gsdx-gles: nvidia driver quick trial (only GLES3.0)

* Fix to create a 3.0 GLES context
* set a default precision to fix most of shader compilation issue
* Crash later because of GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT
    => need to test opensource driver

plugins/GSdx/GLLoader.cpp

@@ -183,7 +183,9 @@ namespace GLLoader {
 
 		const char* vendor = (const char*)glGetString(GL_VENDOR);
 		fprintf(stderr, "Supported Opengl version: %s on GPU: %s. Vendor: %s\n", s, glGetString(GL_RENDERER), vendor);
+#ifndef ENABLE_GLES
 		fprintf(stderr, "Note: the maximal version supported by GSdx is 3.3 (even if you driver support more)!\n");
+#endif
 
 		// Name change but driver is still bad!
 		if (strstr(vendor, "ATI") || strstr(vendor, "Advanced Micro Devices"))
@@ -222,10 +224,12 @@ namespace GLLoader {
 #else
 		found_geometry_shader = false;
 #endif
+#ifndef ENABLE_GLES
 		if ( (major_gl < major) || ( major_gl == major && minor_gl < minor ) ) {
 			fprintf(stderr, "OPENGL %d.%d is not supported\n", major, minor);
 			return false;
 		}
+#endif
 
         return true;
     }
@@ -234,6 +238,7 @@ namespace GLLoader {
 		int max_ext = 0;
 		glGetIntegerv(GL_NUM_EXTENSIONS, &max_ext);
 
+#ifndef ENABLE_GLES
 		if (gl_GetStringi && max_ext) {
 			for (GLint i = 0; i < max_ext; i++) {
 				string ext((const char*)gl_GetStringi(GL_EXTENSIONS, i));
@@ -279,6 +284,7 @@ namespace GLLoader {
 #endif
 			}
 		}
+#endif
 
 		bool status = true;
 #ifndef ENABLE_GLES

plugins/GSdx/GSShaderOGL.cpp

@@ -420,6 +420,7 @@ std::string GSShaderOGL::GenGlslHeader(const std::string& entry, GLenum type, co
 	// intel linux refuse to define it
 #ifdef ENABLE_GLES
 	header += "#define pGL_ES 1\n";
+	header += "precision highp float;\n";
 #else
 	header += "#define pGL_ES 0\n";
 #endif

plugins/GSdx/GSWndEGL.cpp

@@ -32,31 +32,28 @@ GSWndEGL::GSWndEGL()
 void GSWndEGL::CreateContext(int major, int minor)
 {
 	EGLConfig eglConfig;
-	EGLint numConfigs;
+	EGLint numConfigs = 0;
 	EGLint contextAttribs[] =
-#ifdef ENABLE_GLES
-	{
-		 EGL_CONTEXT_CLIENT_VERSION, 2,
-		 EGL_NONE
-	};
-#else
 	{
 		EGL_CONTEXT_MAJOR_VERSION_KHR, major,
 		EGL_CONTEXT_MINOR_VERSION_KHR, minor,
+#ifndef ENABLE_GLES
 #ifdef ENABLE_OGL_DEBUG
 		EGL_CONTEXT_FLAGS_KHR, EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR,
 #endif
 		EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR, EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT_KHR,
+#endif
 		EGL_NONE
 	};
-#endif
 	EGLint NullContextAttribs[] = { EGL_NONE };
 	EGLint attrList[] = {
 		EGL_RED_SIZE, 8,
 		EGL_GREEN_SIZE, 8,
 		EGL_BLUE_SIZE, 8,
 		EGL_DEPTH_SIZE, 24,
+#ifndef ENABLE_GLES
 		EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
+#endif
 		EGL_NONE
 	};
 
@@ -64,7 +61,8 @@ void GSWndEGL::CreateContext(int major, int minor)
 	eglBindAPI(EGL_OPENGL_API);
 #endif
 
-	if ( !eglChooseConfig(m_eglDisplay, attrList, &eglConfig, 1, &numConfigs) )
+	eglChooseConfig(m_eglDisplay, attrList, &eglConfig, 1, &numConfigs);
+	if ( numConfigs == 0 )
 	{
 		fprintf(stderr,"EGL: Failed to get a frame buffer config!\n");
 		throw GSDXRecoverableError();
@@ -137,7 +135,12 @@ bool GSWndEGL::Attach(void* handle, bool managed)
 	m_NativeDisplay = XOpenDisplay(NULL);
 	OpenEGLDisplay();
 
+#ifdef ENABLE_GLES
+	// FIXME: update it to GLES 3.1 when  they support it
+	CreateContext(3, 0);
+#else
 	CreateContext(3, 3);
+#endif
 
 	AttachContext();
 
@@ -184,7 +187,12 @@ bool GSWndEGL::Create(const string& title, int w, int h)
 	m_NativeWindow = XCreateSimpleWindow(m_NativeDisplay, DefaultRootWindow(m_NativeDisplay), 0, 0, w, h, 0, 0, 0);
 	XMapWindow (m_NativeDisplay, m_NativeWindow);
 
+#ifdef ENABLE_GLES
+	// FIXME: update it to GLES 3.1 when  they support it
+	CreateContext(3, 0);
+#else
 	CreateContext(3, 3);
+#endif
 
 	AttachContext();