DAC: Difference between revisions

From QB64 Phoenix Edition Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
 
(4 intermediate revisions by 2 users not shown)
Line 1: Line 1:
   '''DAC''' stands for the QBASIC Digital to Analog Converter color attributes used in screens 0, 7 and 9.
   '''DAC''' stands for the QBasic Digital to Analog Converter color attributes used in screens 0, 7 and 9.




::::: ''' IMPORTANT: QB64 screens do not use the DAC index!'''
::::: ''' IMPORTANT: QB64 screens do not use the DAC index!'''
* DAC colors are preset and cannot be changed in Qbasic easily(see example).
* DAC colors are preset and cannot be changed in QBasic easily(see example).
* DAC color attribute settings cannot be changed using [[PALETTE]] or [[OUT]] RGB statements.
* DAC color attribute settings cannot be changed using [[PALETTE]] or [[OUT]] RGB statements.
* Screen 0 and 9 can use up to 64 DAC color hues. Only attributes 0 to 5 and 7 can have RGB values altered using [[OUT]].
* Screen 0 and 9 can use up to 64 DAC color hues. Only attributes 0 to 5 and 7 can have RGB values altered using [[OUT]].
* [[PALETTE]] swap statements can assign one attribute's DAC color setting to another attribute color in [[SCREEN]]s 0 to 9.
* [[PALETTE]] swap statements can assign one attribute's DAC color setting to another attribute color in [[SCREEN]]s 0 to 9.
* Screen attributes 0 to 5 and 7 can have their RGB settings altered using OUT as shown in '''Bold''' below:  
* Screen attributes 0 to 5 and 7 can have their RGB settings altered using OUT as shown in '''Bold''' below:
{{WhiteStart}}
{{FixedStart}}
             '''''SCREEN 0 or 9                    SCREEN 7'''''
             '''''SCREEN 0 or 9                    SCREEN 7'''''
         Attribute = DAC setting        Attribute = DAC setting
         Attribute = DAC setting        Attribute = DAC setting
Line 24: Line 24:


     '''OUT can change RGB intensities where the DAC value matches the attribute value.'''
     '''OUT can change RGB intensities where the DAC value matches the attribute value.'''
{{WhiteEnd}}
{{FixedEnd}}


''Example 1:'' Changing the DAC attributes to use [[OUT]] for custom colors.
''Example 1:'' Changing the DAC attributes to use [[OUT]] for custom colors.
{{CodeStart}} '' ''
{{CodeStart}}
  {{Cl|SCREEN (statement)|SCREEN}} 9  'use 0, 7 or 9 only"
  {{Cl|SCREEN}} 9  'use 0, 7 or 9 only"
  InitDAC% = {{Cl|INP}}({{Cl|&H}}3DA)    ' prepare DAC port for access
  InitDAC% = {{Cl|INP}}({{Cl|&H}}3DA)    ' prepare DAC port for access
  {{Cl|FOR...NEXT|FOR}} attribute% = 6 {{Cl|TO}} 15 ' attributes 0 to 5 are already non-DAC
  {{Cl|FOR...NEXT|FOR}} attribute% = 6 {{Cl|TO}} 15 ' attributes 0 to 5 are already non-DAC
Line 36: Line 36:
  {{Cl|OUT}} {{Cl|&H}}3C0, 32            ' close port access
  {{Cl|OUT}} {{Cl|&H}}3C0, 32            ' close port access
{{CodeEnd}}
{{CodeEnd}}
:''Explanation:'' The procedure is a MUST to import 4 BPP bitmap colors in SCREEN 7 or 9. The InitDAC% value is not used, but that code line opens the DAC color port. Now all color attributes 0 to 15 can be used for custom or imported bitmap RGB color settings.  
:''Explanation:'' The procedure is a MUST to import 4 BPP bitmap colors in SCREEN 7 or 9. The InitDAC% value is not used, but that code line opens the DAC color port. Now all color attributes 0 to 15 can be used for custom or imported bitmap RGB color settings.




