isysxp / tek40xx Goto Github PK

The error is as following:

gcc -o tek40xx tek_main.o tek_display.o tek_telnet.o tek_drawline.o font-5x7.o `sdl2-config --libs` -lm
/usr/bin/ld: tek_display.o:~/Tek40xx/tek_video.h:103: multiple definition of `tek_socket'; tek_main.o:~/Tek40xx/tek_video.h:103: first defined here
/usr/bin/ld: tek_drawline.o:~/Tek40xx/tek_video.h:103: multiple definition of `tek_socket'; tek_main.o:~/Tek40xx/tek_video.h:103: first defined here
collect2: error: ld returned 1 exit status
make: *** [makefile:12: tek40xx] Error 1

note that after this error is given, issuing gcc -o tek40xx tek_main.o tek_display.o tek_telnet.o tek_drawline.o font-5x7.o \sdl2-config --libs` -lm -Wl,--allow-multiple-definition` will compile the binary fine.

Using tek40xx to connect to some emulated php-11 system and I have written code that uses "write through graphics" mode to draw animations. The first lines drawn look fine, but they fade to darker than the greenish BACKGROUND value; then when another write through graphics line is drawn, it will not light up pixels that were previously faded to "darker than background". This causes repeating animation drawings to basically be mostly black and not drawing.

I have found that I can make the problem go away if I change the alphablend function in tel_drawline.c from this:

if (!wrthru || p[1] == BACKGROUND) {

to this:

if (!wrthru || p[1] <= BACKGROUND) {

the repeat animations now work fine. The write through lines still fade to darker-than-background which seems like a separate issue. I have tried changing the value of BACKGROUND lower but anything below about 20 seems to hang the program.

FYI, this emulator works fine with ITS' :tctyp tek terminal type and Macsyma function plotting.