solvespace/export.cpp

770 lines
26 KiB
C++

//-----------------------------------------------------------------------------
// The 2d vector output stuff that isn't specific to any particular file
// format: getting the appropriate lines and curves, performing hidden line
// removal, calculating bounding boxes, and so on. Also raster and triangle
// mesh output.
//-----------------------------------------------------------------------------
#include "solvespace.h"
#include <png.h>
void SolveSpace::ExportSectionTo(char *filename) {
Vector gn = (SS.GW.projRight).Cross(SS.GW.projUp);
gn = gn.WithMagnitude(1);
Group *g = SK.GetGroup(SS.GW.activeGroup);
g->GenerateDisplayItems();
if(g->displayMesh.IsEmpty()) {
Error("No solid model present; draw one with extrudes and revolves, "
"or use Export 2d View to export bare lines and curves.");
return;
}
// The plane in which the exported section lies; need this because we'll
// reorient from that plane into the xy plane before exporting.
Vector origin, u, v, n;
double d;
SS.GW.GroupSelection();
#define gs (SS.GW.gs)
if((gs.n == 0 && g->activeWorkplane.v != Entity::FREE_IN_3D.v)) {
Entity *wrkpl = SK.GetEntity(g->activeWorkplane);
origin = wrkpl->WorkplaneGetOffset();
n = wrkpl->Normal()->NormalN();
u = wrkpl->Normal()->NormalU();
v = wrkpl->Normal()->NormalV();
} else if(gs.n == 1 && gs.faces == 1) {
Entity *face = SK.GetEntity(gs.entity[0]);
origin = face->FaceGetPointNum();
n = face->FaceGetNormalNum();
if(n.Dot(gn) < 0) n = n.ScaledBy(-1);
u = n.Normal(0);
v = n.Normal(1);
} else if(gs.n == 3 && gs.vectors == 2 && gs.points == 1) {
Vector ut = SK.GetEntity(gs.entity[0])->VectorGetNum(),
vt = SK.GetEntity(gs.entity[1])->VectorGetNum();
ut = ut.WithMagnitude(1);
vt = vt.WithMagnitude(1);
if(fabs(SS.GW.projUp.Dot(vt)) < fabs(SS.GW.projUp.Dot(ut))) {
SWAP(Vector, ut, vt);
}
if(SS.GW.projRight.Dot(ut) < 0) ut = ut.ScaledBy(-1);
if(SS.GW.projUp. Dot(vt) < 0) vt = vt.ScaledBy(-1);
origin = SK.GetEntity(gs.point[0])->PointGetNum();
n = ut.Cross(vt);
u = ut.WithMagnitude(1);
v = (n.Cross(u)).WithMagnitude(1);
} else {
Error("Bad selection for export section. Please select:\n\n"
" * nothing, with an active workplane "
"(workplane is section plane)\n"
" * a face (section plane through face)\n"
" * a point and two line segments "
"(plane through point and parallel to lines)\n");
return;
}
SS.GW.ClearSelection();
n = n.WithMagnitude(1);
d = origin.Dot(n);
SEdgeList el;
ZERO(&el);
SBezierList bl;
ZERO(&bl);
// If there's a mesh, then grab the edges from it.
g->runningMesh.MakeEdgesInPlaneInto(&el, n, d);
// If there's a shell, then grab the edges and possibly Beziers.
g->runningShell.MakeSectionEdgesInto(n, d,
&el,
(SS.exportPwlCurves || fabs(SS.exportOffset) > LENGTH_EPS) ? NULL : &bl);
// All of these are solid model edges, so use the appropriate style.
SEdge *se;
for(se = el.l.First(); se; se = el.l.NextAfter(se)) {
se->auxA = Style::SOLID_EDGE;
}
SBezier *sb;
for(sb = bl.l.First(); sb; sb = bl.l.NextAfter(sb)) {
sb->auxA = Style::SOLID_EDGE;
}
el.CullExtraneousEdges();
bl.CullIdenticalBeziers();
// And write the edges.