Line 42: Line 42:
{{CodeStart}}
{{CodeStart}}
  D = {{Cl|INP}}(&H3DA)    'prepares port for access
  D = {{Cl|INP}}(&H3DA)    'prepares port for access
  {{Cl|OUT}} &H3C0, &H30  
  {{Cl|OUT}} &H3C0, &H30
  {{Cl|OUT}} &H3C0, 4 '' ''
  {{Cl|OUT}} &H3C0, 4
{{CodeEnd}}
{{CodeEnd}}
:''Explanation:'' Make attributes 8-15 available to both foreground AND background colors. In other words it will make fullscreen behave like windowed mode. For the same effect in QB64, use [[_BLINK]] OFF.
:''Explanation:'' Make attributes 8-15 available to both foreground AND background colors. In other words it will make fullscreen behave like windowed mode. For the same effect in QB64, use [[_BLINK]] OFF.
Line 50: Line 50:
{{CodeStart}}
{{CodeStart}}
  D = {{Cl|INP}}(&H3DA)    'prepares port for access
  D = {{Cl|INP}}(&H3DA)    'prepares port for access
  {{Cl|OUT}} &H3C0, &H30  
  {{Cl|OUT}} &H3C0, &H30
  {{Cl|OUT}} &H3C0, 12 '' ''
  {{Cl|OUT}} &H3C0, 12
{{CodeEnd}}
{{CodeEnd}}
:'''NOTE: QB64''' allows blinking mode in both fullscreen and windowed modes '''without''' using the code above. To reenable blinking in QB64 after using [[_BLINK]] OFF, use [[_BLINK]] ON.
:'''NOTE: QB64''' allows blinking mode in both fullscreen and windowed modes '''without''' using the code above. To reenable blinking in QB64 after using [[_BLINK]] OFF, use [[_BLINK]] ON.




 
{{PageSeeAlso}}
''See also:''
* [[SCREEN]], [[COLOR]]
 
* [[SCREEN (statement)|SCREEN]], [[COLOR]]  
* [[PALETTE]]
* [[PALETTE]]




{{PageNavigation}}
{{PageNavigation}}

Latest revision as of 00:28, 29 January 2023

  DAC stands for the QBasic Digital to Analog Converter color attributes used in screens 0, 7 and 9.


IMPORTANT: QB64 screens do not use the DAC index!
  • DAC colors are preset and cannot be changed in QBasic easily(see example).
  • DAC color attribute settings cannot be changed using PALETTE or OUT RGB statements.
  • Screen 0 and 9 can use up to 64 DAC color hues. Only attributes 0 to 5 and 7 can have RGB values altered using OUT.
  • PALETTE swap statements can assign one attribute's DAC color setting to another attribute color in SCREENs 0 to 9.
  • Screen attributes 0 to 5 and 7 can have their RGB settings altered using OUT as shown in Bold below:
            SCREEN 0 or 9                     SCREEN 7
        Attribute = DAC setting         Attribute = DAC setting
           0 to 5 = 0 to 5                 0 to 5 = 0 to 5
                6 = 20                          6 = 6
                7 = 7                           7 = 7
                8 = 56                          8 = 16
                9 = 57                          9 = 17
               10 = 58                         10 = 18
               11 = 59                         11 = 19
               12 = 60                         12 = 20
               13 = 61                         13 = 21
               14 = 62                         14 = 22
               15 = 63                         15 = 23

    OUT can change RGB intensities where the DAC value matches the attribute value.

Example 1: Changing the DAC attributes to use OUT for custom colors. 

 SCREEN 9   'use 0, 7 or 9 only"
 InitDAC% = INP(&H3DA)    ' prepare DAC port for access
 FOR attribute% = 6 TO 15 ' attributes 0 to 5 are already non-DAC
    OUT &H3C0, attribute% ' send attribute to change
    OUT &H3C0, attribute% ' change DAC value to normal number
 NEXT attribute%"
 OUT &H3C0, 32            ' close port access
Explanation: The procedure is a MUST to import 4 BPP bitmap colors in SCREEN 7 or 9. The InitDAC% value is not used, but that code line opens the DAC color port. Now all color attributes 0 to 15 can be used for custom or imported bitmap RGB color settings.


Example 2: Disabling blinking colors in fullscreen SCREEN 0 mode enabling high intensity only. (DAC) 

 D = INP(&H3DA)    'prepares port for access
 OUT &H3C0, &H30
 OUT &H3C0, 4
Explanation: Make attributes 8-15 available to both foreground AND background colors. In other words it will make fullscreen behave like windowed mode. For the same effect in QB64, use _BLINK OFF.

Enabling: The following code disables above code and returns SCREEN 0 blinking to normal. 

 D = INP(&H3DA)    'prepares port for access
 OUT &H3C0, &H30
 OUT &H3C0, 12
NOTE: QB64 allows blinking mode in both fullscreen and windowed modes without using the code above. To reenable blinking in QB64 after using _BLINK OFF, use _BLINK ON.


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=DAC&oldid=7257"