pcsx2/plugins/GSdx/Renderers/OpenGL/GLLoader.cpp

/* *	Copyright (C) 2011-2014 Gregory hainaut
 *	Copyright (C) 2007-2009 Gabest
 *
 *  This Program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This Program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA USA.
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#include "stdafx.h"
#include "GLLoader.h"
#include "GSdx.h"
#include "GS.h"

PFNGLBLENDCOLORPROC                    gl_BlendColor                       = NULL;

PFNGLATTACHSHADERPROC                  glAttachShader                      = NULL;
PFNGLBINDBUFFERPROC                    glBindBuffer                        = NULL;
PFNGLBINDBUFFERBASEPROC                glBindBufferBase                    = NULL;
PFNGLBINDBUFFERRANGEPROC               glBindBufferRange                   = NULL;
PFNGLBINDFRAMEBUFFERPROC               glBindFramebuffer                   = NULL;
PFNGLBINDSAMPLERPROC                   glBindSampler                       = NULL;
PFNGLBINDVERTEXARRAYPROC               glBindVertexArray                   = NULL;
PFNGLBLENDEQUATIONSEPARATEIARBPROC     glBlendEquationSeparateiARB         = NULL;
PFNGLBLENDFUNCSEPARATEIARBPROC         glBlendFuncSeparateiARB             = NULL;
PFNGLBLITFRAMEBUFFERPROC               glBlitFramebuffer                   = NULL;
PFNGLBUFFERDATAPROC                    glBufferData                        = NULL;
PFNGLCHECKFRAMEBUFFERSTATUSPROC        glCheckFramebufferStatus            = NULL;
PFNGLCLEARBUFFERFVPROC                 glClearBufferfv                     = NULL;
PFNGLCLEARBUFFERIVPROC                 glClearBufferiv                     = NULL;
PFNGLCLEARBUFFERUIVPROC                glClearBufferuiv                    = NULL;
PFNGLCOLORMASKIPROC                    glColorMaski                        = NULL;
PFNGLCREATESHADERPROGRAMVPROC          glCreateShaderProgramv              = NULL;
PFNGLDELETEBUFFERSPROC                 glDeleteBuffers                     = NULL;
PFNGLDELETEFRAMEBUFFERSPROC            glDeleteFramebuffers                = NULL;
PFNGLDELETEPROGRAMPROC                 glDeleteProgram                     = NULL;
PFNGLDELETESAMPLERSPROC                glDeleteSamplers                    = NULL;
PFNGLDELETEVERTEXARRAYSPROC            glDeleteVertexArrays                = NULL;
PFNGLDETACHSHADERPROC                  glDetachShader                      = NULL;
PFNGLDRAWBUFFERSPROC                   glDrawBuffers                       = NULL;
PFNGLDRAWELEMENTSBASEVERTEXPROC        glDrawElementsBaseVertex            = NULL;
PFNGLENABLEVERTEXATTRIBARRAYPROC       glEnableVertexAttribArray           = NULL;
PFNGLFRAMEBUFFERRENDERBUFFERPROC       glFramebufferRenderbuffer           = NULL;
PFNGLFRAMEBUFFERTEXTURE2DPROC          glFramebufferTexture2D              = NULL;
PFNGLGENBUFFERSPROC                    glGenBuffers                        = NULL;
PFNGLGENFRAMEBUFFERSPROC               glGenFramebuffers                   = NULL;
PFNGLGENVERTEXARRAYSPROC               glGenVertexArrays                   = NULL;
PFNGLGETBUFFERPARAMETERIVPROC          glGetBufferParameteriv              = NULL;
PFNGLGETDEBUGMESSAGELOGARBPROC         glGetDebugMessageLogARB             = NULL;
PFNGLDEBUGMESSAGECALLBACKPROC          glDebugMessageCallback              = NULL;
PFNGLGETPROGRAMINFOLOGPROC             glGetProgramInfoLog                 = NULL;
PFNGLGETPROGRAMIVPROC                  glGetProgramiv                      = NULL;
PFNGLGETSHADERIVPROC                   glGetShaderiv                       = NULL;
PFNGLGETSTRINGIPROC                    glGetStringi                        = NULL;
PFNGLISFRAMEBUFFERPROC                 glIsFramebuffer                     = NULL;
PFNGLMAPBUFFERPROC                     glMapBuffer                         = NULL;
PFNGLMAPBUFFERRANGEPROC                glMapBufferRange                    = NULL;
PFNGLPROGRAMPARAMETERIPROC             glProgramParameteri                 = NULL;
PFNGLSAMPLERPARAMETERFPROC             glSamplerParameterf                 = NULL;
PFNGLSAMPLERPARAMETERIPROC             glSamplerParameteri                 = NULL;
PFNGLSHADERSOURCEPROC                  glShaderSource                      = NULL;
PFNGLUNIFORM1IPROC                     glUniform1i                         = NULL;
PFNGLUNMAPBUFFERPROC                   glUnmapBuffer                       = NULL;
