vo_gpu: opengl: reduce versions in mpgl_preferred_gl_versions

Currently mpv requires a bare minimum of GL 2.1, although it tries to
use 3.2+ core contexts when possible.

The GLX and EGL spec effectively guarantee that the implementation will
give you the highest compatible version possible. In other words:

Requesting 3.2 core profile will always give you core profile and the
version will be in the 3.2 .. 4.6 range - as supported by the drivers.

Similarly for 2.1 - implementation will give you either:
 - 2.1 .. 3.1, or
 - 3.2 .. 4.6 compat profile

This has been verified against the Mesa drivers (i965, iris, swrast) and
Nvidia binary drivers.

As such, drop the list to 320, 210 and terminating 0.

v2:
 - mpgl_preferred_gl_versions -> mpgl_min_required_gl_versions
 - update ^^ comment

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

4 files changed, 7 insertions, 13 deletions

diff --git a/video/out/opengl/context.c b/video/out/opengl/context.c
index c491039b66..c9f8445246 100644
--- a/video/out/opengl/context.c
+++ b/video/out/opengl/context.c
@@ -21,15 +21,9 @@
 #include "utils.h"
 
 // 0-terminated list of desktop GL versions a backend should try to
-// initialize. The first entry is the most preferred version.
-const int mpgl_preferred_gl_versions[] = {
-    440,
-    430,
-    400,
-    330,
+// initialize. Each entry is the minimum required version.
+const int mpgl_min_required_gl_versions[] = {
     320,
-    310,
-    300,
     210,
     0
 };
diff --git a/video/out/opengl/context.h b/video/out/opengl/context.h
index 2dd2517ef5..d78d17094c 100644
--- a/video/out/opengl/context.h
+++ b/video/out/opengl/context.h
@@ -4,7 +4,7 @@
 #include "video/out/gpu/context.h"
 #include "common.h"
 
-extern const int mpgl_preferred_gl_versions[];
+extern const int mpgl_min_required_gl_versions[];
 
 // Returns whether or not a candidate GL version should be accepted or not
 // (based on the --opengl opts). Implementations may call this before
diff --git a/video/out/opengl/context_glx.c b/video/out/opengl/context_glx.c
index 4d9d993121..ee1fb30abf 100644
--- a/video/out/opengl/context_glx.c
+++ b/video/out/opengl/context_glx.c
@@ -312,8 +312,8 @@ static bool glx_init(struct ra_ctx *ctx)
         goto uninit;
 
     bool success = false;
-    for (int n = 0; mpgl_preferred_gl_versions[n]; n++) {
-        int version = mpgl_preferred_gl_versions[n];
+    for (int n = 0; mpgl_min_required_gl_versions[n]; n++) {
+        int version = mpgl_min_required_gl_versions[n];
         MP_VERBOSE(ctx, "Creating OpenGL %d.%d context...\n",
                    MPGL_VER_P(version));
         if (version >= 300) {
diff --git a/video/out/opengl/egl_helpers.c b/video/out/opengl/egl_helpers.c
index bcd85bfb73..2bdf3df0f2 100644
--- a/video/out/opengl/egl_helpers.c
+++ b/video/out/opengl/egl_helpers.c
@@ -184,8 +184,8 @@ static bool create_context(struct ra_ctx *ctx, EGLDisplay display,
 
         egl_ctx = eglCreateContext(display, config, EGL_NO_CONTEXT, attrs);
     } else {
-        for (int n = 0; mpgl_preferred_gl_versions[n]; n++) {
-            int ver = mpgl_preferred_gl_versions[n];
+        for (int n = 0; mpgl_min_required_gl_versions[n]; n++) {
+            int ver = mpgl_min_required_gl_versions[n];
             if (!ra_gl_ctx_test_version(ctx, ver, false))
                 continue;