Rewrite expose to preserve the depth buffer

[grits] / src / grits-opengl.c

diff --git a/src/grits-opengl.c b/src/grits-opengl.c
index a39fbda1733f87d8f55c9c8b1b354b00cabeb8ba..961a875207c57b1109503d64877a38399c31c4d5 100644 (file)
--- a/src/grits-opengl.c
+++ b/src/grits-opengl.c
@@ -57,13 +57,30 @@ struct RenderLevel {
  ***********/
 static void _set_visuals(GritsOpenGL *opengl)
 {
+       double lat, lon, elev, rx, ry, rz;
+       grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
+       grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
+
+       /* Set projection and clipping planes */
+       glMatrixMode(GL_PROJECTION);
+       glLoadIdentity();
+
+       double width  = GTK_WIDGET(opengl)->allocation.width;
+       double height = GTK_WIDGET(opengl)->allocation.height;
+       double ang    = atan(height/FOV_DIST);
+       double atmos  = 100000;
+       double near   = MAX(elev*0.75 - atmos, 50); // View 100km of atmosphere
+       double far    = elev + 2*EARTH_R + atmos;   // on both sides of the earth
+
+       grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
+       glViewport(0, 0, width, height);
+       gluPerspective(rad2deg(ang)*2, width/height, near, far);
+
+       /* Setup camera and lighting */
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
 
        /* Camera 1 */
-       double lat, lon, elev, rx, ry, rz;
-       grits_viewer_get_location(GRITS_VIEWER(opengl), &lat, &lon, &elev);
-       grits_viewer_get_rotation(GRITS_VIEWER(opengl), &rx, &ry, &rz);
        glRotatef(rx, 1, 0, 0);
        glRotatef(rz, 0, 0, 1);
 
@@ -159,16 +176,7 @@ static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpoi
 {
        g_debug("GritsOpenGL: on_configure");
 
-       double width  = GTK_WIDGET(opengl)->allocation.width;
-       double height = GTK_WIDGET(opengl)->allocation.height;
-
-       /* Setup OpenGL Window */
-       glViewport(0, 0, width, height);
-       glMatrixMode(GL_PROJECTION);
-       glLoadIdentity();
-       double ang = atan(height/FOV_DIST);
-       gluPerspective(rad2deg(ang)*2, width/height, 10, 100*EARTH_R);
-
+       _set_visuals(opengl);
 #ifndef ROAM_DEBUG
        g_mutex_lock(opengl->sphere_lock);
        roam_sphere_update_errors(opengl->sphere);
@@ -180,22 +188,39 @@ static gboolean on_configure(GritsOpenGL *opengl, GdkEventConfigure *event, gpoi
 
 static gboolean _draw_level(gpointer key, gpointer value, gpointer user_data)
 {
-       g_debug("GritsOpenGL: _draw_level - level=%-4ld", (glong)key);
        GritsOpenGL *opengl = user_data;
+       glong lnum = (glong)key;
        struct RenderLevel *level = value;
+
+       g_debug("GritsOpenGL: _draw_level - level=%-4ld", lnum);
        int nsorted = 0, nunsorted = 0;
        GList *cur = NULL;
 
-       /* Draw opaque objects without sorting */
-       glDepthMask(TRUE);
-       glClear(GL_DEPTH_BUFFER_BIT);
+       /* Configure individual levels */
+       if (lnum < GRITS_LEVEL_WORLD) {
+               /* Disable depth for background levels */
+               glDepthMask(FALSE);
+               glDisable(GL_ALPHA_TEST);
+       } else if (lnum < GRITS_LEVEL_OVERLAY) {
+               /* Enable depth and alpha for world levels */
+               glEnable(GL_ALPHA_TEST);
+               glAlphaFunc(GL_GREATER, 0.1);
+               glDepthMask(TRUE);
+       } else {
+               /* Disable depth for Overlay/HUD levels */
+               // This causes rendering glitches not sure why..
+               //glDepthMask(FALSE);
+       }
+
+       /* Draw unsorted objects without depth testing,
+        * these are polygons, etc, rather than physical objects */
+       glDisable(GL_DEPTH_TEST);
        for (cur = level->unsorted.next; cur; cur = cur->next, nunsorted++)
                grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 
-       /* Freeze depth buffer and draw transparent objects sorted */
-       /* TODO: sorting */
-       //glDepthMask(FALSE);
-       glAlphaFunc(GL_GREATER, 0.1);
+       /* Draw sorted objects using depth testing
+        * These are things that are actually part of the world */
+       glEnable(GL_DEPTH_TEST);
        for (cur = level->sorted.next; cur; cur = cur->next, nsorted++)
                grits_object_draw(GRITS_OBJECT(cur->data), opengl);
 
@@ -210,7 +235,9 @@ static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _
 {
        g_debug("GritsOpenGL: on_expose - begin");
 
-       glClear(GL_COLOR_BUFFER_BIT);
+       gtk_gl_begin(GTK_WIDGET(opengl));
+
+       glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
        _set_visuals(opengl);
 #ifdef ROAM_DEBUG
@@ -223,13 +250,9 @@ static gboolean on_expose(GritsOpenGL *opengl, GdkEventExpose *event, gpointer _
        //roam_sphere_draw_normals(opengl->sphere);
 #else
        g_mutex_lock(opengl->objects_lock);
-       g_tree_foreach(opengl->objects, _draw_level, opengl);
-       if (opengl->wireframe) {
-               glClear(GL_DEPTH_BUFFER_BIT);
+       if (opengl->wireframe)
                glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-               roam_sphere_draw(opengl->sphere);
-               g_tree_foreach(opengl->objects, _draw_level, opengl);
-       }
+       g_tree_foreach(opengl->objects, _draw_level, opengl);
        g_mutex_unlock(opengl->objects_lock);
 #endif
 
@@ -551,7 +574,8 @@ static void grits_opengl_init(GritsOpenGL *opengl)
        opengl->sphere       = roam_sphere_new(opengl);
        opengl->sphere_lock  = g_mutex_new();
        gtk_gl_enable(GTK_WIDGET(opengl));
-       g_signal_connect(opengl, "realize", G_CALLBACK(on_realize), NULL);
+       gtk_widget_add_events(GTK_WIDGET(opengl), GDK_KEY_PRESS_MASK);
+       g_signal_connect(opengl, "map", G_CALLBACK(on_realize), NULL);
 }
 static void grits_opengl_dispose(GObject *_opengl)
 {