COLOR: Difference between revisions

From QB64 Phoenix Edition Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
 
(8 intermediate revisions by 2 users not shown)
Line 1: Line 1:
The [[COLOR]] statement is used to change the foreground and background colors for printing text.
The [[COLOR]] statement is used to change the foreground and background colors for printing text.


{{PageSyntax}}
{{PageSyntax}}
Line 6: Line 7:


{{PageDescription}}
{{PageDescription}}
* {{Parameter|background&}} colors are available in all QB64 color SCREEN modes.  
* {{Parameter|background&}} colors are available in all QB64 color SCREEN modes.
* [[SCREEN]] mode 10 has only 3 white foreground attributes including flashing.  
* [[SCREEN]] mode 10 has only 3 white foreground attributes including flashing.
* To change the {{Parameter|background&}} color only, use a comma and the desired color. Ex: [[COLOR]] , {{Parameter|background&}}
* To change the {{Parameter|background&}} color only, use a comma and the desired color. Ex: [[COLOR]] , {{Parameter|background&}}
* Graphic drawing statements like [[PSET]], [[PRESET]], [[LINE]], etc, also use the colors set by the [[COLOR]] statement if no color is passed when they are called.
* Graphic drawing statements like [[PSET]], [[PRESET]], [[LINE]], etc, also use the colors set by the [[COLOR]] statement if no color is passed when they are called.
Line 13: Line 14:




==Screen Mode Attributes==
== Screen Mode Attributes ==
* '''SCREEN 0''' {{Parameter|background&}} colors 0 to 7 can be changed each text character without affecting other text. Use [[CLS]] after a background color statement to create a fullscreen background color. 64 [[DAC]] hues with 16 high intensity blinking foreground (16 to 31) color attributes. See [[_BLINK]].
* '''SCREEN 0''' {{Parameter|background&}} colors 0 to 7 can be changed each text character without affecting other text. Use [[CLS]] after a background color statement to create a fullscreen background color. 64 [[DAC]] hues with 16 high intensity blinking foreground (16 to 31) color attributes. See [[_BLINK]].
** See example 7 below for more SCREEN 0 background colors.
** See example 7 below for more SCREEN 0 background colors.
* '''SCREEN 1''' has '''4 background color attributes''': 0 = black, 1 = blue, 2 = green, 3 = grey. White foreground color only.
* '''SCREEN 1''' has '''4 background color attributes''': 0 = black, 1 = blue, 2 = green, 3 = grey. White foreground color only.
* '''SCREEN 2''' is '''monochrome''' with white forecolor and black background.
* '''SCREEN 2''' is '''monochrome''' with white forecolor and black background.
* '''SCREEN 7''' can use 16 ([[DAC]]) colors with background colors. RGB settings can be changed in colors 0 to 7 using [[_PALETTECOLOR]].  
* '''SCREEN 7''' can use 16 ([[DAC]]) colors with background colors. RGB settings can be changed in colors 0 to 7 using [[_PALETTECOLOR]].
* '''SCREEN 8''' has 16 color attributes with 16 background colors.  
* '''SCREEN 8''' has 16 color attributes with 16 background colors.
* '''SCREEN 9''' can use up to 64 [[DAC]] color hues in 16 color attributes with background colors assigned to attribute 0 with a [[_PALETTECOLOR]] swap. RGB settings can be changed in colors 0 to 5 and 7 using [[_PALETTECOLOR]].
* '''SCREEN 9''' can use up to 64 [[DAC]] color hues in 16 color attributes with background colors assigned to attribute 0 with a [[_PALETTECOLOR]] swap. RGB settings can be changed in colors 0 to 5 and 7 using [[_PALETTECOLOR]].
* '''SCREEN 10''' has '''only 4 color attributes''' with black background. COLOR 0 = black, 1 = grey, 2 = flash white and 3 = bright white.
* '''SCREEN 10''' has '''only 4 color attributes''' with black background. COLOR 0 = black, 1 = grey, 2 = flash white and 3 = bright white.
Line 29: Line 30:
* [[_DEFAULTCOLOR]] returns the current color being used on an image or screen page handle.
* [[_DEFAULTCOLOR]] returns the current color being used on an image or screen page handle.


