Commit b102f57b authored by Luis Peñaranda's avatar Luis Peñaranda
Browse files

some numerical stability

parent e6fa883b

openglcanvas.cpp

+40 −33
Original line number Diff line number Diff line
@@ -22,6 +22,11 @@ 
#define VERT_SHADER_FILE "test_vertex_shader.vert"

#define FRAG_SHADER_FILE "fragment_shader.frag"



#define CONST_PI        3.141592653589793238462

#define CONST_PI_2      1.57079632679489661923

#define CONST_PI_F      3.14159265358979f

#define CONST_PI_2_F    1.570796326794897f // TODO: check this one



OpenGLCanvas::OpenGLCanvas(QWidget *parent) :

    QGLWidget(parent)

{
@@ -50,8 +55,8 @@ void OpenGLCanvas::change_fov(double f){ 
        fov=f;

    if (fov<=fov_max)

        scale=1.f;

    else if (fov>295.f)

        scale = 0.02f; // TODO: check this value wrt fov_max

    //else if (fov>295.f)

    //    scale = 0.02f; // TODO: check this value wrt fov_max

    else {

        if (fov_scale_relation == "Naive")

            scale=fov_max/fov;
@@ -69,7 +74,7 @@ void OpenGLCanvas::change_fov(double f){ 


//    scale = 0.3f;



    fprintf(stderr,"change fov=%f, fov_max=%f\n",fov,fov_max);

    fprintf(stderr,"change fov, fov=%f, fov_max=%f, scale=%f\n",fov,fov_max,scale);

    emit fov_changed((int)fov);



    updateGL();
@@ -77,15 +82,17 @@ void OpenGLCanvas::change_fov(double f){ 
}



void OpenGLCanvas::change_fov(int new_fov){

    if(new_fov<=360&&new_fov>=1)

            change_fov((double)new_fov);

}



void OpenGLCanvas::change_fov_max(int new_fov_max){

    if(new_fov_max<=360&&new_fov_max>=0)

            fov_max=(double)new_fov_max;

    if (fov<=fov_max)

        scale=1.f;

    else if (fov>295.f)

        scale = 0.02f; // TODO: check this value wrt fov_max

    //else if (fov>295.f)

    //    scale = 0.02f; // TODO: check this value wrt fov_max

    else {

        if (fov_scale_relation == "Naive")

            scale=fov_max/fov;
@@ -100,7 +107,7 @@ void OpenGLCanvas::change_fov_max(int new_fov_max){ 
        else if (fov_scale_relation == "Logarithm")

            scale=log(exp(1.f)+(1.f-exp(1.f))*(fov-fov_max)/(360.-2*fov_max));

    }

    fprintf(stderr,"change fov_max=%f, new scale=%f\n",fov_max,scale);

    fprintf(stderr,"change fov_max, fov=%f, fov_max=%f, new scale=%f\n",fov,fov_max,scale);

    emit max_fov_changed((int)fov_max);

    updateGL();

}
@@ -114,7 +121,7 @@ void OpenGLCanvas::change_fov_max(int new_fov_max){ 


void OpenGLCanvas::change_center_lambda(double lambda){



    if (center_lambda!=lambda && lambda>=-3.14f && lambda<=3.14f) {

    if (center_lambda!=lambda && lambda>=-CONST_PI && lambda<=CONST_PI) {

        center_lambda = lambda;

        updateGL();

    }
@@ -123,7 +130,7 @@ void OpenGLCanvas::change_center_lambda(double lambda){ 


void OpenGLCanvas::change_center_phi(double phi){



    if (center_phi!=phi && phi>=-1.57f && phi<=1.57f) {

    if (center_phi!=phi && phi>=-CONST_PI_2 && phi<=CONST_PI_2) {

        center_phi = phi;

        updateGL();

    }
@@ -139,8 +146,8 @@ void OpenGLCanvas::re_center(){ 
void OpenGLCanvas::change_fov_scale_relation(QString name){



   fov_scale_relation = name;

   if (fov<60.f) scale = 1.f;

   else if (fov>295.f) scale = 0.01f;

   if (fov<fov_max) scale = 1.f;

   //else if (fov>295.f) scale = 0.01f;

   else{

       if (fov_scale_relation == "Naive")

           scale=fov_max/fov;
@@ -278,7 +285,7 @@ void OpenGLCanvas::initializeGL(){ 
    if (texCoord == NULL){

        printf("problem allocating memory for texture coordinates \n");

    }

    define_texture_coordinates(texCoord, m, n, -1.57f, 1.57f, -3.14f, 3.14f);

    define_texture_coordinates(texCoord, m, n, -CONST_PI_2_F, CONST_PI_2_F, -CONST_PI_F, CONST_PI_F);



