From guest Mon Apr 4 13:33:44 1994 Message-Id: <9404042033.AA29541@merl.com> Organization: Mitsubishi Electric Research Laboratories, Inc. Cambridge, Massachusetts, USA X-Sender: barrus@mailhost.merl.com Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 4 Apr 1994 16:33:38 -0500 To: info-performer@sgi.sgi.com From: barrus@merl.com (John W. Barrus) Subject: DXF format specs Status: OR I would like to read in some DXF format files and I was wondering where to get the specs for the format. Any suggestions? Of course if I was using Performer 1.2, I could use LoadDxf(), right? Too bad we haven't received it yet. If anyone is willing to part with some code that already reads DXF, I would be interested and very appreciative. Thanks, John B. ------------------------- John Barrus barrus@merl.com Mitsubishi Electric Research Laboratories 617.621.7535 (VOICE) 201 Broadway 617.621.7550 (FAX) Cambridge, MA 02139 From guest Mon Apr 4 14:52:23 1994 From: "Michael Jones" Message-Id: <9404041406.ZM5343@babar.asd.sgi.com> Date: Mon, 4 Apr 1994 14:06:40 -0700 In-Reply-To: barrus@merl.com (John W. Barrus) "DXF format specs" (Apr 4, 4:33pm) References: <9404042033.AA29541@merl.com> X-Mailer: Z-Mail (3.1.0 22feb94 MediaMail) To: barrus@merl.com (John W. Barrus), info-performer@sgi.sgi.com Subject: Re: DXF format specs Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 Status: OR The DXF format specs ship with IRIS Performer 1.2. Here's the simple loader from 1.2 -- you'll want the new pfuBuilder() from 1.2 to compile this. Hint: upgrade to SC4-PERF-1.2 (the 1..2 release) right away! If you have support, ask when you'll get your upgrade. /* * Copyright (c) 1993 Silicon Graphics, Inc. * * Permission to use, copy, modify, distribute, and sell this software * and its documentation for any purpose is hereby granted without * fee, provided that (i) the above copyright notices and this * permission notice appear in all copies of the software and related * documentation, and (ii) the name of Silicon Graphics may not be * used in any advertising or publicity relating to the software * without the specific, prior written permission of Silicon Graphics. * * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. * * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR ANY SPECIAL, * INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY * THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE * OR PERFORMANCE OF THIS SOFTWARE. * */ /* * pfdxf.c: $Revision: 1.24 $ $Date: 1994/03/16 11:56:18 $ */ #include #include "pfsgi.h" #include "pfutil.h" /* * This AutoCAD reader was created almost verbatim from the * AutoCAD DXF file to DKB data file converter written and * placed in the public domain 8/13/90 by Aaron A. Collins. * * It parses a limited, but useful, subset of the AutoCAD * DXF file format. No effort has been made to handle the * complete range of possible DXF opcodes and commands. */ #include #include #include #define BUFFER_SIZE 2048 static int groupcode; static char linbuf[BUFFER_SIZE]; static char curobj[80]; static int curcolor; static float curr; static float curg; static float curb; static float xcoords[BUFFER_SIZE]; static float ycoords[BUFFER_SIZE]; static float zcoords[BUFFER_SIZE]; static float floats[10]; static float angles[10]; static int ints[10]; static long numTris; static long numVoid; /* function type and argument declarations */ static FILE *openFile(char *fileName); static pfGeoState* defaultGeoState(void); static int getLine(FILE *fp); static void addGeometry(pfuBuilder *); static void getColor(int ndx, float *red, float *green, float *blue); static int isDegenerate(int a, int b, int c); static int findEntity(FILE *fp); static int readEntity(FILE *fp, pfuBuilder *builder); /* * LoadDxf -- load DXF format ".dxf" files into IRIS Performer */ extern