RGB32: Difference between revisions

From QB64 Phoenix Edition Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 17: Line 17:




{{Parameters}}
{{PageParameters}}
* {{Parameter|red&}} specifies the red [[LONG]] component intensity from 0 to 255.
* {{Parameter|red&}} specifies the red [[LONG]] component intensity from 0 to 255.
* {{Parameter|green&}} specifies the green [[LONG]] component intensity from 0 to 255.
* {{Parameter|green&}} specifies the green [[LONG]] component intensity from 0 to 255.

Revision as of 02:17, 24 January 2023

The _RGB32 function returns the 32-bit RGBA color value with specified red, green and blue component intensities and optional alpha.


Syntax

Original syntax:

color32value~& = _RGB32(red&, green&, blue&)

Alternative Syntax 2:

color32value~& = _RGB32(red&, green&, blue&, alpha&)

Alternative Syntax 3:

color32value~& = _RGB32(intensity&, alpha&)

Alternative Syntax 4:

color32value~& = _RGB32(intensity&)


Parameters

  • red& specifies the red LONG component intensity from 0 to 255.
  • green& specifies the green LONG component intensity from 0 to 255.
  • blue& specifies the blue LONG component intensity from 0 to 255.
  • alpha& specifies the alpha LONG component from 0 to 255.
  • intensity& specifies the red, green and blue LONG components intensity from 0 to 255 simultaneously, to generate a shade of gray.

Description

  • The value returned is always a 32-bit _UNSIGNED LONG color value, as is the POINT value.
  • Return variable types must be _UNSIGNED LONG or LONG, otherwise resulting color may lose the _BLUE value.
  • Parameter values outside of the 0 to 255 range are clipped.
  • Returns LONG 32 bit hexadecimal values from &H00000000 to &HFFFFFFFF.
  • When LONG values are PUT to file, the ARGB values become BGRA. Use LEFT$(MKL$(color32value~&), 3) to place 3 colors.
  • NOTE: Default 32-bit backgrounds are clear black or _RGB32(0, 0). Use CLS to make the black opaque.


Availability

  • Alternative syntaxes available with version 1.3 and up.


Examples

Example 1: Converting the color port RGB intensity palette values 0 to 63 to 32 bit hexadecimal values.

SCREEN 12
DIM hex32$(15)
FOR attribute = 1 TO 15
  OUT &H3C7, attribute      'set color attribute to read
  red = INP(&H3C9) * 4      'multiply by 4 to convert intensity to 0 to 255 RGB values
  grn = INP(&H3C9) * 4
  blu = INP(&H3C9) * 4
  hex32$(attribute) = "&H" + HEX$(_RGB32(red, grn, blu))   'always returns the 32 bit value
  COLOR attribute
  PRINT "COLOR" + STR$(_RGB(red, grn, blu)) + " = " + hex32$(attribute)  'closest attribute
NEXT
COLOR 1 = &HFF0000A8
COLOR 2 = &HFF00A800
COLOR 3 = &HFF00A8A8
COLOR 4 = &HFFA80000
COLOR 5 = &HFFA800A8
COLOR 6 = &HFFA85400
COLOR 7 = &HFFA8A8A8
COLOR 8 = &HFF545454
COLOR 9 = &HFF5454FC
COLOR 10 = &HFF54FC54
COLOR 11 = &HFF54FCFC
COLOR 12 = &HFFFC5454
COLOR 13 = &HFFFC54FC
COLOR 14 = &HFFFCFC54
COLOR 15 = &HFFFCFCFC
Note: This procedure also shows how the returns from _RGB and _RGB32 differ in a non-32 bit screen mode.


Example 2: Working with 32 bit colors.

SCREEN _NEWIMAGE(640, 480, 32)

CLS , _RGB32(0, 0, 128) 'deep blue background

LINE (100, 100)-(540, 380), _RGB(255, 0, 0), BF ' a red box
LINE (200, 200)-(440, 280), _RGB(0, 255, 0), BF ' a green box


SLEEP 'Just so we can see our pretty background before we print anything on it.


COLOR _RGB32(255, 255, 255), 0 'White on NO BACKGROUND

FOR i = 1 TO 10
    PRINT "This is just a whole bunch of happy nothing!  Happy World!!"
NEXT
PRINT: PRINT: PRINT:

COLOR 0, _RGB32(0, 0, 0) 'And here, we're going with NO COLOR text, with a BLACK background.
'Notice how this doesn't change the color on the screen at all, where the text is, but does toss a black background to it.

LOCATE , 15: PRINT "NOTICE HOW OUR 0 COLOR WORKS?"
PRINT
LOCATE , 15: PRINT "NEAT, HUH?"
SLEEP
SYSTEM
Code by Steve McNeill


Example 3: Comparing the output of the new _RGB32 syntaxes (starting with version 1.3) and their equivalents in previous versions.

SCREEN _NEWIMAGE(400, 400, 32)

COLOR _RGB32(255, 255, 255)
PRINT "White"
COLOR _RGB32(255)
PRINT "White, too, but with less typing"
PRINT

COLOR _RGB32(80, 80, 80)
PRINT "Dark gray"
COLOR _RGB32(80)
PRINT "Same gray, but with less typing"
PRINT

COLOR _RGBA32(255, 255, 255, 120)
PRINT "White with alpha of 120 (out of 255)"
COLOR _RGB32(255, 120)
PRINT "White with alpha of 120 - but with less typing"
PRINT

COLOR _RGBA32(255, 0, 255, 110)
PRINT "Magenta, 110 alpha"
COLOR _RGB32(255, 0, 255, 110)
PRINT "Magenta too, 110 alpha - but with less typing"


See also



Navigation:
Main Page with Articles and Tutorials
Keyword Reference - Alphabetical
Keyword Reference - By usage
Report a broken link