VectorFileWriter *out = VectorFileWriter::ForFile(filename);
if(out) {
// parallel projection (no perspective), and no mesh
ExportLinesAndMesh(&el, &bl, NULL,
u, v, n, origin, 0,
out);
}
el.Clear();
bl.Clear();
}
void SolveSpace::ExportViewOrWireframeTo(char *filename, bool wireframe) {
int i;
SEdgeList edges;
ZERO(&edges);
SBezierList beziers;
ZERO(&beziers);
SMesh *sm = NULL;
if(SS.GW.showShaded) {
Group *g = SK.GetGroup(SS.GW.activeGroup);
g->GenerateDisplayItems();
sm = &(g->displayMesh);
}
if(sm && sm->IsEmpty()) {
sm = NULL;
}
for(i = 0; i < SK.entity.n; i++) {
Entity *e = &(SK.entity.elem[i]);
if(!e->IsVisible()) continue;
if(e->construction) continue;
if(SS.exportPwlCurves || (sm && !SS.GW.showHdnLines) ||
fabs(SS.exportOffset) > LENGTH_EPS)
{
// We will be doing hidden line removal, which we can't do on
// exact curves; so we need things broken down to pwls. Same
// problem with cutter radius compensation.
e->GenerateEdges(&edges);
} else {
e->GenerateBezierCurves(&beziers);
}
}
if(SS.GW.showEdges) {
Group *g = SK.GetGroup(SS.GW.activeGroup);
g->GenerateDisplayItems();
SEdgeList *selr = &(g->displayEdges);
SEdge *se;
for(se = selr->l.First(); se; se = selr->l.NextAfter(se)) {
edges.AddEdge(se->a, se->b, Style::SOLID_EDGE);
}
}
if(SS.GW.showConstraints) {
Constraint *c;
for(c = SK.constraint.First(); c; c = SK.constraint.NextAfter(c)) {
c->GetEdges(&edges);
}
}
if(wireframe) {
VectorFileWriter *out = VectorFileWriter::ForFile(filename);
if(out) {
ExportWireframeCurves(&edges, &beziers, out);
}
} else {
Vector u = SS.GW.projRight,
v = SS.GW.projUp,
n = u.Cross(v),
origin = SS.GW.offset.ScaledBy(-1);
VectorFileWriter *out = VectorFileWriter::ForFile(filename);
if(out) {
ExportLinesAndMesh(&edges, &beziers, sm,
u, v, n, origin, SS.CameraTangent()*SS.GW.scale,
out);
}
if(out && !out->HasCanvasSize()) {
// These file formats don't have a canvas size, so they just
// get exported in the raw coordinate system. So indicate what
// that was on-screen.
SS.justExportedInfo.draw = true;
SS.justExportedInfo.pt = origin;
SS.justExportedInfo.u = u;
SS.justExportedInfo.v = v;
InvalidateGraphics();
}
}
edges.Clear();
beziers.Clear();
}
void SolveSpace::ExportWireframeCurves(SEdgeList *sel, SBezierList *sbl,
VectorFileWriter *out)
{
SBezierLoopSetSet sblss;
ZERO(&sblss);
SEdge *se;
for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
SBezier sb = SBezier::From(
(se->a).ScaledBy(1.0 / SS.exportScale),
(se->b).ScaledBy(1.0 / SS.exportScale));
sblss.AddOpenPath(&sb);
}
sbl->ScaleSelfBy(1.0/SS.exportScale);
SBezier *sb;
for(sb = sbl->l.First(); sb; sb = sbl->l.NextAfter(sb)) {
sblss.AddOpenPath(sb);
}
out->Output(&sblss, NULL);
sblss.Clear();
}
void SolveSpace::ExportLinesAndMesh(SEdgeList *sel, SBezierList *sbl, SMesh *sm,
Vector u, Vector v, Vector n,
Vector origin, double cameraTan,
VectorFileWriter *out)
{
double s = 1.0 / SS.exportScale;
// Project into the export plane; so when we're done, z doesn't matter,
// and x and y are what goes in the DXF.
