]> Pileus Git - grits/blobdiff - src/gis-opengl.c
Add z-index to tiles
[grits] / src / gis-opengl.c
index c1d6fd5e03729a8b7211645f8ef7de5d89485c99..57cfb471e901894d3b510c9f0e3b99aabbf50b10 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* Tessellation, "finding intersecting triangles" */
-/* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
-/* http://www.opengl.org/wiki/Alpha_Blending */
+/**
+ * SECTION:gis-opengl
+ * @short_description: OpenGL based virtual globe
+ *
+ * #GisOpenGL is the core rendering engine used by libgis. Theoretically other
+ * renderers could be writte, but they have not been. GisOpenGL uses the ROAM
+ * algorithm for updating surface mesh the planet. The only thing GisOpenGL can
+ * actually render on it's own is a wireframe of a sphere.
+ *
+ * GisOpenGL relies on #GtkGlExt and requires (at least) OpenGL 2.0.
+ */
 
 #include <config.h>
 #include <math.h>
 #include "objects/gis-marker.h"
 #include "objects/gis-callback.h"
 
-#define FOV_DIST   2000.0
-#define MPPX(dist) (4*dist/FOV_DIST)
-
 // #define ROAM_DEBUG
 
+/* Tessellation, "finding intersecting triangles" */
+/* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
+/* http://www.opengl.org/wiki/Alpha_Blending */
+
 /***********
  * Helpers *
  ***********/
-static void _set_visuals(GisOpenGL *self)
+static void _set_visuals(GisOpenGL *opengl)
 {
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
 
        /* Camera 1 */
        double lat, lon, elev, rx, ry, rz;
-       gis_viewer_get_location(GIS_VIEWER(self), &lat, &lon, &elev);
-       gis_viewer_get_rotation(GIS_VIEWER(self), &rx, &ry, &rz);
+       gis_viewer_get_location(GIS_VIEWER(opengl), &lat, &lon, &elev);
+       gis_viewer_get_rotation(GIS_VIEWER(opengl), &rx, &ry, &rz);
        glRotatef(rx, 1, 0, 0);
        glRotatef(rz, 0, 0, 1);
 
@@ -106,19 +115,19 @@ static void _set_visuals(GisOpenGL *self)
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        //glShadeModel(GL_FLAT);
 
-       roam_sphere_update_view(self->sphere);
+       g_mutex_lock(opengl->sphere_lock);
+       roam_sphere_update_view(opengl->sphere);
+       g_mutex_unlock(opengl->sphere_lock);
 }
 
 
 /********************
  * Object handleing *
  ********************/
-static void _draw_tile(GisOpenGL *self, GisTile *tile)
+static void _draw_tile(GisOpenGL *opengl, GisTile *tile, GList *triangles)
 {
        if (!tile || !tile->data)
                return;
-       GList *triangles = roam_sphere_get_intersect(self->sphere, FALSE,
-                       tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
        if (!triangles)
                g_warning("GisOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
                        tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
@@ -169,7 +178,9 @@ static void _draw_tile(GisOpenGL *self, GisTile *tile)
                if (lat[2] == 90 || lat[2] == -90) xy[2][0] = 0.5;
 
                glEnable(GL_TEXTURE_2D);
+               glEnable(GL_POLYGON_OFFSET_FILL);
                glBindTexture(GL_TEXTURE_2D, *(guint*)tile->data);
+               glPolygonOffset(0, -tile->zindex);
                glBegin(GL_TRIANGLES);
                glNormal3dv(tri->p.r->norm); glTexCoord2dv(xy[0]); glVertex3dv((double*)tri->p.r);
                glNormal3dv(tri->p.m->norm); glTexCoord2dv(xy[1]); glVertex3dv((double*)tri->p.m);
@@ -179,30 +190,57 @@ static void _draw_tile(GisOpenGL *self, GisTile *tile)
        g_list_free(triangles);
 }
 
