IBM RT Series Hardware Reference Manual page 362

TNL SN20-9844 (March 1987) to 75X0235
Relative Draw (X'2D')
The relative draw graphic operation operates in the same manner as the graphic operation type
X'2C' above, except the drawn vector does not end with a null.
Example: Relative Draw (Xl and YI values are from the current contents of RI and RO).
Queue Queue Action
By
Function
Address Data Queue Processing
Que Ptr X'5100'
Load DX into R5
Que Ptr-l
X'6200'
Load DY into R6
Que Ptr-2 X'D2DO' Execute relative draw. R5
=
Xl
+
DX
R6
=
YI
+
DY
Draw vector from (XI,YI)
to (Xl
+
DX,YI
+
DY)
Relative Move to (X'2E')
The relative move to graphic operation allows the user to add a delta or increment to the last
start point coordinates specified rather than to require that new absolute coordinates to be
specified.
Example: Relative Move To (Update the contents of RI and RO for new Xl and YI).
Queue Queue Action
By
Function
Address Data Queue Processing
Que Ptr X'2100' Load DX into R2 R2
=
Xl
+
DX
Que Ptr-l X'6200' Load DY TO
>
R6 R6
=
YI
+
DY
Que Ptr-2 X'D2EO' Execute relative move to
No vector is drawn, only
X I and Y I are updated
for later use.
50
Extended Monochrome Graphics Adapter