NAME

VI_Merge − set merge mode

SYNOPSIS

VI_Merge(merge)
int merge;/∗ merge mode ∗/

DESCRIPTION

The merge mode is a number from 0 to 15 that specifies how the bits generated by primitives are to be combined with bits already on the screen, as shown in the following table:

Merge ModeMeaning
  0OFF
1NOR
2NOT DATA AND SCREEN
3NOT DATA
4DATA AND NOT SCREEN
5NOT SCREEN
6XOR (NEQ)
7NAND
8AND
9EQ
10SCREEN (ignore)
11NOT DATA OR SCREEN
12DATA (replace)
13DATA OR NOT SCREEN
14OR
15ON

The merge mode is initially set to 12, for replace mode.  Data bits replace screen bits.  The merge mode is simply an encoding of the logical function used to combine screen bits and data bits.  Encoding the desired result of each of the combinations in the table below generates the merge mode that should be used to get that effect.  For example, to or the data you are adding with the data already present on the screen, you would use a merge mode of 14:

Data Bit1100
Screen Bit1010
 
Example:
OR mode1110= 14

NOTE

VI_Merge applies only to the IBM Academic Information Systems experimental display. 

SEE ALSO

circle(3G), color(3G), line(3G), query(3G)

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  30 Sep 1985