-static void _draw_tiles(GisOpenGL *self, GisTile *tile)
+static void _draw_tiles(GisOpenGL *opengl, GisTile *tile)
 {
        /* Only draw children if possible */
-       gboolean has_children = TRUE;
+       gboolean has_children = FALSE;
        GisTile *child;
        gis_tile_foreach(tile, child)
-               if (!child || !child->data)
-                       has_children = FALSE;
-       if (has_children)
-               /* Only draw children */
-               gis_tile_foreach(tile, child)
-                       _draw_tiles(self, child);
-       else
-               /* No children, draw this tile */
-               _draw_tile(self, tile);
+               if (child && child->data)
+                       has_children = TRUE;
+
+       GList *triangles = NULL;
+       if (has_children) {
+               /* TODO: simplify this */
+               const gdouble rows = G_N_ELEMENTS(tile->children);
+               const gdouble cols = G_N_ELEMENTS(tile->children[0]);
+               const gdouble lat_dist = tile->edge.n - tile->edge.s;
+               const gdouble lon_dist = tile->edge.e - tile->edge.w;
+               const gdouble lat_step = lat_dist / rows;
+               const gdouble lon_step = lon_dist / cols;
+               int row, col;
+               gis_tile_foreach_index(tile, row, col) {
+                       GisTile *child = tile->children[row][col];
+                       if (child && child->data) {
+                               _draw_tiles(opengl, child);
+                       } else {
+                               const gdouble n = tile->edge.n-(lat_step*(row+0));
+                               const gdouble s = tile->edge.n-(lat_step*(row+1));
+                               const gdouble e = tile->edge.w+(lon_step*(col+1));
+                               const gdouble w = tile->edge.w+(lon_step*(col+0));
+                               GList *these = roam_sphere_get_intersect(opengl->sphere, FALSE, n, s, e, w);
+                               triangles = g_list_concat(triangles, these);
+                       }
+               }
+       } else {
+               triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
+                               tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+       }
+       if (triangles)
+               _draw_tile(opengl, tile, triangles);
 }
 
-static void _draw_marker(GisOpenGL *self, GisMarker *marker)
+static void _draw_marker(GisOpenGL *opengl, GisMarker *marker)
 {
-       GisPoint *point = gis_object_center(GIS_OBJECT(marker));
+       GisPoint *point = gis_object_center(marker);
        gdouble px, py, pz;
-       gis_viewer_project(GIS_VIEWER(self),
+       gis_viewer_project(GIS_VIEWER(opengl),
                        point->lat, point->lon, point->elev,
                        &px, &py, &pz);
+
+       gint win_width  = GTK_WIDGET(opengl)->allocation.width;
+       gint win_height = GTK_WIDGET(opengl)->allocation.height;
+       py = win_height - py;
        if (pz > 1)
                return;
 
@@ -214,8 +252,7 @@ static void _draw_marker(GisOpenGL *self, GisMarker *marker)
 
        glMatrixMode(GL_PROJECTION); glLoadIdentity();
        glMatrixMode(GL_MODELVIEW);  glLoadIdentity();
-       glOrtho(0, GTK_WIDGET(self)->allocation.width,
-               0, GTK_WIDGET(self)->allocation.height, -1, 1);
+       glOrtho(0, win_width, win_height, 0, -1, 1);
        glTranslated(px - marker->xoff,
                     py - marker->yoff, 0);
 
