Add hacky lazy damage tracking implementation

README.md

@@ -30,6 +30,7 @@ The dependencies required are:
 
 - [wlroots](https://github.com/swaywm/wlroots)
 - lua or luajit
+- pixman
 - meson (build)
 - ninja (build)
 - git (build, optional)

include/desktop/layer_shell.h

@@ -25,6 +25,8 @@ struct kiwmi_layer {
 
     struct wl_listener destroy;
     struct wl_listener commit;
+    struct wl_listener map;
+    struct wl_listener unmap;
 
     struct wlr_box geom;
 };

include/desktop/output.h

@@ -23,6 +23,8 @@ struct kiwmi_output {
     struct wl_list layers[4]; // struct kiwmi_layer_surface::link
     struct wlr_box usable_area;
 
+    bool damaged;
+
     struct {
         struct wl_signal destroy;
         struct wl_signal resize;

kiwmi/desktop/layer_shell.c

@@ -24,6 +24,8 @@ kiwmi_layer_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
 
     wl_list_remove(&layer->link);
     wl_list_remove(&layer->destroy.link);
+    wl_list_remove(&layer->map.link);
+    wl_list_remove(&layer->unmap.link);
 
     wlr_layer_surface_v1_close(layer->layer_surface);
 
@@ -38,7 +40,12 @@ kiwmi_layer_commit_notify(struct wl_listener *listener, void *UNUSED(data))
     struct kiwmi_layer *layer   = wl_container_of(listener, layer, commit);
     struct kiwmi_output *output = layer->output;
 
+    struct wlr_box old_geom = layer->geom;
+
+    arrange_layers(output);
+
     bool layer_changed = layer->layer != layer->layer_surface->current.layer;
+    bool geom_changed  = memcmp(&old_geom, &layer->geom, sizeof(old_geom)) != 0;
 
     if (layer_changed) {
         wl_list_remove(&layer->link);
@@ -46,7 +53,25 @@ kiwmi_layer_commit_notify(struct wl_listener *listener, void *UNUSED(data))
         wl_list_insert(&output->layers[layer->layer], &layer->link);
     }
 
-    arrange_layers(output);
+    if (layer_changed || geom_changed) {
+        output->damaged = true;
+    }
+}
+
+static void
+kiwmi_layer_map_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_layer *layer = wl_container_of(listener, layer, map);
+
+    layer->output->damaged = true;
+}
+
+static void
+kiwmi_layer_unmap_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_layer *layer = wl_container_of(listener, layer, unmap);
+
+    layer->output->damaged = true;
 }
 
 static void
@@ -390,6 +415,12 @@ layer_shell_new_surface_notify(struct wl_listener *listener, void *data)
     layer->commit.notify = kiwmi_layer_commit_notify;
     wl_signal_add(&layer_surface->surface->events.commit, &layer->commit);
 
+    layer->map.notify = kiwmi_layer_map_notify;
+    wl_signal_add(&layer_surface->events.map, &layer->map);
+
+    layer->unmap.notify = kiwmi_layer_unmap_notify;
+    wl_signal_add(&layer_surface->events.unmap, &layer->unmap);
+
     wl_list_insert(&output->layers[layer->layer], &layer->link);
 
     // Temporarily set the layer's current state to client_pending

kiwmi/desktop/output.c

@@ -31,29 +31,35 @@ static void
 render_layer_surface(struct wlr_surface *surface, int x, int y, void *data)
 {
     struct kiwmi_render_data *rdata = data;
-    struct wlr_output *output       = rdata->output;
+    struct wlr_output *wlr_output   = rdata->output;
     struct wlr_box *geom            = rdata->data;
+    struct kiwmi_output *output     = wlr_output->data;
 
     struct wlr_texture *texture = wlr_surface_get_texture(surface);
     if (!texture) {
         return;
     }
 