 
=== 24/32-Bit colors using QB64 ===
===24/32-Bit colors using QB64===
* Pixel color intensities for red, green, blue and alpha range from 0 to 255 when used with [[_RGB]], [[_RGBA]], [[_RGB32]] and [[RGBA32]].
* Pixel color intensities for red, green, blue and alpha range from 0 to 255 when used with [[_RGB]], [[_RGBA]], [[_RGB32]] and [[RGBA32]].
* Combined RGB function values returned are [[LONG]] values. '''Blue intensity values may be cut off using [[SINGLE]] variables.'''
* Combined RGB function values returned are [[LONG]] values. '''Blue intensity values may be cut off using [[SINGLE]] variables.'''
* [[_ALPHA]] transparency values can range from 0 as transparent up to 255 which is fully opaque.  
* [[_ALPHA]] transparency values can range from 0 as transparent up to 255 which is fully opaque.
* [[_CLEARCOLOR]] can also be used to set a color as transparent.
* [[_CLEARCOLOR]] can also be used to set a color as transparent.
* Colors can be mixed by using [[_BLEND]] (default) in 32-bit screen modes. [[_DONTBLEND]] disables blending.
* Colors can be mixed by using [[_BLEND]] (default) in 32-bit screen modes. [[_DONTBLEND]] disables blending.
Line 40: Line 40:
<p style="text-align: center">([[#toc|Return to Table of Contents]])</p>
<p style="text-align: center">([[#toc|Return to Table of Contents]])</p>


==RGB Palette Intensities==
 
== RGB Palette Intensities ==
RGB intensity values can be converted to hexadecimal values to create the [[LONG]] [[_PALETTECOLOR]] value in non-32-bit screens:
RGB intensity values can be converted to hexadecimal values to create the [[LONG]] [[_PALETTECOLOR]] value in non-32-bit screens:
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|SCREEN}} 12
{{Cl|SCREEN}} 12
alpha$ = "FF" 'solid alpha colors only
alpha$ = "FF" 'solid alpha colors only
{{Cl|PRINT}} "Attribute = Hex value      Red          Green        Blue "
{{Cl|PRINT}} "Attribute = Hex value      Red          Green        Blue "
{{Cl|PRINT}}
{{Cl|PRINT}}
{{Cl|COLOR}} 7  
{{Cl|COLOR}} 7
{{Cl|FOR...NEXT|FOR}} attribute = 1 {{Cl|TO}} 15
{{Cl|FOR...NEXT|FOR}} attribute = 1 {{Cl|TO}} 15
   {{Cl|OUT}} {{Cl|&H}}3C7, attribute 'set color attribute to read
   {{Cl|OUT}} {{Cl|&H}}3C7, attribute 'set color attribute to read
   red$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 4) 'convert port setting to 32 bit values
   red$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 255 / 63) 'convert port setting to 32 bit values
   grn$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 4)
   grn$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 255 / 63)
   blu$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 4)
   blu$ = {{Cl|HEX$}}({{Cl|INP}}({{Cl|&H}}3C9) * 255 / 63)
   {{Cl|IF...THEN|IF}} {{Cl|LEN}}(red$) = 1 {{Cl|THEN}} red$ = "0" + red$ '2 hex digits required
   {{Cl|IF...THEN|IF}} {{Cl|LEN}}(red$) = 1 {{Cl|THEN}} red$ = "0" + red$ '2 hex digits required
   {{Cl|IF...THEN|IF}} {{Cl|LEN}}(grn$) = 1 {{Cl|THEN}} grn$ = "0" + grn$ 'for low or zero hex values
   {{Cl|IF...THEN|IF}} {{Cl|LEN}}(grn$) = 1 {{Cl|THEN}} grn$ = "0" + grn$ 'for low or zero hex values
Line 60: Line 61:
   {{Cl|IF...THEN|IF}} attribute {{Cl|THEN}} {{Cl|COLOR}} attribute 'exclude black color print
   {{Cl|IF...THEN|IF}} attribute {{Cl|THEN}} {{Cl|COLOR}} attribute 'exclude black color print
   {{Cl|PRINT}} "{{Cl|COLOR}}" + {{Cl|STR$}}(attribute) + " = " + hex32$, red$, grn$, blu$ 'returns closest attribute
   {{Cl|PRINT}} "{{Cl|COLOR}}" + {{Cl|STR$}}(attribute) + " = " + hex32$, red$, grn$, blu$ 'returns closest attribute
{{Cl|NEXT}} '' ''
{{Cl|NEXT}}
{{CodeEnd}}
{{CodeEnd}}
{{OutputStart}}Attribute  Hex value      Red        Green      Blue  
{{OutputStart}}Attribute  Hex value      Red        Green      Blue


