variant fisheye projection

classes.cpp

@@ -1031,7 +1031,7 @@ enum eModel : int {
   // 39..48
   mdPoorMan, mdPanini, mdRetroCraig, mdRetroLittrow, mdRetroHammer, mdThreePoint, mdLiePerspective, mdLieOrthogonal, mdRelPerspective, mdRelOrthogonal,
   // 49..50
-  mdHorocyclicEqa, mdConformalSquare,
+  mdHorocyclicEqa, mdConformalSquare, mdFisheye2,
   // 51..
   mdGUARD, mdPixel, mdHyperboloidFlat, mdPolynomial, mdManual
   };
@@ -1095,6 +1095,7 @@ EX vector<modelinfo> mdinf = {
   {X3("relativistic orthogonal"), mf::euc_boring},
   {X3("horocyclic equal-area"), mf::euc_boring | mf::equiarea | mf::orientation | mf::horocyclic},
   {X3("conformal square"), mf::orientation | mf::broken | mf::transition},
+  {X3("variant fisheye"), 0},
   {X3("guard"), mf::technical},
   {X3("pixel"), mf::technical},
   {X3("hypflat"), mf::technical},

graph.cpp

@@ -3273,7 +3273,7 @@ EX int haveaura() {
   if(sphere && mdAzimuthalEqui()) return 0;
   if(among(pmodel, mdJoukowsky, mdJoukowskyInverted) && hyperbolic && pconf.model_transition < 1) 
     return 2;
-  if(pmodel == mdFisheye) return 1;
+  if(among(pmodel, mdFisheye, mdFisheye2)) return 1;
   return pmodel == mdDisk && (!sphere || pconf.alpha > 10) && !euclid;
   }
   

help.cpp

@@ -240,7 +240,8 @@ EX void buildCredits() {
     "Kojiguchi Kazuki, baconcow, Alan, SurelyYouJest, hotdogPi, DivisionByZero, xXxWeedGokuxXx, jpystynen, Dmitry Marakasov, Alexandre Moine, Arthur O'Dwyer, "
     "Triple_Agent_AAA, bluetailedgnat, Allalinor, Shitford, KittyTac, Christopher King, KosGD, TravelDemon, Bubbles, rdococ, frozenlake, MagmaMcFry, "
     "Snakebird Priestess, roaringdragon2, Stopping Dog, bengineer8, Sir Light IJIJ, ShadeBlade, Saplou, shnourok, Ralith, madasa, 6% remaining, Chimera245, Remik Pi, alien foxcat thing, "
-    "Piotr Grochowski, Ann, still-flow, tyzone, Paradoxica, LottieRatWorld, aismallard, albatross, EncodedSpirit, Jacob Mandelson, CrashTuvai, cvoight, jennlbw, Kali Ranya, spiritbackup, Dylan, L_Lord, AntiRogue"
+    "Piotr Grochowski, Ann, still-flow, tyzone, Paradoxica, LottieRatWorld, aismallard, albatross, EncodedSpirit, Jacob Mandelson, CrashTuvai, cvoight, jennlbw, Kali Ranya, spiritbackup, Dylan, L_Lord, AntiRogue, "
+    "masonlgreen"
     );
 #ifdef EXTRALICENSE
   help += EXTRALICENSE;

hypgraph.cpp

@@ -1055,6 +1055,27 @@ EX void apply_other_model(shiftpoint H_orig, hyperpoint& ret, eModel md) {
       break;
       }
     
+    case mdFisheye2: {
+      ld zlev;
+      if(nonisotropic) {
+        H = lp_apply(inverse_exp(H_orig));
+        zlev = 1;
+        }
+      else {
+        zlev = find_zlev(H);
+        H = space_to_perspective(H);
+        }
+      H /= pconf.fisheye_param;
+      auto H1 = perspective_to_space(H, pconf.fisheye_alpha, gcSphere);
+      auto H2 = perspective_to_space(hyperpoint(1e6, 0, 0, 0), pconf.fisheye_alpha, gcSphere);
+      H1[2] += 1;
+      H1 /= H1[2];
+      H1 /= H2[0] / (H2[2]+1);
+      ret = H1;
+      if(GDIM == 3) ret[LDIM] = zlev;
+      break;
+      }
+
     case mdSimulatedPerspective: {
       models::scr_to_ori(H);
       auto yz = move_z_to_y(H);
@@ -2475,7 +2496,7 @@ EX transmatrix atscreenpos(ld x, ld y, ld size) {
 
 void circle_around_center(ld radius, color_t linecol, color_t fillcol, PPR prio) {
   #if CAP_QUEUE
-  if(among(pmodel, mdDisk, mdEquiarea, mdEquidistant, mdFisheye) && !(pmodel == mdDisk && hyperbolic && pconf.alpha <= -1) && models::camera_straight) {
+  if(among(pmodel, mdDisk, mdEquiarea, mdEquidistant, mdFisheye, mdFisheye2) && !(pmodel == mdDisk && hyperbolic && pconf.alpha <= -1) && models::camera_straight) {
     hyperpoint ret;
     applymodel(shiftless(xpush0(radius)), ret);
     ld r = hypot_d(2, ret);
@@ -2733,7 +2754,7 @@ EX void draw_boundary(int w) {
     }
 
   if(w == 1) return;
-  if(nonisotropic || (euclid && !among(pmodel, mdFisheye, mdConformalSquare, mdHemisphere)) || gproduct) return;
+  if(nonisotropic || (euclid && !among(pmodel, mdFisheye, mdFisheye2, mdConformalSquare, mdHemisphere)) || gproduct) return;
   #if CAP_VR
   if(vrhr::active() && pmodel == mdHyperboloid) return;
   #endif

models.cpp

@@ -619,6 +619,11 @@ EX namespace models {
     if(vpmodel == mdFisheye) 
       add_edit(vpconf.fisheye_param);
 
+    if(vpmodel == mdFisheye2) {
+      add_edit(vpconf.fisheye_param);
+      add_edit(vpconf.fisheye_alpha);
+      }
+
     if(is_hyperboloid(vpmodel))
       add_edit(pconf.show_hyperboloid_flat);
     
@@ -974,6 +979,13 @@ EX namespace models {
       -> editable(1e-3, 10, .1, "fisheye parameter", "Size of the fish eye.", 'b')
       -> set_sets(dialog::scaleLog);
 
+      param_f(p.fisheye_alpha, pp+"fishalpha", sp+"off-center parameter", 0)
+      -> editable(1e-1, 10, .1, "off-center parameter",
+        "This projection is obtained by composing gnomonic projection and inverse stereographic projection. "
+        "This parameter changes the center of the first projection (0 = gnomonic, 1 = stereographic). Use a value closer to 1 "
+        "to make the projection more conformal.",
+        'o');
+
       param_f(p.stretch, pp+"stretch", 1)
       -> editable(0, 10, .1, "vertical stretch", "Vertical stretch factor.", 's')
       -> set_extra(stretch_extra);