vertical stretch parameter is now available in all models; more details in equi-area

basegraph.cpp

@@ -828,14 +828,14 @@ ld realradius() {
 void drawmessage(const string& s, int& y, int col) {
   int rrad = (int) realradius();
   int space;
-  if(y > vid.ycenter + rrad)
+  if(y > vid.ycenter + rrad * vid.stretch)
     space = vid.xres;
   else if(y > vid.ycenter)
-    space = vid.xcenter - rhypot(rrad, y-vid.ycenter);
+    space = vid.xcenter - rhypot(rrad, (y-vid.ycenter) / vid.stretch);
   else if(y > vid.ycenter - vid.fsize)
     space = vid.xcenter - rrad;
-  else if(y > vid.ycenter - vid.fsize - rrad)
+  else if(y > vid.ycenter - vid.fsize - rrad * vid.stretch)
-    space = vid.xcenter - rhypot(rrad, vid.ycenter-vid.fsize-y);
+    space = vid.xcenter - rhypot(rrad, (vid.ycenter-vid.fsize-y) / vid.stretch);
   else
     space = vid.xres;
 
@@ -920,7 +920,7 @@ void drawCircle(int x, int y, int size, int color) {
     if(ISMOBILE && pts > 72) pts = 72;
     for(int r=0; r<pts; r++) {
       float rr = (M_PI * 2 * r) / pts;
-      glcoords.push_back(make_array<GLfloat>(x + size * sin(rr), y + size * cos(rr), stereo::scrdist));
+      glcoords.push_back(make_array<GLfloat>(x + size * sin(rr), y + size * vid.stretch * cos(rr), stereo::scrdist));
       }
     glhr::vertices(glcoords);
     glhr::set_depthtest(false);
@@ -932,7 +932,10 @@ void drawCircle(int x, int y, int size, int color) {
 #if CAP_XGD
   gdpush(4); gdpush(color); gdpush(x); gdpush(y); gdpush(size);
 #elif CAP_SDLGFX
+  if(vid.stretch == 1)
     ((vid.antialias && AA_NOGL)?aacircleColor:circleColor) (s, x, y, size, color);
+  else
+    ((vid.antialias && AA_NOGL)?aaellipseColor:ellipseColor) (s, x, y, size, size * vid.stretch, color);
 #elif CAP_SDL
   int pts = size * 4;
   if(pts > 1500) pts = 1500;

conformal.cpp

@@ -641,9 +641,7 @@ namespace conformal {
       dialog::addSelItem(XLAT("parameter"), fts3(vid.twopoint_param), 'l');
       }
 
-    if(among(pmodel, mdBandEquidistant, mdBandEquiarea)) {
+    dialog::addSelItem(XLAT("vertical stretch"), fts3(vid.stretch), 's');
-      dialog::addSelItem(XLAT("parameter"), fts3(vid.stretch), 'l');
-      }
       
     dialog::addBreak(100);
     dialog::addItem(XLAT("history mode"), 'a');
@@ -689,10 +687,31 @@ namespace conformal {
 #endif
       else if(uni == 'l' && pmodel == mdHalfplane)
         lower_halfplane = !lower_halfplane;
-      else if(uni == 'l' && among(pmodel, mdBandEquiarea, mdBandEquidistant))
+      else if(uni == 's') {
-        dialog::editNumber(vid.stretch, 0, 10, .1, 1, XLAT("parameter"), 
+       dialog::editNumber(vid.stretch, 0, 10, .1, 1, XLAT("vertical stretch"), 
           "Vertical stretch factor."
           );
+        dialog::extra_options = [] () {
+          dialog::addBreak(100);
+          if(sphere && pmodel == mdBandEquiarea) {
+            dialog::addBoolItem("Gall-Peters", vid.stretch == 2, 'o');
+            dialog::add_action([] { vid.stretch = 2; dialog::ne.s = "2"; });
+            }
+          if(pmodel == mdBandEquiarea) {
+            // y = K * sin(phi)
+            // cos(phi) * cos(phi) = 1/K
+            if(sphere && vid.stretch >= 1) {
+              ld phi = acos(sqrt(1/vid.stretch));
+              dialog::addInfo(XLAT("The current value makes the map conformal at the latitude of %1 (%2°).", fts(phi), fts(phi * 180 / M_PI)));
+              }
+            else if(hyperbolic && abs(vid.stretch) <= 1 && abs(vid.stretch) >= 1e-9) {
+              ld phi = acosh(abs(sqrt(1/vid.stretch)));
+              dialog::addInfo(XLAT("The current value makes the map conformal %1 units from the main line.", fts(phi)));
+              }
+            else dialog::addInfo("");
+            }
+          };
+        }
       else if(uni == 'a')
         pushScreen(history_menu);
       else if(uni == 'l' && pmodel == mdHemisphere && euclid)  {

graph.cpp

@@ -2260,7 +2260,7 @@ void drawaura() {
     for(int x=0; x<vid.xres; x++) {
 
       ld hx = (x * 1. - vid.xcenter) / rad;
-      ld hy = (y * 1. - vid.ycenter) / rad;
+      ld hy = (y * 1. - vid.ycenter) / rad / vid.stretch;
   
       if(vid.camera_angle) camrotate(hx, hy);
       