pfNode * LoadDxf (char *fileName, pfGeoState *geostate) { int i; FILE *dxfFile; pfuBuilder *builder = NULL; pfList *gsetList = NULL; pfGeode *geode = NULL; pfNode *node = NULL; pfNode *hierarchy = NULL; double startTime = pfGetTime(); double elapsedTime = 0.0; /* open DXF file file */ if ((dxfFile = openFile(fileName)) == NULL) return NULL; /* give object a default geostate if nothing is passed in */ if (geostate == NULL) geostate = defaultGeoState(); /* initialize utility library triangle/geoset builder */ builder = pfuNewBuilder(); /* initialize current object */ numTris = 0; numVoid = 0; curobj[0] = '\0'; curcolor = 7; getColor(curcolor, &curr, &curg, &curb); /* read DXF file */ while (findEntity(dxfFile)) readEntity(dxfFile, builder); /* close DXF file */ fclose(dxfFile); /* signal failure if no geometry loaded */ if (numTris == 0) { pfuDelBuilder(builder); return NULL; } /* construct geode */ geode = pfNewGeode(); node = (pfNode *)geode; /* convert current face list into one or more geosets */ gsetList = pfuMakeGSets(builder); for (i = 0; i < pfGetNum(gsetList); i++) { pfGeoSet *geoset = (pfGeoSet*)pfGet(gsetList, i); pfGSetGState(geoset, geostate); pfAddGSet(geode, geoset); } pfuDelBuilder(builder); /* print statistics */ if(pfGetNotifyLevel() >= PFNFY_INFO) { elapsedTime = pfGetTime() - startTime; fprintf(stderr, "LoadDxf:\n"); fprintf(stderr, " file name = %s\n", fileName); fprintf(stderr, " triangles = %8ld\n", numTris); fprintf(stderr, " numVoid = %8ld\n", numVoid); if (elapsedTime > 0.0) { fprintf(stderr, " loading time = %12.3f sec\n", elapsedTime); fprintf(stderr, " loading rate = %12.3f tri/sec\n", numTris/elapsedTime); } } /* #define BREAKUP_GEODE */ #ifdef BREAKUP_GEODE /* convert geode to recursive spatial hierarchy */ startTime = pfGetTime(); hierarchy = pfuBreakup(geode, 10.0f, 24, 8); elapsedTime = pfGetTime() - startTime; /* replace monolithic geode with recursive spatial hierarchy */ if (hierarchy != NULL) { node = hierarchy; pfDelete(geode); } /* print statistics */ if (pfGetNotifyLevel() >= PFNFY_INFO && elapsedTime > 0.0) { fprintf(stderr, " breakup time = %12.3f sec\n", elapsedTime); fprintf(stderr, " breakup rate = %12.3f tri/sec\n", numTris/elapsedTime); } #endif /* print statistics */ if (pfGetNotifyLevel() >= PFNFY_INFO) fprintf(stderr, "\n"); return node; } static FILE * openFile (char *fileName) { FILE *file = NULL; char filePath[BUFFER_SIZE]; /* check argument */ if (fileName == NULL || *fileName == '\0') return NULL; /* find file in IRIS Performer directory-search path */ if (!pfFindFile(fileName, filePath, R_OK)) { pfNotify(PFNFY_WARN, PFNFY_RESOURCE, "openFile: Could not find file \"%s\"", fileName); return NULL; } /* open file */ if ((file = fopen(filePath, "r")) == NULL) { pfNotify(PFNFY_WARN, PFNFY_RESOURCE, "openFile: Could not open file \"%s\"", filePath); return NULL; } return file; } /* * read a group code and the next line from dxfFile */ static int getLine(FILE *fp) { /* get a line from DXF file */ fgets(linbuf, BUFFER_SIZE, fp); if (feof(fp)) return 1; /* scan out group code */ sscanf(linbuf, "%3d", &groupcode); /* get a line from DXF file */ fgets(linbuf, BUFFER_SIZE, fp); if (feof(fp)) return 1; return 0; } /* * dump out current object we should have all info on */ static void addGeometry(pfuBuilder *builder) { static pfuPoly polygon; static int state=0; static int nb_points; static int nb_cotes; static int indice_point; /* 2 back-to-back triangles */ if (strstr(curobj, "TRACE")) { if (isDegenerate(0, 1, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[1], ycoords[1], zcoords[1]); pfSetVec3(polygon.coords[2], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; if (isDegenerate(0, 3, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.coords[2], xcoords[3], ycoords[3], zcoords[3]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; return; } /* 