PFNGLUSEPROGRAMSTAGESPROC              glUseProgramStages                  = NULL;
PFNGLVERTEXATTRIBIPOINTERPROC          glVertexAttribIPointer              = NULL;
PFNGLVERTEXATTRIBPOINTERPROC           glVertexAttribPointer               = NULL;
PFNGLBUFFERSUBDATAPROC                 glBufferSubData                     = NULL;
PFNGLFENCESYNCPROC                     glFenceSync                         = NULL;
PFNGLDELETESYNCPROC                    glDeleteSync                        = NULL;
PFNGLCLIENTWAITSYNCPROC                glClientWaitSync                    = NULL;
PFNGLFLUSHMAPPEDBUFFERRANGEPROC        glFlushMappedBufferRange            = NULL;
PFNGLBLENDEQUATIONSEPARATEPROC         glBlendEquationSeparate             = NULL;
PFNGLBLENDFUNCSEPARATEPROC             glBlendFuncSeparate                 = NULL;
// Shader compilation (Broken driver)
PFNGLCOMPILESHADERPROC                 glCompileShader                     = NULL;
PFNGLCREATEPROGRAMPROC                 glCreateProgram                     = NULL;
PFNGLCREATESHADERPROC                  glCreateShader                      = NULL;
PFNGLDELETESHADERPROC                  glDeleteShader                      = NULL;
PFNGLLINKPROGRAMPROC                   glLinkProgram                       = NULL;
PFNGLUSEPROGRAMPROC                    glUseProgram                        = NULL;
PFNGLGETSHADERINFOLOGPROC              glGetShaderInfoLog                  = NULL;
PFNGLPROGRAMUNIFORM1IPROC              glProgramUniform1i                  = NULL;
// Query object
PFNGLBEGINQUERYPROC                    glBeginQuery                        = NULL;
PFNGLENDQUERYPROC                      glEndQuery                          = NULL;
PFNGLGETQUERYIVPROC                    glGetQueryiv                        = NULL;
PFNGLGETQUERYOBJECTIVPROC              glGetQueryObjectiv                  = NULL;
PFNGLGETQUERYOBJECTUIVPROC             glGetQueryObjectuiv                 = NULL;
PFNGLQUERYCOUNTERPROC                  glQueryCounter                      = NULL;
PFNGLGETQUERYOBJECTI64VPROC            glGetQueryObjecti64v                = NULL;
PFNGLGETQUERYOBJECTUI64VPROC           glGetQueryObjectui64v               = NULL;
PFNGLGETINTEGER64VPROC                 glGetInteger64v                     = NULL;
PFNGLCREATEQUERIESPROC                 glCreateQueries                     = NULL;
PFNGLDELETEQUERIESPROC                 glDeleteQueries                     = NULL;
// GL4.0
// GL4.1
PFNGLBINDPROGRAMPIPELINEPROC           glBindProgramPipeline               = NULL;
PFNGLDELETEPROGRAMPIPELINESPROC        glDeleteProgramPipelines            = NULL;
PFNGLGETPROGRAMPIPELINEIVPROC          glGetProgramPipelineiv              = NULL;
PFNGLVALIDATEPROGRAMPIPELINEPROC       glValidateProgramPipeline           = NULL;
PFNGLGETPROGRAMPIPELINEINFOLOGPROC     glGetProgramPipelineInfoLog         = NULL;
PFNGLGETPROGRAMBINARYPROC              glGetProgramBinary                  = NULL;
PFNGLVIEWPORTINDEXEDFPROC              glViewportIndexedf                  = NULL;
PFNGLVIEWPORTINDEXEDFVPROC             glViewportIndexedfv                 = NULL;
PFNGLSCISSORINDEXEDPROC                glScissorIndexed                    = NULL;
PFNGLSCISSORINDEXEDVPROC               glScissorIndexedv                   = NULL;
// GL4.3
PFNGLCOPYIMAGESUBDATAPROC              glCopyImageSubData                  = NULL;
PFNGLINVALIDATETEXIMAGEPROC            glInvalidateTexImage                = NULL;
PFNGLPUSHDEBUGGROUPPROC                glPushDebugGroup                    = NULL;
PFNGLPOPDEBUGGROUPPROC                 glPopDebugGroup                     = NULL;
PFNGLDEBUGMESSAGEINSERTPROC            glDebugMessageInsert                = NULL;
PFNGLDEBUGMESSAGECONTROLPROC           glDebugMessageControl               = NULL;
PFNGLOBJECTLABELPROC                   glObjectLabel                       = NULL;
PFNGLOBJECTPTRLABELPROC                glObjectPtrLabel                    = NULL;
// GL4.2
PFNGLBINDIMAGETEXTUREPROC              glBindImageTexture                  = NULL;
PFNGLMEMORYBARRIERPROC                 glMemoryBarrier                     = NULL;
// GL4.4
PFNGLCLEARTEXIMAGEPROC                 glClearTexImage                     = NULL;
PFNGLCLEARTEXSUBIMAGEPROC              glClearTexSubImage                  = NULL;
PFNGLBUFFERSTORAGEPROC                 glBufferStorage                     = NULL;

