CompuServe Thread

I have been experimenting (black box methods) to determine the manner in which 3DS v4 will respond to opcode/user code return values following BXP_INITIALIZE and prior to returning BXP_INIT_DONE in the opcode member. I have extended the USER code handling of the sample BXP.C, and include my adaptations later in this message. The modifications I made assigned UPM_xxx defines for my private user_codes. When I send back >> case UPM_DONT_UNLOAD: >> CallTrace("UPM_DONT_UNLOAD", -1); >> localbuf.opcode=BXP_IMAGE_INFO; >> localbuf.usercode=UPM_IMAGE_INFO; >> break; then the next time BXP is called, I do not receive the expected UPM_IMAGE_INFO, but rather receive the BXP_SAVE_IMAGE, even though I did not explicitly send BXP_INIT_DONE. Now I note that the example BXP.C was not entirely "consistent" in the management or use of "status=" assignments, so I was wondering if 3DS automatically assumes BXP_INIT-DONE when it sees the opcode request for BXP_IMAGE_INFO, or does it assume an error in procedure and simply pick up at the lext logical place in the sequence. —————————— THE BXP.C code follows ————————— #include <stdio.h> #include <math.h> #include <stdlib.h> #include <string.h> #include "bxp.h" /* Codes 0x0001-0x01FF Reserved for internal interface codes */ /* Codes 0x0200-0x0FFF Reserved for user codes */ // UPM_xxxx user/op codes are USER PRIVATE MESSAGE defined codes // The UPM_xx are all implementation specific. They have no fundamental // association to 3DS itself or any BXP generically. #define UPM_SAVE_GINFO 0x0010 #define UPM_DONT_UNLOAD 0x0011 #define UPM_IMAGE_INFO 0x0012 // define or undefine TRACE_IS_ON to enable/disable trace text output #define TRACE_IS_ON #ifdef TRACE_IS_ON #define CallTrace(t,i) traceit(t,i) #else #define CallTrace(t,i) #endif int studio_version(void); char gp_buffer[256]; typedef struct { ulong magic; /* Magic number */ int opcode; /* What .EXP wants to do in 3D Studio */ int usercode;/* What .EXP wants to do when it gets back */ int status; /* How it all came out */ } BufHdr; static int bufsize=sizeof(EXPbuf); /* Pointers to bitmaps living in 3D Studio's memory */ /* These are "_far" pointers — 48 bits worth */ static EXPbuf _far *fexpbuf; /* Comm buffer struct ptr */ /*————————————————-*/ /* Local Data */ static EXPbuf localbuf; static int version=200; static int init_done = 0; /* Non-Client External Procedures (Utility) in Client Module */ extern void traceit (char *pText, int ival); // debug trace strings /* long xpmagic, xpmainseg, xpbuffer; */ void main(void) { /* Check magic number */ if(xpmagic!=BXP_MAGIC) { bad_magic: localbuf.status=0; return; } /* Copy comm buffer data to our structure */ FP_SET(fexpbuf, xpbuffer, xpmainseg); far_to_near(&localbuf, fexpbuf, bufsize); /* Double-check its magic number */ if(localbuf.magic!=BXP_MAGIC) goto bad_magic; if(localbuf.ver.magic==VER_MAGIC) version=localbuf.ver.version; switch(localbuf.usercode) { case BXP_INITIALIZE: /* A chance for user setup right after load */ CallTrace("BXP_INITIALIZE", -1); localbuf.opcode=EXP_GFX_INFO; /* Grab graphics info */ localbuf.usercode=UPM_SAVE_GINFO; /* (for gfx_debug_print) */ break; case UPM_SAVE_GINFO: CallTrace("UPM_SAVE_GINFO", -1); memcpy(GI, &localbuf.data.ginfo, sizeof(GFXInfo)); /* Hold onto this */ GC=localbuf.data.ginfo.buf; localbuf.opcode=EXP_DONT_UNLOAD; localbuf.usercode=UPM_DONT_UNLOAD; break; case UPM_DONT_UNLOAD: CallTrace("UPM_DONT_UNLOAD", -1); localbuf.opcode=BXP_IMAGE_INFO; localbuf.usercode=UPM_IMAGE_INFO; break; case UPM_IMAGE_INFO: CallTrace("UPM_IMAGE_INFO", -1); localbuf.opcode=BXP_INIT_DONE; localbuf.status=1; init_done = 1; break; case BXP_LOAD_START: /* Phase 1 of image load */ CallTrace("BXP_LOAD_START -> ClientLoadStart", -1); ClientLoadStart(&localbuf); break; case BXP_LOAD_FINISH: /* Phase 2 of image load */ CallTrace("BXP_LOAD_FINISH -> ClientLoadFinish", -1); ClientLoadFinish(&localbuf); break; case BXP_GET_FRAME: CallTrace("BXP_GET_FRAME -> ClientGetFrame", -1); ClientGetFrame(&localbuf); break; case BXP_IMAGE_INFO: CallTrace("BXP_IMAGE_INFO -> ClientImageInfo", -1); ClientImageInfo(&localbuf); break; case BXP_SAVE_IMAGE: /* Image save */ CallTrace("BXP_SAVE_IMAGE -> ClientSaveImage", -1); ClientSaveImage(&localbuf); break; case EXP_TERMINATE: CallTrace("EXP_TERMINATE", -1); localbuf.opcode=EXP_TERMINATE; /* Terminate! */ localbuf.status=1; /* OK status */ break; default: CallTrace("ERROR IN BXP", -1); printf("ERROR IN BXP.C: %X\n", localbuf.usercode); localbuf.opcode=EXP_TERMINATE; /* Terminate! */ localbuf.status=0; /* ERROR status */ break; } if (localbuf.opcode == EXP_TERMINATE) { traceit(&"ClientTerminate", -1); ClientTerminate(); } near_to_far(fexpbuf, &localbuf, bufsize); return; } int studio_version() { CallTrace("studio_version", -1); return(version); }