@@ -224,32 +261,42 @@ static void _draw_marker(GisOpenGL *self, GisMarker *marker)
        glDisable(GL_DEPTH_TEST);
        glEnable(GL_TEXTURE_2D);
        glBindTexture(GL_TEXTURE_2D, marker->tex);
+       glDisable(GL_CULL_FACE);
        glBegin(GL_QUADS);
-       glTexCoord2f(1, 1); glVertex3f(width, 0     , 0);
-       glTexCoord2f(1, 0); glVertex3f(width, height, 0);
-       glTexCoord2f(0, 0); glVertex3f(0    , height, 0);
-       glTexCoord2f(0, 1); glVertex3f(0    , 0     , 0);
+       glTexCoord2f(1, 0); glVertex3f(width, 0     , 0);
+       glTexCoord2f(1, 1); glVertex3f(width, height, 0);
+       glTexCoord2f(0, 1); glVertex3f(0    , height, 0);
+       glTexCoord2f(0, 0); glVertex3f(0    , 0     , 0);
        glEnd();
 }
 
-static void _draw_callback(GisOpenGL *self, GisCallback *callback)
+static void _draw_callback(GisOpenGL *opengl, GisCallback *callback)
 {
        callback->callback(callback, callback->user_data);
 }
 
-static void _draw_object(GisOpenGL *self, GisObject *object)
+static void _draw_object(GisOpenGL *opengl, GisObject *object)
 {
        //g_debug("GisOpenGL: draw_object");
        /* Skip out of range objects */
        if (object->lod > 0) {
+               /* LOD test */
                gdouble eye[3], obj[3];
-               gis_viewer_get_location(GIS_VIEWER(self), &eye[0], &eye[1], &eye[2]);
+               gis_viewer_get_location(GIS_VIEWER(opengl), &eye[0], &eye[1], &eye[2]);
+               gdouble elev = eye[2];
                lle2xyz(eye[0], eye[1], eye[2], &eye[0], &eye[1], &eye[2]);
                lle2xyz(object->center.lat, object->center.lon, object->center.elev,
                        &obj[0], &obj[1], &obj[2]);
                gdouble dist = distd(obj, eye);
                if (object->lod < dist)
                        return;
+
+               /* Horizon testing */
+               gdouble c = EARTH_R+elev;
+               gdouble a = EARTH_R;
+               gdouble horizon = sqrt(c*c - a*a);
+               if (dist > horizon)
+                       return;
        }
 
        /* Draw */
@@ -257,18 +304,22 @@ static void _draw_object(GisOpenGL *self, GisObject *object)
        glMatrixMode(GL_MODELVIEW);  glPushMatrix();
        glPushAttrib(GL_ALL_ATTRIB_BITS);
        if (GIS_IS_MARKER(object)) {
-               _draw_marker(self, GIS_MARKER(object));
+               _draw_marker(opengl, GIS_MARKER(object));
        } else if (GIS_IS_CALLBACK(object)) {
-               _draw_callback(self, GIS_CALLBACK(object));
+               _draw_callback(opengl, GIS_CALLBACK(object));
        } else if (GIS_IS_TILE(object)) {
-               _draw_tiles(self, GIS_TILE(object));
+               glEnable(GL_DEPTH_TEST);
+               glDepthFunc(GL_LESS);
+               g_mutex_lock(opengl->sphere_lock);
+               _draw_tiles(opengl, GIS_TILE(object));
+               g_mutex_unlock(opengl->sphere_lock);
        }
        glPopAttrib();
        glMatrixMode(GL_PROJECTION); glPopMatrix();
        glMatrixMode(GL_MODELVIEW);  glPopMatrix();
 }
 
-static void _load_object(GisOpenGL *self, GisObject *object)
+static void _load_object(GisOpenGL *opengl, GisObject *object)
 {
        g_debug("GisOpenGL: load_object");
        if (GIS_IS_MARKER(object)) {
@@ -291,7 +342,7 @@ static void _load_object(GisOpenGL *self, GisObject *object)
        }
 }
 
-static void _unload_object(GisOpenGL *self, GisObject *object)
+static void _unload_object(GisOpenGL *opengl, GisObject *object)
 {
        g_debug("GisOpenGL: unload_object");
        if (GIS_IS_MARKER(object)) {
@@ -312,27 +363,12 @@ struct RenderLevel {
        GList sorted;
 };
 