SEdge *e;
for(e = sel->l.First(); e; e = sel->l.NextAfter(e)) {
// project into the specified csys, and apply export scale
(e->a) = e->a.InPerspective(u, v, n, origin, cameraTan).ScaledBy(s);
(e->b) = e->b.InPerspective(u, v, n, origin, cameraTan).ScaledBy(s);
}
SBezier *b;
if(sbl) {
for(b = sbl->l.First(); b; b = sbl->l.NextAfter(b)) {
*b = b->InPerspective(u, v, n, origin, cameraTan);
int i;
for(i = 0; i <= b->deg; i++) {
b->ctrl[i] = (b->ctrl[i]).ScaledBy(s);
}
}
}
// If cutter radius compensation is requested, then perform it now
if(fabs(SS.exportOffset) > LENGTH_EPS) {
// assemble those edges into a polygon, and clear the edge list
SPolygon sp;
ZERO(&sp);
sel->AssemblePolygon(&sp, NULL);
sel->Clear();
SPolygon compd;
ZERO(&compd);
sp.normal = Vector::From(0, 0, -1);
sp.FixContourDirections();
sp.OffsetInto(&compd, SS.exportOffset*s);
sp.Clear();
compd.MakeEdgesInto(sel);
compd.Clear();
}
// Now the triangle mesh; project, then build a BSP to perform
// occlusion testing and generated the shaded surfaces.
SMesh smp;
ZERO(&smp);
if(sm) {
Vector l0 = (SS.lightDir[0]).WithMagnitude(1),
l1 = (SS.lightDir[1]).WithMagnitude(1);
STriangle *tr;
for(tr = sm->l.First(); tr; tr = sm->l.NextAfter(tr)) {
STriangle tt = *tr;
tt.a = (tt.a).InPerspective(u, v, n, origin, cameraTan).ScaledBy(s);
tt.b = (tt.b).InPerspective(u, v, n, origin, cameraTan).ScaledBy(s);
tt.c = (tt.c).InPerspective(u, v, n, origin, cameraTan).ScaledBy(s);
// And calculate lighting for the triangle
Vector n = tt.Normal().WithMagnitude(1);
double lighting = SS.ambientIntensity +
max(0, (SS.lightIntensity[0])*(n.Dot(l0))) +
max(0, (SS.lightIntensity[1])*(n.Dot(l1)));
double r = min(1, REDf (tt.meta.color)*lighting),
g = min(1, GREENf(tt.meta.color)*lighting),
b = min(1, BLUEf (tt.meta.color)*lighting);
tt.meta.color = RGBf(r, g, b);
smp.AddTriangle(&tt);
}
}
// Use the BSP routines to generate the split triangles in paint order.
SBsp3 *bsp = SBsp3::FromMesh(&smp);
SMesh sms;
ZERO(&sms);
bsp->GenerateInPaintOrder(&sms);
// And cull the back-facing triangles
STriangle *tr;
sms.l.ClearTags();
for(tr = sms.l.First(); tr; tr = sms.l.NextAfter(tr)) {
Vector n = tr->Normal();
if(n.z < 0) {
tr->tag = 1;
}
}
sms.l.RemoveTagged();
// And now we perform hidden line removal if requested
SEdgeList hlrd;
ZERO(&hlrd);
if(sm && !SS.GW.showHdnLines) {
SKdNode *root = SKdNode::From(&smp);
// Generate the edges where a curved surface turns from front-facing
// to back-facing.
if(SS.GW.showEdges) {
root->MakeCertainEdgesInto(sel, SKdNode::TURNING_EDGES,
false, NULL, NULL);
}
root->ClearTags();
int cnt = 1234;
SEdge *se;
for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
if(se->auxA == Style::CONSTRAINT) {
// Constraints should not get hidden line removed; they're
// always on top.
