glx/drirc: add a force_direct_glx_context option

Some applications may request an indirect context but this feature is
disabled by default on Xorg and thus context creation will fail.

This commit adds a drirc setting to force the creation of direct glx
context, regardless of what the app is requesting.

Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13246>

6 files changed, 35 insertions, 0 deletions

diff --git a/src/glx/create_context.c b/src/glx/create_context.c
index 7e1cec98c64..c44d579c954 100644
--- a/src/glx/create_context.c
+++ b/src/glx/create_context.c
@@ -92,6 +92,15 @@ glXCreateContextAttribsARB(Display *dpy, GLXFBConfig config,
 
    assert(screen == psc->scr);
 
+   /* Some application may request an indirect context but we may want to force a direct
+    * one because Xorg only allows indirect contexts if they were enabled.
+    */
+   if (!direct &&
+       psc->force_direct_context) {
+      direct = true;
+   }
+
+
    if (direct && psc->vtable->create_context_attribs) {
       /* GLX drops the error returned by the driver.  The expectation is that
        * an error will also be returned by the server.  The server's error
diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
index fbbfe1f6d57..4092842cccd 100644
--- a/src/glx/dri2_glx.c
+++ b/src/glx/dri2_glx.c
@@ -1280,6 +1280,14 @@ dri2CreateScreen(int screen, struct glx_display * priv)
                                     &tmp) == 0)
       __IndirectGlParseExtensionOverride(&psc->base, tmp);
 
+   if (psc->config->base.version > 1) {
+      uint8_t force = false;
+      if (psc->config->configQueryb(psc->driScreen, "force_direct_glx_context",
+                                    &force) == 0) {
+         psc->base.force_direct_context = force;
+      }
+   }
+
    /* DRI2 supports SubBuffer through DRI2CopyRegion, so it's always
     * available.*/
    psp->copySubBuffer = dri2CopySubBuffer;
diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
index 3b3918cf6c1..3c0d60bdf21 100644
--- a/src/glx/dri3_glx.c
+++ b/src/glx/dri3_glx.c
@@ -1014,6 +1014,14 @@ dri3_create_screen(int screen, struct glx_display * priv)
                                     &tmp) == 0)
       __IndirectGlParseExtensionOverride(&psc->base, tmp);
 
+   if (psc->config->base.version > 1) {
+      uint8_t force = false;
+      if (psc->config->configQueryb(psc->driScreen, "force_direct_glx_context",
+                                    &force) == 0) {
+         psc->base.force_direct_context = force;
+      }
+   }
+
    free(driverName);
 
    tmp = getenv("LIBGL_SHOW_FPS");
diff --git a/src/glx/glxclient.h b/src/glx/glxclient.h
index 50aa4d892cb..880f4fbaefa 100644
--- a/src/glx/glxclient.h
+++ b/src/glx/glxclient.h
@@ -521,6 +521,7 @@ struct glx_screen
 
    Display *dpy;
    int scr;
+   bool force_direct_context;
 
 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
     /**
diff --git a/src/glx/glxcmds.c b/src/glx/glxcmds.c
index ecf94eeb04c..901de99f942 100644
--- a/src/glx/glxcmds.c
+++ b/src/glx/glxcmds.c
@@ -339,6 +339,14 @@ CreateContext(Display *dpy, int generic_id, struct glx_config *config,
    if (generic_id == None)
       return NULL;
 
+   /* Some application may request an indirect context but we may want to force a direct
+    * one because Xorg only allows indirect contexts if they were enabled.
+    */
+   if (!allowDirect &&
+       psc->force_direct_context) {
+      allowDirect = 1;
+   }
+
    gc = NULL;
 #ifdef GLX_USE_APPLEGL
    gc = applegl_create_context(psc, config, shareList, renderType);
diff --git a/src/glx/tests/fake_glx_screen.h b/src/glx/tests/fake_glx_screen.h
index 39b250ffc8f..02b212ad7ec 100644
--- a/src/glx/tests/fake_glx_screen.h
+++ b/src/glx/tests/fake_glx_screen.h
@@ -34,6 +34,7 @@ public:
       this->scr = num;
       this->visuals = 0;
       this->configs = 0;
+      this->force_direct_context = false;
 
       this->display = glx_dpy;
       this->dpy = (glx_dpy != NULL) ? glx_dpy->dpy : NULL;