// GL4.5
PFNGLCREATETEXTURESPROC                glCreateTextures                    = NULL;
PFNGLTEXTURESTORAGE2DPROC              glTextureStorage2D                  = NULL;
PFNGLTEXTURESUBIMAGE2DPROC             glTextureSubImage2D                 = NULL;
PFNGLCOPYTEXTURESUBIMAGE2DPROC         glCopyTextureSubImage2D             = NULL;
PFNGLBINDTEXTUREUNITPROC               glBindTextureUnit                   = NULL;
PFNGLGETTEXTUREIMAGEPROC               glGetTextureImage                   = NULL;
PFNGLTEXTUREPARAMETERIPROC             glTextureParameteri                 = NULL;
PFNGLGENERATETEXTUREMIPMAPPROC         glGenerateTextureMipmap             = NULL;

PFNGLCREATEFRAMEBUFFERSPROC            glCreateFramebuffers                = NULL;
PFNGLCLEARNAMEDFRAMEBUFFERFVPROC       glClearNamedFramebufferfv           = NULL;
PFNGLCLEARNAMEDFRAMEBUFFERIVPROC       glClearNamedFramebufferiv           = NULL;
PFNGLCLEARNAMEDFRAMEBUFFERUIVPROC      glClearNamedFramebufferuiv          = NULL;
PFNGLNAMEDFRAMEBUFFERTEXTUREPROC       glNamedFramebufferTexture           = NULL;
PFNGLNAMEDFRAMEBUFFERDRAWBUFFERSPROC   glNamedFramebufferDrawBuffers       = NULL;
PFNGLNAMEDFRAMEBUFFERREADBUFFERPROC    glNamedFramebufferReadBuffer        = NULL;
PFNGLNAMEDFRAMEBUFFERPARAMETERIPROC    glNamedFramebufferParameteri        = NULL;
PFNGLCHECKNAMEDFRAMEBUFFERSTATUSPROC   glCheckNamedFramebufferStatus       = NULL;

PFNGLCREATEBUFFERSPROC                 glCreateBuffers                     = NULL;
PFNGLNAMEDBUFFERSTORAGEPROC            glNamedBufferStorage                = NULL;
PFNGLNAMEDBUFFERDATAPROC               glNamedBufferData                   = NULL;
PFNGLNAMEDBUFFERSUBDATAPROC            glNamedBufferSubData                = NULL;
PFNGLMAPNAMEDBUFFERPROC                glMapNamedBuffer                    = NULL;
PFNGLMAPNAMEDBUFFERRANGEPROC           glMapNamedBufferRange               = NULL;
PFNGLUNMAPNAMEDBUFFERPROC              glUnmapNamedBuffer                  = NULL;
PFNGLFLUSHMAPPEDNAMEDBUFFERRANGEPROC   glFlushMappedNamedBufferRange       = NULL;

