using dirty bits for poll-based frame events

glonkers.c

@@ -60,9 +60,9 @@ int main(int argc, char *argv[]) {
     while (running) {
         double time = time_since_start();
 
-        struct event event;
+        struct event event = wait_for_event(&state);
-        wait_for_event(&state, &event);
         if (event.type == EVENT_DRAW) {
+            printf("drawing!!!!\n");
             int width = event.data.draw.width;
             int height = event.data.draw.height;
             render(&renderer, width, height, time, shader_path, 0);

wayland.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include "wayland.h"
 
 /// Starting values.
@@ -47,6 +48,7 @@ static void xdg_toplevel_configure (
     while (next->data.xdg_toplevel != xdg_toplevel) { next = next->next; }
     next->data.width = width;
     next->data.height = height;
+    printf("🧟🧟🧟\n");
     wl_egl_window_resize(next->data.egl_window, width, height, 0, 0);
 }
 
@@ -76,6 +78,7 @@ static void zwlr_layer_surface_v1_configure(void *data, struct zwlr_layer_surfac
     next->data.height = height;
     wl_egl_window_resize(next->data.egl_window, width, height, 0, 0);
     zwlr_layer_surface_v1_ack_configure(zwlr_layer_surface_v1, serial);
+    printf("🐍🐍🐍🐍\n");
 }
 
 static void zwlr_layer_surface_v1_closed(void *data, struct zwlr_layer_surface_v1 * zwlr_layer_surface_v1) {
@@ -88,6 +91,43 @@ static const struct zwlr_layer_surface_v1_listener zwlr_layer_surface_v1_listene
     .closed = zwlr_layer_surface_v1_closed,
 };
 
+static const struct wl_callback_listener wl_surface_frame_listener;
+
+static void
+wl_surface_frame_done(void *data, struct wl_callback *cb, uint32_t time) {
+    printf("FRAME CALLBACK 🐷🐷\n");
+
+	/* Destroy this callback */
+	wl_callback_destroy(cb);
+
+	struct surface *surface = data;
+    surface->dirty = true;
+    //struct client_state *state = surface->state;
+
+	/* Request another frame */
+    // TODO make sure this is done after the frame has been handled.
+	//cb = wl_surface_frame(surface->wl_surface);
+	//wl_callback_add_listener(cb, &wl_surface_frame_listener, surface);
+
+	///* Update scroll amount at 24 pixels per second */
+	//if (state->last_frame != 0) {
+	//	int elapsed = time - state->last_frame;
+	//	state->offset += elapsed / 1000.0 * 24;
+	//}
+
+	///* Submit a frame for this event */
+	//struct wl_buffer *buffer = draw_frame(state);
+	//wl_surface_attach(state->wl_surface, buffer, 0, 0);
+	//wl_surface_damage_buffer(state->wl_surface, 0, 0, INT32_MAX, INT32_MAX);
+	//wl_surface_commit(state->wl_surface);
+
+	//state->last_frame = time;
+}
+
+static const struct wl_callback_listener wl_surface_frame_listener = {
+	.done = wl_surface_frame_done,
+};
+
 static void registry_handle_global(
         void *data,
         struct wl_registry *registry,
@@ -126,10 +166,17 @@ static void registry_handle_global(
             .wl_surface = wl_surface,
             .xdg_surface = xdg_surface,
             .xdg_toplevel = xdg_toplevel,
+            .dirty = false,
+            .width = DEFAULT_WIDTH,
+            .height = DEFAULT_HEIGHT,
         };
         state->surface_list = malloc(sizeof(struct surface_list));
         state->surface_list->data = surface;
         state->surface_list->next = NULL;
+
+        // frame callback
+        struct wl_callback *cb = wl_surface_frame(wl_surface);
+        wl_callback_add_listener(cb, &wl_surface_frame_listener, &state->surface_list->data);
     }
     if ((strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) && (state->output_type == OUTPUT_LAYER)) {
         state->zwlr_layer_shell_v1 = wl_registry_bind(registry, name, &zwlr_layer_shell_v1_interface, 4);
@@ -159,18 +206,29 @@ static void registry_handle_global(
         struct surface surface = {
             .wl_surface = wl_surface,
             .zwlr_layer_surface_v1 = zwlr_layer_surface_v1,
+            .dirty = false,
+            .width = DEFAULT_WIDTH,
+            .height = DEFAULT_HEIGHT,
         };
+        // persistent pointer for the callback
+        struct surface *surface_location;
         if (state->surface_list == NULL) {
             state->surface_list = malloc(sizeof(struct surface_list));
             state->surface_list->data = surface;
             state->surface_list->next = NULL;
+            surface_location = &state->surface_list->data;
         } else {
             struct surface_list *next = state->surface_list;
             while (next->next != NULL) { next = next->next; }
             next->next = malloc(sizeof(struct surface_list));
             next->next->data = surface;
             next->next->next = NULL;
+            surface_location = &next->next->data;
         }
+
+        // frame callback
+        struct wl_callback *cb = wl_surface_frame(wl_surface);
+        wl_callback_add_listener(cb, &wl_surface_frame_listener, surface_location);
     }
 }
 