{{text|COLOR 1 <nowiki>=</nowiki> &HFF0000A8       00        00        A8|#0000A8}}
{{Text|COLOR 1 <nowiki>=</nowiki> &HFF0000AA       00        00        AA|#0000AA}}
{{text|COLOR 2 <nowiki>=</nowiki> &HFF00A800       00        A8         00|#00A800}}
{{Text|COLOR 2 <nowiki>=</nowiki> &HFF00AA00       00        AA         00|#00AA00}}
{{text|COLOR 3 <nowiki>=</nowiki> &HFF00A8A8       00        A8         A8|#00A8A8}}
{{Text|COLOR 3 <nowiki>=</nowiki> &HFF00AAAA       00        AA         AA|#00AAAA}}
{{text|COLOR 4 <nowiki>=</nowiki> &HFFA80000       A8         00        00|#A80000}}
{{Text|COLOR 4 <nowiki>=</nowiki> &HFFAA0000       AA         00        00|#AA0000}}
{{text|COLOR 5 <nowiki>=</nowiki> &HFFA800A8       A8         00        A8|#A800A8}}
{{Text|COLOR 5 <nowiki>=</nowiki> &HFFAA00AA       AA         00        AA|#AA00AA}}
{{text|COLOR 6 <nowiki>=</nowiki> &HFFA85400       A8         54         00|#A85400}}
{{Text|COLOR 6 <nowiki>=</nowiki> &HFFAA5500       AA         55         00|#AA5500}}
{{text|COLOR 7 <nowiki>=</nowiki> &HFFA8A8A8       A8         A8         A8|#A8A8A8}}
{{Text|COLOR 7 <nowiki>=</nowiki> &HFFAAAAAA       AA         AA         AA|#AAAAAA}}
{{text|COLOR 8 <nowiki>=</nowiki> &HFF545454       54         54         54|#545454}}
{{Text|COLOR 8 <nowiki>=</nowiki> &HFF555555       55         55         55|#555555}}
{{text|COLOR 9 <nowiki>=</nowiki> &HFF5454FC       54         54         FC|#5454FC}}
{{Text|COLOR 9 <nowiki>=</nowiki> &HFF5555FF       55         55         FF|#5555FF}}
{{text|COLOR 10 <nowiki>=</nowiki> &HFF54FC54     54         FC         54|#54FC54}}
{{Text|COLOR 10 <nowiki>=</nowiki> &HFF55FF55     55         FF         55|#55FF55}}
{{text|COLOR 11 <nowiki>=</nowiki> &HFF5454FC     54         FC         FC|#54FCFC}}
{{Text|COLOR 11 <nowiki>=</nowiki> &HFF55FFFF     55         FF         FF|#55FFFF}}
{{text|COLOR 12 <nowiki>=</nowiki> &HFFFC5454     FC         54         54|#FC5454}}
{{Text|COLOR 12 <nowiki>=</nowiki> &HFFFF5555     FF         55         55|#FF5555}}
{{text|COLOR 13 <nowiki>=</nowiki> &HFFFC54FC     FC         54         FC|#FC54FC}}
{{Text|COLOR 13 <nowiki>=</nowiki> &HFFFF55FF     FF         55         FF|#FF55FF}}
{{text|COLOR 14 <nowiki>=</nowiki> &HFFFCFC54     FC         FC         54|#FCFC54}}
{{Text|COLOR 14 <nowiki>=</nowiki> &HFFFFFF55     FF         FF         55|#FFFF55}}
{{text|COLOR 15 <nowiki>=</nowiki> &HFFFCFCFC     FC         FC         FC|#FCFCFC}}
{{Text|COLOR 15 <nowiki>=</nowiki> &HFFFFFFFF     FF         FF         FF|#F5F5F5}}
{{OutputEnd}}
{{OutputEnd}}
:''Explanation:'' The RGB intensity values are multiplied by 4 to get the [[_RGB]] intensity values as [[HEX$|hexadecimal]] values. The individual 2 digit [[HEX$]] intensity values can be added to "&HFF" to make up the 32-bit hexadecimal string value necessary for [[VAL]] to return to [[_PALETTECOLOR]]. The statement is only included in the example to show how that can be done with any 32-bit color value.
:''Explanation:'' The DAC intensity values are multiplied by (255 / 63) to get the [[_RGB]] intensity values as [[HEX$|hexadecimal]] values. The individual 2 digit [[HEX$]] intensity values can be added to "&HFF" to make up the 32-bit hexadecimal string value necessary for [[VAL]] to return to [[_PALETTECOLOR]]. The statement is only included in the example to show how that can be done with any 32-bit color value.