PFNGLCREATESAMPLERSPROC                glCreateSamplers                    = NULL;
PFNGLCREATEPROGRAMPIPELINESPROC        glCreateProgramPipelines            = NULL;

PFNGLCLIPCONTROLPROC                   glClipControl                       = NULL;
PFNGLTEXTUREBARRIERPROC                glTextureBarrier                    = NULL;
PFNGLGETTEXTURESUBIMAGEPROC            glGetTextureSubImage                = NULL;

#ifdef _WIN32
PFNGLACTIVETEXTUREPROC                 gl_ActiveTexture                    = NULL;
PFNGLTEXSTORAGE2DPROC                  glTexStorage2D                      = NULL;
PFNGLGENPROGRAMPIPELINESPROC           glGenProgramPipelines               = NULL;
PFNGLGENSAMPLERSPROC                   glGenSamplers                       = NULL;
PFNGLGENERATEMIPMAPPROC                glGenerateMipmap                    = NULL;
#endif

namespace ReplaceGL {
	void APIENTRY ScissorIndexed(GLuint index, GLint left, GLint bottom, GLsizei width, GLsizei height)
	{
		glScissor(left, bottom, width, height);
	}

	void APIENTRY ViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h)
	{
		glViewport(GLint(x), GLint(y), GLsizei(w), GLsizei(h));
	}

	void APIENTRY TextureBarrier()
	{
	}

}

#ifdef _WIN32
namespace Emulate_DSA {
	// Texture entry point
	void APIENTRY BindTextureUnit(GLuint unit, GLuint texture) {
		gl_ActiveTexture(GL_TEXTURE0 + unit);
		glBindTexture(GL_TEXTURE_2D, texture);
	}

	void APIENTRY CreateTexture(GLenum target, GLsizei n, GLuint *textures) {
		glGenTextures(1, textures);
	}

	void APIENTRY TextureStorage(GLuint texture, GLsizei levels, GLenum internalformat, GLsizei width, GLsizei height) {
		BindTextureUnit(7, texture);
		glTexStorage2D(GL_TEXTURE_2D, levels, internalformat, width, height);
	}

	void APIENTRY TextureSubImage(GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, const void *pixels) {
		BindTextureUnit(7, texture);
		glTexSubImage2D(GL_TEXTURE_2D, level, xoffset, yoffset, width, height, format, type, pixels);
	}

	void APIENTRY CopyTextureSubImage(GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLint x, GLint y, GLsizei width, GLsizei height) {
		BindTextureUnit(7, texture);
		glCopyTexSubImage2D(GL_TEXTURE_2D, level, xoffset, yoffset, x, y, width, height);
	}

	void APIENTRY GetTexureImage(GLuint texture, GLint level, GLenum format, GLenum type, GLsizei bufSize, void *pixels) {
		BindTextureUnit(7, texture);
		glGetTexImage(GL_TEXTURE_2D, level, format, type, pixels);
	}

	void APIENTRY TextureParameteri (GLuint texture, GLenum pname, GLint param) {
		BindTextureUnit(7, texture);
		glTexParameteri(GL_TEXTURE_2D, pname, param);
	}

	void APIENTRY GenerateTextureMipmap(GLuint texture) {
		BindTextureUnit(7, texture);
		glGenerateMipmap(GL_TEXTURE_2D);
	}

	// Misc entry point
	// (only purpose is to have a consistent API otherwise it is useless)
	void APIENTRY CreateProgramPipelines(GLsizei n, GLuint *pipelines) {
		glGenProgramPipelines(n, pipelines);
	}

	void APIENTRY CreateSamplers(GLsizei n, GLuint *samplers) {
		glGenSamplers(n, samplers);
	}

