qdosmsq:traps:trap_3:wpap

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

qdosmsq:traps:trap_3:wpap [2009/05/17 10:05]
george.gwilt created
qdosmsq:traps:trap_3:wpap [2009/05/17 10:07]
george.gwilt Change iop.wpap to iop_wpap
Line 1: Line 1:
 +====== IOP_WPAP ======
 +
 +This SMSQ/E trap sets the wallpaper.
 +
 +^Call Parameters^^Return Parameters^^
 +|D0.B|$6B|D0.L|Error code|
 +|D1.L|Colour code |D1.L|Preserved?​|
 +|D2.L|Image code |D2.L|Preserved?​|
 +|D3.W|Timeout|D3.L|Preserved.|
 +|A0.L|Channel ID |A0.L|Preserved.|
 +|A1.L|Address of Image|A1.L|Preserved.|
 +
 +===== Errors =====
 +
 +
 +|ERR_NC|Not complete.|
 +|ERR_NO|Channel not open.|
 +
 +
 +===== Notes =====
 +  * All registers not shown above are not used on entry and are probably preserved on exit.
 +  * The code in D1.L has the following meanings:
 +    *-1 if the background colour is not to be changed.
 +    *0 for a black background.
 +    *1-255 for a stippled QL colour background.
 +    *n*256 for a 24 bit true colour background.
 +  * The code in D2.L is -1 for no background image and 0 for an image.
 +  * The address in A1 is only needed when D2 = 0. In this case the image to which A1 points must be a snapshot of the screen in the current mode and resolution.
 +
 +===== Example =====
 +The example below shows the use of this trap call to set a QL colour background. It is assumed that A0 contains the ID of a valid screen channel.
 +
 +<​code>​
 +wallp   ​moveq ​  #​-1,​d3 ​         ; Timeout
 +        moveq   #​119,​d1 ​        ; A QL stipple colour
 +        moveq   #​-1,​d2 ​         ; No image
 +        moveq   #​iop_wpap,​d0 ​   ; $6B
 +        trap    #3              ; Set the background colour
 +        tst.l   ​d0 ​             ; OK? . .
 +        bne     ​error ​          ; . . no!
 +</​code>​
 +
  
  • qdosmsq/traps/trap_3/wpap.txt
  • Last modified: 2009/05/17 10:07
  • by george.gwilt