From 547d9ccaa2daa9278b061b3b716e09d2de3f77b2 Mon Sep 17 00:00:00 2001
From: Bastien <bastien@magestik.fr>
Date: Fri, 21 Sep 2018 13:04:19 +0200
Subject: [PATCH] Add context creation helper function

---
 examples/opengl/CMakeLists.txt |  2 +-
 examples/opengl/context.inl    | 69 ++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 examples/opengl/context.inl

diff --git a/examples/opengl/CMakeLists.txt b/examples/opengl/CMakeLists.txt
index 9f41d76..2d7d886 100644
--- a/examples/opengl/CMakeLists.txt
+++ b/examples/opengl/CMakeLists.txt
@@ -3,7 +3,7 @@ set(OpenGL_GL_PREFERENCE GLVND)
 find_package(OpenGL REQUIRED)
 find_package(OpenHMD REQUIRED)
 
-add_executable(openglexample gl.c gl.h main.c vr_context.c vr_context.h)
+add_executable(openglexample gl.c gl.h main.c vr_context.c vr_context.h context.inl)
 target_include_directories(openglexample PRIVATE ${OPENGL_INCLUDE_DIRS})
 target_link_libraries(openglexample PRIVATE ${OPENGL_LIBRARIES})
 target_link_libraries(openglexample PRIVATE m)
diff --git a/examples/opengl/context.inl b/examples/opengl/context.inl
new file mode 100644
index 0000000..5fa3316
--- /dev/null
+++ b/examples/opengl/context.inl
@@ -0,0 +1,69 @@
+#include <EGL/egl.h>
+#include <stdbool.h>
+
+static inline bool create_context(EGLNativeDisplayType nativeDisplay, EGLNativeWindowType nativeWindow, const EGLint * config_attribs, const EGLint * context_attribs, const EGLint * surface_attribs, EGLDisplay * outDisplay, EGLContext * outContext, EGLSurface * outSurface)
+{
+	//
+	// get an EGL display connection
+	EGLDisplay display = eglGetDisplay(nativeDisplay);
+
+	if (EGL_NO_DISPLAY == display)
+	{
+		return false;
+	}
+
+	//
+	// initialize the EGL display connection
+	EGLint major, minor;
+
+	if (!eglInitialize(display, &major, &minor))
+	{
+		return false;
+	}
+
+	//
+	// bind OpenGL API
+	eglBindAPI(EGL_OPENGL_API);
+
+	//
+	// get an appropriate EGL frame buffer configuration
+	EGLint num_config;
+	EGLConfig configs[128];
+
+	if (!eglChooseConfig(display, config_attribs, configs, 128, &num_config))
+	{
+		return false;
+	}
+
+	EGLConfig config = configs[0]; // FIXME
+
+	//
+	// create context
+	EGLContext context = eglCreateContext(display, config, EGL_NO_CONTEXT, context_attribs);
+
+	if (EGL_NO_CONTEXT == context)
+	{
+		return false;
+	}
+
+	//
+	// Create Surface
+	EGLSurface surface = eglCreateWindowSurface(display, config, nativeWindow, surface_attribs);
+	if (EGL_NO_SURFACE == surface)
+	{
+		return false;
+	}
+
+	//
+	// Set current context
+	if (!eglMakeCurrent(display, surface, surface, context))
+	{
+		return false;
+	}
+
+	*outDisplay = display;
+	*outContext = context;
+	*outSurface = surface;
+
+	return true;
+}