Mesa (main): frontend/dri: add environment variable DRI_NO_MSAA for performance comparisons

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 8f935317e6c081673adfca211000b7f1131a20b5
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=8f935317e6c081673adfca211000b7f1131a20b5

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Sun Mar  7 10:28:52 2021 -0500

frontend/dri: add environment variable DRI_NO_MSAA for performance comparisons

Reviewed-by: Emma Anholt <emma at anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12491>

---

 docs/envvars.rst                       | 7 +++++++
 src/gallium/frontends/dri/dri_screen.c | 5 ++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/docs/envvars.rst b/docs/envvars.rst
index df9c0434ab3..598d452b45d 100644
--- a/docs/envvars.rst
+++ b/docs/envvars.rst
@@ -365,6 +365,13 @@ Radeon driver environment variables (radeon, r200, and r300g)
 :envvar:`RADEON_NO_TCL`
    if set, disable hardware-accelerated Transform/Clip/Lighting.
 
+DRI environment variables
+-------------------------
+
+:envvar:`DRI_NO_MSAA`
+   disable MSAA for GLX/EGL MSAA visuals
+
+
 EGL environment variables
 -------------------------
 
diff --git a/src/gallium/frontends/dri/dri_screen.c b/src/gallium/frontends/dri/dri_screen.c
index 0ec2b259e97..8198dde4cd2 100644
--- a/src/gallium/frontends/dri/dri_screen.c
+++ b/src/gallium/frontends/dri/dri_screen.c
@@ -378,7 +378,10 @@ dri_fill_st_visual(struct st_visual *stvis,
    }
 
    if (mode->samples > 0) {
-      stvis->samples = mode->samples;
+      if (debug_get_bool_option("DRI_NO_MSAA", false))
+         stvis->samples = 0;
+      else
+         stvis->samples = mode->samples;
    }
 
    switch (mode->depthBits) {