From a5318a15a1599d418c648a6a6f399c77bc2a2723 Mon Sep 17 00:00:00 2001
From: Leonardo Koller Sacht <leo-ks@impa.br>
Date: Mon, 12 Aug 2013 10:46:42 -0300
Subject: [PATCH] Added Stereographic and Mercator to the interface

---
 openglcanvas.cpp                | 45 +++++++++++++++++++++++++++------
 panowindow1.ui                  | 12 ++++++++-
 shaders/test_vertex_shader.vert | 20 +++++++++++----
 3 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/openglcanvas.cpp b/openglcanvas.cpp
index 8dd0a96..af7298e 100644
--- a/openglcanvas.cpp
+++ b/openglcanvas.cpp
@@ -38,7 +38,7 @@ OpenGLCanvas::OpenGLCanvas(QWidget *parent) :
     center_lambda = 0.f;
     center_phi = 0.f;
     fov_scale_relation = "Naive";
-    visualization = "Perspective";
+    visualization = "Moebius";
     auto_fov_max=false;
 
     time_frames = 0;
@@ -439,10 +439,9 @@ void OpenGLCanvas::vertex_transformation(float *positions, int m, int n, float c
             lambda = atan2(x,-z)/CONST_PI_F;
             phi = asin(y)/CONST_PI_2_F;
 
-            u = x/(-z);
-            v = y/(-z);
-
-            if (visualization=="Perspective"){
+            if (visualization=="Moebius"){
+                u = x/(-z);
+                v = y/(-z);
                 positions[3*(j+i*n)] = u/extent;
                 positions[3*(j+i*n)+1] = v/extent;
                 positions[3*(j+i*n)+2] = z;
@@ -460,6 +459,22 @@ void OpenGLCanvas::vertex_transformation(float *positions, int m, int n, float c
                 positions[3*(j+i*n)+2] = z;
             }
 
+            if (visualization=="Stereographic"){
+                u = 2*x/(-z+1);
+                v = 2*y/(-z+1);
+                positions[3*(j+i*n)] = u/extent;
+                positions[3*(j+i*n)+1] = v/extent;
+                positions[3*(j+i*n)+2] = z;
+            }
+
+            if (visualization=="Mercator"){
+                u = lambda;
+                v = log((1.0/cos(phi)) + tan(phi));
+                positions[3*(j+i*n)] = u/extent;
+                positions[3*(j+i*n)+1] = v/extent;
+                positions[3*(j+i*n)+2] = z;
+            }
+
         }
     }
 
@@ -517,8 +532,20 @@ float OpenGLCanvas::calculate_extent(float fov_rads){
     x = (4.*u)/(u*u+v*v+4.);
     y = (4.*v)/(u*u+v*v+4.);
     z = (u*u+v*v-4.)/(u*u+v*v+4.);
-    u = x/(-z);
-    v = y/(-z);
+    if (visualization=="Moebius"){
+        u = x/(-z);
+        v = y/(-z);
+    }
+    else if (visualization=="Stereographic"){
+        u = 2*x/(-z+1);
+        v = 2*y/(-z+1);
+    }
+    else if (visualization=="Mercator"){
+        u = fov_rads;
+        // Warning: this extent calculation is wrong.
+        // Write now it's olny showing the entire panorama intead of
+        // the corresponging FOV.
+    }
     return u;
 }
 
@@ -692,9 +719,11 @@ void OpenGLCanvas::paintGL(){
     // defining transformation parameters (that will be passed to the vertex shader)
     float extent = calculate_extent(fov_rads);
     float vis_mode=.0;
-    if (visualization=="Perspective") vis_mode=1.0;
+    if (visualization=="Moebius") vis_mode=1.0;
     else if (visualization=="3D Sphere") vis_mode=2.0;
     else if (visualization=="Equi-Rectangular") vis_mode=3.0;
+    else if (visualization=="Stereographic") vis_mode=4.0;
+    else if (visualization=="Mercator") vis_mode=5.0;
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     glOrtho(0.0, 2.0/extent, 0.0, 2.0/scale, 0.0, -2.0/vis_mode);
diff --git a/panowindow1.ui b/panowindow1.ui
index 051fa5c..f6880c3 100644
--- a/panowindow1.ui
+++ b/panowindow1.ui
@@ -179,7 +179,7 @@
     <widget class="QComboBox" name="comboBox_2">
      <item>
       <property name="text">
-       <string>Perspective</string>
+       <string>Moebius</string>
       </property>
      </item>
      <item>
@@ -192,6 +192,16 @@
        <string>Equi-Rectangular</string>
       </property>
      </item>
+     <item>
+      <property name="text">
+       <string>Stereographic</string>
+      </property>
+     </item>
+     <item>
+      <property name="text">
+       <string>Mercator</string>
+      </property>
+     </item>
     </widget>
    </item>
    <item row="12" column="1">
diff --git a/shaders/test_vertex_shader.vert b/shaders/test_vertex_shader.vert
index ff4bd58..7107ae7 100644
--- a/shaders/test_vertex_shader.vert
+++ b/shaders/test_vertex_shader.vert
@@ -57,14 +57,24 @@ void main(void){
     lambda = atan(x,-z)/3.1415;
     phi = asin(y)/1.5708;
 
-    // perspective projection
-    u = x/(-z);
-    v = y/(-z);
-
     // Visualize using specified visualization (remove for timings in the paper! Use only "Perspective" in the paper!)
-    if (vis_mode==1.0) gl_Position = vec4(u/extent,v/extent,z,1.0);
+    if (vis_mode==1.0) {
+        u = x/(-z);
+        v = y/(-z);
+        gl_Position = vec4(u/extent,v/extent,z,1.0);
+    }
     else if (vis_mode==2.0) gl_Position = vec4(0.9*x,0.9*y,z,1.0);
     else if (vis_mode==3.0) gl_Position = vec4(lambda,phi,z,1.0);
+    else if (vis_mode==4.0) {
+        u = 2.f*x/(-z+1);
+        v = 2.f*y/(-z+1);
+        gl_Position = vec4(u/extent,v/extent,z,1.0);
+    }
+    else if (vis_mode==5.0) {
+        u = lambda;
+        v = log((1.0/cos(phi)) + tan(phi));
+        gl_Position = vec4(u,v,z,1.0);
+    }
 
 //    gl_Position = vec4(u/2.0,v/2.0,z,1.0);
 
-- 
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