fprintf(f,

);

// Start the ID somewhere beyond the header IDs.

id = 200;

fprintf(f,

"#175 = SHAPE_DEFINITION_REPRESENTATION(#176, #169);\n"

"#176 = PRODUCT_DEFINITION_SHAPE('Version', 'Test Part', #177);\n"

"#177 = PRODUCT_DEFINITION('Version', 'Test Part', #182, #178);\n"

"#178 = DESIGN_CONTEXT('3D Mechanical Parts', #181, 'design');\n"

"#179 = PRODUCT('1', 'Product', 'Test Part', (#180));\n"

"#180 = MECHANICAL_CONTEXT('3D Mechanical Parts', #181, 'mechanical');\n"

"#181 = APPLICATION_CONTEXT(\n"

"'configuration controlled 3d designs of mechanical parts and assemblies');\n"

"#182 = PRODUCT_DEFINITION_FORMATION_WITH_SPECIFIED_SOURCE('Version',\n"

"'Test Part', #179, .MADE.);\n"

"\n"

);

int i, ret = id;

fprintf(f, "#%d=(\n", ret);

fprintf(f, "BOUNDED_CURVE()\n");

fprintf(f, "B_SPLINE_CURVE(%d,(", sb->deg);

for(i = 0; i <= sb->deg; i++) {

fprintf(f, "#%d", ret + i + 1);

if(i != sb->deg) fprintf(f, ",");

}

fprintf(f, "),.UNSPECIFIED.,.F.,.F.)\n");

fprintf(f, "B_SPLINE_CURVE_WITH_KNOTS((%d,%d),",

(sb->deg + 1), (sb-> deg + 1));

fprintf(f, "(0.000,1.000),.UNSPECIFIED.)\n");

fprintf(f, "CURVE()\n");

fprintf(f, "GEOMETRIC_REPRESENTATION_ITEM()\n");

fprintf(f, "RATIONAL_B_SPLINE_CURVE((");

for(i = 0; i <= sb->deg; i++) {

fprintf(f, "%.10f", sb->weight[i]);

if(i != sb->deg) fprintf(f, ",");

}

fprintf(f, "))\n");

fprintf(f, "REPRESENTATION_ITEM('')\n);\n");

for(i = 0; i <= sb->deg; i++) {

fprintf(f, "#%d=CARTESIAN_POINT('',(%.10f,%.10f,%.10f));\n",

id + 1 + i,

CO(sb->ctrl[i]));

}

fprintf(f, "\n");

id = ret + 1 + (sb->deg + 1);

return ret;

ssassert(loop->l.n >= 1, "Expected at least one loop");

List<int> listOfTrims = {};

SBezier *sb = loop->l.Last();

// Generate "exactly closed" contours, with the same vertex id for the

// finish of a previous edge and the start of the next one. So we need

// the finish of the last Bezier in the loop before we start our process.

fprintf(f, "#%d=CARTESIAN_POINT('',(%.10f,%.10f,%.10f));\n",

id, CO(sb->Finish()));

fprintf(f, "#%d=VERTEX_POINT('',#%d);\n", id+1, id);

int lastFinish = id + 1, prevFinish = lastFinish;

id += 2;

for(sb = loop->l.First(); sb; sb = loop->l.NextAfter(sb)) {

int curveId = ExportCurve(sb);

int thisFinish;

if(loop->l.NextAfter(sb) != NULL) {

fprintf(f, "#%d=CARTESIAN_POINT('',(%.10f,%.10f,%.10f));\n",

id, CO(sb->Finish()));

fprintf(f, "#%d=VERTEX_POINT('',#%d);\n", id+1, id);

thisFinish = id + 1;

id += 2;

} else {

thisFinish = lastFinish;

}

fprintf(f, "#%d=EDGE_CURVE('',#%d,#%d,#%d,%s);\n",

id, prevFinish, thisFinish, curveId, ".T.");

fprintf(f, "#%d=ORIENTED_EDGE('',*,*,#%d,.T.);\n",

id+1, id);

int oe = id+1;

listOfTrims.Add(&oe);

id += 2;

prevFinish = thisFinish;

}

fprintf(f, "#%d=EDGE_LOOP('',(", id);

int *oe;

for(oe = listOfTrims.First(); oe; oe = listOfTrims.NextAfter(oe)) {

fprintf(f, "#%d", *oe);

if(listOfTrims.NextAfter(oe) != NULL) fprintf(f, ",");

