Panini projection

config.cpp

@@ -713,6 +713,8 @@ EX void initConfig() {
   addsaver(camera_speed, "camera-speed", 1);
   addsaver(camera_rot_speed, "camera-rot-speed", 1);
 
+  addsaver(panini_alpha, "panini_alpha", 0);
+
   callhooks(hooks_configfile);
 
 #if CAP_CONFIG
@@ -1551,17 +1553,48 @@ EX void explain_detail() {
     ));
   }
 
-EX void add_edit_fov(char key IS('f')) {
+EX ld max_fov_angle() {
-  dialog::addSelItem(XLAT("field of view"), fts(vid.fov) + "°", key);
+  return acos(-panini_alpha) * 2 / degree;
-  dialog::add_action([] {
+  }
-    dialog::editNumber(vid.fov, 1, 170, 1, 45, "field of view", 
+
+EX void add_edit_fov(char key IS('f'), bool pop IS(false)) {
+
+  string sfov = fts(vid.fov) + "°";
+  if(panini_alpha) {
+    sfov += " / " + fts(max_fov_angle()) + "°";
+    }
+  dialog::addSelItem(XLAT("field of view"), sfov, key);
+  dialog::add_action([=] {
+    if(pop) popScreen();
+    dialog::editNumber(vid.fov, 1, max_fov_angle(), 1, 45, "field of view", 
       XLAT(
         "Horizontal field of view, in angles. "
         "This affects the Hypersian Rug mode (even when stereo is OFF) "
-        "and non-disk models.")
+        "and non-disk models.") + "\n\n" +
+      XLAT(
+        "Must be less than %1°. Panini projection can be used to get higher values.",
+        fts(max_fov_angle())
+        )
         );
     dialog::bound_low(1e-8);
-    dialog::bound_up(179);
+    dialog::bound_up(max_fov_angle() - 0.01);
+    dialog::extra_options = [] {
+      dialog::addSelItem(XLAT("Panini projection"), fts(panini_alpha), 'P');
+      dialog::add_action([] {
+        popScreen();
+        dialog::editNumber(panini_alpha, 0, 1, 0.1, 0, "Panini parameter", 
+          XLAT(
+            "The Panini projection is an alternative perspective projection "
+            "which allows very wide field-of-view values. HyperRogue uses "
+            "a quick implementation, so parameter values too close to 1 may "
+            "be buggy; try e.g. 0.9 instead.")
+            );
+        dialog::reaction = ray::reset_raycaster;
+        dialog::extra_options = [] {
+          add_edit_fov('F', true);
+          };
+        });
+      };
     });
   }
 

glhr.cpp

@@ -154,7 +154,7 @@ void display(const glmatrix& m) {
   printf("\n");
   }
 
-glmatrix operator * (glmatrix m1, glmatrix m2) {
+EX glmatrix operator * (glmatrix m1, glmatrix m2) {
   glmatrix res;
   for(int i=0; i<4; i++)
   for(int j=0; j<4; j++) {

graph.cpp

@@ -22,6 +22,8 @@ EX bool spatial_graphics;
 EX bool wmspatial, wmescher, wmplain, wmblack, wmascii, wmascii3;
 EX bool mmspatial, mmhigh, mmmon, mmitem;
 
+EX ld panini_alpha = 0;
+
 EX int detaillevel = 0;
 
 EX bool first_cell_to_draw = true;
@@ -4878,7 +4880,8 @@ EX void calcparam() {
   cd->xcenter += cd->scrsize * pconf.xposition;
   cd->ycenter += cd->scrsize * pconf.yposition;
   
-  cd->tanfov = tan(vid.fov * degree / 2);
+  ld fov = vid.fov * degree / 2;
+  cd->tanfov = sin(fov) / (cos(fov) + panini_alpha);
   
   callhooks(hooks_calcparam);
   reset_projection();

models.cpp

@@ -208,6 +208,7 @@ EX namespace models {
   EX bool has_orientation(eModel m) {
     if(m == mdHorocyclic)
       return hyperbolic;
+    if((m == mdPerspective || m == mdGeodesic) && panini_alpha) return true;
     return
       among(m, mdHalfplane, mdPolynomial, mdPolygonal, mdTwoPoint, mdJoukowsky, mdJoukowskyInverted, mdSpiral, mdSimulatedPerspective, mdTwoHybrid, mdHorocyclic, mdAxial, mdAntiAxial, mdQuadrant,
         mdWerner, mdAitoff, mdHammer, mdLoximuthal, mdWinkelTripel) || mdBandAny();
@@ -868,6 +869,10 @@ EX namespace models {
       PHASEFROM(2); 
       shift_arg_formula(vpconf.skiprope);
       }
+    else if(argis("-palpha")) { 
+      PHASEFROM(2); 
+      shift_arg_formula(panini_alpha, reset_all_shaders);
+      }
     else if(argis("-zoom")) { 
       PHASEFROM(2); shift_arg_formula(vpconf.scale);
       }

raycaster.cpp

@@ -370,14 +370,34 @@ void enable_raycaster() {
     "  mediump mat4 vw = uStart * xzspin(-lambda) * xpush(eye) * yzspin(phi);\n"
     "  mediump vec4 at0 = vec4(0., 0., 1., 0.);\n";
     
