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 0e06233..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,
@@ -38,11 +43,11 @@ 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,
+    EGL_GREEN_SIZE, 8,
+    EGL_RED_SIZE, 8,
 #else
     EGL_BLUE_SIZE, 1,
     EGL_GREEN_SIZE, 1,
@@ -58,7 +63,7 @@ int fghChooseConfig(EGLConfig* config) {
 
   EGLint num_config;
   if (!eglChooseConfig(fgDisplay.pDisplay.egl.Display,
-                      attribs, config, 1, &num_config)) {
+               attribs, config, 1, &num_config)) {
     fgWarning("eglChooseConfig: error %x\n", eglGetError());
     return 0;
   }
@@ -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
@@ -105,9 +118,9 @@ void fgPlatformSetWindow ( SFG_Window *window )
 {
   if ( window != fgStructure.CurrentWindow && window) {
     if (eglMakeCurrent(fgDisplay.pDisplay.egl.Display,
-                      window->Window.pContext.egl.Surface,
-                      window->Window.pContext.egl.Surface,
-                      window->Window.Context) == EGL_FALSE)
+               window->Window.pContext.egl.Surface,
+               window->Window.pContext.egl.Surface,
+               window->Window.Context) == EGL_FALSE)
       fgError("eglMakeCurrent: err=%x\n", eglGetError());
   }
 }
@@ -138,9 +151,28 @@ void fghPlatformOpenWindowEGL( SFG_Window* window )
  */
 void fghPlatformCloseWindowEGL( SFG_Window* window )
 {
-  eglMakeCurrent(fgDisplay.pDisplay.egl.Display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+  /* Based on fg_window_mswin fgPlatformCloseWindow */
+  if( fgStructure.CurrentWindow == window )
+    eglMakeCurrent(fgDisplay.pDisplay.egl.Display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+
   if (window->Window.Context != EGL_NO_CONTEXT) {
-    eglDestroyContext(fgDisplay.pDisplay.egl.Display, window->Window.Context);
+    /* Step through the list of windows. If the rendering context is not being used by another window, then delete it */
+    {
+      GLboolean used = GL_FALSE;
+      SFG_Window *iter;
+
+      for( iter = (SFG_Window*)fgStructure.Windows.First;
+           iter && used == GL_FALSE;
+           iter = (SFG_Window*)iter->Node.Next)
+      {
+        if( (iter->Window.Context == window->Window.Context) &&
+            (iter != window) )
+          used = GL_TRUE;
+      }
+
+      if( !used )
+        eglDestroyContext(fgDisplay.pDisplay.egl.Display, window->Window.Context);
+    }
     window->Window.Context = EGL_NO_CONTEXT;
   }