From cc9e03ddb83f26a1424660c6f92fe06b2ff12f3a Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sat, 9 Nov 2019 13:14:42 +0100
Subject: [PATCH] product:: product projections

---
 hypgraph.cpp     | 15 ++++++++++++++-
 models.cpp       | 23 ++++++++++++++++++++++-
 nonisotropic.cpp |  2 +-
 shaders.cpp      |  8 ++++----
 4 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/hypgraph.cpp b/hypgraph.cpp
index 68bcc8ce..7d4f67a7 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -315,6 +315,15 @@ EX void applymodel(hyperpoint H, hyperpoint& ret) {
 
   hyperpoint H_orig = H;
   
+  if(models::product_model()) {
+    ld zlev = zlevel(H);
+    H /= exp(zlev);
+    hybrid::in_underlying_geometry([&] { applymodel(H, ret); });
+    ret[2] = zlev * models::product_z_scale;
+    ret = nisot::local_perspective * ret;
+    return;    
+    }
+  
   switch(pmodel) {
     case mdPerspective: {
       ld ratio = vid.xres / current_display->tanfov / current_display->radius / 2;
@@ -509,6 +518,10 @@ EX void applymodel(hyperpoint H, hyperpoint& ret) {
         ret = lp_apply(H);
         break;
         }    
+      if(prod) {
+        ret = H;
+        break;
+        }
       if(pmodel == mdHyperboloid) {
         ld& topz = models::top_z;
         if(H[2] > topz) {
@@ -754,7 +767,7 @@ EX void applymodel(hyperpoint H, hyperpoint& ret) {
       break;
     
     case mdEquidistant: case mdEquiarea: case mdEquivolume: {
-      if(nonisotropic) {
+      if(nonisotropic || prod) {
         ret = lp_apply(inverse_exp(H, iTable, false));
         ret[3] = 1;
         break;
diff --git a/models.cpp b/models.cpp
index a70dca32..390966c0 100644
--- a/models.cpp
+++ b/models.cpp
@@ -159,6 +159,8 @@ EX namespace models {
   EX ld spiral_cone = 360;
   EX ld spiral_cone_rad;
   EX bool ring_not_spiral;
+  
+  EX ld product_z_scale = 1;
 
   EX void configure() {
     ld ball = -vid.ballangle * degree;
@@ -198,7 +200,11 @@ EX namespace models {
     }
   
   EX bool model_available(eModel pm) {
-    if(prod) return pm == mdPerspective;
+    if(prod) {
+      if(pm == mdPerspective) return true;
+      if(among(pm, mdBall, mdHemisphere)) return false;
+      return PIU(model_available(pm));
+      }
     if(sl2) return pm == mdGeodesic;
     if(nonisotropic) return among(pm, mdDisk, mdPerspective, mdHorocyclic, mdGeodesic, mdEquidistant, mdFisheye);
     if(pm == mdGeodesic && !sol) return false;
@@ -220,11 +226,18 @@ EX namespace models {
     return among(pmodel, mdJoukowsky, mdJoukowskyInverted, mdBand) && GDIM == 2;
     }
   
+  EX bool product_model() {
+    if(!prod) return false;
+    if(among(pmodel, mdPerspective, mdHyperboloid, mdEquidistant)) return false;
+    return true;
+    }
+  
   int editpos = 0;
   
   EX string get_model_name(eModel m) {
     if(m == mdDisk && GDIM == 3 && (hyperbolic || nonisotropic)) return XLAT("ball model/Gans");
     if(m == mdPerspective && prod) return XLAT("native perspective");
+    if(prod) return PIU(get_model_name(m));
     if(nonisotropic) {
       if(m == mdHorocyclic && !sol) return XLAT("simple model: projection");
       if(m == mdPerspective) return XLAT("simple model: perspective");
@@ -630,6 +643,14 @@ EX namespace models {
 
     dialog::addSelItem(XLAT("vertical stretch"), fts(vid.stretch), 's');
     dialog::add_action(edit_stretch);
+    
+    if(product_model()) {
+      dialog::addSelItem(XLAT("product Z stretch"), fts(product_z_scale), 'Z');
+      dialog::add_action([] {
+        dialog::editNumber(product_z_scale, 0.1, 10, 0.1, 1, XLAT("product Z stretch"), "");        
+        dialog::scaleLog();
+        });
+      }
 
     dialog::addBoolItem(XLAT("use GPU to compute projections"), vid.consider_shader_projection, 'G');
     bool shaderside_projection = get_shader_flags() & SF_DIRECT;
diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index 6ef84cb9..b9b18f31 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -1167,7 +1167,7 @@ EX namespace product {
   EX void drawcell_stack(cellwalker cw, transmatrix V) {
     cell *c = cw.at;
     if(sphere) gmatrix[c] = V; /* some computations need gmatrix0 for underlying geometry */
-    bool s = sphere;
+    bool s = sphere || pmodel != mdPerspective;
     hybrid::in_actual([&] { 
       cell *c0 = hybrid::get_at(c, hybrid::current_view_level);
       cwall_offset = hybrid::wall_offset(c0);
diff --git a/shaders.cpp b/shaders.cpp
index f2e0bc92..d57abbd3 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -117,13 +117,13 @@ shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
   else if(!vid.consider_shader_projection) {
     shader_flags |= SF_PIXELS;
     }
-  else if(pmodel == mdDisk && MDIM == 3 && !spherespecial) {
+  else if(pmodel == mdDisk && MDIM == 3 && !spherespecial && !prod) {
     shader_flags |= SF_DIRECT;
     }
   else if(glhr::noshaders) {
     shader_flags |= SF_PIXELS;
     }
-  else if(pmodel == mdDisk && GDIM == 3 && !spherespecial && !nonisotropic) {
+  else if(pmodel == mdDisk && GDIM == 3 && !spherespecial && !nonisotropic && !prod) {
     coordinator += "t /= (t[3] + uAlpha);\n";
     vsh += "uniform mediump float uAlpha;";
     shader_flags |= SF_DIRECT | SF_BOX;
@@ -197,7 +197,7 @@ shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
         break;
       }      
     }
-  else if(geometry == gProduct && !hybrid::over_sphere()) {
+  else if(geometry == gProduct && !hybrid::over_sphere() && pmodel == mdPerspective) {
     shader_flags |= SF_PERS3 | SF_DIRECT;
     coordinator +=      
       "float z = log(t[2] * t[2] - t[0] * t[0] - t[1] * t[1]) / 2.;\n"
@@ -209,7 +209,7 @@ shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
     distfun = "sqrt(z*z+d*d)";
     treset = true;
     }
-  else if(geometry == gProduct && hybrid::over_sphere()) {
+  else if(geometry == gProduct && hybrid::over_sphere() && pmodel == mdPerspective) {
     shader_flags |= SF_PERS3 | SF_DIRECT;
     distfun = "length(t.xyz)", treset = true;
     }