vo_opengl: egl_helpers: add a way to override config selection

Preparation for the following commits. Since at least theoretically the
config selection depends on the context type (EGL_RENDERABLE_TYPE has
separate bits for ES 2, ES 3, and desktop GL), doing it any other way
would be too painful.

2 files changed, 21 insertions, 2 deletions

diff --git a/video/out/opengl/egl_helpers.c b/video/out/opengl/egl_helpers.c
index 3594f72022..0169ab264e 100644
--- a/video/out/opengl/egl_helpers.c
+++ b/video/out/opengl/egl_helpers.c
@@ -72,15 +72,27 @@ static bool create_context(EGLDisplay display, struct mp_log *log, bool probing,
     };
 
     EGLint config_count;
-    EGLConfig config;
+    EGLConfig *configs = NULL;
 
-    eglChooseConfig(display, attributes, &config, 1, &config_count);
+    eglChooseConfig(display, attributes, NULL, 0, &config_count);
+
+    if (config_count) {
+        configs = talloc_array(NULL, EGLConfig, config_count);
+        eglChooseConfig(display, attributes, configs, config_count, &config_count);
+    }
 
     if (!config_count) {
         mp_msg(log, msgl, "Could not find EGL configuration!\n");
         return false;
     }
 
+    int chosen = 0;
+    if (opts->refine_config)
+        chosen = opts->refine_config(opts->user_data, configs, config_count);
+    EGLConfig config = configs[chosen];
+
+    talloc_free(configs);
+
     EGLContext *ctx = NULL;
 
     if (es_version) {
diff --git a/video/out/opengl/egl_helpers.h b/video/out/opengl/egl_helpers.h
index 15033834f4..ea751d4c5e 100644
--- a/video/out/opengl/egl_helpers.h
+++ b/video/out/opengl/egl_helpers.h
@@ -14,6 +14,13 @@ bool mpegl_create_context(EGLDisplay display, struct mp_log *log, int vo_flags,
 struct mpegl_opts {
     // combination of VOFLAG_* values.
     int vo_flags;
+
+    // for callbacks
+    void *user_data;
+
+    // if set, pick the desired config from the given list and return its index
+    // defaults to 0 (they are sorted by eglChooseConfig)
+    int (*refine_config)(void *user_data, EGLConfig *configs, int num_configs);
 };
 
 bool mpegl_create_context_opts(EGLDisplay display, struct mp_log *log,