-    else fmain += 
+    else {
-    "  mediump mat4 vw = uStart;\n"
+      fmain += 
-    "  mediump vec4 at0 = at;\n"
+        "  mediump mat4 vw = uStart;\n"
-    "  gl_FragColor = vec4(0,0,0,1);\n"
+        "  mediump vec4 at0 = at;\n"
-    "  mediump float left = 1.;\n"
+        "  gl_FragColor = vec4(0,0,0,1);\n"
-    "  at0.y = -at.y;\n"
+        "  mediump float left = 1.;\n"
-    "  at0.w = 0.;\n"
+        "  at0.y = -at.y;\n"
-    "  at0.xyz = at0.xyz / length(at0.xyz);\n";
+        "  at0.w = 0.;\n";
+      
+      if(panini_alpha) fmain += 
+          "mediump float hr = at0.x*at0.x;\n"
+          "mediump float alpha = " + to_glsl(panini_alpha) + ";\n"
+          "mediump float A = 1. + hr;\n"
+          "mediump float B = -2.*hr*alpha;\n"
+          "mediump float C = 1. - hr*alpha*alpha;\n"
+          "B /= A; C /= A;\n"
+    
+          "mediump float hz = B / 2. + sqrt(C + B*B/4.);\n"
+          "if(abs(hz) > 1e-3) {"
+          "at0.xyz *= hz+alpha;\n"
+          "at0.z = hz;\n}"
+          " else at0.z = 0.;\n"
+"\n"
+          ;
+
+      fmain +=
+        "  at0.xyz = at0.xyz / length(at0.xyz);\n";   
+      }
       
     if(hyperbolic) fsh += "  mediump float len(mediump vec4 x) { return x[3]; }\n";
     else if(sphere && rotspace) fsh += "  mediump float len(mediump vec4 x) { return 1.+x.x*x.x+x.y*x.y-x.z*x.z-x.w*x.w; }\n";
@@ -1091,6 +1111,7 @@ void enable_raycaster() {
       }
 
     #ifndef GLES_ONLY
+    /* todo: fix for Panini */
     fmain +=    
       "      gl_FragDepth = (" + to_glsl(-vnear-vfar)+"+w*" + to_glsl(2*vnear*vfar)+"/z)/" + to_glsl(vnear-vfar)+";\n"
       "      gl_FragDepth = (gl_FragDepth + 1.) / 2.;\n";

shaders.cpp

@@ -60,6 +60,12 @@ glhr::glmatrix model_orientation_gl() {
   return s;
   }
 
+EX void reset_all_shaders() {
+  ray::reset_raycaster();
+  compiled_programs.clear();
+  matched_programs.clear();
+  }
+
 shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
   string varying, vsh, fsh, vmain = "void main() {\n", fmain = "void main() {\n";
 
@@ -332,6 +338,21 @@ shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
       }
     if(shader_flags & GF_LEVELS) vmain += "vPos = t;\n";  
     if(treset) vmain += "t[3] = 1.0;\n";
+    
+    if(WDIM == 3 && panini_alpha) {
+      vmain += "t = uPP * t;", vsh += "uniform mediump mat4 uPP;";
+      /* panini */
+      vmain += "t.w += 1.; t *= 2. / t.w; t.w -= 1.;\n";
+      vmain += "float s = t.z;";
+      vmain += "float l = length(t.xyz);";
+      vmain += "t /= max(length(t.xz), 1e-2);\n";
+      vmain += "t.z += " + glhr::to_glsl(panini_alpha) + ";\n";
+      vmain += "t *= l;\n";
+      vmain += "t.w = 1.;\n";
+      frustum_culling = false;
+      shader_flags |= SF_ORIENT;
+      }
+      
     vmain += "gl_Position = uP * t;\n";
     }
 
@@ -485,7 +506,8 @@ void display_data::set_projection(int ed, ld shift) {
         for(int i=0; i<3; i++) NLP[3][i] = NLP[i][3] = 0;
         NLP[3][3] = 1;
         }
-      glhr::projection_multiply(glhr::tmtogl_transpose(NLP));
+      if(!(shader_flags & SF_ORIENT))
+        glhr::projection_multiply(glhr::tmtogl_transpose(NLP));
       }
     if(ed) {
       glhr::using_eyeshift = true;
@@ -520,6 +542,9 @@ void display_data::set_projection(int ed, ld shift) {
     if(get_shader_flags() & SF_USE_ALPHA)
       pp[3][2] = GLfloat(pconf.alpha);
 
+    if(nisot::local_perspective_used()) 
+      pp = glhr::tmtogl_transpose(NLP) * pp;
+
     if(get_shader_flags() & SF_ORIENT) {
       if(GDIM == 3) for(int a=0; a<4; a++) 
         models::apply_orientation_yz(pp[a][1], pp[a][2]);