+    if (!output->damaged) {
+        wlr_surface_send_frame_done(surface, rdata->when);
+        return;
+    }
+
     int ox = x + geom->x;
     int oy = y + geom->y;
 
     struct wlr_box box = {
-        .x      = ox * output->scale,
+        .x      = ox * wlr_output->scale,
-        .y      = oy * output->scale,
+        .y      = oy * wlr_output->scale,
-        .width  = surface->current.width * output->scale,
+        .width  = surface->current.width * wlr_output->scale,
-        .height = surface->current.height * output->scale,
+        .height = surface->current.height * wlr_output->scale,
     };
 
     float matrix[9];
     enum wl_output_transform transform =
         wlr_output_transform_invert(surface->current.transform);
     wlr_matrix_project_box(
-        matrix, &box, transform, 0, output->transform_matrix);
+        matrix, &box, transform, 0, wlr_output->transform_matrix);
 
     wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
 
@@ -77,28 +83,34 @@ render_surface(struct wlr_surface *surface, int sx, int sy, void *data)
 {
     struct kiwmi_render_data *rdata = data;
     struct kiwmi_view *view         = rdata->data;
-    struct wlr_output *output       = rdata->output;
+    struct wlr_output *wlr_output   = rdata->output;
+    struct kiwmi_output *output     = wlr_output->data;
 
     struct wlr_texture *texture = wlr_surface_get_texture(surface);
     if (!texture) {
         return;
     }
 
+    if (!output->damaged) {
+        wlr_surface_send_frame_done(surface, rdata->when);
+        return;
+    }
+
     int ox = rdata->output_lx + sx + view->x - view->geom.x;
     int oy = rdata->output_ly + sy + view->y - view->geom.y;
 
     struct wlr_box box = {
-        .x      = ox * output->scale,
+        .x      = ox * wlr_output->scale,
-        .y      = oy * output->scale,
+        .y      = oy * wlr_output->scale,
-        .width  = surface->current.width * output->scale,
+        .width  = surface->current.width * wlr_output->scale,
-        .height = surface->current.height * output->scale,
+        .height = surface->current.height * wlr_output->scale,
     };
 
     float matrix[9];
     enum wl_output_transform transform =
         wlr_output_transform_invert(surface->current.transform);
     wlr_matrix_project_box(
-        matrix, &box, transform, 0, output->transform_matrix);
+        matrix, &box, transform, 0, wlr_output->transform_matrix);
 
     wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
 
@@ -128,7 +140,9 @@ output_frame_notify(struct wl_listener *listener, void *data)
     wlr_output_effective_resolution(wlr_output, &width, &height);
 
     wlr_renderer_begin(renderer, width, height);
-    wlr_renderer_clear(renderer, desktop->bg_color);
+    if (output->damaged) {
+        wlr_renderer_clear(renderer, desktop->bg_color);
+    }
 
     double output_lx = 0;
     double output_ly = 0;
@@ -154,9 +168,13 @@ output_frame_notify(struct wl_listener *listener, void *data)
 
         rdata.data = view;
 
-        wl_signal_emit(&view->events.pre_render, &rdata);
+        if (output->damaged) {
-        view_for_each_surface(view, render_surface, &rdata);
+            wl_signal_emit(&view->events.pre_render, &rdata);
-        wl_signal_emit(&view->events.post_render, &rdata);
+            view_for_each_surface(view, render_surface, &rdata);
+            wl_signal_emit(&view->events.post_render, &rdata);
+        } else {
+            view_for_each_surface(view, render_surface, &rdata);
+        }
     }
 
     render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &rdata);
@@ -165,6 +183,8 @@ output_frame_notify(struct wl_listener *listener, void *data)
     wlr_output_render_software_cursors(wlr_output, NULL);
     wlr_renderer_end(renderer);
 
