <nowiki>=</nowiki> &HFF54FC54|#54FC54}}
{{text|COLOR 11 <nowiki>=</nowiki> &HFF54FCFC|#54FCFC}}
{{text|COLOR 12 <nowiki>=</nowiki> &HFFFC5454|#FC5454}}
{{text|COLOR 13 <nowiki>=</nowiki> &HFFFC54FC|#FC54FC}}
{{text|COLOR 14 <nowiki>=</nowiki> &HFFFCFC54|#FCFC54}}
{{text|COLOR 15 <nowiki>=</nowiki> &HFFFCFCFC|#FCFCFC}}
:''Note:'' This procedure also shows how the returns from [[_RGB]] and [[_RGB32]] differ in a non-32 bit screen mode.
* [[_RGBA]], [[_RGB32]], [[_RGBA32]]
* [[_RED]], [[_GREEN]], [[_BLUE]]
* [[HEX$ 32 Bit Values]], [[POINT]]
* [[SAVEIMAGE]] {{text|(bitmap creator)}}
* [http://www.w3schools.com/html/html_colornames.asp Hexadecimal Color Values]

Revision as of 03:43, 25 July 2017

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