_PALETTECOLOR (function) - QB64 Wiki

_PALETTECOLOR (function)

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The _PALETTECOLOR function is used to return the 32 bit attribute color setting of an image or screen page handle's palette.


Contents

Syntax

color32Value& = _PALETTECOLOR(attributeNumber%, imgHandle&)


Description

  • attributeNumber% is the color attribute value from 0 to 255 for 1, 4 or 8 bit images.
  • imgHandle& is the image handle being read for color data. Zero can be used to read the current screen mode palette.
  • Returns the 32 bit color value to be used by the 32 bit RGB functions.
  • For 32 bit images send the _PALETTECOLOR return value to _RED32, _GREEN32 and _BLUE32 functions to get the red, green, and blue intensity values.
  • Although 32 bit palette values are returned, the function cannot be used with 32 bit images or screen modes.


Examples

Example: How _PALETTECOLOR works on 32 bit RGB compared to a 4 BPP(SCREEN 12) Qbasic procedure.

SCREEN 12 'can use any Qbasic legacy screen mode DIM RGB(0 TO 47) AS INTEGER 'color intensity array FOR c& = 0 TO 15 'OUT &H3C7, c& 'set color attribute to read value32& = _PALETTECOLOR(c&, 0) 'sets color value to read of an image page handle. 'red% = INP(&H3C9) red% = _RED32(value32&) 'green% = INP(&H3C9) green% = _GREEN32(value32&) 'blue% = INP(&H3C9) blue% = _BLUE32(value32&) RGB(c& * 3) = red%: RGB((c& * 3) + 1) = green%: RGB((c& * 3) + 2) = blue% NEXT FOR i = 0 TO 47 STEP 3 RGBval$ = LTRIM$(STR$(RGB(i))) + "," + STR$(RGB(i + 1)) + "," + STR$(RGB(i + 2)) + ")" PRINT "Color"; i / 3, "_RGB(" + RGBval$; PRINT NEXT END

Explanation: To save a bitmap or other image you need the RGB color settings or the colors will look all wrong. You can store that information into a larger image array and GET the image AFTER the color settings. Just GET the image starting at Array(48).


See also



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