Support EGL protected content extension

A protected context is required to allow the GPU
to operate on protected resources, including protected
surfaces and protected EGLImages.

For example, GPU can post-process on protected content
like DRM protected content so that complex, nonlinear
video effects or mapping onto textures can be used.

The surface format option may be relevant for DirectX
and Vulkan in the future:

  https://microsoft.github.io/DirectX-Specs/d3d/ProtectedResources.html
  https://www.khronos.org/registry/vulkan/specs/1.1-khr-extensions/html/chap12.html#memory-protected-memory

Change-Id: I2d155f0e68b830276690b4833b22a2bc452cdcad
Reviewed-by: Elvis Lee <kwangwoong.lee@lge.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/gui/opengl/platform/egl/qeglplatformcontext.cpp b/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
index 47e0b890d8..5727b94aa2 100644
--- a/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
+++ b/src/gui/opengl/platform/egl/qeglplatformcontext.cpp
@@ -155,6 +155,17 @@ QEGLPlatformContext::QEGLPlatformContext(const QSurfaceFormat &format, QPlatform
         }
     }
 
+#ifdef EGL_EXT_protected_content
+    if (format.testOption(QSurfaceFormat::ProtectedContent)) {
+        if (q_hasEglExtension(m_eglDisplay, "EGL_EXT_protected_content")) {
+            contextAttrs.append(EGL_PROTECTED_CONTENT_EXT);
+            contextAttrs.append(EGL_TRUE);
+        } else {
+            m_format.setOption(QSurfaceFormat::ProtectedContent, false);
+        }
+    }
+#endif
+
     // Special Options for OpenVG surfaces
     if (m_format.renderableType() == QSurfaceFormat::OpenVG) {
         contextAttrs.append(EGL_ALPHA_MASK_SIZE);