-static void on_realize(GisOpenGL *self, gpointer _)
-{
-       g_debug("GisOpenGL: on_realize");
-
-       GdkGLContext   *glcontext  = gtk_widget_get_gl_context(GTK_WIDGET(self));
-       GdkGLDrawable  *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(self));
-       if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
-               g_assert_not_reached();
-
-       _set_visuals(self);
-       g_mutex_lock(self->sphere_lock);
-       roam_sphere_update_errors(self->sphere);
-       g_mutex_unlock(self->sphere_lock);
-}
-
-static gboolean on_configure(GisOpenGL *self, GdkEventConfigure *event, gpointer _)
+static gboolean on_configure(GisOpenGL *opengl, GdkEventConfigure *event, gpointer _)
 {
        g_debug("GisOpenGL: on_configure");
 
-       double width  = GTK_WIDGET(self)->allocation.width;
-       double height = GTK_WIDGET(self)->allocation.height;
+       double width  = GTK_WIDGET(opengl)->allocation.width;
+       double height = GTK_WIDGET(opengl)->allocation.height;
 
        /* Setup OpenGL Window */
        glViewport(0, 0, width, height);
@@ -342,18 +378,31 @@ static gboolean on_configure(GisOpenGL *self, GdkEventConfigure *event, gpointer
        gluPerspective(rad2deg(ang)*2, width/height, 1, 10*EARTH_R);
 
 #ifndef ROAM_DEBUG
-       g_mutex_lock(self->sphere_lock);
-       roam_sphere_update_errors(self->sphere);
-       g_mutex_unlock(self->sphere_lock);
+       g_mutex_lock(opengl->sphere_lock);
+       roam_sphere_update_errors(opengl->sphere);
+       g_mutex_unlock(opengl->sphere_lock);
 #endif
 
        return FALSE;
 }
 
+static void on_realize(GisOpenGL *opengl, gpointer _)
+{
+       g_debug("GisOpenGL: on_realize");
+
+       GdkGLContext   *glcontext  = gtk_widget_get_gl_context(GTK_WIDGET(opengl));
+       GdkGLDrawable  *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
+       if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
+               g_assert_not_reached();
+
+       _set_visuals(opengl);
+       on_configure(opengl, NULL, NULL);
+}
+
 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
 {
        g_debug("GisOpenGL: _draw_level - level=%-4d", (int)key);
-       GisOpenGL *self = user_data;
+       GisOpenGL *opengl = user_data;
        struct RenderLevel *level = value;
        int nsorted = 0, nunsorted = 0;
        GList *cur = NULL;
@@ -362,14 +411,14 @@ static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
        glDepthMask(TRUE);
        glClear(GL_DEPTH_BUFFER_BIT);
        for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
-               _draw_object(self, GIS_OBJECT(cur->data));
+               _draw_object(opengl, GIS_OBJECT(cur->data));
 
        /* Freeze depth buffer and draw transparent objects sorted */
        /* TODO: sorting */
        //glDepthMask(FALSE);
        glAlphaFunc(GL_GREATER, 0.1);
        for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
-               _draw_object(self, GIS_OBJECT(cur->data));
+               _draw_object(opengl, GIS_OBJECT(cur->data));
 
        /* TODO: Prune empty levels */
 
@@ -378,36 +427,36 @@ static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
        return FALSE;
 }
 
-static gboolean on_expose(GisOpenGL *self, GdkEventExpose *event, gpointer _)
+static gboolean on_expose(GisOpenGL *opengl, GdkEventExpose *event, gpointer _)
 {
        g_debug("GisOpenGL: on_expose - begin");
 
        glClear(GL_COLOR_BUFFER_BIT);
 