 
=== Read & write color port intensities with [[INP]] & [[OUT]] ===
===Read & write color port intensities with [[INP]] & [[OUT]]===
* Legacy code may use [[INP]] and [[OUT]] to read or set color port intensities. '''QB64''' emulates VGA memory to maintain compatibility.
* Legacy code may use [[INP]] and [[OUT]] to read or set color port intensities. '''QB64''' emulates VGA memory to maintain compatibility.
* The same can be achieved using [[_PALETTECOLOR]] ('''recommended practice''').
* The same can be achieved using [[_PALETTECOLOR]] ('''recommended practice''').


:'''{{text|OUT &H3C7, attribute|green}}''' 'Set port to read RGB settings with:
:'''{{Text|OUT &H3C7, attribute|green}}''' 'Set port to read RGB settings with:
:'''{{text|color_intensity <nowiki>=</nowiki> INP(&H3C9)|green}}''' 'reads present intensity setting
:'''{{Text|color_intensity <nowiki>=</nowiki> INP(&H3C9)|green}}''' 'reads present intensity setting
 
:'''{{text|OUT &H3C8, attribute|green}}''' 'Set port to write RGB settings with:
:'''{{Text|OUT &H3C8, attribute|green}}''' 'Set port to write RGB settings with:
:'''{{text|OUT &H3C9, color_intensity|green}}''' 'writes new intensity setting
:'''{{Text|OUT &H3C9, color_intensity|green}}''' 'writes new intensity setting


* After every 3 reads or writes, changes to next higher color attribute. Loops can be used to set more than one attribute's intensities.
* After every 3 reads or writes, changes to next higher color attribute. Loops can be used to set more than one attribute's intensities.
Line 102: Line 102:
{{PageExamples}}
{{PageExamples}}
''Example 1:'' Reading the default RGB color settings of color attribute 15.
''Example 1:'' Reading the default RGB color settings of color attribute 15.
{{CodeStart}} '' ''
{{CodeStart}}
  {{Cl|OUT}} &H3C7, 15
  {{Cl|OUT}} &H3C7, 15
  red% = {{Cl|INP}}(&H3C9)
  red% = {{Cl|INP}}(&H3C9)
  green% = {{Cl|INP}}(&H3C9)
  green% = {{Cl|INP}}(&H3C9)
  blue% = {{Cl|INP}}(&H3C9)
  blue% = {{Cl|INP}}(&H3C9)
  {{Cl|PRINT}} red%, green%, blue% '' ''
  {{Cl|PRINT}} red%, green%, blue%
{{CodeEnd}}
{{CodeEnd}}


Line 116: Line 116:


''Example 2:'' Changing the color settings of attribute 0 (the background) to blue in [[SCREEN]]s 12 or 13.
''Example 2:'' Changing the color settings of attribute 0 (the background) to blue in [[SCREEN]]s 12 or 13.
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|SCREEN}} 12
{{Cl|SCREEN}} 12
{{Cl|OUT}} {{Cl|&H}}3C8, 0          'set color port attribute to write
{{Cl|OUT}} {{Cl|&H}}3C8, 0          'set color port attribute to write
{{Cl|OUT}} {{Cl|&H}}3C9, 0          'red intensity
{{Cl|OUT}} {{Cl|&H}}3C9, 0          'red intensity
{{Cl|OUT}} {{Cl|&H}}3C9, 0          'green intensity
{{Cl|OUT}} {{Cl|&H}}3C9, 0          'green intensity
{{Cl|OUT}} {{Cl|&H}}3C9, 42        'blue intensity  
{{Cl|OUT}} {{Cl|&H}}3C9, 42        'blue intensity


