fix(linux): initialize EGL via GLAD correctly

[psyke83]

• misc.cpp: phase 1 load (symbols only, defaults to EGL 1.0).
• graphics.cpp: phase 2 load using correct display configuration with
  eglGetPlatformDisplayEXT (initializes proper EGL version dispatch).
• Retain eglGetPlatformDisplay fallback if proprietary drivers need it.
• Add missing/required extensions to GLAD makefile based on existing
  extensions queried & new eglGetPlatformDisplayEXT requirement.
• Remove hardcoded definitions that are part of previously missing
  extensions.

Description

Screenshot

Issues Fixed or Closed

Roadmap Issues

Type of Change

• feat: New feature (non-breaking change which adds functionality)
• fix: Bug fix (non-breaking change which fixes an issue)
• docs: Documentation only changes
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semicolons, etc.)
• refactor: Code change that neither fixes a bug nor adds a feature
• perf: Code change that improves performance
• test: Adding missing tests or correcting existing tests
• build: Changes that affect the build system or external dependencies
• ci: Changes to CI configuration files and scripts
• chore: Other changes that don't modify src or test files
• revert: Reverts a previous commit
• BREAKING CHANGE: Introduces a breaking change (can be combined with any type above)

Checklist

• Code follows the style guidelines of this project
• Code has been self-reviewed
• Code has been commented, particularly in hard-to-understand areas
• Code docstring/documentation-blocks for new or existing methods/components have been added or updated
• Unit tests have been added or updated for any new or modified functionality

AI Usage

• None: No AI tools were used in creating this PR
• Light: AI provided minor assistance (formatting, simple suggestions)
• Moderate: AI helped with code generation or debugging specific parts
• Heavy: AI generated most or all of the code changes

[psyke83]

Tested and confirmed working against kmsgrab and portalgrab backends, and creates the EGL context successfully from ssh as well.

It should work on nvidia based on cursory search online, e.g.: https://docs.nvidia.com/drive/drive-os-5.2.0.0L/drive-os/index.html#page/DRIVE_OS_Linux_SDK_Development_Guide/Windows%20Systems/window_system_egl.html

...but it might be a good idea for a nvidia user to test to be sure.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[psyke83]

After looking at the glad sources, another optimization that could be applied that might improve VAAPI encoding (and anything else that relies on EGL; Vulkan doesn't apply). I'll send a separate PR after you've merged this branch, but this is the current version:

diff --git a/cmake/dependencies/glad.cmake b/cmake/dependencies/glad.cmake
index bf8f4b1e..99f9e52b 100644
--- a/cmake/dependencies/glad.cmake
+++ b/cmake/dependencies/glad.cmake
@@ -179,6 +179,7 @@ glad_add_library(glad_egl
             EGL_EXT_platform_base
             EGL_EXT_platform_wayland
             EGL_EXT_platform_x11
+            EGL_IMG_context_priority
             EGL_KHR_create_context
             EGL_KHR_image_base
             EGL_KHR_surfaceless_context
diff --git a/src/platform/linux/graphics.cpp b/src/platform/linux/graphics.cpp
index 38eb0071..522631ad 100644
--- a/src/platform/linux/graphics.cpp
+++ b/src/platform/linux/graphics.cpp
@@ -405,20 +405,36 @@ namespace egl {
       return std::nullopt;
     }
 
-    constexpr int attr[] {
-      EGL_CONTEXT_CLIENT_VERSION,
-      3,
-      EGL_NONE
-    };
+    const char *extension_st = eglQueryString(display, EGL_EXTENSIONS);
+
+    std::vector<EGLint> attr;
+    attr.push_back(EGL_CONTEXT_CLIENT_VERSION);
+    attr.push_back(3);
+
+    // Only add the priority attribute if the driver explicitly supports it
+    if (extension_st && std::strstr(extension_st, "EGL_IMG_context_priority")) {
+      BOOST_LOG(debug) << "EGL: High priority context supported"sv;
+      attr.push_back(EGL_CONTEXT_PRIORITY_LEVEL_IMG);
+      attr.push_back(EGL_CONTEXT_PRIORITY_HIGH_IMG);
+    }
+    attr.push_back(EGL_NONE);
 
-    ctx_t ctx {display, eglCreateContext(display, conf, EGL_NO_CONTEXT, attr)};
-    if (fail()) {
+    EGLContext raw_ctx = eglCreateContext(display, conf, EGL_NO_CONTEXT, attr.data());
+    if (raw_ctx == EGL_NO_CONTEXT) {
       BOOST_LOG(error) << "Couldn't create EGL context: ["sv << util::hex(eglGetError()).to_string_view() << ']';
       return std::nullopt;
     }
 
-    TUPLE_EL_REF(ctx_p, 1, ctx.el);
-    if (!eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, ctx_p)) {
+    ctx_t ctx {display, raw_ctx};
+
+    EGLint actual_priority = EGL_CONTEXT_PRIORITY_MEDIUM_IMG;
+    if (eglQueryContext(display, raw_ctx, EGL_CONTEXT_PRIORITY_LEVEL_IMG, &actual_priority)) {
+      if (actual_priority == EGL_CONTEXT_PRIORITY_HIGH_IMG) {
+        BOOST_LOG(info) << "EGL Context Priority: HIGH"sv;
+      }
+    }
+
+    if (!eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, raw_ctx)) {
       BOOST_LOG(error) << "Couldn't make current display"sv;
       return std::nullopt;
     }

[codecov]

Bundle Report

Bundle size has no change ✅

[codecov]

Codecov Report

❌ Patch coverage is 0% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 17.51%. Comparing base (597a241) to head (c7f7042).
⚠️ Report is 1 commits behind head on build/linux/generate-glad-sources-at-compile-time.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/platform/linux/graphics.cpp	0.00%	12 Missing ⚠️
src/platform/linux/misc.cpp	0.00%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@                                  Coverage Diff                                  @@
##           build/linux/generate-glad-sources-at-compile-time    #4852      +/-   ##
=====================================================================================
- Coverage                                              17.52%   17.51%   -0.02%     
=====================================================================================
  Files                                                    106      106              
  Lines                                                  21850    21856       +6     
  Branches                                                9751     9756       +5     
=====================================================================================
- Hits                                                    3829     3827       -2     
+ Misses                                                 16110    14962    -1148     
- Partials                                                1911     3067    +1156     

Flag	Coverage Δ
Archlinux	12.00% <0.00%> (-0.01%)	⬇️
FreeBSD-14.3-amd64	13.81% <0.00%> (-0.02%)	⬇️
Homebrew-ubuntu-22.04	14.30% <0.00%> (-0.01%)	⬇️
Linux-AppImage	12.45% <0.00%> (-0.01%)	⬇️
Windows-AMD64	14.49% <ø> (ø)
Windows-ARM64	13.11% <ø> (ø)
macOS-arm64	18.22% <ø> (ø)
macOS-x86_64	16.71% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/platform/linux/misc.cpp	15.28% <0.00%> (-0.38%)	⬇️
src/platform/linux/graphics.cpp	2.38% <0.00%> (-0.03%)	⬇️

... and 45 files with indirect coverage changes