-       _set_visuals(self);
+       _set_visuals(opengl);
 #ifdef ROAM_DEBUG
        glColor4f(0.0, 0.0, 9.0, 0.6);
        glDisable(GL_TEXTURE_2D);
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-       roam_sphere_draw(self->sphere);
-       //roam_sphere_draw_normals(self->sphere);
+       roam_sphere_draw(opengl->sphere);
+       //roam_sphere_draw_normals(opengl->sphere);
 #else
-       g_tree_foreach(self->objects, _draw_level, self);
-       if (self->wireframe) {
+       g_tree_foreach(opengl->objects, _draw_level, opengl);
+       if (opengl->wireframe) {
                glClear(GL_DEPTH_BUFFER_BIT);
                glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-               roam_sphere_draw(self->sphere);
+               roam_sphere_draw(opengl->sphere);
        }
 #endif
 
-       GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(self));
+       GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(GTK_WIDGET(opengl));
        gdk_gl_drawable_swap_buffers(gldrawable);
 
        g_debug("GisOpenGL: on_expose - end\n");
        return FALSE;
 }
 
-static gboolean on_key_press(GisOpenGL *self, GdkEventKey *event, gpointer _)
+static gboolean on_key_press(GisOpenGL *opengl, GdkEventKey *event, gpointer _)
 {
        g_debug("GisOpenGL: on_key_press - key=%x, state=%x, plus=%x",
                        event->keyval, event->state, GDK_plus);
@@ -416,47 +465,52 @@ static gboolean on_key_press(GisOpenGL *self, GdkEventKey *event, gpointer _)
        gdk_threads_leave();
        /* Testing */
        if (kv == GDK_w) {
-               self->wireframe = !self->wireframe;
-               gtk_widget_queue_draw(GTK_WIDGET(self));
+               opengl->wireframe = !opengl->wireframe;
+               gtk_widget_queue_draw(GTK_WIDGET(opengl));
        }
 #ifdef ROAM_DEBUG
-       else if (kv == GDK_n) roam_sphere_split_one(self->sphere);
-       else if (kv == GDK_p) roam_sphere_merge_one(self->sphere);
-       else if (kv == GDK_r) roam_sphere_split_merge(self->sphere);
-       else if (kv == GDK_u) roam_sphere_update_errors(self->sphere);
+       else if (kv == GDK_n) roam_sphere_split_one(opengl->sphere);
+       else if (kv == GDK_p) roam_sphere_merge_one(opengl->sphere);
+       else if (kv == GDK_r) roam_sphere_split_merge(opengl->sphere);
+       else if (kv == GDK_u) roam_sphere_update_errors(opengl->sphere);
        gdk_threads_enter();
-       gtk_widget_queue_draw(GTK_WIDGET(self));
+       gtk_widget_queue_draw(GTK_WIDGET(opengl));
 #else
        gdk_threads_enter();
 #endif
        return FALSE;
 }
 
-static gboolean _update_errors_cb(gpointer sphere)
+static gboolean _update_errors_cb(gpointer _opengl)
 {
-       roam_sphere_update_errors(sphere);
+       GisOpenGL *opengl = _opengl;
+       g_mutex_lock(opengl->sphere_lock);
+       roam_sphere_update_errors(opengl->sphere);
+       g_mutex_unlock(opengl->sphere_lock);
+       opengl->ue_source = 0;
        return FALSE;
 }
-static void on_view_changed(GisOpenGL *self,
+static void on_view_changed(GisOpenGL *opengl,
                gdouble _1, gdouble _2, gdouble _3)
 {
        g_debug("GisOpenGL: on_view_changed");
-       _set_visuals(self);
+       _set_visuals(opengl);
 #ifndef ROAM_DEBUG
-       self->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
-                       _update_errors_cb, self->sphere, NULL);
-       //roam_sphere_update_errors(self->sphere);
+       if (!opengl->ue_source)
+               opengl->ue_source = g_idle_add_full(G_PRIORITY_HIGH_IDLE+30,
+                               _update_errors_cb, opengl, NULL);
+       //roam_sphere_update_errors(opengl->sphere);
 #endif
 }
 