@@ -2315,7 +2315,7 @@ void drawaura() {
     float rad0 = vid.alpha > -1 ? rad * facs[z] : rad / facs[z];
     int rm = r % AURA;
     cx[r][z][0] = rad0 * sin(rr);
-    cx[r][z][1] = rad0 * cos(rr);
+    cx[r][z][1] = rad0 * cos(rr) * vid.stretch;
     for(int u=0; u<3; u++)
       cx[r][z][u+2] = bak[u] + (aurac[rm][u] / (aurac[rm][3]+.1) - bak[u]) * cmul[z];
     }

hud.cpp

@@ -418,7 +418,7 @@ void drawStats() {
         int spots = 0;
         for(int u=vid.fsize; u<vid.xres/2-s; u += s)
         for(int v=vid.fsize; v<vid.yres/2-s; v += s)
-          if(hypot(vid.xres/2-u-s, vid.yres/2-v-s) > rad) {
+          if(hypot(vid.xres/2-u-s, (vid.yres/2-v-s) / vid.stretch) > rad) {
             spots++;
             }
         if(spots >= bycorner[cor] && spots >= 3) {
@@ -431,7 +431,7 @@ void drawStats() {
             }
           for(int u=vid.fsize; u<vid.xres/2-s; u += s)
           for(int v=vid.fsize; v<vid.yres/2-s; v += s)
-            if(hypot(vid.xres/2-u-s, vid.yres/2-v-s) > rad) {
+            if(hypot(vid.xres/2-u-s, (vid.yres/2-v-s) / vid.stretch) > rad) {
               if(next >= isize(glyphstoshow)) break;
 
               int cx = u;

hypgraph.cpp

@@ -317,7 +317,7 @@ void applymodel(hyperpoint H, hyperpoint& ret) {
           break;
           }
         case mdBandEquiarea: {
-          y = sin_auto(y) * vid.stretch;
+          y = sin_auto(y);
           break;
           }
         case mdSinusoidal: {
@@ -325,7 +325,6 @@ void applymodel(hyperpoint H, hyperpoint& ret) {
           break;
           }
         case mdBandEquidistant: {
-          y *= vid.stretch;
           break;
           }
         default: {

polygons.cpp

@@ -178,6 +178,7 @@ void addpoint(const hyperpoint& H) {
     hyperpoint Hscr;
     applymodel(H, Hscr); 
     for(int i=0; i<3; i++) Hscr[i] *= vid.radius;
+    Hscr[1] *= vid.stretch;
     // if(vid.alpha + H[2] <= BEHIND_LIMIT && pmodel == mdDisk) poly_flags |= POLY_BEHIND;
     
     if(spherespecial) {
@@ -315,6 +316,8 @@ void glapplymatrix(const transmatrix& V) {
   mat[14] = GLfloat(vid.alpha);
   mat[15] = 1;  
   
+  if(vid.stretch != 1) mat[1] *= vid.stretch, mat[5] *= vid.stretch, mat[9] *= vid.stretch, mat[13] *= vid.stretch;
+
   glhr::set_modelview(glhr::as_glmatrix(mat));
   }
 
@@ -451,7 +454,7 @@ void fixMercator(bool tinf) {
   
   if(pmodel == mdSinusoidal)
     for(int i = 0; i<isize(glcoords); i++) 
-      glcoords[i][mercator_coord] /= cos(glcoords[i][1] / vid.radius * M_PI);
+      glcoords[i][mercator_coord] /= cos(glcoords[i][1] / vid.radius / vid.stretch * M_PI);
     
   ld hperiod = mercator_period / 2;
   
