dri: get rid of LIBGL_SHOW_FPS

The same functionnality can be achieved using GALLIUM_HUD=stdout,fps (and for
now a fallback is doing this if LIBGL_SHOW_FPS=1 is used).

This removes one entry from the vtable and simplify dri3_handle_present_event.

Reviewed-by: Emma Anholt <emma@anholt.net>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20494>

docs/envvars.rst

@@ -30,11 +30,6 @@ LibGL environment variables
    if set to ``true``, do not use DrawArrays GLX protocol (for
    debugging)
 
-.. envvar:: LIBGL_SHOW_FPS
-
-   print framerate to stdout based on the number of ``glXSwapBuffers``
-   calls per second.
-
 .. envvar:: LIBGL_DRI2_DISABLE
 
    disable DRI2 if set to ``true``.

src/egl/drivers/dri2/platform_x11_dri3.c

@@ -101,7 +101,6 @@ static const struct loader_dri3_vtable egl_dri3_vtable = {
    .get_dri_context = egl_dri3_get_dri_context,
    .get_dri_screen = egl_dri3_get_dri_screen,
    .flush_drawable = egl_dri3_flush_drawable,
-   .show_fps = NULL,
 };
 
 static EGLBoolean

src/glx/dri2_glx.c

@@ -654,29 +654,6 @@ unsigned dri2GetSwapEventType(Display* dpy, XID drawable)
       return glx_dpy->codes.first_event + GLX_BufferSwapComplete;
 }
 
-static void show_fps(struct dri2_drawable *draw)
-{
-   const int interval =
-      ((struct dri2_screen *) draw->base.psc)->show_fps_interval;
-   struct timeval tv;
-   uint64_t current_time;
-
-   gettimeofday(&tv, NULL);
-   current_time = (uint64_t)tv.tv_sec*1000000 + (uint64_t)tv.tv_usec;
-
-   draw->frames++;
-
-   if (draw->previous_time + interval * 1000000 <= current_time) {
-      if (draw->previous_time) {
-         fprintf(stderr, "libGL: FPS = %.2f\n",
-                 ((uint64_t)draw->frames * 1000000) /
-                 (double)(current_time - draw->previous_time));
-      }
-      draw->frames = 0;
-      draw->previous_time = current_time;
-   }
-}
-
 static int64_t
 dri2XcbSwapBuffers(Display *dpy,
                   __GLXDRIdrawable *pdraw,
@@ -744,10 +721,6 @@ dri2SwapBuffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
     ret = dri2XcbSwapBuffers(pdraw->psc->dpy, pdraw,
                              target_msc, divisor, remainder);
 
-    if (psc->show_fps_interval) {
-       show_fps(priv);
-    }
-
     return ret;
 }
 

src/glx/dri3_glx.c

@@ -131,37 +131,12 @@ glx_dri3_flush_drawable(struct loader_dri3_drawable *draw, unsigned flags)
    loader_dri3_flush(draw, flags, __DRI2_THROTTLE_SWAPBUFFER);
 }
 
-static void
-glx_dri3_show_fps(struct loader_dri3_drawable *draw, uint64_t current_ust)
-{
-   struct dri3_drawable *priv = loader_drawable_to_dri3_drawable(draw);
-   const uint64_t interval =
-      ((struct dri3_screen *) priv->base.psc)->show_fps_interval;
-
-   if (!interval)
-      return;
-
-   priv->frames++;
-
-   /* DRI3+Present together uses microseconds for UST. */
-   if (priv->previous_ust + interval * 1000000 <= current_ust) {
-      if (priv->previous_ust) {
-         fprintf(stderr, "libGL: FPS = %.2f\n",
-                 ((uint64_t) priv->frames * 1000000) /
-                 (double)(current_ust - priv->previous_ust));
-      }
-      priv->frames = 0;
-      priv->previous_ust = current_ust;
-   }
-}
-
 static const struct loader_dri3_vtable glx_dri3_vtable = {
    .set_drawable_size = glx_dri3_set_drawable_size,
    .in_current_context = glx_dri3_in_current_context,
    .get_dri_context = glx_dri3_get_dri_context,
    .get_dri_screen = glx_dri3_get_dri_screen,
    .flush_drawable = glx_dri3_flush_drawable,
-   .show_fps = glx_dri3_show_fps,
 };
 
 
@@ -1021,11 +996,6 @@ dri3_create_screen(int screen, struct glx_display * priv)
 
    free(driverName);
 
-   tmp = getenv("LIBGL_SHOW_FPS");
-   psc->show_fps_interval = tmp ? atoi(tmp) : 0;
-   if (psc->show_fps_interval < 0)
-      psc->show_fps_interval = 0;
-
    InfoMessageF("Using DRI3 for screen %d\n", screen);
 
    psc->prefer_back_buffer_reuse = 1;

src/glx/dri3_priv.h

@@ -109,8 +109,6 @@ struct dri3_screen {
    /* fd for display GPU in case of prime */
    int fd_display_gpu;
 
-   int show_fps_interval;
-
    struct loader_dri3_extensions loader_dri3_ext;
 };
 

src/loader/loader_dri3_helper.c

@@ -543,9 +543,6 @@ dri3_handle_present_event(struct loader_dri3_drawable *draw,
 #endif
          draw->last_present_mode = ce->mode;
 
-         if (draw->vtable->show_fps)
-            draw->vtable->show_fps(draw, ce->ust);
-
          draw->ust = ce->ust;
          draw->msc = ce->msc;
       } else if (ce->serial == draw->eid) {

src/loader/loader_dri3_helper.h

@@ -111,7 +111,6 @@ struct loader_dri3_vtable {
    __DRIcontext *(*get_dri_context)(struct loader_dri3_drawable *);
    __DRIscreen *(*get_dri_screen)(void);
    void (*flush_drawable)(struct loader_dri3_drawable *, unsigned);
-   void (*show_fps)(struct loader_dri3_drawable *, uint64_t);
 };
 
 #define LOADER_DRI3_NUM_BUFFERS (1 + LOADER_DRI3_MAX_BACK)