{{Cl|OUT}} {{Cl|&H}}3C7, 0
{{Cl|OUT}} {{Cl|&H}}3C7, 0
{{Cl|PRINT}} {{Cl|INP}}({{Cl|&H}}3C9); {{Cl|INP}}({{Cl|&H}}3C9); {{Cl|INP}}({{Cl|&H}}3C9)
{{Cl|PRINT}} {{Cl|INP}}({{Cl|&H}}3C9); {{Cl|INP}}({{Cl|&H}}3C9); {{Cl|INP}}({{Cl|&H}}3C9)
{{Cl|END}}'' ''
{{Cl|END}}
{{CodeEnd}}
{{CodeEnd}}
{{OutputStartBG1}}{{text| 0  0  42|#FCFCFC}}{{OutputEnd}}
{{OutputStartBG1}}{{Text| 0  0  42|#FCFCFC}}{{OutputEnd}}




''Example 3:'' Printing in fullscreen SCREEN 0 mode with a color background under the text only.
''Example 3:'' Printing in fullscreen SCREEN 0 mode with a color background under the text only.
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|SCREEN}} 0: {{Cl|_FULLSCREEN}} ' used for fullscreen instead of window
{{Cl|SCREEN}} 0: {{Cl|_FULLSCREEN}} ' used for fullscreen instead of window
{{Cl|COLOR}} 14, 6: {{Cl|LOCATE}} 4, 4: {{Cl|PRINT}} "Hello!" '' ''
{{Cl|COLOR}} 14, 6: {{Cl|LOCATE}} 4, 4: {{Cl|PRINT}} "Hello!"
{{CodeEnd}}
{{CodeEnd}}
{{OutputStart}}
{{OutputStart}}
Line 143: Line 143:


''Example 4:'' Using [[CLS]] after setting the background color in SCREEN 0 to make the color cover the entire screen.
''Example 4:'' Using [[CLS]] after setting the background color in SCREEN 0 to make the color cover the entire screen.
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|SCREEN}} 0: {{Cl|_FULLSCREEN}}
{{Cl|SCREEN}} 0: {{Cl|_FULLSCREEN}}
{{Cl|COLOR}} , 7: {{Cl|CLS}}
{{Cl|COLOR}} , 7: {{Cl|CLS}}
{{Cl|COLOR}} 9: {{Cl|PRINT}} "Hello" '' ''
{{Cl|COLOR}} 9: {{Cl|PRINT}} "Hello"
{{CodeEnd}}
{{CodeEnd}}
{{OutputStartBG7}}
{{OutputStartBG7}}
Line 154: Line 154:


''Example 5:'' Using a different foreground color for each letter:
''Example 5:'' Using a different foreground color for each letter:
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|SCREEN}} 0
{{Cl|SCREEN}} 0
{{Cl|COLOR}} 1: {{Cl|PRINT}} "H";
{{Cl|COLOR}} 1: {{Cl|PRINT}} "H";
Line 165: Line 165:
{{Cl|COLOR}} 12: {{Cl|PRINT}} "R";
{{Cl|COLOR}} 12: {{Cl|PRINT}} "R";
{{Cl|COLOR}} 13: {{Cl|PRINT}} "L";
{{Cl|COLOR}} 13: {{Cl|PRINT}} "L";
{{Cl|COLOR}} 14: {{Cl|PRINT}} "D" '' ''
{{Cl|COLOR}} 14: {{Cl|PRINT}} "D"
{{CodeEnd}}
{{CodeEnd}}


{{OutputStart}}
{{OutputStart}}
{{text|H|#0000aa}}{{text|E|#00aaaa}}{{text|L|#aa0000}}{{text|L|#aa00aa}}{{text|O|#aa5500}}
{{Text|H|#0000aa}}{{Text|E|#00aaaa}}{{Text|L|#aa0000}}{{Text|L|#aa00aa}}{{Text|O|#aa5500}}
{{text|W|#5454fc}}{{text|O|#54fcfc}}{{text|R|#fc5454}}{{text|L|#fc54fc}}{{text|D|#fcfc54}}
{{Text|W|#5454fc}}{{Text|O|#54fcfc}}{{Text|R|#fc5454}}{{Text|L|#fc54fc}}{{Text|D|#fcfc54}}
{{OutputEnd}}
{{OutputEnd}}


Line 187: Line 187:
* [[_BACKGROUNDCOLOR]]
* [[_BACKGROUNDCOLOR]]
* [[_PALETTECOLOR]]
* [[_PALETTECOLOR]]
* [[Windows_Libraries#Color_Dialog_Box|Color Dialog Box]]
* [[Windows Libraries#Color_Dialog_Box|Color Dialog Box]]
* [http://www.w3schools.com/html/html_colornames.asp Hexadecimal Color Values]
* [https://qb64phoenix.com/qb64wiki/resources/Color0.html $COLOR:0 Name Table]
* [https://qb64phoenix.com/qb64wiki/resources/Color32.html $COLOR:32 Name Table]




{{PageNavigation}}
{{PageNavigation}}

Latest revision as of 19:27, 13 June 2024

The COLOR statement is used to change the foreground and background colors for printing text.