@@ -253,6 +311,7 @@ static void egl_init(struct client_state *state) {
     // EGL window
     struct surface_list *next = state->surface_list;
     while (next != NULL) {
+        printf("Creating egl window of size: %dx%d\n", next->data.width, next->data.height);
         next->data.egl_window = wl_egl_window_create(next->data.wl_surface,
                                   next->data.width, next->data.height);
         if (next->data.egl_window == EGL_NO_SURFACE) {
@@ -295,9 +354,6 @@ void wayland_init(struct client_state *state, int output_type) {
     }
 
     egl_init(state);
-    
-    // TODO fix frame callbacks for all surfaces
-
 }
 
 /// Swaps front/backbuffers and dispatches pending wayland commands.
@@ -320,7 +376,29 @@ void commit(struct client_state *state) {
     }
 }
 
-void wait_for_event(struct client_state *state, struct event event) {
+struct event wait_for_event(struct client_state *state) {
+    for (;;) {
+        // before dispatch: check that there is nothing elese to do
+        // check for dirty surface
+        struct surface_list *next = state->surface_list;
+        printf("listtttt\n");
+        while (next != NULL) {
+            if (next->data.dirty) {
+                printf("dirty\n");
+                struct event event = {
+                    .type = EVENT_DRAW,
+                    .data = {
+                        .draw = {
+                            .width = next->data.width,
+                            .height = next->data.height,
+                        }
+                    }
+                };
+                return event;
+            }
+            next = next->next;
+        }
         wl_display_dispatch(state->wl_display);
+    }
 }
 

wayland.h

@@ -8,9 +8,15 @@
 /// A desktop layer (wallpaper)
 #define OUTPUT_LAYER 1
 
+#define DEFAULT_WIDTH 400
+#define DEFAULT_HEIGHT 400
+
 struct surface {
     int width, height;
 
+    /// Wating to be redrawn.
+    bool dirty;
+
     struct wl_surface *wl_surface;
     struct xdg_surface *xdg_surface;
     struct xdg_toplevel *xdg_toplevel;
@@ -43,7 +49,8 @@ struct client_state {
     EGLContext egl_context;
 };
 
-#define EVENT_DRAW 0
+#define EVENT_NONE 0
+#define EVENT_DRAW 1
 
 struct event {
     int type;
@@ -58,5 +65,5 @@ struct event {
 void wayland_init(struct client_state *state, int output_type);
 void commit(struct client_state *state);
 /// Provide pointer to be filled.
-void wait_for_event(struct client_state *state, struct event event);
+struct event wait_for_event(struct client_state *state);