* improved context creation

dglOpenGLES.pas

@@ -1838,7 +1838,10 @@ type
 
 function InitOpenGLES(const aOpenGLESLibName: String = LIBNAME_OPENGLES; aEGLLibName: String = LIBNAME_EGL): Boolean;
 
-function CreateRenderingContext(const aDisplayType: EGLNativeDisplayType; const aWindowType: PEGLNativeWindowType; const aAttributes: PEGLint): TdglRenderContext;
+function CreateRenderingContext(const aDisplayType: EGLNativeDisplayType;
+                                const aWindowType: PEGLNativeWindowType;
+                                const aConfigAttribs: PEGLint;
+                                const aContextAttribs: PEGLint): TdglRenderContext;
 procedure DestroyRenderingContext(const aContext: TdglRenderContext);
 function ActivateRenderingContext(const aContext: TdglRenderContext): Boolean;
 function DeactivateRenderingContext(const aContext: TdglRenderContext): Boolean;
@@ -1949,7 +1952,8 @@ begin
   raise EeglError.Create(aMsg + ' ErrorCode: 0x' + IntToHex(err, 8), err);
 end;
 
-function CreateRenderingContext(const aDisplayType: EGLNativeDisplayType; const aWindowType: PEGLNativeWindowType; const aAttributes: PEGLint): TdglRenderContext;
+function CreateRenderingContext(const aDisplayType: EGLNativeDisplayType; const aWindowType: PEGLNativeWindowType;
+  const aConfigAttribs: PEGLint; const aContextAttribs: PEGLint): TdglRenderContext;
 var
   ConfigCount: EGLint;
   Config: EGLConfig;
@@ -1965,15 +1969,18 @@ begin
   if (eglInitialize(result.Display, nil, nil) <> EGL_TRUE) then
     RaiseEglError('unable to initialize egl.');
 
-  if (eglChooseConfig(result.Display, aAttributes, @Config, 1, @ConfigCount) <> EGL_TRUE) or
-     (ConfigCount <> 1) then
+  if (eglChooseConfig(result.Display, aConfigAttribs, @Config, 1, @ConfigCount) <> EGL_TRUE) or
+     (ConfigCount < 1) then
     RaiseEglError('unable to get suitable config.');
 
+  if (eglBindAPI(EGL_OPENGL_ES_API) <> EGL_TRUE) then
+    RaiseEglError('unable to get an appropriate EGL frame buffer configuration.');
+
   result.Surface := eglCreateWindowSurface(result.Display, Config, aWindowType, nil);
   if (result.Surface = EGL_NO_SURFACE) then
     RaiseEglError('unable to create window surface.');
 
-  result.Context := eglCreateContext(result.Display, Config, EGL_NO_CONTEXT, nil);
+  result.Context := eglCreateContext(result.Display, Config, EGL_NO_CONTEXT, aContextAttribs);
   if (result.Context = EGL_NO_CONTEXT) then begin
     eglDestroySurface(result.Display, result.Surface);
     RaiseEglError('unable to create context.');