_PALETTECOLOR (function)

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

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.

Example(s)

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

• _PALETTECOLOR (statement)
• _NEWIMAGE, _LOADIMAGE
• SAVEIMAGE (example code)