improved hyperboloid model

basegraph.cpp

@@ -255,7 +255,7 @@ void stereo::set_viewport(int ed) {
   }    
 
 bool model_needs_depth() {
-  return pmodel == mdBall || pmodel == mdHyperboloid || pmodel == mdHemisphere;
+  return pmodel == mdBall || pmodel == mdHemisphere;
   }
 
 void setGLProjection(color_t col) {

conformal.cpp

@@ -297,6 +297,7 @@ namespace conformal {
   ld model_orientation, halfplane_scale;
   ld ocos, osin;
   bool model_straight;
+  ld top_z = 5;
 
   bool autoband = false;
   bool autobandhistory = false;
@@ -658,6 +659,9 @@ namespace conformal {
       dialog::addSelItem(XLAT("camera rotation in 3D models"), fts3(vid.ballangle), 'b');
       }    
     
+    if(pmodel == mdHyperboloid)
+      dialog::addSelItem(XLAT("topz"), fts3(top_z), 'l');
+    
     if(pmodel == mdHemisphere && euclid) {
       dialog::addSelItem(XLAT("parameter"), fts3(vid.euclid_to_sphere), 'l');
       }
@@ -710,6 +714,8 @@ namespace conformal {
 #endif
       else if(uni == 'l' && model_has_orientation())
         dialog::editNumber(model_orientation, 0, 360, 90, 0, XLAT("model orientation"), "");
+      else if(uni == 'l' && pmodel == mdHyperboloid) 
+        dialog::editNumber(top_z, 1, 20, 0.25, 4, XLAT("topz"), "");
       else if(uni == 'b' && pmodel == mdHalfplane)
         dialog::editNumber(model_orientation, 0, 2, 0.25, 1, XLAT("halfplane scale"), "");
       else if(uni == 's') {

graph.cpp

@@ -5562,15 +5562,43 @@ void drawfullmap() {
     if(pmodel == mdBall) ballgeometry();
     }
   
-  if(pmodel == mdHyperboloid) {
+  if(pmodel == mdHyperboloid && hyperbolic) {
 #if CAP_QUEUE
-    color_t col = darkena(0x80, 0, 0x80);
+    curvepoint(hpxyz(0,0,1));
-    queueline(hpxyz(0,0,1), hpxyz(0,0,-vid.alpha), col, 0, PPR::CIRCLE);
+    curvepoint(hpxyz(0,0,-vid.alpha));
-    queueline(xpush0(+4), hpxyz(0,0,0), col, 0, PPR::CIRCLE);
+    queuecurve(ringcolor, 0, PPR::CIRCLE);
-    queueline(xpush0(+4), hpxyz(0,0,-vid.alpha), col, 0, PPR::CIRCLE);
+    
-    queueline(xpush0(-4), hpxyz(0,0,0), col, 0, PPR::CIRCLE);
+    ld& tz = conformal::top_z;
-    queueline(xpush0(-4), hpxyz(0,0,-vid.alpha), col, 0, PPR::CIRCLE);
+    ld z = acosh(tz);
-    queueline(hpxyz(-1,0,0), hpxyz(1,0,0), col, 0, PPR::CIRCLE);
+
+    hyperpoint a = xpush0(z);
+    ld ball = -vid.ballangle * M_PI / 180;
+    ld cb = cos(ball), sb = sin(ball);
+    
+    a[1] = sb * a[2] / -cb;
+    a[0] = sqrt(-1 + a[2] * a[2] - a[1] * a[1]);
+
+    curvepoint(hpxyz(0,0,-vid.alpha));
+    curvepoint(a);
+    curvepoint(hpxyz(0,0,0));
+    a[0] = -a[0];
+    curvepoint(a);
+    curvepoint(hpxyz(0,0,-vid.alpha));
+    queuecurve(ringcolor, 0, PPR::CIRCLE);
+
+    curvepoint(hpxyz(-1,0,0));
+    curvepoint(hpxyz(1,0,0));
+    queuecurve(ringcolor, 0, PPR::CIRCLE);
+
+    a[1] = sb * tz / -cb;
+    a[0] = sqrt(tz * tz - a[1] * a[1]);
+    a[2] = tz - vid.alpha;
+
+    curvepoint(a);
+    curvepoint(hpxyz(0,0,-vid.alpha));
+    a[0] = -a[0];
+    curvepoint(a);
+    queuecurve(ringcolor, 0, PPR::CIRCLE);
 #endif
     }
   

hyper.h

@@ -1265,7 +1265,7 @@ enum eModel {
   mdEquidistant, mdEquiarea, mdBall, mdHyperboloid, 
   mdHemisphere, mdBandEquidistant, mdBandEquiarea, mdSinusoidal, mdTwoPoint, 
   mdFisheye,
-  mdGUARD, mdUnchanged };
+  mdGUARD, mdUnchanged, mdHyperboloidFlat };
 
 namespace conformal {
   extern bool on;
@@ -1280,6 +1280,7 @@ namespace conformal {
   extern ld halfplane_scale;
   extern ld ocos, osin;
   extern bool model_straight;
+  extern ld top_z;
   
   // screen coordinates to logical coordinates: apply_orientation(x,y)
   // logical coordinates back to screen coordinates: apply_orientation(y,x)

hypgraph.cpp

@@ -192,7 +192,31 @@ void applymodel(hyperpoint H, hyperpoint& ret) {
     return;
     }
 