+    output->damaged = false;
+
     wlr_output_commit(wlr_output);
 }
 
@@ -176,6 +196,7 @@ output_commit_notify(struct wl_listener *listener, void *data)
 
     if (event->committed & WLR_OUTPUT_STATE_TRANSFORM) {
         arrange_layers(output);
+        output->damaged = true;
 
         wl_signal_emit(&output->events.resize, output);
     }
@@ -204,6 +225,7 @@ output_mode_notify(struct wl_listener *listener, void *UNUSED(data))
     struct kiwmi_output *output = wl_container_of(listener, output, mode);
 
     arrange_layers(output);
+    output->damaged = true;
 
     wl_signal_emit(&output->events.resize, output);
 }
@@ -222,6 +244,8 @@ output_create(struct wlr_output *wlr_output, struct kiwmi_desktop *desktop)
     output->usable_area.width  = wlr_output->width;
     output->usable_area.height = wlr_output->height;
 
+    output->damaged = true;
+
     output->frame.notify = output_frame_notify;
     wl_signal_add(&wlr_output->events.frame, &output->frame);
 

kiwmi/desktop/xdg_shell.c

@@ -26,6 +26,11 @@ xdg_surface_map_notify(struct wl_listener *listener, void *UNUSED(data))
     struct kiwmi_view *view = wl_container_of(listener, view, map);
     view->mapped            = true;
 
+    struct kiwmi_output *output;
+    wl_list_for_each (output, &view->desktop->outputs, link) {
+        output->damaged = true;
+    }
+
     wl_signal_emit(&view->desktop->events.view_map, view);
 }
 
@@ -37,6 +42,11 @@ xdg_surface_unmap_notify(struct wl_listener *listener, void *UNUSED(data))
     if (view->mapped) {
         view->mapped = false;
 
+        struct kiwmi_output *output;
+        wl_list_for_each (output, &view->desktop->outputs, link) {
+            output->damaged = true;
+        }
+
         wl_signal_emit(&view->events.unmap, view);
     }
 }
@@ -46,6 +56,13 @@ xdg_surface_commit_notify(struct wl_listener *listener, void *UNUSED(data))
 {
     struct kiwmi_view *view = wl_container_of(listener, view, commit);
 
+    if (pixman_region32_not_empty(&view->wlr_surface->buffer_damage)) {
+        struct kiwmi_output *output;
+        wl_list_for_each (output, &view->desktop->outputs, link) {
+            output->damaged = true;
+        }
+    }
+
     wlr_xdg_surface_get_geometry(view->xdg_surface, &view->geom);
 }
 

kiwmi/input/cursor.c

@@ -126,6 +126,10 @@ process_cursor_motion(struct kiwmi_server *server, uint32_t time)
     } else {
         wlr_seat_pointer_clear_focus(seat);
     }
+
+    wl_list_for_each (output, &server->desktop.outputs, link) {
+        output->damaged = true;
+    }
 }
 
 static void

kiwmi/input/seat.c

@@ -111,6 +111,14 @@ request_set_cursor_notify(struct wl_listener *listener, void *data)
         return;
     }
 
+    struct kiwmi_input *input   = seat->input;
+    struct kiwmi_server *server = wl_container_of(input, server, input);
+
+    struct kiwmi_output *output;
+    wl_list_for_each (output, &server->desktop.outputs, link) {
+        output->damaged = true;
+    }
+
     wlr_cursor_set_surface(
         cursor->cursor, event->surface, event->hotspot_x, event->hotspot_y);
 }

kiwmi/meson.build

@@ -25,6 +25,7 @@ kiwmi_sources = files(
 
 kiwmi_deps = [
   lua,
+  pixman,
   protocols_server,
   wayland_server,
   wlroots,

meson.build

@@ -18,6 +18,7 @@ add_project_arguments(
 
 git               = find_program('git', required: false)
 lua               = dependency(get_option('lua-pkg'))
+pixman            = dependency('pixman-1')
 wayland_client    = dependency('wayland-client')
 wayland_protocols = dependency('wayland-protocols')
 wayland_scanner   = dependency('wayland-scanner')