[Mesa-dev] gallium/hud: control visibility at startup and runtime.

[boombatower]

- env GALLIUM_HUD_VISIBLE: control default visibility
- env GALLIUM_HUD_SIGNAL_TOGGLE: toggle visibility via signal
---
 docs/envvars.html                       |  6 ++++++
 src/gallium/auxiliary/hud/hud_context.c | 23 +++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/docs/envvars.html b/docs/envvars.html
index bdfe999..530bbb7 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -179,6 +179,12 @@ Mesa EGL supports different sets of environment variables.  See the
 <li>GALLIUM_HUD - draws various information on the screen, like framerate,
     cpu load, driver statistics, performance counters, etc.
     Set GALLIUM_HUD=help and run e.g. glxgears for more info.
+<li>GALLIUM_HUD_VISIBLE - control default visibility, defaults to true.
+<li>GALLIUM_HUD_TOGGLE_SIGNAL - toggle visibility via user specified signal.
+    Especially useful to toggle hud at specific points of application and
+    disable for unencumbered viewing the rest of the time. For example, set
+    GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_SIGNAL_TOGGLE to 10 (SIGUSR1).
+    Use kill -10 <pid> to toggle the hud as desired.
 <li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc.
     rather than stderr.
 <li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment
diff --git a/src/gallium/auxiliary/hud/hud_context.c b/src/gallium/auxiliary/hud/hud_context.c
index ffe30b8..f6bfa80 100644
--- a/src/gallium/auxiliary/hud/hud_context.c
+++ b/src/gallium/auxiliary/hud/hud_context.c
@@ -33,6 +33,7 @@
  * Set GALLIUM_HUD=help for more info.
  */
 
+#include <signal.h>
 #include <stdio.h>
 
 #include "hud/hud_context.h"
@@ -51,8 +52,10 @@
 #include "tgsi/tgsi_text.h"
 #include "tgsi/tgsi_dump.h"
 
+static boolean __visible_toggle = false;
 
 struct hud_context {
+   boolean visible;
    struct pipe_context *pipe;
    struct cso_context *cso;
    struct u_upload_mgr *uploader;
@@ -95,6 +98,11 @@ struct hud_context {
    } text, bg, whitelines;
 };
 
+static void
+signal_visible_handler(int signo)
+{
+   __visible_toggle = true;
+}
 
 static void
 hud_draw_colored_prims(struct hud_context *hud, unsigned prim,
@@ -431,8 +439,15 @@ hud_alloc_vertices(struct hud_context *hud, struct vertex_queue *v,
 void
 hud_draw(struct hud_context *hud, struct pipe_resource *tex)
 {
+   if (__visible_toggle) {
+      hud->visible = !hud->visible;
+      __visible_toggle = false;
+   }
+   if (!hud->visible) return;
+
    struct cso_context *cso = hud->cso;
    struct pipe_context *pipe = hud->pipe;
+
    struct pipe_framebuffer_state fb;
    struct pipe_surface surf_templ, *surf;
    struct pipe_viewport_state viewport;
@@ -1124,7 +1139,9 @@ hud_create(struct pipe_context *pipe, struct cso_context *cso)
    struct hud_context *hud;
    struct pipe_sampler_view view_templ;
    unsigned i;
+   boolean visible = debug_get_bool_option("GALLIUM_HUD_VISIBLE", true);
    const char *env = debug_get_option("GALLIUM_HUD", NULL);
+   long signo = debug_get_num_option("GALLIUM_HUD_TOGGLE_SIGNAL", 0);
 
    if (!env || !*env)
       return NULL;
@@ -1138,6 +1155,7 @@ hud_create(struct pipe_context *pipe, struct cso_context *cso)
    if (!hud)
       return NULL;
 
+   hud->visible = visible;
    hud->pipe = pipe;
    hud->cso = cso;
    hud->uploader = u_upload_create(pipe, 256 * 1024, 16,
@@ -1267,6 +1285,11 @@ hud_create(struct pipe_context *pipe, struct cso_context *cso)
 
    LIST_INITHEAD(&hud->pane_list);
 
+   if (signo < 1 || signo >= NSIG)
+      fprintf(stderr, "gallium_hud: invalid signal %ld\n", signo);
+   else if (signal(signo, signal_visible_handler) == SIG_ERR)
+      fprintf(stderr, "gallium_hud: unable to set handler for signal %ld\n", signo);
+
    hud_parse_env_var(hud, env);
    return hud;
 }
-- 
2.6.2