hlrd.AddEdge(se->a, se->b, se->auxA);
continue;
}
SEdgeList out;
ZERO(&out);
// Split the original edge against the mesh
out.AddEdge(se->a, se->b, se->auxA);
root->OcclusionTestLine(*se, &out, cnt);
// the occlusion test splits unnecessarily; so fix those
out.MergeCollinearSegments(se->a, se->b);
cnt++;
// And add the results to our output
SEdge *sen;
for(sen = out.l.First(); sen; sen = out.l.NextAfter(sen)) {
hlrd.AddEdge(sen->a, sen->b, sen->auxA);
}
out.Clear();
}
sel = &hlrd;
}
// We kept the line segments and Beziers separate until now; but put them
// all together, and also project everything into the xy plane, since not
// all export targets ignore the z component of the points.
for(e = sel->l.First(); e; e = sel->l.NextAfter(e)) {
SBezier sb = SBezier::From(e->a, e->b);
sb.auxA = e->auxA;
sbl->l.Add(&sb);
}
for(b = sbl->l.First(); b; b = sbl->l.NextAfter(b)) {
for(int i = 0; i <= b->deg; i++) {
b->ctrl[i].z = 0;
}
}
// If possible, then we will assemble these output curves into loops. They
// will then get exported as closed paths.
SBezierLoopSetSet sblss;
ZERO(&sblss);
SBezierList leftovers;
ZERO(&leftovers);
SSurface srf = SSurface::FromPlane(Vector::From(0, 0, 0),
Vector::From(1, 0, 0),
Vector::From(0, 1, 0));
SPolygon spxyz;
ZERO(&spxyz);
bool allClosed;
SEdge notClosedAt;
sbl->l.ClearTags();
sblss.FindOuterFacesFrom(sbl, &spxyz, &srf,
SS.ChordTolMm()*s,
&allClosed, &notClosedAt,
NULL, NULL,
&leftovers);
for(b = leftovers.l.First(); b; b = leftovers.l.NextAfter(b)) {
sblss.AddOpenPath(b);
}
// Now write the lines and triangles to the output file
out->Output(&sblss, &sms);
leftovers.Clear();
spxyz.Clear();
sblss.Clear();
smp.Clear();
sms.Clear();
hlrd.Clear();
}
double VectorFileWriter::MmToPts(double mm) {
// 72 points in an inch
return (mm/25.4)*72;
}
VectorFileWriter *VectorFileWriter::ForFile(char *filename) {
VectorFileWriter *ret;
if(StringEndsIn(filename, ".dxf")) {
static DxfFileWriter DxfWriter;
ret = &DxfWriter;
} else if(StringEndsIn(filename, ".ps") || StringEndsIn(filename, ".eps")) {
static EpsFileWriter EpsWriter;
ret = &EpsWriter;
} else if(StringEndsIn(filename, ".pdf")) {
static PdfFileWriter PdfWriter;
ret = &PdfWriter;
} else if(StringEndsIn(filename, ".svg")) {
static SvgFileWriter SvgWriter;
ret = &SvgWriter;
} else if(StringEndsIn(filename, ".plt")||StringEndsIn(filename, ".hpgl")) {
static HpglFileWriter HpglWriter;
ret = &HpglWriter;
} else if(StringEndsIn(filename, ".step")||StringEndsIn(filename, ".stp")) {
static Step2dFileWriter Step2dWriter;
ret = &Step2dWriter;
} else if(StringEndsIn(filename, ".txt")) {
static GCodeFileWriter GCodeWriter;
ret = &GCodeWriter;
} else {
Error("Can't identify output file type from file extension of "
"filename '%s'; try "
".step, .stp, .dxf, .svg, .plt, .hpgl, .pdf, .txt, "
".eps, or .ps.",
filename);
return NULL;
}
FILE *f = fopen(filename, "wb");
if(!f) {
Error("Couldn't write to '%s'", filename);
return NULL;
}
ret->f = f;
return ret;
}
static void AddUnregMessageCallback(void *fndata, Vector a, Vector b)
{
SBezierLoopSetSet *sblss = (SBezierLoopSetSet *)fndata;
SBezier sb = SBezier::From(a, b);
sb.auxA = Style::SELECTED;
sblss->AddOpenPath(&sb);
}
void VectorFileWriter::Output(SBezierLoopSetSet *sblss, SMesh *sm) {
STriangle *tr;
SBezier *b;
// First calculate the bounding box.
