HDR: Force an envmap update when the view changes

Nasal/hdr.nas

@@ -38,30 +38,64 @@ setprop("/sim/rendering/hdr/atmos/ground-albedo[3]", 0.4);
 ################################################################################
 # Environment map
 ################################################################################
+
 var envmap_frame_listener = nil;
 var is_envmap_updating = false;
+
 var is_prefiltering_active = false;
 var current_envmap_face = 0;
 
-var envmap_update_frame = func {
+var all_faces_active = false;
+
+var envmap_set_render_face = func(face, active) {
+    setprop("/sim/rendering/hdr/envmap/should-render-face-" ~ face, active);
+}
+
+var envmap_set_render_all_faces = func(active) {
+    for (var i = 0; i < 6; i += 1) {
+        envmap_set_render_face(i, active);
+    }
+}
+
+var envmap_set_prefilter = func(active) {
+    setprop("/sim/rendering/hdr/envmap/should-prefilter", active);
+}
+
+# Update all the faces of the environment cubemap in a single frame
+var envmap_update_all_faces_callback = func {
+    if (all_faces_active) {
+        if (envmap_frame_listener != nil)
+            removelistener(envmap_frame_listener);
+        envmap_set_render_all_faces(false);
+        envmap_set_prefilter(false);
+        is_envmap_updating = false;
+        all_faces_active = false;
+    } else {
+        envmap_set_render_all_faces(true);
+        envmap_set_prefilter(true);
+        all_faces_active = true;
+    }
+}
+
+# Update a single cubemap face each frame. The prefiltering step is also done
+# in a separate step, totalling 7 frames to update the entire environment map.
+var envmap_update_frame_callback = func {
     if (is_prefiltering_active) {
         # Last frame we activated the prefiltering, which is the last step.
         # Now disable it and reset all variables for the next update cycle.
         removelistener(envmap_frame_listener);
-        setprop("/sim/rendering/hdr/envmap/should-prefilter", false);
+        envmap_set_prefilter(false);
         is_prefiltering_active = false;
         is_envmap_updating = false;
         return;
     }
     if (current_envmap_face < 6) {
         # Render the current face
-        setprop("/sim/rendering/hdr/envmap/should-render-face-"
+        envmap_set_render_face(current_envmap_face, true);
-                ~ current_envmap_face, true);
     }
     if (current_envmap_face > 0) {
         # Stop rendering the previous face
-        setprop("/sim/rendering/hdr/envmap/should-render-face-"
+        envmap_set_render_face(current_envmap_face - 1, false);
-                ~ (current_envmap_face - 1), false);
     }
     if (current_envmap_face < 6) {
         # Go to next face and update it next frame
@@ -71,25 +105,38 @@ var envmap_update_frame = func {
         # prefilter the envmap.
         current_envmap_face = 0;
         is_prefiltering_active = true;
-        setprop("/sim/rendering/hdr/envmap/should-prefilter", true);
+        envmap_set_prefilter(true);
     }
 }
 
-var update_envmap = func {
+var update_envmap = func(instant = false) {
-    if (!is_envmap_updating) {
+    if (is_envmap_updating) {
+        # We are currently updating the envmap, so cancel and start over
+        if (envmap_frame_listener != nil)
+            removelistener(envmap_frame_listener);
+
+        is_prefiltering_active = false;
+        all_faces_active = false;
+        current_envmap_face = 0;
+
+        envmap_set_render_all_faces(false);
+        envmap_set_prefilter(false);
+    } else {
         is_envmap_updating = true;
-        # We use a listener to the frame signal because it is guaranteed to be
-        # fired at a defined moment, while a settimer() with interval 0 might
-        # not if subsystems are re-ordered.
-        envmap_frame_listener = setlistener("/sim/signals/frame",
-                                            envmap_update_frame);
     }
+
+    var callback = instant ? envmap_update_all_faces_callback
+        : envmap_update_frame_callback;
+    # We use a listener to the frame signal because it is guaranteed to be
+    # fired at a defined moment, while a settimer() with interval 0 might
+    # not if subsystems are re-ordered.
+    envmap_frame_listener = setlistener("/sim/signals/frame", callback);
 }
 
 # Manual update
 setlistener("/sim/rendering/hdr/envmap/force-update", func(p) {
     if (p.getValue()) {
-        update_envmap();
+        update_envmap(true);
         p.setValue(false);
     }
 }, 0, 0);
@@ -107,6 +154,8 @@ setlistener("/sim/signals/fdm-initialized", func {
     settimer(update_envmap, 5);
 });
 
+# If the update rate is modified at runtime, force an envmap update and restart
+# the timer with the new period.
 setlistener("/sim/rendering/hdr/envmap/update-rate-s", func(p) {
     if (envmap_timer.isRunning) {
         update_envmap();
@@ -115,7 +164,11 @@ setlistener("/sim/rendering/hdr/envmap/update-rate-s", func(p) {
 });
 
 # Update the envmap much faster when time warp is active
-var envmap_timer_warp = maketimer(1, update_envmap);
+var envmap_timer_warp = maketimer(1, func() {
+    update_envmap(true);
+});
+envmap_timer_warp.simulatedTime = true;
+
 setlistener("/sim/time/warp-delta", func(p) {
     if (p.getValue() != 0) {
         envmap_timer_warp.start();
@@ -126,3 +179,8 @@ setlistener("/sim/time/warp-delta", func(p) {
         settimer(update_envmap, 1);
     }
 });
+
+# Update the envmap when the view changes
+setlistener("/sim/current-view/view-number", func {
+    update_envmap(true);
+}, 0, 0);