Syntax

COLOR [foreground&][, background&]


Description

  • background& colors are available in all QB64 color SCREEN modes.
  • SCREEN mode 10 has only 3 white foreground attributes including flashing.
  • To change the background& color only, use a comma and the desired color. Ex: COLOR , background&
  • Graphic drawing statements like PSET, PRESET, LINE, etc, also use the colors set by the COLOR statement if no color is passed when they are called.
  • The $COLOR metacommand adds named color constants for both text and 32-bit modes.


Screen Mode Attributes

  • SCREEN 0 background& colors 0 to 7 can be changed each text character without affecting other text. Use CLS after a background color statement to create a fullscreen background color. 64 DAC hues with 16 high intensity blinking foreground (16 to 31) color attributes. See _BLINK.
    • See example 7 below for more SCREEN 0 background colors.
  • SCREEN 1 has 4 background color attributes: 0 = black, 1 = blue, 2 = green, 3 = grey. White foreground color only.
  • SCREEN 2 is monochrome with white forecolor and black background.
  • SCREEN 7 can use 16 (DAC) colors with background colors. RGB settings can be changed in colors 0 to 7 using _PALETTECOLOR.
  • SCREEN 8 has 16 color attributes with 16 background colors.
  • SCREEN 9 can use up to 64 DAC color hues in 16 color attributes with background colors assigned to attribute 0 with a _PALETTECOLOR swap. RGB settings can be changed in colors 0 to 5 and 7 using _PALETTECOLOR.
  • SCREEN 10 has only 4 color attributes with black background. COLOR 0 = black, 1 = grey, 2 = flash white and 3 = bright white.
  • SCREEN 11 is monochrome with white forecolor and a black background.
  • SCREEN 12 can use 16 color attributes with a black background. 256K possible RGB color hues. Background colors can be used with QB64.
  • SCREEN 13 can use 256 color attributes with a black background. 256K possible RGB hues.
  • PALETTE swaps can be made in SCREEN 7 and 9 only. Those screens were DAC screen modes in QBasic.
  • _DEST can be used to set the destination page or image to color using QB64.
  • _DEFAULTCOLOR returns the current color being used on an image or screen page handle.

24/32-Bit colors using QB64

  • Pixel color intensities for red, green, blue and alpha range from 0 to 255 when used with _RGB, _RGBA, _RGB32 and RGBA32.
  • Combined RGB function values returned are LONG values. Blue intensity values may be cut off using SINGLE variables.
  • _ALPHA transparency values can range from 0 as transparent up to 255 which is fully opaque.
  • _CLEARCOLOR can also be used to set a color as transparent.
  • Colors can be mixed by using _BLEND (default) in 32-bit screen modes. _DONTBLEND disables blending.
  • NOTE: Default 32-bit backgrounds are clear black or _RGBA(0, 0, 0, 0). Use CLS to make the black opaque.

(Return to Table of Contents)


RGB Palette Intensities

RGB intensity values can be converted to hexadecimal values to create the LONG _PALETTECOLOR value in non-32-bit screens: 

SCREEN 12
alpha$ = "FF" 'solid alpha colors only
PRINT "Attribute = Hex value      Red          Green         Blue "
PRINT
COLOR 7
FOR attribute = 1 TO 15
  OUT &H3C7, attribute 'set color attribute to read
  red$ = HEX$(INP(&H3C9) * 255 / 63) 'convert port setting to 32 bit values
  grn$ = HEX$(INP(&H3C9) * 255 / 63)
  blu$ = HEX$(INP(&H3C9) * 255 / 63)
  IF LEN(red$) = 1 THEN red$ = "0" + red$ '2 hex digits required
  IF LEN(grn$) = 1 THEN grn$ = "0" + grn$ 'for low or zero hex values
  IF LEN(blu$) = 1 THEN blu$ = "0" + blu$
  hex32$ = "&H" + alpha$ + red$ + grn$ + blu$
  _PALETTECOLOR attribute, VAL(hex32$) 'VAL converts hex string to a LONG 32 bit value
  IF attribute THEN COLOR attribute 'exclude black color print
  PRINT "COLOR" + STR$(attribute) + " = " + hex32$, red$, grn$, blu$ 'returns closest attribute
NEXT