    //defining positions of the sphere vertices

    int meshNumVertices = m*n;
@@ -311,8 +318,8 @@ void OpenGLCanvas::define_texture_coordinates(float *texCoord, int m, int n, flo 


    for (int i = 0; i<m; i++){

        for (int j = 0; j<n; j++){

            texCoord[2*(j+i*n)] = (min_lambda+delta_lambda*j)/(6.2832) + 0.5;

            texCoord[2*(j+i*n)+1] = (min_phi+delta_phi*i)/(3.1416) + 0.5;

            texCoord[2*(j+i*n)] = (min_lambda+delta_lambda*j)/(2*CONST_PI_F) + 0.5;

            texCoord[2*(j+i*n)+1] = (min_phi+delta_phi*i)/(CONST_PI_F) + 0.5;

        }

    }
@@ -320,10 +327,10 @@ void OpenGLCanvas::define_texture_coordinates(float *texCoord, int m, int n, flo 


void OpenGLCanvas::vertex_transformation(float *positions, int m, int n, float center_lambda, float center_phi, float fov_rads, float scale){



    float min_lambda = -3.1415f;

    float max_lambda = 3.1415f;

    float min_phi = -1.5708f;

    float max_phi = 1.5708f;

    float min_lambda = -CONST_PI_F;

    float max_lambda = CONST_PI_F;

    float min_phi = -CONST_PI_2_F;

    float max_phi = CONST_PI_2_F;



    float delta_lambda = (max_lambda-min_lambda)/(1.0*(n-1));

    float delta_phi = (max_phi-min_phi)/(1.0*(m-1));
@@ -391,8 +398,8 @@ void OpenGLCanvas::vertex_transformation(float *positions, int m, int n, float c 
            y = (4.f*v)/(u*u+v*v+4.f);

            z = (u*u+v*v-4.f)/(u*u+v*v+4.f);



            lambda = atan2(x,-z)/3.1415;

            phi = asin(y)/1.5708;

            lambda = atan2(x,-z)/CONST_PI_F;

            phi = asin(y)/CONST_PI_2_F;



            u = x/(-z);

            v = y/(-z);
@@ -422,10 +429,10 @@ void OpenGLCanvas::vertex_transformation(float *positions, int m, int n, float c 


void OpenGLCanvas::load_sphere_mesh(float *positions, int m, int n){



    float min_lambda = -3.1415f;

    float max_lambda = 3.1415f;

    float min_phi = -1.5708f;

    float max_phi = 1.5708f;

    float min_lambda = -CONST_PI_F;

    float max_lambda = CONST_PI_F;

    float min_phi = -CONST_PI_2_F;

    float max_phi = CONST_PI_2_F;



    float delta_lambda = (max_lambda-min_lambda)/(1.0*(n-1));

    float delta_phi = (max_phi-min_phi)/(1.0*(m-1));
@@ -454,24 +461,24 @@ void OpenGLCanvas::load_sphere_mesh(float *positions, int m, int n){ 


float OpenGLCanvas::calculate_extent(float fov_rads){



    float lambda, phi, x, y, z, u, v, r, theta;

    double lambda, phi, x, y, z, u, v, r, theta;

    //calculating the extent of the projection for the given FOV

    lambda = fov_rads;

    phi = 0.f;

    phi = 0.;

    // OpenGL: x is the vertical axes pointg downwards, and y is horizontal axes

    y = sin(phi);

    x = -sin(lambda)*cos(phi);

    z = -cos(lambda)*cos(phi);

    u = 2.f*x/(-z+1.f);

    v = 2.f*y/(-z+1.f);

    u = 2.*x/(-z+1.);

    v = 2.*y/(-z+1.);

    r = sqrt(u*u+v*v);

    theta = atan2(u,v);

    r *= scale;

    u = -r*sin(theta);

    v = r*cos(theta);

    x = (4.f*u)/(u*u+v*v+4.f);

    y = (4.f*v)/(u*u+v*v+4.f);

    z = (u*u+v*v-4.f)/(u*u+v*v+4.f);

    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);

    return u;
@@ -670,8 +677,8 @@ void OpenGLCanvas::mouseMoveEvent(QMouseEvent *event){ 
    // scroll with the left button

    if(event->buttons()==Qt::LeftButton){

        // compute the delta and move the image

        center_lambda+=(event->x()-lastPos.x())*3.1415926f/image_size_x;

        center_phi+=(event->y()-lastPos.y())*3.1415926f/image_size_y;

        center_lambda+=(event->x()-lastPos.x())*CONST_PI_F/image_size_x;

        center_phi+=(event->y()-lastPos.y())*CONST_PI_F/image_size_y;

        lastPos=event->pos();

        updateGL();

    }
@@ -689,7 +696,7 @@ void OpenGLCanvas::wheelEvent(QWheelEvent *event){ 


void OpenGLCanvas::paintGL(){



    float fov_rads = (fov/180.f)*1.5708f;

    float fov_rads = (fov/360.)*CONST_PI;



//    // changing scale to generate the figures for the paper (remove it after)

//    scale = 0.8;