ptMin = Vector::From(VERY_POSITIVE, VERY_POSITIVE, VERY_POSITIVE);
ptMax = Vector::From(VERY_NEGATIVE, VERY_NEGATIVE, VERY_NEGATIVE);
if(sm) {
for(tr = sm->l.First(); tr; tr = sm->l.NextAfter(tr)) {
(tr->a).MakeMaxMin(&ptMax, &ptMin);
(tr->b).MakeMaxMin(&ptMax, &ptMin);
(tr->c).MakeMaxMin(&ptMax, &ptMin);
}
}
if(sblss) {
SBezierLoopSet *sbls;
for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {
SBezierLoop *sbl;
for(sbl = sbls->l.First(); sbl; sbl = sbls->l.NextAfter(sbl)) {
for(b = sbl->l.First(); b; b = sbl->l.NextAfter(b)) {
for(int i = 0; i <= b->deg; i++) {
(b->ctrl[i]).MakeMaxMin(&ptMax, &ptMin);
}
}
}
}
}
// And now we compute the canvas size.
double s = 1.0 / SS.exportScale;
if(SS.exportCanvasSizeAuto) {
// It's based on the calculated bounding box; we grow it along each
// boundary by the specified amount.
ptMin.x -= s*SS.exportMargin.left;
ptMax.x += s*SS.exportMargin.right;
ptMin.y -= s*SS.exportMargin.bottom;
ptMax.y += s*SS.exportMargin.top;
} else {
ptMin.x = -(s*SS.exportCanvas.dx);
ptMin.y = -(s*SS.exportCanvas.dy);
ptMax.x = ptMin.x + (s*SS.exportCanvas.width);
ptMax.y = ptMin.y + (s*SS.exportCanvas.height);
}
// If the demo period has expired and there's no license, then print
// a message in any exported file.
if((!SS.license.licensed) && (SS.license.trialDaysRemaining <= 0) && sblss){
char *str =
"eval / nonprofit use only -- buy at http://solvespace.com/";
double aspect = (glxStrWidth(str, 1) / glxStrHeight(1));
double w = ptMax.x - ptMin.x, h = ptMax.y - ptMin.y;
Vector u, v, t;
double th;
if(w > h) {
th = w / aspect;
u = Vector::From(1, 0, 0);
v = Vector::From(0, 1, 0);
t = Vector::From(ptMin.x + (w/2), ptMin.y - 1.5*th, 0);
} else {
th = h / aspect;
u = Vector::From( 0, 1, 0);
v = Vector::From(-1, 0, 0);
t = Vector::From(ptMax.x + 1.5*th, ptMin.y + (h/2) , 0);
}
glxWriteTextRefCenter(
str,
0.9 * th * SS.GW.scale,
t, u, v,
AddUnregMessageCallback, sblss);
if(w > h) {
ptMin.y -= th*3;
} else {
ptMax.x += th*3;
}
}
StartFile();
if(sm && SS.exportShadedTriangles) {
for(tr = sm->l.First(); tr; tr = sm->l.NextAfter(tr)) {
Triangle(tr);
}
}
if(sblss) {
SBezierLoopSet *sbls;
for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {
SBezierLoop *sbl;
sbl = sbls->l.First();
if(!sbl) continue;
b = sbl->l.First();
if(!b || !Style::Exportable(b->auxA)) continue;
hStyle hs = { b->auxA };
Style *stl = Style::Get(hs);
double lineWidth = Style::WidthMm(b->auxA)*s;
DWORD strokeRgb = Style::Color(b->auxA, true);