Attribute  Hex value      Red        Green       Blue

COLOR 1 = &HFF0000AA       00         00         AA
COLOR 2 = &HFF00AA00       00         AA         00
COLOR 3 = &HFF00AAAA       00         AA         AA
COLOR 4 = &HFFAA0000       AA         00         00
COLOR 5 = &HFFAA00AA       AA         00         AA
COLOR 6 = &HFFAA5500       AA         55         00
COLOR 7 = &HFFAAAAAA       AA         AA         AA
COLOR 8 = &HFF555555       55         55         55
COLOR 9 = &HFF5555FF       55         55         FF
COLOR 10 = &HFF55FF55      55         FF         55
COLOR 11 = &HFF55FFFF      55         FF         FF
COLOR 12 = &HFFFF5555      FF         55         55
COLOR 13 = &HFFFF55FF      FF         55         FF
COLOR 14 = &HFFFFFF55      FF         FF         55
COLOR 15 = &HFFFFFFFF      FF         FF         FF
Explanation: The DAC intensity values are multiplied by (255 / 63) to get the _RGB intensity values as hexadecimal values. The individual 2 digit HEX$ intensity values can be added to "&HFF" to make up the 32-bit hexadecimal string value necessary for VAL to return to _PALETTECOLOR. The statement is only included in the example to show how that can be done with any 32-bit color value.

Read & write color port intensities with INP & OUT

  • Legacy code may use INP and OUT to read or set color port intensities. QB64 emulates VGA memory to maintain compatibility.
  • The same can be achieved using _PALETTECOLOR (recommended practice).
OUT &H3C7, attribute 'Set port to read RGB settings with:
color_intensity = INP(&H3C9) 'reads present intensity setting
OUT &H3C8, attribute 'Set port to write RGB settings with:
OUT &H3C9, color_intensity 'writes new intensity setting
  • After every 3 reads or writes, changes to next higher color attribute. Loops can be used to set more than one attribute's intensities.
  • Color port setting of red, green and blue intensities can be done in ascending order.
  • Color port attribute intensity values range from 0 to 63 (1/4 of the 32-bit values) in QBasic's legacy 4 and 8 bit screen modes.

(Return to Table of Contents)


Examples

Example 1: Reading the default RGB color settings of color attribute 15. 

 OUT &H3C7, 15
 red% = INP(&H3C9)
 green% = INP(&H3C9)
 blue% = INP(&H3C9)
 PRINT red%, green%, blue%

 63       63       63


Example 2: Changing the color settings of attribute 0 (the background) to blue in SCREENs 12 or 13. 

SCREEN 12
OUT &H3C8, 0          'set color port attribute to write
OUT &H3C9, 0          'red intensity
OUT &H3C9, 0          'green intensity
OUT &H3C9, 42         'blue intensity

OUT &H3C7, 0
PRINT INP(&H3C9); INP(&H3C9); INP(&H3C9)
END

 0  0  42


Example 3: Printing in fullscreen SCREEN 0 mode with a color background under the text only. 

SCREEN 0: _FULLSCREEN ' used for fullscreen instead of window
COLOR 14, 6: LOCATE 4, 4: PRINT "Hello!"



    Hello!


Example 4: Using CLS after setting the background color in SCREEN 0 to make the color cover the entire screen. 

SCREEN 0: _FULLSCREEN
COLOR , 7: CLS
COLOR 9: PRINT "Hello"

Hello


Example 5: Using a different foreground color for each letter: 

SCREEN 0
COLOR 1: PRINT "H";
COLOR 3: PRINT "E";
COLOR 4: PRINT "L";
COLOR 5: PRINT "L";
COLOR 6: PRINT "O"
COLOR 9: PRINT "W";
COLOR 11: PRINT "O";
COLOR 12: PRINT "R";
COLOR 13: PRINT "L";
COLOR 14: PRINT "D"

HELLO
WORLD


See also


Navigation:
Main Page with Articles and Tutorials
Keyword Reference - Alphabetical
Keyword Reference - By usage
Report a broken link
Retrieved from "https://qb64phoenix.com/qb64wiki/index.php?title=COLOR&oldid=8973"