From 5a73eccd4cd4a1978ef489c9a32007f5fcee45ae Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sun, 27 Mar 2022 09:05:47 +0200
Subject: [PATCH] an option to add more projections via plugins

---
 hypgraph.cpp | 7 +++++++
 models.cpp   | 5 +++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/hypgraph.cpp b/hypgraph.cpp
index ebbd365d..1768a73c 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -497,6 +497,8 @@ EX void threepoint_projection(const hyperpoint& H, hyperpoint& ret) {
   }
 #endif
 
+EX vector<hr::function<void(shiftpoint& H_orig, hyperpoint& H, hyperpoint& ret)>> extra_projections;
+
 EX void apply_other_model(shiftpoint H_orig, hyperpoint& ret, eModel md) {
 
   hyperpoint H = H_orig.h;
@@ -1345,6 +1347,11 @@ EX void apply_other_model(shiftpoint H_orig, hyperpoint& ret, eModel md) {
       }
     
     case mdGUARD: case mdManual: break;
+
+    default:
+      if(md < isize(extra_projections) && extra_projections[md])
+        extra_projections[md](H_orig, H, ret);
+      break;
     }
 
   ghcheck(ret,H_orig);
diff --git a/models.cpp b/models.cpp
index f63af00e..56d88b7d 100644
--- a/models.cpp
+++ b/models.cpp
@@ -186,6 +186,7 @@ EX namespace models {
     }
   
   EX bool model_available(eModel pm) {
+    if(mdinf[pm].flags & mf::technical) return false;
     if(prod) {
       if(pm == mdPerspective) return true;
       if(among(pm, mdBall, mdHemisphere)) return false;
@@ -360,7 +361,7 @@ EX namespace models {
     USING_NATIVE_GEOMETRY_IN_RUG;
     #endif
 
-    for(int i=0; i<mdGUARD; i++) {
+    for(int i=0; i<isize(mdinf); i++) {
       eModel m = eModel(i);
       if(m == mdFormula && ISMOBILE) continue;
       if(model_available(m)) {
@@ -773,7 +774,7 @@ EX namespace models {
 
   #if CAP_COMMANDLINE
   
-  eModel read_model(const string& ss) {
+  EX eModel read_model(const string& ss) {
     for(int i=0; i<isize(mdinf); i++) {
       if(appears(mdinf[i].name_hyperbolic, ss)) return eModel(i);
       if(appears(mdinf[i].name_euclidean, ss)) return eModel(i);