Add grits_viewer_unproject function

[grits] / src / grits-opengl.c

diff --git a/src/grits-opengl.c b/src/grits-opengl.c
index 961a875207c57b1109503d64877a38399c31c4d5..3d7b7dd12a718ddf6bac02c83509e2c5df706f8e 100644 (file)
--- a/src/grits-opengl.c
+++ b/src/grits-opengl.c
@@ -316,6 +316,11 @@ static gboolean on_motion_notify(GritsOpenGL *opengl, GdkEventMotion *event, gpo
        g_ptr_array_free(objects, TRUE);
        g_mutex_unlock(opengl->objects_lock);
 
+       /* Test unproject */
+       gdouble lat, lon, elev;
+       grits_viewer_unproject(GRITS_VIEWER(opengl),
+                       gl_x, gl_y, -1, &lat, &lon, &elev);
+
        /* Cleanup */
        glMatrixMode(GL_PROJECTION);
        glPopMatrix();
@@ -459,6 +464,30 @@ static void grits_opengl_project(GritsViewer *_opengl,
                px, py, pz);
 }
 
+static void grits_opengl_unproject(GritsViewer *_opengl,
+               gdouble px, gdouble py, gdouble pz,
+               gdouble *lat, gdouble *lon, gdouble *elev)
+{
+       GritsOpenGL *opengl = GRITS_OPENGL(_opengl);
+       gdouble x, y, z;
+       if (pz < 0) {
+               gfloat tmp = 0;
+               glReadPixels(px, py, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &tmp);
+               pz = tmp;
+       }
+       gluUnProject(px, py, pz,
+               opengl->sphere->view->model,
+               opengl->sphere->view->proj,
+               opengl->sphere->view->view,
+               &x, &y, &z);
+       xyz2lle(x, y, z, lat, lon, elev);
+       //g_message("GritsOpenGL: unproject - "
+       //              "%4.0lf,%4.0lf,(%5.3lf) -> "
+       //              "%8.0lf,%8.0lf,%8.0lf -> "
+       //              "%6.2lf,%7.2lf,%4.0lf",
+       //      px, py, pz, x, y, z, *lat, *lon, *elev);
+}
+
 static void grits_opengl_set_height_func(GritsViewer *_opengl, GritsBounds *bounds,
                RoamHeightFunc height_func, gpointer user_data, gboolean update)
 {
@@ -615,6 +644,7 @@ static void grits_opengl_class_init(GritsOpenGLClass *klass)
        GritsViewerClass *viewer_class = GRITS_VIEWER_CLASS(klass);
        viewer_class->center_position   = grits_opengl_center_position;
        viewer_class->project           = grits_opengl_project;
+       viewer_class->unproject         = grits_opengl_unproject;
        viewer_class->clear_height_func = grits_opengl_clear_height_func;
        viewer_class->set_height_func   = grits_opengl_set_height_func;
        viewer_class->add               = grits_opengl_add;