	// Replace function pointer to emulate DSA behavior
	void Init() {
		fprintf(stderr, "DSA is not supported. Expect slower performance\n");
		glBindTextureUnit             = BindTextureUnit;
		glCreateTextures              = CreateTexture;
		glTextureStorage2D            = TextureStorage;
		glTextureSubImage2D           = TextureSubImage;
		glCopyTextureSubImage2D       = CopyTextureSubImage;
		glGetTextureImage             = GetTexureImage;
		glTextureParameteri           = TextureParameteri;

		glCreateProgramPipelines      = CreateProgramPipelines;
		glCreateSamplers              = CreateSamplers;
	}
}
#endif

namespace GLLoader {

	bool s_first_load = true;

	bool amd_legacy_buggy_driver = false;
	bool vendor_id_amd      = false;
	bool vendor_id_nvidia   = false;
	bool vendor_id_intel    = false;
	bool mesa_driver        = false;
	bool in_replayer        = false;
	bool buggy_sso_dual_src = false;


	bool found_geometry_shader = true; // we require GL3.3 so geometry must be supported by default
	bool found_GL_EXT_texture_filter_anisotropic = false;
	bool found_GL_ARB_clear_texture = false;
	bool found_GL_ARB_get_texture_sub_image = false; // Not yet used
	// DX11 GPU
	bool found_GL_ARB_gpu_shader5 = false; // Require IvyBridge
	bool found_GL_ARB_shader_image_load_store = false; // Intel IB. Nvidia/AMD miss Mesa implementation.
	bool found_GL_ARB_viewport_array = false; // Intel IB. AMD/NVIDIA DX10
	// Bonus to monitor the VRAM
	bool found_GL_NVX_gpu_memory_info = false;

	// Mandatory
	bool found_GL_ARB_buffer_storage = false;
	bool found_GL_ARB_clip_control = false;
	bool found_GL_ARB_copy_image = false;
	bool found_GL_ARB_direct_state_access = false;
	bool found_GL_ARB_separate_shader_objects = false;
	bool found_GL_ARB_shading_language_420pack = false;
	bool found_GL_ARB_texture_barrier = false;
	bool found_GL_ARB_texture_storage = false;
	bool found_GL_KHR_debug = false;

	static bool status_and_override(bool& found, const std::string& name, bool mandatory = false)
	{
		if (mandatory) {
			if (!found) {
				fprintf(stderr, "ERROR: %s is NOT SUPPORTED\n", name.c_str());
			}
			return found;
		}

		if (s_first_load) {
			if (!found) {
				fprintf(stdout, "INFO: %s is NOT SUPPORTED\n", name.c_str());
			} else {
				fprintf(stdout, "INFO: %s is available\n", name.c_str());
			}
		}

		std::string opt("override_");
		opt += name;

		if (theApp.GetConfigI(opt.c_str()) != -1) {
			found = theApp.GetConfigB(opt.c_str());
			fprintf(stderr, "Override %s detection (%s)\n", name.c_str(), found ? "Enabled" : "Disabled");
		}

		return true;
	}

    bool check_gl_version(int major, int minor) {

		const GLubyte* s = glGetString(GL_VERSION);
		if (s == NULL) {
			fprintf(stderr, "Error: GLLoader failed to get GL version\n");
			return false;
		}
		GLuint v = 1;
		while (s[v] != '\0' && s[v-1] != ' ') v++;

		const char* vendor = (const char*)glGetString(GL_VENDOR);
		if (s_first_load)
			fprintf(stdout, "OpenGL information. GPU: %s. Vendor: %s. Driver: %s\n", glGetString(GL_RENDERER), vendor, &s[v]);

		// Name changed but driver is still bad!
		if (strstr(vendor, "Advanced Micro Devices") || strstr(vendor, "ATI Technologies Inc.") || strstr(vendor, "ATI"))
			vendor_id_amd = true;
		/*if (vendor_id_amd && (
				strstr((const char*)&s[v], " 10.") || // Blacklist all 2010 AMD drivers.
				strstr((const char*)&s[v], " 11.") || // Blacklist all 2011 AMD drivers.
				strstr((const char*)&s[v], " 12.") || // Blacklist all 2012 AMD drivers.
				strstr((const char*)&s[v], " 13.") || // Blacklist all 2013 AMD drivers.
				strstr((const char*)&s[v], " 14.") || // Blacklist all 2014 AMD drivers.
				strstr((const char*)&s[v], " 15.") || // Blacklist all 2015 AMD drivers.
				strstr((const char*)&s[v], " 16.") || // Blacklist all 2016 AMD drivers.
				strstr((const char*)&s[v], " 17.") // Blacklist all 2017 AMD drivers for now.
				))
			amd_legacy_buggy_driver = true;
		*/
		if (strstr(vendor, "NVIDIA Corporation"))
			vendor_id_nvidia = true;