+  if(pmodel == mdHyperboloidFlat) {
+    H[2] += vid.alpha;
+    H[0] /= H[2];
+    H[1] /= H[2];
+    H[2] = 1 - vid.alpha;
+
+    ld ball = -vid.ballangle * M_PI / 180;
+    ld cb = cos(ball), sb = sin(ball);
+
+    ret[0] = H[0] / 3;
+    ret[1] = (1 - H[2]) / 3 * cb - H[1] / 3 * sb;
+    ret[2] = -(-H[1] / 3 * cb - (1 - H[2]) / 3 * sb);
+
+    ghcheck(ret,H);
+    return;
+    }
+
   if(pmodel == mdHyperboloid) {
+    ld& tz = conformal::top_z;
+    if(H[2] > tz) {
+      ld scale = sqrt(tz*tz-1) / hypot(H[0], H[1]);
+      H[0] *= scale;
+      H[1] *= scale;
+      H[2] = tz;
+      }
 
     ld ball = -vid.ballangle * M_PI / 180;
     ld cb = cos(ball), sb = sin(ball);

polygons.cpp

@@ -183,11 +183,28 @@ bool knowgood;
 hyperpoint goodpoint;
 vector<pair<int, hyperpoint>> tofix;
 
+bool two_sided_model() {
+  if(pmodel == mdHyperboloid) return !euclid;
+  // if(pmodel == mdHemisphere) return true;
+  if(pmodel == mdDisk) return sphere;
+  return false;
+  }
+
 bool correct_side(const hyperpoint& H) {
+  if(pmodel == mdDisk && sphere) {
     double curnorm = H[0]*H[0]+H[1]*H[1]+H[2]*H[2];
     double horizon = curnorm / vid.alpha;
     return (spherespecial>0) ^ (H[2] <= -horizon);
     }
+  if(pmodel == mdHyperboloid && hyperbolic) {
+    ld ball = -vid.ballangle * M_PI / 180;
+    ld cb = cos(ball), sb = sin(ball);
+    return (spherespecial > 0) ^ (
+      sb * H[2] > -cb * H[1]
+      );
+    }
+  return true;
+  }
 
 void fixpoint(array<float, 3>& hscr, hyperpoint H) {
   hyperpoint bad = H, good = goodpoint;
@@ -215,7 +232,7 @@ void addpoint(const hyperpoint& H) {
         poly_flags |= POLY_INFRONT, last_infront = false;
         if(!knowgood || (spherespecial > 0 ? H[2]>goodpoint[2] : H[2]<goodpoint[2])) goodpoint = H, knowgood = true;
         } 
-      else if(poly_flags & POLY_ISSIDE) {
+      else if(sphere && (poly_flags & POLY_ISSIDE)) {
         double curnorm = H[0]*H[0]+H[1]*H[1]+H[2]*H[2];
         double horizon = curnorm / vid.alpha;
         poly_flags |= POLY_NOTINFRONT;
@@ -810,12 +827,12 @@ void dqi_poly::draw() {
     return;
     }
   
-  if(spherespecial && prio == PPR::MOBILE_ARROW) {
+  /* if(spherespecial && prio == PPR::MOBILE_ARROW) {
     if(spherephase == 0) return;
     dynamicval<int> ss(spherespecial, 0);
     draw();
     return;
-    }
+    } */
 
 #if CAP_GL
   if(vid.usingGL && using_perspective) {
@@ -867,7 +884,7 @@ void dqi_poly::draw() {
 
   if(poly_flags & POLY_NIF_ERROR) return;
   
-  if(spherespecial == 1 && (poly_flags & POLY_INFRONT) && (poly_flags & POLY_NOTINFRONT) && vid.alpha <= 1) {
+  if(spherespecial == 1 && sphere && (poly_flags & POLY_INFRONT) && (poly_flags & POLY_NOTINFRONT) && vid.alpha <= 1) {
     bool around_center = false;
     for(int i=0; i<isize(glcoords)-1; i++) {
       double x1 = glcoords[i][0];
@@ -882,7 +899,7 @@ void dqi_poly::draw() {
     if(around_center) return;
     }
     
-  if((spherespecial > 0 || (sphere && equi)) && !(poly_flags & POLY_ISSIDE)) {
+  if(sphere && (spherespecial > 0 || equi) && !(poly_flags & POLY_ISSIDE)) {
   
     if(!tinf) {
     
@@ -1314,7 +1331,14 @@ void drawqueue() {
   stereo::set_projection(0);
   
   // on the sphere, parts on the back are drawn first
-  if(sphere && pmodel == 0) {
+  if(two_sided_model()) {
+  
+    if(pmodel == mdHyperboloid) {
+      dynamicval dv(pmodel, mdHyperboloidFlat);
+      for(auto& ptd: ptds) 
+        if(!among(ptd->prio, PPR::MOBILE_ARROW, PPR::OUTCIRCLE, PPR::CIRCLE))
+          ptd->draw();
+      }
 
     // in SVG, draw boundary circle first
     if(svg::in) for(auto& ptd: ptds) ptd->draw_pre();
@@ -1324,7 +1348,9 @@ void drawqueue() {
 
     reverse_side_priorities();
     for(int i=ptds.size()-1; i>=0; i--) 
+      if(!among(ptds[i]->prio, PPR::MOBILE_ARROW, PPR::OUTCIRCLE, PPR::CIRCLE))
         ptds[i]->draw_back();
+    
     glflush();
     reverse_side_priorities();
     spherespecial *= -1;
@@ -1332,7 +1358,10 @@ void drawqueue() {
     stereo::set_projection(0);
     }
   
-  for(auto& ptd: ptds) ptd->draw();
+  for(auto& ptd: ptds) {
+    dynamicval<int> ss(spherespecial, among(ptd->prio, PPR::MOBILE_ARROW, PPR::OUTCIRCLE, PPR::CIRCLE) ? 0 : spherespecial);
+    ptd->draw();
+    }
   glflush();
 
 #if CAP_GL