-static gboolean on_idle(GisOpenGL *self)
+static gboolean on_idle(GisOpenGL *opengl)
 {
        //g_debug("GisOpenGL: on_idle");
        gdk_threads_enter();
-       g_mutex_lock(self->sphere_lock);
-       if (roam_sphere_split_merge(self->sphere))
-               gtk_widget_queue_draw(GTK_WIDGET(self));
-       g_mutex_unlock(self->sphere_lock);
+       g_mutex_lock(opengl->sphere_lock);
+       if (roam_sphere_split_merge(opengl->sphere))
+               gtk_widget_queue_draw(GTK_WIDGET(opengl));
+       g_mutex_unlock(opengl->sphere_lock);
        gdk_threads_leave();
        return TRUE;
 }
@@ -465,45 +519,54 @@ static gboolean on_idle(GisOpenGL *self)
 /*********************
  * GisViewer methods *
  *********************/
+/**
+ * gis_opengl_new:
+ * @plugins: the plugins store to use
+ * @prefs:   the preferences object to use
+ *
+ * Create a new OpenGL renderer.
+ *
+ * Returns: the new #GisOpenGL
+ */
 GisViewer *gis_opengl_new(GisPlugins *plugins, GisPrefs *prefs)
 {
        g_debug("GisOpenGL: new");
-       GisViewer *self = g_object_new(GIS_TYPE_OPENGL, NULL);
-       gis_viewer_setup(self, plugins, prefs);
-       return self;
+       GisViewer *opengl = g_object_new(GIS_TYPE_OPENGL, NULL);
+       gis_viewer_setup(opengl, plugins, prefs);
+       return opengl;
 }
 
-static void gis_opengl_center_position(GisViewer *_self, gdouble lat, gdouble lon, gdouble elev)
+static void gis_opengl_center_position(GisViewer *_opengl, gdouble lat, gdouble lon, gdouble elev)
 {
-       GisOpenGL *self = GIS_OPENGL(_self);
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
        glRotatef(lon, 0, 1, 0);
        glRotatef(-lat, 1, 0, 0);
        glTranslatef(0, 0, elev2rad(elev));
 }
 
-static void gis_opengl_project(GisViewer *_self,
+static void gis_opengl_project(GisViewer *_opengl,
                gdouble lat, gdouble lon, gdouble elev,
                gdouble *px, gdouble *py, gdouble *pz)
 {
-       GisOpenGL *self = GIS_OPENGL(_self);
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
        gdouble x, y, z;
        lle2xyz(lat, lon, elev, &x, &y, &z);
        gluProject(x, y, z,
-               self->sphere->view->model,
-               self->sphere->view->proj,
-               self->sphere->view->view,
+               opengl->sphere->view->model,
+               opengl->sphere->view->proj,
+               opengl->sphere->view->view,
                px, py, pz);
 }
 
-static void gis_opengl_set_height_func(GisViewer *_self, GisTile *tile,
+static void gis_opengl_set_height_func(GisViewer *_opengl, GisTile *tile,
                RoamHeightFunc height_func, gpointer user_data, gboolean update)
 {
-       GisOpenGL *self = GIS_OPENGL(_self);
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
        if (!tile)
                return;
        /* TODO: get points? */
-       g_mutex_lock(self->sphere_lock);
-       GList *triangles = roam_sphere_get_intersect(self->sphere, TRUE,
+       g_mutex_lock(opengl->sphere_lock);
+       GList *triangles = roam_sphere_get_intersect(opengl->sphere, TRUE,
                        tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
        for (GList *cur = triangles; cur; cur = cur->next) {
                RoamTriangle *tri = cur->data;
@@ -518,7 +581,7 @@ static void gis_opengl_set_height_func(GisViewer *_self, GisTile *tile,
                }
        }
        g_list_free(triangles);
-       g_mutex_unlock(self->sphere_lock);
+       g_mutex_unlock(opengl->sphere_lock);
 }
 
 static void _gis_opengl_clear_height_func_rec(RoamTriangle *root)
@@ -535,23 +598,23 @@ static void _gis_opengl_clear_height_func_rec(RoamTriangle *root)
        _gis_opengl_clear_height_func_rec(root->kids[1]);
 }
 