1 or 2 triangles */ else if (strstr(curobj, "SOLID")) { if (isDegenerate(0, 1, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[1], ycoords[1], zcoords[1]); pfSetVec3(polygon.coords[2], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; /* is one triangle enough... */ if (xcoords[2] == xcoords[3] && ycoords[2] == ycoords[3] && zcoords[2] == zcoords[3]) return; if (isDegenerate(0, 3, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.coords[2], xcoords[3], ycoords[3], zcoords[3]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; return; } /* 1 or 2 triangles */ else if (strstr(curobj, "3DFACE")) { if (isDegenerate(0, 1, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[1], ycoords[1], zcoords[1]); pfSetVec3(polygon.coords[2], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; /* is one triangle enough... */ if (xcoords[2] == xcoords[3] && ycoords[2] == ycoords[3] && zcoords[2] == zcoords[3]) return; if (isDegenerate(0, 3, 2)) { numVoid++; return; } polygon.numVerts = 3; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; pfSetVec3(polygon.coords[0], xcoords[0], ycoords[0], zcoords[0]); pfSetVec3(polygon.coords[1], xcoords[2], ycoords[2], zcoords[2]); pfSetVec3(polygon.coords[2], xcoords[3], ycoords[3], zcoords[3]); pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; return; } else if (strstr(curobj, "SEQEND")) { if (state == 1 && polygon.numVerts > 2) { pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; } state = 0; /* end of something */ } else if (strstr(curobj, "POLYLINE")) { state = 1; /* begin of a polyline */ indice_point = 1; nb_points = ints[1]; nb_cotes = ints[2]; if (nb_points >= (BUFFER_SIZE-1)) { state = 0; return; } polygon.numVerts = 0; polygon.tbind = PFGS_OFF; polygon.nbind = PFGS_OFF; polygon.cbind = PFGS_OVERALL; } /* a new vertex in a polyline */ else if (strstr(curobj, "VERTEX") && state == 1) { /* is it a new vertex ? */ if (indice_point <= nb_points) { /* copying point */ xcoords[indice_point] = xcoords[0]; ycoords[indice_point] = ycoords[0]; zcoords[indice_point] = zcoords[0]; indice_point++; } else /* creating edges */ if (nb_cotes > 0) { /* closing an older polygon */ if ((ints[1] > 0) && (polygon.numVerts > 2)) { pfSetVec3(polygon.colors[0], curr, curg, curb); pfuAddPoly(builder, &polygon); numTris += polygon.numVerts - 2; } /* creating a new polygon */ if (ints[1] > 0) { polygon.numVerts = 0; pfSetVec3(polygon.coords[polygon.numVerts++], xcoords[ints[1]], ycoords[ints[1]], zcoords[ints[1]]); } if (ints[2] > 0) { pfSetVec3(polygon.coords[polygon.numVerts++], xcoords[ints[2]], ycoords[ints[2]], zcoords[ints[2]]); } if (ints[3] > 0) { pfSetVec3(polygon.coords[polygon.numVerts++], xcoords[ints[3]], ycoords[ints[3]], zcoords[ints[3]]); } } } /* not implemented */ else if ( strstr(curobj, "LINE") || strstr(curobj, "POINT") || strstr(curobj, "CIRCLE") || strstr(curobj, "ARC") || strstr(curobj, "TEXT") || strstr(curobj, "SHAPE") || strstr(curobj, "BLOCK") || strstr(curobj, "ENDBLK") || strstr(curobj, "INSERT") || strstr(curobj, "ATTDEF") || strstr(curobj, "ATTRIB") || strstr(curobj, "3DLINE") || strstr(curobj, "DIMENSION")) { return; } /* no current object defined */ else return; } /* * colors defined by basic AutoCAD color table */ static void getColor (int ndx, float *red, float *green, float *blue) { /* AutoCAD color table */ static float colors[][3] = { {0.0f, 0.0f, 0.0f}, /* 0 == black */ {1.0f, 0.0f, 0.0f}, /* 1 == red */ {1.0f, 1.0f, 0.0f}, /* 2 == yellow */ {0.0f, 1.0f, 0.0f}, /* 3 == green */ {0.0f, 1.0f, 1.0f}, /* 4 == cyan */ {0.0f, 0.0f, 1.0f}, /* 5 == blue */ {1.0f, 0.0f, 1.0f}, /* 6 == magenta */ {1.0f, 1.0f, 1.0f}, /* 7 == white */ {0.5f, 0.5f, 0.5f}, /* 8 == dk grey */ {0.75f, 0.75f, 0.75f} /* 9 == lt grey */ }; /* use white (color 7) as default color */ if (ndx < 0 || ndx > 9) ndx = 7; /* set colors in reference arguments */ *red = colors[ndx][0]; *green = colors[ndx][1]; *blue = colors[ndx][2]; return; } /* * check for degenerate triangle structure */ static int isDegenerate(int a, int b, int c) { if ((xcoords[a] == xcoords[b] && ycoords[a] == ycoords[b] && zcoords[a] == zcoords[b]) || (xcoords[b] == xcoords[c] && ycoords[b] == ycoords[c] && zcoords[b] == zcoords[c]) || (xcoords[a] == xcoords[c] && ycoords[a] == ycoords[c] && zcoords[a] == zcoords[c])) return 1; else return 0; } /* * move forward to ENTITIES section */ static int findEntity(FILE *fp) { while (1) { /* is there more to read */ if (feof(fp)) return 0; /* get a group code and a line */ if (getLine(fp)) return 0; /* file section mark */ if (groupcode == 0) { if (strstr(linbuf, "EOF")) return 0; if (strstr(linbuf, "SECTION")) { if (getLine(fp)) return 0; if (groupcode != 2) continue; if (strstr(linbuf, "ENTITIES")) break; } } } return 1; } /* * read objects from ENTITIES section */ static int readEntity(FILE *fp, pfuBuilder *builder) { while (1) { /* is there more to read */ if (feof(fp)) break; /* get a group code and a line */ if (getLine(fp)) break; /* cardinal group codes */ if (groupcode < 10) { switch(groupcode) { /* start of entity, table, file sep */ case 0: /* add object's polygons to builder */ addGeometry(builder); if (strstr(linbuf, "EOF")) return 0; if (strstr(linbuf, "ENDSEC")) continue; /* reset object */ curobj[0] = '\0'; curcolor = 7; getColor(curcolor, &curr, &curg, &curb); /* get new */ strcpy(curobj, linbuf); break; /* primary text value for entity (?) */ case 1: break; /* block name, attribute tag, etc */ case 2: case 3: case 4: break; /* entity handle (hex string) */ case 5: break; /* line type name */ case 6: break; /* text style name */ case 7: break; /* layer name */ case 8: break; /* variable name ID (only in header) */ case 9: break; } } /* some X coord */ else if (groupcode >= 10 && groupcode < 19) sscanf(linbuf, "%f", &(xcoords[groupcode-10])); /* some Y coord */ else if (groupcode >= 20 && groupcode < 29) sscanf(linbuf, "%f", &(ycoords[groupcode-20])); /* some Z coord */ else if (groupcode >= 30 && groupcode < 38) sscanf(linbuf, "%f", &(zcoords[groupcode-30])); /* entity elevation if nonzero */ else if (groupcode == 38) { } /* entity thickness if nonzero */ else if (groupcode == 39) { } /* misc floats */ else if (groupcode >= 40 && groupcode < 49) sscanf(linbuf, "%f", &(floats[groupcode-40])); /* repeated value groups */ else if (groupcode == 49) { } /* misc angles */ else if (groupcode >= 50 && groupcode < 59) sscanf(linbuf, "%f", &(angles[groupcode-50])); /* color number */ else if (groupcode == 62) { sscanf(linbuf, "%6d", &curcolor); getColor(curcolor, &curr, &curg, &curb); } /* "entities follow" flag */ else if (groupcode == 66) { } /* misc ints */ else if (groupcode >= 70 && groupcode < 79) sscanf(linbuf, "%d", &(ints[groupcode-70])); /* X, Y, Z components of extrusion direction */ else if (groupcode == 210 || groupcode == 220 || groupcode == 230) { } } return 0; } /* * make a reasonable default geostate */ static pfGeoState* defaultGeoState (void) { static void *arena = NULL; static pfMaterial *material = NULL; static pfGeoState *geostate = NULL; if (geostate == NULL) { arena = pfGetSharedArena(); material = pfNewMtl(arena); pfMtlColor(material, PFMTL_AMBIENT, 0.1, 0.1, 0.1); pfMtlColor(material, PFMTL_SPECULAR, 0.8, 0.8, 0.8); pfMtlShininess(material, 10.0); pfMtlColorMode(material, PFMTL_FRONT, LMC_AD); geostate = pfNewGState(arena); pfGStateAttr(geostate, PFSTATE_FRONTMTL, material); } return geostate; } -- Be seeing you, mtj@sgi.com 415.390.1455 M/S 7L-590 Michael Jones Silicon Graphics, Advanced Graphics Division 2011 N. Shoreline Blvd., Mtn. View, CA 94039-7311