#ifdef _WIN32
		if (strstr(vendor, "Intel"))
			vendor_id_intel = true;
#else
		// On linux assumes the free driver if it isn't nvidia or amd pro driver
		mesa_driver = !vendor_id_nvidia && !vendor_id_amd;
#endif
		// As of 2019 SSO is still broken on intel (Kaby Lake confirmed).
		buggy_sso_dual_src = vendor_id_intel || vendor_id_amd /*|| amd_legacy_buggy_driver*/;

		if (theApp.GetConfigI("override_geometry_shader") != -1) {
			found_geometry_shader = theApp.GetConfigB("override_geometry_shader");
			fprintf(stderr, "Overriding geometry shaders detection\n");
		}

		GLint major_gl = 0;
		GLint minor_gl = 0;
		glGetIntegerv(GL_MAJOR_VERSION, &major_gl);
		glGetIntegerv(GL_MINOR_VERSION, &minor_gl);
		if ( (major_gl < major) || ( major_gl == major && minor_gl < minor ) ) {
			fprintf(stderr, "OpenGL %d.%d is not supported. Only OpenGL %d.%d\n was found", major, minor, major_gl, minor_gl);
			return false;
		}

        return true;
    }

	bool check_gl_supported_extension() {
		int max_ext = 0;
		glGetIntegerv(GL_NUM_EXTENSIONS, &max_ext);

		if (glGetStringi && max_ext) {
			for (GLint i = 0; i < max_ext; i++) {
				std::string ext{(const char*)glGetStringi(GL_EXTENSIONS, i)};
				// Bonus
				if (ext.compare("GL_EXT_texture_filter_anisotropic") == 0) found_GL_EXT_texture_filter_anisotropic = true;
				if (ext.compare("GL_NVX_gpu_memory_info") == 0) found_GL_NVX_gpu_memory_info = true;
				// GL4.0
				if (ext.compare("GL_ARB_gpu_shader5") == 0) found_GL_ARB_gpu_shader5 = true;
				// GL4.1
				if (ext.compare("GL_ARB_viewport_array") == 0) found_GL_ARB_viewport_array = true;
				if (ext.compare("GL_ARB_separate_shader_objects") == 0) found_GL_ARB_separate_shader_objects = true;
				// GL4.2
				if (ext.compare("GL_ARB_shading_language_420pack") == 0) found_GL_ARB_shading_language_420pack = true;
				if (ext.compare("GL_ARB_texture_storage") == 0) found_GL_ARB_texture_storage = true;
				if (ext.compare("GL_ARB_shader_image_load_store") == 0) found_GL_ARB_shader_image_load_store = true;
				// GL4.3
				if (ext.compare("GL_ARB_copy_image") == 0) found_GL_ARB_copy_image = true;
				if (ext.compare("GL_KHR_debug") == 0) found_GL_KHR_debug = true;
				// GL4.4
				if (ext.compare("GL_ARB_buffer_storage") == 0) found_GL_ARB_buffer_storage = true;
				if (ext.compare("GL_ARB_clear_texture") == 0) found_GL_ARB_clear_texture = true;
				// GL4.5
				if (ext.compare("GL_ARB_direct_state_access") == 0) found_GL_ARB_direct_state_access = true;
				if (ext.compare("GL_ARB_clip_control") == 0) found_GL_ARB_clip_control = true;
				if (ext.compare("GL_ARB_texture_barrier") == 0) found_GL_ARB_texture_barrier = true;
				if (ext.compare("GL_ARB_get_texture_sub_image") == 0) found_GL_ARB_get_texture_sub_image = true;