-static void gis_opengl_clear_height_func(GisViewer *_self)
+static void gis_opengl_clear_height_func(GisViewer *_opengl)
 {
-       GisOpenGL *self = GIS_OPENGL(_self);
-       for (int i = 0; i < G_N_ELEMENTS(self->sphere->roots); i++)
-               _gis_opengl_clear_height_func_rec(self->sphere->roots[i]);
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
+       for (int i = 0; i < G_N_ELEMENTS(opengl->sphere->roots); i++)
+               _gis_opengl_clear_height_func_rec(opengl->sphere->roots[i]);
 }
 
-static gpointer gis_opengl_add(GisViewer *_self, GisObject *object,
+static gpointer gis_opengl_add(GisViewer *_opengl, GisObject *object,
                gint key, gboolean sort)
 {
-       g_assert(GIS_IS_OPENGL(_self));
-       GisOpenGL *self = GIS_OPENGL(_self);
-       _load_object(self, object);
-       struct RenderLevel *level = g_tree_lookup(self->objects, (gpointer)key);
+       g_assert(GIS_IS_OPENGL(_opengl));
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
+       _load_object(opengl, object);
+       struct RenderLevel *level = g_tree_lookup(opengl->objects, (gpointer)key);
        if (!level) {
                level = g_new0(struct RenderLevel, 1);
-               g_tree_insert(self->objects, (gpointer)key, level);
+               g_tree_insert(opengl->objects, (gpointer)key, level);
        }
        GList *list = sort ? &level->sorted : &level->unsorted;
        /* Put the link in the list */
@@ -563,13 +626,13 @@ static gpointer gis_opengl_add(GisViewer *_self, GisObject *object,
        return next;
 }
 
-static GisObject *gis_opengl_remove(GisViewer *_self, gpointer _link)
+static GisObject *gis_opengl_remove(GisViewer *_opengl, gpointer _link)
 {
-       g_assert(GIS_IS_OPENGL(_self));
-       GisOpenGL *self = GIS_OPENGL(_self);
+       g_assert(GIS_IS_OPENGL(_opengl));
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
        GList *link = _link;
        GisObject *object = link->data;
-       _unload_object(self, object);
+       _unload_object(opengl, object);
        /* Just unlink and free it, link->prev is assured */
        link->prev->next = link->next;
        if (link->next)
@@ -599,7 +662,7 @@ static void _objects_free(gpointer value)
 }
 
 G_DEFINE_TYPE(GisOpenGL, gis_opengl, GIS_TYPE_VIEWER);
-static void gis_opengl_init(GisOpenGL *self)
+static void gis_opengl_init(GisOpenGL *opengl)
 {
        g_debug("GisOpenGL: init");
        /* OpenGL setup */
@@ -608,56 +671,56 @@ static void gis_opengl_init(GisOpenGL *self)
                        GDK_GL_MODE_DOUBLE | GDK_GL_MODE_ALPHA);
        if (!glconfig)
                g_error("Failed to create glconfig");
-       if (!gtk_widget_set_gl_capability(GTK_WIDGET(self),
+       if (!gtk_widget_set_gl_capability(GTK_WIDGET(opengl),
                                glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE))
                g_error("GL lacks required capabilities");
        g_object_unref(glconfig);
 
-       self->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
-       self->sphere = roam_sphere_new(self);
-       self->sphere_lock = g_mutex_new();
+       opengl->objects = g_tree_new_full(_objects_cmp, NULL, NULL, _objects_free);
+       opengl->sphere = roam_sphere_new(opengl);
+       opengl->sphere_lock = g_mutex_new();
 