}

fprintf(f, "));\n");

int fb = id + 1;

fprintf(f, "#%d=%s('',#%d,.T.);\n",

fb, inner ? "FACE_BOUND" : "FACE_OUTER_BOUND", id);

id += 2;

listOfTrims.Clear();

return fb;

int i, j, srfid = id;

// First, we create the untrimmed surface. We always specify a rational

// B-spline surface (in fact, just a Bezier surface).

fprintf(f, "#%d=(\n", srfid);

fprintf(f, "BOUNDED_SURFACE()\n");

fprintf(f, "B_SPLINE_SURFACE(%d,%d,(", ss->degm, ss->degn);

for(i = 0; i <= ss->degm; i++) {

fprintf(f, "(");

for(j = 0; j <= ss->degn; j++) {

fprintf(f, "#%d", srfid + 1 + j + i*(ss->degn + 1));

if(j != ss->degn) fprintf(f, ",");

}

fprintf(f, ")");

if(i != ss->degm) fprintf(f, ",");

}

fprintf(f, "),.UNSPECIFIED.,.F.,.F.,.F.)\n");

fprintf(f, "B_SPLINE_SURFACE_WITH_KNOTS((%d,%d),(%d,%d),",

(ss->degm + 1), (ss->degm + 1),

(ss->degn + 1), (ss->degn + 1));

fprintf(f, "(0.000,1.000),(0.000,1.000),.UNSPECIFIED.)\n");

fprintf(f, "GEOMETRIC_REPRESENTATION_ITEM()\n");

fprintf(f, "RATIONAL_B_SPLINE_SURFACE((");

for(i = 0; i <= ss->degm; i++) {

fprintf(f, "(");

for(j = 0; j <= ss->degn; j++) {

fprintf(f, "%.10f", ss->weight[i][j]);

if(j != ss->degn) fprintf(f, ",");

}

fprintf(f, ")");

if(i != ss->degm) fprintf(f, ",");

}

fprintf(f, "))\n");

fprintf(f, "REPRESENTATION_ITEM('')\n");

fprintf(f, "SURFACE()\n");

fprintf(f, ");\n");

// The control points for the untrimmed surface.

for(i = 0; i <= ss->degm; i++) {

for(j = 0; j <= ss->degn; j++) {

fprintf(f, "#%d=CARTESIAN_POINT('',(%.10f,%.10f,%.10f));\n",

srfid + 1 + j + i*(ss->degn + 1),

CO(ss->ctrl[i][j]));

}

}

fprintf(f, "\n");

id = srfid + 1 + (ss->degm + 1)*(ss->degn + 1);

// Now we do the trim curves. We must group each outer loop separately

// along with its inner faces, so do that now.

SBezierLoopSetSet sblss = {};

SPolygon spxyz = {};

bool allClosed;

SEdge notClosedAt;

// We specify a surface, so it doesn't check for coplanarity; and we

// don't want it to give us any open contours. The polygon and chord

// tolerance are required, because they are used to calculate the

// contour directions and determine inner vs. outer contours.

sblss.FindOuterFacesFrom(sbl, &spxyz, ss,

SS.ExportChordTolMm(),

&allClosed, &notClosedAt,

NULL, NULL,

NULL);

// So in our list of SBezierLoopSet, each set contains at least one loop

// (the outer boundary), plus any inner loops associated with that outer

// loop.

SBezierLoopSet *sbls;

for(sbls = sblss.l.First(); sbls; sbls = sblss.l.NextAfter(sbls)) {

SBezierLoop *loop = sbls->l.First();

List<int> listOfLoops = {};

// Create the face outer boundary from the outer loop.

int fob = ExportCurveLoop(loop, /*inner=*/false);

listOfLoops.Add(&fob);

// And create the face inner boundaries from any inner loops that

// lie within this contour.

loop = sbls->l.NextAfter(loop);

for(; loop; loop = sbls->l.NextAfter(loop)) {

int fib = ExportCurveLoop(loop, /*inner=*/true);

listOfLoops.Add(&fib);

}

// And now create the face that corresponds to this outer loop

// and all of its holes.

int advFaceId = id;

fprintf(f, "#%d=ADVANCED_FACE('',(", advFaceId);

int *fb;

for(fb = listOfLoops.First(); fb; fb = listOfLoops.NextAfter(fb)) {

fprintf(f, "#%d", *fb);

if(listOfLoops.NextAfter(fb) != NULL) fprintf(f, ",");

}

fprintf(f, "),#%d,.T.);\n", srfid);

advancedFaces.Add(&advFaceId);

// Export the surface color and transparency

// https://www.cax-if.org/documents/rec_prac_styling_org_v16.pdf sections 4.4.2 4.2.4 etc.

