gallium: Add destroy callback to all *_winsys interfaces.

For consistency and to simplify these objects' destruction.

src/gallium/drivers/cell/ppu/cell_screen.c

@@ -132,6 +132,11 @@ cell_is_format_supported( struct pipe_screen *screen,
 static void
 cell_destroy_screen( struct pipe_screen *screen )
 {
+   struct pipe_winsys *winsys = screen->winsys;
+
+   if(winsys->destroy)
+      winsys->destroy(winsys);
+
    FREE(screen);
 }
 

src/gallium/drivers/i915simple/i915_context.c

@@ -44,6 +44,9 @@ static void i915_destroy( struct pipe_context *pipe )
    struct i915_context *i915 = i915_context( pipe );
 
    draw_destroy( i915->draw );
+   
+   if(i915->winsys)
+      i915->winsys->destroy(i915->winsys);
 
    FREE( i915 );
 }

src/gallium/drivers/i915simple/i915_screen.c

@@ -193,6 +193,11 @@ i915_is_format_supported( struct pipe_screen *screen,
 static void
 i915_destroy_screen( struct pipe_screen *screen )
 {
+   struct pipe_winsys *winsys = screen->winsys;
+
+   if(winsys->destroy)
+      winsys->destroy(winsys);
+
    FREE(screen);
 }
 

src/gallium/drivers/i915simple/i915_winsys.h

@@ -75,6 +75,8 @@ struct pipe_screen;
  */
 struct i915_winsys {
 
+   void (*destroy)( struct i915_winsys *sws );
+   
    /**
     * Get the current batch buffer from the winsys.
     */

src/gallium/drivers/i965simple/brw_context.c

@@ -52,6 +52,9 @@ static void brw_destroy(struct pipe_context *pipe)
 {
    struct brw_context *brw = brw_context(pipe);
 
+   if(brw->winsys->destroy)
+      brw->winsys->destroy(brw->winsys);
+   
    FREE(brw);
 }
 

src/gallium/drivers/i965simple/brw_screen.c

@@ -206,6 +206,11 @@ brw_is_format_supported( struct pipe_screen *screen,
 static void
 brw_destroy_screen( struct pipe_screen *screen )
 {
+   struct pipe_winsys *winsys = screen->winsys;
+
+   if(winsys->destroy)
+      winsys->destroy(winsys);
+
    FREE(screen);
 }
 

src/gallium/drivers/i965simple/brw_winsys.h

@@ -112,6 +112,8 @@ enum brw_cache_id {
  */
 struct brw_winsys {
 
+   void (*destroy)(struct brw_winsys *);
+   
    /**
     * Reserve space on batch buffer.
     *

src/gallium/drivers/softpipe/sp_screen.c

@@ -139,6 +139,11 @@ softpipe_is_format_supported( struct pipe_screen *screen,
 static void
 softpipe_destroy_screen( struct pipe_screen *screen )
 {
+   struct pipe_winsys *winsys = screen->winsys;
+
+   if(winsys->destroy)
+      winsys->destroy(winsys);
+
    FREE(screen);
 }
 

src/gallium/include/pipe/p_winsys.h

@@ -62,6 +62,8 @@ struct pipe_surface;
  */
 struct pipe_winsys
 {
+   void (*destroy)( struct pipe_winsys *ws );
+
    /** Returns name of this winsys interface */
    const char *(*get_name)( struct pipe_winsys *ws );