StartPath(strokeRgb, lineWidth, stl->filled, stl->fillColor);
for(sbl = sbls->l.First(); sbl; sbl = sbls->l.NextAfter(sbl)) {
for(b = sbl->l.First(); b; b = sbl->l.NextAfter(b)) {
Bezier(b);
}
}
FinishPath(strokeRgb, lineWidth, stl->filled, stl->fillColor);
}
}
FinishAndCloseFile();
}
void VectorFileWriter::BezierAsPwl(SBezier *sb) {
List<Vector> lv;
ZERO(&lv);
sb->MakePwlInto(&lv, SS.ChordTolMm() / SS.exportScale);
int i;
for(i = 1; i < lv.n; i++) {
SBezier sb = SBezier::From(lv.elem[i-1], lv.elem[i]);
Bezier(&sb);
}
lv.Clear();
}
void VectorFileWriter::BezierAsNonrationalCubic(SBezier *sb, int depth) {
Vector t0 = sb->TangentAt(0), t1 = sb->TangentAt(1);
// The curve is correct, and the first derivatives are correct, at the
// endpoints.
SBezier bnr = SBezier::From(
sb->Start(),
sb->Start().Plus(t0.ScaledBy(1.0/3)),
sb->Finish().Minus(t1.ScaledBy(1.0/3)),
sb->Finish());
double tol = SS.ChordTolMm() / SS.exportScale;
// Arbitrary choice, but make it a little finer than pwl tolerance since
// it should be easier to achieve that with the smooth curves.
tol /= 2;
bool closeEnough = true;
int i;
for(i = 1; i <= 3; i++) {
double t = i/4.0;
Vector p0 = sb->PointAt(t),
pn = bnr.PointAt(t);
double d = (p0.Minus(pn)).Magnitude();
if(d > tol) {
closeEnough = false;
}
}
if(closeEnough || depth > 3) {
Bezier(&bnr);
} else {
SBezier bef, aft;
sb->SplitAt(0.5, &bef, &aft);
BezierAsNonrationalCubic(&bef, depth+1);
BezierAsNonrationalCubic(&aft, depth+1);
}
}
//-----------------------------------------------------------------------------
// Export a triangle mesh, in the requested format.
//-----------------------------------------------------------------------------
void SolveSpace::ExportMeshTo(char *filename) {
SMesh *m = &(SK.GetGroup(SS.GW.activeGroup)->displayMesh);
if(m->IsEmpty()) {
Error("Active group mesh is empty; nothing to export.");
return;
}
FILE *f = fopen(filename, "wb");
if(!f) {
Error("Couldn't write to '%s'", filename);
return;
}
if(StringEndsIn(filename, ".stl")) {
ExportMeshAsStlTo(f, m);
} else if(StringEndsIn(filename, ".obj")) {
ExportMeshAsObjTo(f, m);
} else {
Error("Can't identify output file type from file extension of "
"filename '%s'; try .stl, .obj.", filename);
}
fclose(f);
}
//-----------------------------------------------------------------------------
// Export the mesh as an STL file; it should always be vertex-to-vertex and
// not self-intersecting, so not much to do.
