gsdx-ogl: bump base requirement to 3.3

A couple of fallbacks were introduced for the Mesa driver that only support 3.0
DSA will require a recent Mesa which already support GL3.3

Require at least SandyBridge for Intel GPU

plugins/GSdx/GLLoader.cpp

@@ -160,8 +160,7 @@ namespace GLLoader {
 
 	// Optional
 	bool found_GL_ARB_separate_shader_objects = false;
-	bool found_geometry_shader = true;
+	bool found_geometry_shader = true; // we require GL3.3 so geometry must be supported by default
-	bool found_only_gl30	= false; // Drop it when mesa support GLSL330
 	bool found_GL_ARB_clear_texture = false; // Don't know if GL3 GPU can support it
 	bool found_GL_ARB_buffer_storage = false;
 	bool found_GL_ARB_explicit_uniform_location = false; // need by subroutine
@@ -238,10 +237,6 @@ namespace GLLoader {
 		GLuint minor_gl = s[dot+1]-'0';
 
 #ifndef ENABLE_GLES
-		if ( (major_gl < 3) || ( major_gl == 3 && minor_gl < 2 ) ) {
-			fprintf(stderr, "Geometry shaders are not supported. Required openGL 3.2\n");
-			found_geometry_shader = false;
-		}
 		if (mesa_amd_buggy_driver || intel_buggy_driver) {
 			fprintf(stderr, "Buggy driver detected. Geometry shaders will be disabled\n");
 			found_geometry_shader = false;
@@ -250,10 +245,6 @@ namespace GLLoader {
 			found_geometry_shader = !!theApp.GetConfig("override_geometry_shader", -1);
 			fprintf(stderr, "Override geometry shaders detection\n");
 		}
-		if ( (major_gl == 3) && minor_gl < 3) {
-			// Opensource driver spotted
-			found_only_gl30 = true;
-		}
 #else
 		found_geometry_shader = false;
 #endif

plugins/GSdx/GLLoader.h

@@ -425,7 +425,6 @@ namespace GLLoader {
 	extern bool found_GL_ARB_shading_language_420pack;
 	extern bool found_GL_ARB_copy_image;
 	extern bool found_geometry_shader;
-	extern bool found_only_gl30;
 	extern bool found_GL_ARB_gpu_shader5;
 	extern bool found_GL_ARB_shader_image_load_store;
 	extern bool found_GL_ARB_clear_texture;

plugins/GSdx/GSDeviceOGL.cpp

@@ -161,7 +161,7 @@ GSTexture* GSDeviceOGL::FetchSurface(int type, int w, int h, bool msaa, int form
 bool GSDeviceOGL::Create(GSWnd* wnd)
 {
 	if (m_window == NULL) {
-		if (!GLLoader::check_gl_version(3, 0)) return false;
+		if (!GLLoader::check_gl_version(3, 3)) return false;
 
 		if (!GLLoader::check_gl_supported_extension()) return false;
 	}

plugins/GSdx/GSShaderOGL.cpp

@@ -355,11 +355,7 @@ std::string GSShaderOGL::GenGlslHeader(const std::string& entry, GLenum type, co
 {
 	std::string header;
 #ifndef ENABLE_GLES
-	if (GLLoader::found_only_gl30) {
+	header = "#version 330 core\n";
-		header = "#version 130\n";
-	} else {
-		header = "#version 330 core\n";
-	}
 	if (GLLoader::found_GL_ARB_shading_language_420pack) {
 		// Need GL version 420
 		header += "#extension GL_ARB_shading_language_420pack: require\n";
@@ -370,12 +366,6 @@ std::string GSShaderOGL::GenGlslHeader(const std::string& entry, GLenum type, co
 		// Need GL version 410
 		header += "#extension GL_ARB_separate_shader_objects: require\n";
 	}
-	if (GLLoader::found_only_gl30) {
-		// Need version 330
-		header += "#extension GL_ARB_explicit_attrib_location: require\n";
-		// Need version 140
-		header += "#extension GL_ARB_uniform_buffer_object: require\n";
-	}
 	if (GLLoader::found_GL_ARB_shader_subroutine && GLLoader::found_GL_ARB_explicit_uniform_location) {
 		// Need GL version 400
 		header += "#define SUBROUTINE_GL40 1\n";
@@ -385,9 +375,6 @@ std::string GSShaderOGL::GenGlslHeader(const std::string& entry, GLenum type, co
 		// Need GL version 430
 		header += "#extension GL_ARB_explicit_uniform_location: require\n";
 	}
-#ifdef ENABLE_OGL_STENCIL_DEBUG
-	header += "#define ENABLE_OGL_STENCIL_DEBUG 1\n";
-#endif
 	if (GLLoader::found_GL_ARB_shader_image_load_store) {
 		// Need GL version 420
 		header += "#extension GL_ARB_shader_image_load_store: require\n";
@@ -395,13 +382,16 @@ std::string GSShaderOGL::GenGlslHeader(const std::string& entry, GLenum type, co
 		header += "#define DISABLE_GL42_image\n";
 	}
 	if (GLLoader::found_GL_ARB_bindless_texture && GLLoader::found_GL_ARB_explicit_uniform_location) {
-		// Future opengl 5?
+		// ARB extension (4.4)
 		header += "#extension GL_ARB_bindless_texture: require\n";
 		header += "#define ENABLE_BINDLESS_TEX\n";
 	}
 	if (GLLoader::found_GL_ARB_clip_control) {
 		header += "#define ZERO_TO_ONE_DEPTH\n";
 	}
+#ifdef ENABLE_OGL_STENCIL_DEBUG
+	header += "#define ENABLE_OGL_STENCIL_DEBUG 1\n";
+#endif
 #else // ENABLE_GLES
 	header = "#version 310 es\n";
 	header += "#extension GL_EXT_shader_io_blocks: require\n";

plugins/GSdx/GSWndOGL.cpp

@@ -138,10 +138,7 @@ bool GSWndOGL::Attach(void* handle, bool managed)
 
 	m_NativeDisplay = XOpenDisplay(NULL);
 
-	if (theApp.GetConfig("reduce_gl_requirement_for_free_driver", 0) == 1)
+	CreateContext(3, 3);
-		CreateContext(3, 0);
-	else
-		CreateContext(3, 3);
 
 	AttachContext();