Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
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Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
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View Ref-FileACLIP
PSET, PTST()
ALINE, HLINE
ARECT
APOLY
ACHAR, ATEXT
BITBLT adr%, BITBLT x%()
L~A

In the following section a group of instructions are discussed which correspond
in principle to instructions that have already been presented in the graphics
chapter. The output is substantially quicker, however a slightly different
syntax is used. For Line-A graphics, clipping should always be switch on (with
ACLIP), since areas of memory can be overwritten by a line leaving the screen
area, for example. Otherwise the clipping area is that set by the last used
graphics command (AES or VDI), for example OPENW, FILESELECT, ALERT, etc.

A VDI call changes the ACLIP setting previously set with ACLIP. Line-A calls
are independent of the VDI DEFxxx commands.

Note: The colors specified in the Line-A routines correspond to the
      hardware color register numbers (as used by SETCOLOR) and NOT to the
      numbers used by the VDI (COLOR). They convert as follows:

VDI:    00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
Line-A: 00 15 01 02 04 06 03 05 07 08 09 10 12 14 11 13

Line-A: 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
VDI:    00 02 03 06 04 07 05 08 09 10 11 14 12 15 13 01

Memo: Do not use any Line-A calls!  Your application will surely fail on
      different computer models if you do use Line-A calls. If you don't want
      your application to run on all systems or don't care then you can use the
      Line-A calls/variables.

      Opcode Function           GFA command
      ------ ------------------ --------------------------------------
      $A000  Initialization     done automatically by the start-up code
      $A001  Put pixel          PSET
      $A002  Get pixel          PTST()
      $A003  Arbitrary line     ALINE
      $A004  Horizontal line    HLINE
      $A005  Filled rectangle   ARECT
      $A006  Filled polygon     APOLY
      $A007  Bit block transfer GET, PUT, BITBLT, RC_COPY
      $A008  Text block         ACHAR, ATEXT
      $A009  Show mouse         SHOWM
      $A00A  Hide mouse         HIDEM
      $A00B  Transform mouse    n/a
      $A00C  Undraw sprite      SPRITE
      $A00D  Draw sprite        SPRITE
      $A00E  Copy raster        n/a
      $A00F  Seedfill           n/a

Line-A+, Line-A Variable Table+, Line-A Function Reference+