//-----------------------------------------------------------------------------
void SolveSpace::ExportMeshAsStlTo(FILE *f, SMesh *sm) {
char str[80];
memset(str, 0, sizeof(str));
strcpy(str, "STL exported mesh");
fwrite(str, 1, 80, f);
DWORD n = sm->l.n;
fwrite(&n, 4, 1, f);
double s = SS.exportScale;
int i;
for(i = 0; i < sm->l.n; i++) {
STriangle *tr = &(sm->l.elem[i]);
Vector n = tr->Normal().WithMagnitude(1);
float w;
w = (float)n.x; fwrite(&w, 4, 1, f);
w = (float)n.y; fwrite(&w, 4, 1, f);
w = (float)n.z; fwrite(&w, 4, 1, f);
w = (float)((tr->a.x)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->a.y)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->a.z)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->b.x)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->b.y)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->b.z)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->c.x)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->c.y)/s); fwrite(&w, 4, 1, f);
w = (float)((tr->c.z)/s); fwrite(&w, 4, 1, f);
fputc(0, f);
fputc(0, f);
}
}
//-----------------------------------------------------------------------------
// Export the mesh as Wavefront OBJ format. This requires us to reduce all the
// identical vertices to the same identifier, so do that first.
//-----------------------------------------------------------------------------
void SolveSpace::ExportMeshAsObjTo(FILE *f, SMesh *sm) {
SPointList spl;
ZERO(&spl);
STriangle *tr;
for(tr = sm->l.First(); tr; tr = sm->l.NextAfter(tr)) {
spl.IncrementTagFor(tr->a);
spl.IncrementTagFor(tr->b);
spl.IncrementTagFor(tr->c);
}
// Output all the vertices.
SPoint *sp;
for(sp = spl.l.First(); sp; sp = spl.l.NextAfter(sp)) {
fprintf(f, "v %.10f %.10f %.10f\r\n",
sp->p.x / SS.exportScale,
sp->p.y / SS.exportScale,
sp->p.z / SS.exportScale);
}
// And now all the triangular faces, in terms of those vertices. The
// file format counts from 1, not 0.
for(tr = sm->l.First(); tr; tr = sm->l.NextAfter(tr)) {
fprintf(f, "f %d %d %d\r\n",
spl.IndexForPoint(tr->a) + 1,
spl.IndexForPoint(tr->b) + 1,
spl.IndexForPoint(tr->c) + 1);
}
spl.Clear();
}
//-----------------------------------------------------------------------------
// Export a view of the model as an image; we just take a screenshot, by
// rendering the view in the usual way and then copying the pixels.
//-----------------------------------------------------------------------------
void SolveSpace::ExportAsPngTo(char *filename) {
int w = (int)SS.GW.width, h = (int)SS.GW.height;
// No guarantee that the back buffer contains anything valid right now,
// so repaint the scene. And hide the toolbar too.
int prevShowToolbar = SS.showToolbar;
SS.showToolbar = false;
SS.GW.Paint(w, h);
SS.showToolbar = prevShowToolbar;
FILE *f = fopen(filename, "wb");
if(!f) goto err;
png_struct *png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if(!png_ptr) goto err;
png_info *info_ptr = png_create_info_struct(png_ptr);
if(!png_ptr) goto err;
if(setjmp(png_jmpbuf(png_ptr))) goto err;
png_init_io(png_ptr, f);
// glReadPixels wants to align things on 4-boundaries, and there's 3
// bytes per pixel. As long as the row width is divisible by 4, all
// works out.
w &= ~3; h &= ~3;
png_set_IHDR(png_ptr, info_ptr, w, h,
8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
png_write_info(png_ptr, info_ptr);
// Get the pixel data from the framebuffer
BYTE *pixels = (BYTE *)AllocTemporary(3*w*h);
BYTE **rowptrs = (BYTE **)AllocTemporary(h*sizeof(BYTE *));
glReadPixels(0, 0, w, h, GL_RGB, GL_UNSIGNED_BYTE, pixels);
int y;
for(y = 0; y < h; y++) {
// gl puts the origin at lower left, but png puts it top left
rowptrs[y] = pixels + ((h - 1) - y)*(3*w);
}
png_write_image(png_ptr, rowptrs);
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(f);
return;
err:
Error("Error writing PNG file '%s'", filename);
if(f) fclose(f);
return;
}