 #ifndef ROAM_DEBUG
-       self->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33,  (GSourceFunc)on_idle, self, NULL);
-       self->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, self, NULL);
+       opengl->sm_source[0] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+30, 33,  (GSourceFunc)on_idle, opengl, NULL);
+       opengl->sm_source[1] = g_timeout_add_full(G_PRIORITY_HIGH_IDLE+10, 500, (GSourceFunc)on_idle, opengl, NULL);
 #endif
 
-       gtk_widget_add_events(GTK_WIDGET(self), GDK_KEY_PRESS_MASK);
-       g_signal_connect(self, "realize",          G_CALLBACK(on_realize),      NULL);
-       g_signal_connect(self, "configure-event",  G_CALLBACK(on_configure),    NULL);
-       g_signal_connect(self, "expose-event",     G_CALLBACK(on_expose),       NULL);
+       gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
+       g_signal_connect(opengl, "realize",          G_CALLBACK(on_realize),      NULL);
+       g_signal_connect(opengl, "configure-event",  G_CALLBACK(on_configure),    NULL);
+       g_signal_connect(opengl, "expose-event",     G_CALLBACK(on_expose),       NULL);
 
-       g_signal_connect(self, "key-press-event",  G_CALLBACK(on_key_press),    NULL);
+       g_signal_connect(opengl, "key-press-event",  G_CALLBACK(on_key_press),    NULL);
 
-       g_signal_connect(self, "location-changed", G_CALLBACK(on_view_changed), NULL);
-       g_signal_connect(self, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
+       g_signal_connect(opengl, "location-changed", G_CALLBACK(on_view_changed), NULL);
+       g_signal_connect(opengl, "rotation-changed", G_CALLBACK(on_view_changed), NULL);
 }
-static void gis_opengl_dispose(GObject *_self)
+static void gis_opengl_dispose(GObject *_opengl)
 {
        g_debug("GisOpenGL: dispose");
-       GisOpenGL *self = GIS_OPENGL(_self);
-       if (self->sm_source[0]) {
-               g_source_remove(self->sm_source[0]);
-               self->sm_source[0] = 0;
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
+       if (opengl->sm_source[0]) {
+               g_source_remove(opengl->sm_source[0]);
+               opengl->sm_source[0] = 0;
        }
-       if (self->sm_source[1]) {
-               g_source_remove(self->sm_source[1]);
-               self->sm_source[1] = 0;
+       if (opengl->sm_source[1]) {
+               g_source_remove(opengl->sm_source[1]);
+               opengl->sm_source[1] = 0;
        }
-       if (self->ue_source) {
-               g_source_remove(self->ue_source);
-               self->ue_source = 0;
+       if (opengl->ue_source) {
+               g_source_remove(opengl->ue_source);
+               opengl->ue_source = 0;
        }
-       G_OBJECT_CLASS(gis_opengl_parent_class)->dispose(_self);
+       G_OBJECT_CLASS(gis_opengl_parent_class)->dispose(_opengl);
 }
-static void gis_opengl_finalize(GObject *_self)
+static void gis_opengl_finalize(GObject *_opengl)
 {
        g_debug("GisOpenGL: finalize");
-       GisOpenGL *self = GIS_OPENGL(_self);
-       roam_sphere_free(self->sphere);
-       g_tree_destroy(self->objects);
-       g_mutex_free(self->sphere_lock);
-       G_OBJECT_CLASS(gis_opengl_parent_class)->finalize(_self);
+       GisOpenGL *opengl = GIS_OPENGL(_opengl);
+       roam_sphere_free(opengl->sphere);
+       g_tree_destroy(opengl->objects);
+       g_mutex_free(opengl->sphere_lock);
+       G_OBJECT_CLASS(gis_opengl_parent_class)->finalize(_opengl);
 }
 static void gis_opengl_class_init(GisOpenGLClass *klass)
 {