// https://tracker.dev.opencascade.org/view.php?id=31550

fprintf(f, "#%d=COLOUR_RGB('',%.2f,%.2f,%.2f);\n", ++id, ss->color.redF(),

ss->color.greenF(), ss->color.blueF());

// This works in Horison EDA but is more verbose.

++id;

fprintf(f, "#%d=FILL_AREA_STYLE_COLOUR('',#%d);\n", id, id - 1);

++id;

fprintf(f, "#%d=FILL_AREA_STYLE('',(#%d));\n", id, id - 1);

++id;

fprintf(f, "#%d=SURFACE_STYLE_FILL_AREA(#%d);\n", id, id - 1);

fprintf(f, "#%d=SURFACE_STYLE_TRANSPARENT(%.2f);\n", ++id, 1.0 - ss->color.alphaF());

++id;

fprintf(f, "#%d=SURFACE_STYLE_RENDERING_WITH_PROPERTIES(.NORMAL_SHADING.,#%d,(#%d));\n", id, id - 5, id - 1);

++id;

fprintf(f, "#%d=SURFACE_SIDE_STYLE('',(#%d, #%d));\n", id, id - 3, id - 1);

++id;

fprintf(f, "#%d=SURFACE_STYLE_USAGE(.BOTH.,#%d);\n", id, id - 1);

++id;

fprintf(f, "#%d=PRESENTATION_STYLE_ASSIGNMENT((#%d));\n", id, id - 1);

++id;

fprintf(f, "#%d=STYLED_ITEM('',(#%d),#%d);\n", id, id - 1, advFaceId);

fprintf(f, "\n");

id++;

listOfLoops.Clear();

}

sblss.Clear();

spxyz.Clear();

fprintf(f,

);

Group *g = SK.GetGroup(SS.GW.activeGroup);

SShell *shell = &(g->runningShell);

if(shell->surface.IsEmpty()) {

Error("The model does not contain any surfaces to export.%s",

!g->runningMesh.l.IsEmpty()

? "\n\nThe model does contain triangles from a mesh, but "

"a triangle mesh cannot be exported as a STEP file. Try "

"File -> Export Mesh... instead."

: "");

return;

}

f = OpenFile(filename, "wb");

if(!f) {

Error("Couldn't write to '%s'", filename.raw.c_str());

return;

}

WriteHeader();

WriteProductHeader();

advancedFaces = {};

for(SSurface &ss : shell->surface) {

if(ss.trim.IsEmpty())

continue;

// Get all of the loops of Beziers that trim our surface (with each

// Bezier split so that we use the section as t goes from 0 to 1), and

// the piecewise linearization of those loops in xyz space.

SBezierList sbl = {};

ss.MakeSectionEdgesInto(shell, NULL, &sbl);

// Apply the export scale factor.

ss.ScaleSelfBy(1.0/SS.exportScale);

sbl.ScaleSelfBy(1.0/SS.exportScale);

ExportSurface(&ss, &sbl);

sbl.Clear();

}

fprintf(f, "#%d=CLOSED_SHELL('',(", id);

int *af;

for(af = advancedFaces.First(); af; af = advancedFaces.NextAfter(af)) {

fprintf(f, "#%d", *af);

if(advancedFaces.NextAfter(af) != NULL) fprintf(f, ",");

}

fprintf(f, "));\n");

fprintf(f, "#%d=MANIFOLD_SOLID_BREP('brep',#%d);\n", id+1, id);

fprintf(f, "#%d=ADVANCED_BREP_SHAPE_REPRESENTATION('',(#%d,#170),#168);\n",

id+2, id+1);

fprintf(f, "#%d=SHAPE_REPRESENTATION_RELATIONSHIP($,$,#169,#%d);\n",

id+3, id+2);

WriteFooter();

fclose(f);

advancedFaces.Clear();

fprintf(f, "#%d=GEOMETRIC_CURVE_SET('curves',(", id);

int *c;

for(c = curves.First(); c; c = curves.NextAfter(c)) {

fprintf(f, "#%d", *c);

if(curves.NextAfter(c) != NULL) fprintf(f, ",");

}

fprintf(f, "));\n");

fprintf(f, "#%d=GEOMETRICALLY_BOUNDED_WIREFRAME_SHAPE_REPRESENTATION"

"('',(#%d,#170),#168);\n", id+1, id);

fprintf(f, "#%d=SHAPE_REPRESENTATION_RELATIONSHIP($,$,#169,#%d);\n",

id+2, id+1);

id += 3;

curves.Clear();