				//fprintf(stderr, "DEBUG ext: %s\n", ext.c_str());
			}
		}

		bool status = true;
		bool required_for_hw = (theApp.GetCurrentRendererType() == GSRendererType::OGL_HW);

		// Bonus
		status &= status_and_override(found_GL_EXT_texture_filter_anisotropic, "GL_EXT_texture_filter_anisotropic");
		// GL4.0
		status &= status_and_override(found_GL_ARB_gpu_shader5, "GL_ARB_gpu_shader5");
		// GL4.1
		status &= status_and_override(found_GL_ARB_viewport_array, "GL_ARB_viewport_array");
		status &= status_and_override(found_GL_ARB_separate_shader_objects, "GL_ARB_separate_shader_objects", true);
		// GL4.2
		status &= status_and_override(found_GL_ARB_shader_image_load_store, "GL_ARB_shader_image_load_store");
		status &= status_and_override(found_GL_ARB_shading_language_420pack, "GL_ARB_shading_language_420pack", true);
		status &= status_and_override(found_GL_ARB_texture_storage, "GL_ARB_texture_storage", true);
		// GL4.3
		status &= status_and_override(found_GL_ARB_copy_image, "GL_ARB_copy_image", required_for_hw);
		status &= status_and_override(found_GL_KHR_debug, "GL_KHR_debug", true);
		// GL4.4
		status &= status_and_override(found_GL_ARB_buffer_storage,"GL_ARB_buffer_storage", true);
		status &= status_and_override(found_GL_ARB_clear_texture,"GL_ARB_clear_texture");
		// GL4.5
		status &= status_and_override(found_GL_ARB_clip_control, "GL_ARB_clip_control", required_for_hw);
		status &= status_and_override(found_GL_ARB_direct_state_access, "GL_ARB_direct_state_access");
		// Mandatory for the advance HW renderer effect. Unfortunately Mesa LLVMPIPE/SWR renderers doesn't support this extension.
		// Rendering might be corrupted but it could be good enough for test/virtual machine.
		status &= status_and_override(found_GL_ARB_texture_barrier, "GL_ARB_texture_barrier");
		status &= status_and_override(found_GL_ARB_get_texture_sub_image, "GL_ARB_get_texture_sub_image");

		if (s_first_load) {
			if (vendor_id_amd) {
				fprintf(stderr, "The OpenGL hardware renderer is slow on AMD GPUs due to an inefficient driver.\n"
					"Check out the link below for further information.\n"
					"https://github.com/PCSX2/pcsx2/wiki/OpenGL-and-AMD-GPUs---All-you-need-to-know\n");
			}

			if (vendor_id_intel && !found_GL_ARB_texture_barrier && !found_GL_ARB_direct_state_access) {
				// Assume that driver support is good when texture barrier and DSA is supported, disable the log then.
				fprintf(stderr, "The OpenGL renderer is inefficient on Intel GPUs due to an inefficient driver.\n"
					"Check out the link below for further information.\n"
					"https://github.com/PCSX2/pcsx2/wiki/OpenGL-and-Intel-GPUs-All-you-need-to-know\n");
			}
		}

		if (!found_GL_ARB_viewport_array) {
			glScissorIndexed   = ReplaceGL::ScissorIndexed;
			glViewportIndexedf = ReplaceGL::ViewportIndexedf;
			if (s_first_load)
				fprintf(stderr, "GL_ARB_viewport_array is not supported! Function pointer will be replaced\n");
		}

		if (!found_GL_ARB_texture_barrier) {
			glTextureBarrier = ReplaceGL::TextureBarrier;
			if (s_first_load)
				fprintf(stderr, "GL_ARB_texture_barrier is not supported! Blending emulation will not be supported\n");
		}

#ifdef _WIN32
		// Thank you Intel for not providing support of basic features on your IGPUs.
		if (!found_GL_ARB_direct_state_access) {
			Emulate_DSA::Init();
		}
#endif

		if (s_first_load)
			fprintf(stdout, "\n");

		return status;
	}

	void check_gl_requirements()
	{
		if (!GLLoader::check_gl_version(3, 3))
			throw GSDXRecoverableError();

		if (!GLLoader::check_gl_supported_extension())
			throw GSDXRecoverableError();

		s_first_load = false;
	}
}