+/* Compass */
+static void compass_draw_compass(gdouble scale)
+{
+ gfloat thick = scale * 0.20;
+
+ /* Setup lighting */
+ float light_ambient[] = {0.4f, 0.4f, 0.4f, 0.4f};
+ float light_diffuse[] = {0.9f, 0.9f, 0.9f, 1.0f};
+ float light_position[] = {-scale*2, -scale*4, -scale*0.5, 1.0f};
+ glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
+ glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
+ glLightfv(GL_LIGHT0, GL_POSITION, light_position);
+
+ /* Compass data */
+ gdouble colors[][3] = {
+ {1, 0, 0},
+ {1, 1, 1},
+ {1, 1, 1},
+ {1, 1, 1},
+ };
+ gdouble points[][3] = {
+ { 0, -scale, 0},
+ { 0, 0, thick},
+ { thick, -thick, 0},
+ { 0, 0, -thick},
+ {-thick, -thick, 0},
+ };
+ gint faces[][3] = {
+ {1, 0, 2},
+ {2, 0, 3},
+ {3, 0, 4},
+ {4, 0, 1},
+ };
+ gint outline[] = {
+ 2, 0, 4,
+ 1, 2, 3, 4,
+ };
+
+ /* Draw compas */
+ glEnable(GL_POLYGON_OFFSET_FILL);
+ glPolygonOffset(1, 1);
+ for (int i = 0; i < G_N_ELEMENTS(colors); i++) {
+ gdouble *color = colors[i];
+ glColor3dv(color);
+ for (int j = 0; j < G_N_ELEMENTS(faces); j++) {
+ gdouble norm[3];
+ gdouble *v0 = points[faces[j][0]];
+ gdouble *v1 = points[faces[j][1]];
+ gdouble *v2 = points[faces[j][2]];
+ crossd3(v2, v1, v0, norm);
+ glNormal3dv(norm);
+ glBegin(GL_TRIANGLES);
+ glVertex3dv(v0);
+ glVertex3dv(v1);
+ glVertex3dv(v2);
+ glEnd();
+ }
+ glRotatef(90, 0, 0, 1);
+ }
+
+ /* Draw outline */
+ glEnable(GL_POLYGON_OFFSET_LINE);
+ glDisable(GL_LIGHTING);
+ glPolygonOffset(0, 0);
+ glColor4f(0, 0, 0, 0.25);
+ glLineWidth(1);
+ for (int i = 0; i < G_N_ELEMENTS(colors); i++) {
+ glBegin(GL_LINE_STRIP);
+ for (int j = 0; j < G_N_ELEMENTS(outline); j++)
+ glVertex3dv(points[outline[j]]);
+ glEnd();
+ glRotatef(90, 0, 0, 1);
+ }
+}
+
+static gboolean compass_draw_teapot(gdouble scale, GritsPluginEnv *env)
+{
+ static int teatime = 0;
+#ifdef HAVE_GLUT
+ static int init, argc; char *argv[] = {"", NULL};
+ if (!init) {
+ teatime = grits_prefs_get_boolean(env->prefs, "grits/teatime", NULL);
+ glutInit(&argc, argv);
+ init = 1;
+ g_message("teatime=%d", teatime);
+ }
+
+ if (teatime) {
+ /* Setup lighting */
+ float light_ambient[] = {0.1f, 0.1f, 0.0f, 1.0f};
+ float light_diffuse[] = {0.9f, 0.9f, 0.9f, 1.0f};
+ float light_position[] = {-50.0f, -40.0f, -80.0f, 1.0f};
+ glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
+ glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
+ glLightfv(GL_LIGHT0, GL_POSITION, light_position);
+
+ /* Draw teapot */
+ glRotatef(-90, 0, 0, 1);
+ glRotatef(-90, 1, 0, 0);
+ glColor4f(0.9, 0.9, 0.7, 1.0);
+ glutSolidTeapot(scale * 0.60);
+ }
+#endif
+ return teatime;
+}
+
+static void compass_expose(GritsCallback *compass, GritsOpenGL *opengl, gpointer _env)
+{
+ GritsPluginEnv *env = GRITS_PLUGIN_ENV(_env);
+ g_debug("GritsPluginEnv: compass_expose");
+ gdouble x, y, z;
+ grits_viewer_get_rotation(env->viewer, &x, &y, &z);
+
+ /* Setup projection */
+ gint win_width = GTK_WIDGET(opengl)->allocation.width;
+ gint win_height = GTK_WIDGET(opengl)->allocation.height;
+ float scale = CLAMP(MIN(win_width,win_height)/2.0 * 0.1, 40, 100);
+ float offset = scale + 20;
+ glTranslatef(win_width - offset, offset, 0);
+
+ /* Setup state */
+ glClear(GL_DEPTH_BUFFER_BIT);
+ glEnable(GL_COLOR_MATERIAL);
+ glEnable(GL_DEPTH_TEST);
+ glDisable(GL_CULL_FACE);
+ glEnable(GL_POLYGON_SMOOTH);
+ glEnable(GL_LINE_SMOOTH);
+
+ /* Draw compass */
+ x = CLAMP(x, -66, 66);;
+ glRotatef(x, 1, 0, 0);
+ glRotatef(-z, 0, 0, 1);
+ if (!compass_draw_teapot(scale, env))
+ compass_draw_compass(scale);
+}
+
+static gboolean compass_click(GritsCallback *compass, GdkEvent *evnet, GritsViewer *viewer)
+{
+ grits_viewer_set_rotation(viewer, 0, 0, 0);
+ return TRUE;
+}