@@ -460,7 +463,7 @@ void fixMercator(bool tinf) {
   if(mercator_coord)
     swap(cmin, dmin), swap(cmax, dmax);
   if(pmodel == mdSinusoidal)
-    dmin = -vid.radius / 2, dmax = vid.radius / 2;
+    dmin = -vid.stretch * vid.radius / 2, dmax = vid.stretch * vid.radius / 2;
   if(pmodel == mdBandEquidistant)
     dmin = -vid.stretch * vid.radius / 2, dmax = vid.stretch * vid.radius / 2;
   if(pmodel == mdBandEquiarea)
@@ -502,7 +505,7 @@ void fixMercator(bool tinf) {
       mercator_loop_max++, maxcoord += mercator_period;
     if(pmodel == mdSinusoidal)
       for(int i = 0; i<isize(glcoords); i++) 
-        glcoords[i][mercator_coord] *= cos(glcoords[i][1] / vid.radius * M_PI);    
+        glcoords[i][mercator_coord] *= cos(glcoords[i][1] / vid.radius / vid.stretch * M_PI);    
     }
   else {
     if(tinf) { 
@@ -529,7 +532,7 @@ void fixMercator(bool tinf) {
       }
     if(pmodel == mdSinusoidal)
       for(int i = 0; i<isize(glcoords); i++) 
-        glcoords[i][mercator_coord] *= cos(glcoords[i][1] / vid.radius * M_PI);    
+        glcoords[i][mercator_coord] *= cos(glcoords[i][1] / vid.radius / vid.stretch * M_PI);
     glcoords.push_back(glcoords.back());
     glcoords.push_back(glcoords[0]);
     for(int u=1; u<=2; u++) {
@@ -595,7 +598,7 @@ void drawpolyline(polytodraw& p) {
           twopoint_sphere_flips = j;
           hyperpoint h2; applymodel(h1, h2);
           using namespace hyperpoint_vec;
-          glvertex h = glhr::pointtogl(h2 * vid.radius);
+          glvertex h = glhr::pointtogl(h2 * vid.radius); h[1] *= vid.stretch;
           if(i == 0)
             phases[j].push_back(h);
           else {
@@ -624,7 +627,7 @@ void drawpolyline(polytodraw& p) {
           using namespace hyperpoint_vec;
 
           hyperpoint h1 = pp.V * glhr::gltopoint((*pp.tab)[pp.offset+i]);
-          hyperpoint mh1; applymodel(h1, mh1);
+          hyperpoint mh1; applymodel(h1, mh1); mh1[1] *= vid.stretch;
           phases[cpha].push_back(glhr::pointtogl(mh1 * vid.radius));
 
           // check if the i-th edge intersects the boundary of the ellipse
@@ -719,7 +722,7 @@ void drawpolyline(polytodraw& p) {
       hyperpoint hscr;
       hyperpoint h1 = pp.V * intester;
       if(is_behind(h1)) nofill = true; 
-      applymodel(h1, hscr); hscr[0] *= vid.radius; hscr[1] *= vid.radius;
+      applymodel(h1, hscr); hscr[0] *= vid.radius; hscr[1] *= vid.radius * vid.stretch;
       for(int i=0; i<isize(glcoords)-1; i++) {
         double x1 = glcoords[i][0] - hscr[0];
         double y1 = glcoords[i][1] - hscr[1];
@@ -771,7 +774,7 @@ void drawpolyline(polytodraw& p) {
     if(l || lastl) { 
       for(int i=0; i<isize(glcoords); i++) {
         if(pmodel == mdSinusoidal)
-          mercator_period = 2 * vid.radius * cos(glcoords[i][1] / vid.radius * M_PI);
+          mercator_period = 2 * vid.radius * cos(glcoords[i][1] / vid.radius / vid.stretch * M_PI);
         glcoords[i][mercator_coord] += mercator_period * (l - lastl);
         }
       lastl = l;
@@ -783,7 +786,7 @@ void drawpolyline(polytodraw& p) {
         ld h = atan2(glcoords[0][0], glcoords[0][1]);
         for(int i=0; i<=360; i++) {
           ld a = i * M_PI / 180 + h;
-          glcoords.push_back(make_array<GLfloat>(vid.radius * sin(a), vid.radius * cos(a), stereo::scrdist));
+          glcoords.push_back(make_array<GLfloat>(vid.radius * sin(a), vid.radius * vid.stretch * cos(a), stereo::scrdist));
           }
         poly_flags ^= POLY_INVERSE;
         }
@@ -2513,7 +2516,7 @@ void getcoord0(const hyperpoint& h, int& xc, int &yc, int &sc) {
   hyperpoint hscr;
   applymodel(h, hscr);
   xc = vid.xcenter + vid.radius * hscr[0];
-  yc = vid.ycenter + vid.radius * hscr[1];
+  yc = vid.ycenter + vid.radius * vid.stretch * hscr[1];
   sc = 0;
   // EYETODO sc = vid.eye * vid.radius * hscr[2];
   }

screenshot.cpp

@@ -73,9 +73,14 @@ namespace svg {
   
   void circle(int x, int y, int size, int col) {
     int ba = (backcolor << 8) + 0xFF;
-    if(!invisible(col))
+    if(!invisible(col)) {
+      if(vid.stretch == 1)
         fprintf(f, "<circle cx='%s' cy='%s' r='%s' %s/>\n",
           coord(x), coord(y), coord(size), stylestr(ba, col));
+      else
+        fprintf(f, "<circle cx='%s' cy='%s' rx='%s' ry='%s' %s/>\n",
+          coord(x), coord(y), coord(size), coord(size*vid.stretch), stylestr(ba, col));
+      }
     }
   
   const string *link;