Improve re-use of client/compositor shared memory by Wayland buffers

1 files changed, 7 insertions, 34 deletions

diff --git a/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H b/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H
index b6697df40..81a3dbf8f 100644
--- a/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H
+++ b/src/drivers/Wayland/Fl_Wayland_Graphics_Driver.H
@@ -1,7 +1,7 @@
 //
 // Definition of class Fl_Wayland_Graphics_Driver.
 //
-// Copyright 2021-2022 by Bill Spitzak and others.
+// Copyright 2021-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -22,37 +22,10 @@
 #ifndef FL_WAYLAND_GRAPHICS_DRIVER_H
 #define FL_WAYLAND_GRAPHICS_DRIVER_H
 
-
-/* Implementation note about buffers FLTK uses to support display graphics under Wayland.
-
- Each window is associated to an FLTK-defined object of type struct wld_window
- containing itself an FLTK-defined struct fl_wld_buffer object holding all graphics data.
- Among members of this latter structure are:
- - struct wl_buffer wl_buffer
- is a Wayland-defined type for a graphics buffer able to be attached to a wl_surface;
- - void *data
- points to the beginning of the memory zone where wl_buffer stores its graphics data;
- - unsigned char *draw_buffer
- contains a graphics buffer to which all Cairo drawings are directed;
- draw_buffer and data both have the same organization called CAIRO_FORMAT_ARGB32 in Cairo parlance
- and WL_SHM_FORMAT_ARGB8888 in Wayland parlance which means BGRA byte order.
- - int width
- gives the pixel width of the graphics buffer;
- - int stride
- gives the stride of this buffer;
- - size_t data_size
- gives the total buffer size in bytes (thus, data_size / stride gives the buffer height);
- - struct wl_callback *cb
- is used to synchronize drawing with the compositor during progressive drawing.
-
- When a graphics scene is to be committed, the data_size bytes of draw_buffer are copied by memcpy()
- starting at data, and wl_buffer is attached to the wl_surface which is committed for display
- by wl_surface_commit().
- */
-
-
 #include "../Cairo/Fl_Cairo_Graphics_Driver.H"
 #include <stdint.h> // for uint32_t
+#include <wayland-client.h> // for wl_list
+
 
 struct fl_wld_buffer {
   struct wl_buffer *wl_buffer;
@@ -64,19 +37,19 @@ struct fl_wld_buffer {
   struct wl_callback *cb;
   bool draw_buffer_needs_commit;
   cairo_t *cairo_;
+  struct wl_shm_pool *shm_pool;
+  struct wl_list link; // links all buffers from the same wl_shm_pool
 };
-struct wld_window;
 
 
 class Fl_Wayland_Graphics_Driver : public Fl_Cairo_Graphics_Driver {
 private:
   struct fl_wld_buffer *buffer_;
 public:
-  struct wld_shm_pool_data { // attached to wl_shm_pool objects
+  struct wld_shm_pool_data { // one record attached to each wl_shm_pool object
     char *pool_memory; // start of mmap'ed memory encapsulated by the wl_shm_pool
     int pool_size; // size of encapsulated memory
-    int use_count; // nber of active wl_buffer objects in this wl_shm_pool
-    bool destroyed; // true after the wl_shm_pool was destroyed
+    struct wl_list buffers; // to list of fl_wld_buffer's from this pool
   };
   Fl_Wayland_Graphics_Driver();
   static const uint32_t wld_format;