From 416ee95aacf66e6356b30c12d9abb3f8881aa8fe Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sat, 9 Nov 2019 12:49:00 +0100
Subject: [PATCH] horocyclic coordinates model

---
 classes.cpp  |  1 +
 classes.h    |  4 ++--
 hypgraph.cpp | 19 +++++++++++++++++++
 models.cpp   |  7 +++----
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/classes.cpp b/classes.cpp
index 0e9e11d6..55b38360 100644
--- a/classes.cpp
+++ b/classes.cpp
@@ -633,6 +633,7 @@ vector<modelinfo> mdinf = {
   {X3("Mollweide"), mf::euc_boring | mf::pseudoband | mf::equiarea },
   {X3("central cylindrical"), mf::euc_boring | mf::band },
   {X3("Collignon"), mf::pseudoband | mf::equiarea },
+  {X3("horocyclic coordinates"), mf::euc_boring },
   {X3("guard"), 0},
   {X3("polynomial"), mf::conformal}
   };
diff --git a/classes.h b/classes.h
index 42a5d1fe..1847db03 100644
--- a/classes.h
+++ b/classes.h
@@ -312,8 +312,8 @@ enum eModel {
   // 20..24
   mdEquivolume, mdCentralInversion, mdSimulatedPerspective, mdTwoHybrid, mdGeodesic,
   // 25
-  mdMollweide, mdCentralCyl, mdCollignon,
-  // 26..
+  mdMollweide, mdCentralCyl, mdCollignon, mdHorocyclic,
+  // 29..
   mdGUARD, mdPixel, mdHyperboloidFlat, mdPolynomial, mdManual
   };
 
diff --git a/hypgraph.cpp b/hypgraph.cpp
index 3794b449..68bcc8ce 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -444,6 +444,25 @@ EX void applymodel(hyperpoint H, hyperpoint& ret) {
       break;
       }
     
+    case mdHorocyclic: {
+
+      find_zlev(H);
+      
+      models::apply_orientation_yz(H[1], H[2]);
+      models::apply_orientation(H[0], H[1]);
+      
+      ret = hyperbolic ? deparabolic10(H) : H;
+      ret *= .5;
+      ret[LDIM] = 1;
+  
+      models::apply_orientation(ret[1], ret[0]);
+      models::apply_orientation_yz(ret[2], ret[1]);
+      
+      if(nonisotropic) ret = lp_apply(ret);
+      
+      break;
+      }
+    
     case mdHemisphere: {
   
       switch(cgclass) {
diff --git a/models.cpp b/models.cpp
index 5dc067fe..6b4cae66 100644
--- a/models.cpp
+++ b/models.cpp
@@ -200,7 +200,7 @@ EX namespace models {
   EX bool model_available(eModel pm) {
     if(prod) return pm == mdPerspective;
     if(sl2) return pm == mdGeodesic;
-    if(nonisotropic) return among(pm, mdDisk, mdPerspective, mdHyperboloid, mdGeodesic, mdEquidistant, mdFisheye);
+    if(nonisotropic) return among(pm, mdDisk, mdPerspective, mdHorocyclic, mdGeodesic, mdEquidistant, mdFisheye);
     if(pm == mdGeodesic && !sol) return false;
     if(sphere && (pm == mdHalfplane || pm == mdBall))
       return false;
@@ -213,7 +213,7 @@ EX namespace models {
   
   EX bool model_has_orientation() {
     return
-      among(pmodel, mdHalfplane, mdPolynomial, mdPolygonal, mdTwoPoint, mdJoukowsky, mdJoukowskyInverted, mdSpiral, mdSimulatedPerspective, mdTwoHybrid) || mdBandAny();
+      among(pmodel, mdHalfplane, mdPolynomial, mdPolygonal, mdTwoPoint, mdJoukowsky, mdJoukowskyInverted, mdSpiral, mdSimulatedPerspective, mdTwoHybrid, mdHorocyclic) || mdBandAny();
     }
   
   EX bool model_has_transition() {
@@ -226,10 +226,9 @@ EX namespace models {
     if(m == mdDisk && GDIM == 3 && (hyperbolic || nonisotropic)) return XLAT("ball model/Gans");
     if(m == mdPerspective && prod) return XLAT("native perspective");
     if(nonisotropic) {
-      if(m == mdHyperboloid) return XLAT("simple model: projection");
       if(m == mdPerspective) return XLAT("simple model: perspective");
       if(m == mdGeodesic) return XLAT("native perspective");
-      if(m == mdEquidistant || m == mdFisheye) return XLAT(mdinf[m].name_hyperbolic);
+      if(among(m, mdEquidistant, mdFisheye, mdHorocyclic)) return XLAT(mdinf[m].name_hyperbolic);
       }
     if(m == mdDisk && GDIM == 3) return XLAT("perspective in 4D");
     if(m == mdHalfplane && GDIM == 3 && hyperbolic) return XLAT("half-space");