Added comments about GLES 3.0 support with 2.0 references.

[freeglut] / src / egl / fg_window_egl.c

diff --git a/src/egl/fg_window_egl.c b/src/egl/fg_window_egl.c
index 2141c5c..2f78a65 100644 (file)
--- a/src/egl/fg_window_egl.c
+++ b/src/egl/fg_window_egl.c
@@ -30,6 +30,11 @@ int fghChooseConfig(EGLConfig* config) {
   const EGLint attribs[] = {
     EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
 #ifdef GL_ES_VERSION_2_0
+    /*
+     * Khronos does not specify a EGL_OPENGL_ES3_BIT outside of the OpenGL extension "EGL_KHR_create_context". There are numerous references on the internet that
+     * say to use EGL_OPENGL_ES3_BIT, followed by many saying they can't find it in any headers. In fact, the offical updated specification for EGL does not have
+     * any references to OpenGL ES 3.0. Tests have shown that EGL_OPENGL_ES2_BIT will work with ES 3.0.
+     */
     EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
 #elif GL_VERSION_ES_CM_1_0 || GL_VERSION_ES_CL_1_0 || GL_VERSION_ES_CM_1_1 || GL_VERSION_ES_CL_1_1
     EGL_RENDERABLE_TYPE, EGL_OPENGL_ES_BIT,
@@ -38,8 +43,8 @@ int fghChooseConfig(EGLConfig* config) {
 #endif
 #ifdef TARGET_HOST_BLACKBERRY
     /* Only 888 and 565 seem to work. Based on
-       http://qt.gitorious.org/qt/qtbase/source/893deb1a93021cdfabe038cdf1869de33a60cbc9:src/plugins/platforms/qnx/qqnxglcontext.cpp
-       That's all that is used, and that's what BlackBerry uses for their own internal OpenGL setup, so unless something else is determined, use it */
+       http://qt.gitorious.org/qt/qtbase/source/893deb1a93021cdfabe038cdf1869de33a60cbc9:src/plugins/platforms/qnx/qqnxglcontext.cpp and
+       https://twitter.com/BlackBerryDev/status/380720927475912706 */
     EGL_BLUE_SIZE, 8,
     EGL_GREEN_SIZE, 8,
     EGL_RED_SIZE, 8,
@@ -76,7 +81,7 @@ EGLContext fghCreateNewContextEGL( SFG_Window* window ) {
   EGLConfig eglConfig = window->Window.pContext.egl.Config;
 
   /* Ensure OpenGLES 2.0 context */
-  static const EGLint ctx_attribs[] = {
+  static EGLint ctx_attribs[] = {
 #ifdef GL_ES_VERSION_2_0
     EGL_CONTEXT_CLIENT_VERSION, 2,
 #elif GL_VERSION_ES_CM_1_0 || GL_VERSION_ES_CL_1_0 || GL_VERSION_ES_CM_1_1 || GL_VERSION_ES_CL_1_1
@@ -84,6 +89,14 @@ EGLContext fghCreateNewContextEGL( SFG_Window* window ) {
 #endif
     EGL_NONE
   };
+#ifdef GL_ES_VERSION_2_0
+  /*
+   * As GLES 3.0 is backwards compatible with GLES 2.0, we set 2.0 as default unless the user states a different version.
+   * This updates the context attributes and lets us check that the correct version was set when we query it after creation.
+   */
+  int gles2Ver = fgState.MajorVersion <= 2 ? 2 : fgState.MajorVersion;
+  ctx_attribs[1] = gles2Ver;
+#endif
   context = eglCreateContext(eglDisplay, eglConfig, EGL_NO_CONTEXT, ctx_attribs);
   if (context == EGL_NO_CONTEXT) {
     fgWarning("Cannot initialize EGL context, err=%x\n", eglGetError());
@@ -92,7 +105,7 @@ EGLContext fghCreateNewContextEGL( SFG_Window* window ) {
   EGLint ver = -1;
   eglQueryContext(fgDisplay.pDisplay.egl.Display, context, EGL_CONTEXT_CLIENT_VERSION, &ver);
 #ifdef GL_ES_VERSION_2_0
-  if (ver != 2)
+  if (ver != gles2Ver)
 #else
   if (ver != 1)
 #endif