egl: Add debug option to print all EGLConfigs

QT_QPA_EGLFS_DEBUG=1 prints the attributes for the chosen EGLContext.
Make QT_QPA_EGLFS_DEBUG=2 print the same for all EGLContexts.

Change-Id: Id161d04789fbd015e29e5a5a89a0901000096ea3
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
(cherry picked from commit d8c771c53acb58cc79cadbb795d59d5e8db7754e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/gui/opengl/platform/egl/qeglplatformcontext.cpp b/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
index 561079b48f..47e0b890d8 100644
--- a/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
+++ b/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
@@ -194,6 +194,21 @@ QEGLPlatformContext::QEGLPlatformContext(const QSurfaceFormat &format, QPlatform
     if (printConfig) {
         qDebug() << "Created context for format" << format << "with config:";
         q_printEglConfig(m_eglDisplay, m_eglConfig);
+
+        static const bool printAllConfigs = qEnvironmentVariableIntValue("QT_QPA_EGLFS_DEBUG") > 1;
+        if (printAllConfigs) {
+            EGLint numConfigs = 0;
+            eglGetConfigs(m_eglDisplay, nullptr, 0, &numConfigs);
+            QVector<EGLConfig> configs;
+            configs.resize(numConfigs);
+            eglGetConfigs(m_eglDisplay, configs.data(), numConfigs, &numConfigs);
+            qDebug("\nAll EGLConfigs: count=%d", numConfigs);
+            for (EGLint i = 0; i < numConfigs; ++i) {
+                qDebug("EGLConfig #%d", i);
+                q_printEglConfig(m_eglDisplay, configs[i]);
+            }
+            qDebug("\n");
+        }
     }
 
     // Cannot just call updateFormatFromGL() since it relies on virtuals. Defer it to initialize().