llgl.cpp

/** 
 * @file llgl.cpp
 * @brief LLGL implementation
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

// This file sets some global GL parameters, and implements some 
// useful functions for GL operations.

#define GLH_EXT_SINGLE_FILE

#include "linden_common.h"

#include "boost/tokenizer.hpp"

#include "llsys.h"

#include "llgl.h"
#include "llglstates.h"
#include "llrender.h"

#include "llerror.h"
#include "llerrorcontrol.h"
#include "llquaternion.h"
#include "llmath.h"
#include "m4math.h"
#include "llstring.h"
#include "llstacktrace.h"

#include "llglheaders.h"
#include "llglslshader.h"

#if LL_WINDOWS
#include "lldxhardware.h"
#endif

#ifdef _DEBUG
//#define GL_STATE_VERIFY
#endif

#if LL_SDL
#include <SDL.h>
#endif


BOOL gDebugSession = FALSE;
BOOL gClothRipple = FALSE;
BOOL gHeadlessClient = FALSE;
BOOL gGLActive = FALSE;
BOOL gGLDebugLoggingEnabled = TRUE;

static const std::string HEADLESS_VENDOR_STRING("Linden Lab");
static const std::string HEADLESS_RENDERER_STRING("Headless");
static const std::string HEADLESS_VERSION_STRING("1.0");

llofstream gFailLog;

#ifndef APIENTRY
#define APIENTRY
#endif

void APIENTRY gl_debug_callback(GLenum source,
	GLenum type,
	GLuint id,
	GLenum severity,
	GLsizei length,
	const GLchar* message,
	GLvoid* userParam)
{
	if (gGLDebugLoggingEnabled)
	{
		if (severity == GL_DEBUG_SEVERITY_HIGH)
		{
			LL_WARNS() << "----- GL ERROR --------" << LL_ENDL;
		}
		else
		{
			LL_WARNS() << "----- GL WARNING -------" << LL_ENDL;
		}
		LL_WARNS() << "Type: " << std::hex << type << LL_ENDL;
		LL_WARNS() << "ID: " << std::hex << id << LL_ENDL;
		LL_WARNS() << "Severity: " << std::hex << severity << LL_ENDL;
		LL_WARNS() << "Message: " << message << LL_ENDL;
		LL_WARNS() << "-----------------------" << LL_ENDL;
		if (severity == GL_DEBUG_SEVERITY_HIGH)
		{
			LL_ERRS() << "Halting on GL Error" << LL_ENDL;
		}
	}
}

void parse_glsl_version(S32& major, S32& minor);

void ll_init_fail_log(std::string filename)
{
	gFailLog.open(filename.c_str());
}


void ll_fail(std::string msg)
{
	
	if (gDebugSession)
	{
		std::vector<std::string> lines;

		gFailLog << LLError::utcTime() << " " << msg << std::endl;

		gFailLog << "Stack Trace:" << std::endl;

		ll_get_stack_trace(lines);
		
		for(size_t i = 0; i < lines.size(); ++i)
		{
			gFailLog << lines[i] << std::endl;
		}

		gFailLog << "End of Stack Trace." << std::endl << std::endl;

		gFailLog.flush();
	}
};

void ll_close_fail_log()
{
	gFailLog.close();
}

LLMatrix4 gGLObliqueProjectionInverse;

#define LL_GL_NAME_POOLING 0

std::list<LLGLUpdate*> LLGLUpdate::sGLQ;

LLGLManager gGLManager;

LLGLManager::LLGLManager() :
	mInited(FALSE),
	mIsDisabled(FALSE),

	mHasMultitexture(FALSE),
	mHasATIMemInfo(FALSE),
	mHasAMDAssociations(FALSE),
	mHasNVXMemInfo(FALSE),
	mNumTextureUnits(1),
	mHasMipMapGeneration(FALSE),
	mHasCompressedTextures(FALSE),
	mHasFramebufferObject(FALSE),
	mMaxSamples(0),
	mHasBlendFuncSeparate(FALSE),
	mHasSync(FALSE),
	mHasVertexBufferObject(FALSE),
	mHasVertexArrayObject(FALSE),
	mHasMapBufferRange(FALSE),
	mHasFlushBufferRange(FALSE),
	mHasPBuffer(FALSE),
	mHasShaderObjects(FALSE),
	mHasVertexShader(FALSE),
	mHasFragmentShader(FALSE),
	mNumTextureImageUnits(0),
	mHasOcclusionQuery(FALSE),
	mHasTimerQuery(FALSE),
	mHasOcclusionQuery2(FALSE),
	mHasPointParameters(FALSE),
	mHasDrawBuffers(FALSE),
	mHasTextureRectangle(FALSE),
	mHasTextureMultisample(FALSE),
	mHasTransformFeedback(FALSE),
	mMaxSampleMaskWords(0),
	mMaxColorTextureSamples(0),
	mMaxDepthTextureSamples(0),
	mMaxIntegerSamples(0),

	mHasAnisotropic(FALSE),
	mHasARBEnvCombine(FALSE),
	mHasCubeMap(FALSE),
	mHasDebugOutput(FALSE),

	mHasTextureSwizzle(false),
	mIsATI(FALSE),
	mIsNVIDIA(FALSE),
	mIsIntel(FALSE),
	mIsGF2or4MX(FALSE),
	mIsGF3(FALSE),
	mIsGFFX(FALSE),
	mATIOffsetVerticalLines(FALSE),
	mATIOldDriver(FALSE),
#if LL_DARWIN
	mIsMobileGF(FALSE),
#endif
	mHasRequirements(TRUE),

	mHasSeparateSpecularColor(FALSE),

	mDebugGPU(FALSE),

	mDriverVersionMajor(1),
	mDriverVersionMinor(0),
	mDriverVersionRelease(0),
	mGLVersion(1.0f),
	mGLSLVersionMajor(0),
	mGLSLVersionMinor(0),		
	mVRAM(0),
	mGLMaxVertexRange(0),
	mGLMaxIndexRange(0)
{
}

//---------------------------------------------------------------------
// Global initialization for GL
//---------------------------------------------------------------------
#if LL_WINDOWS && !LL_MESA_HEADLESS
void LLGLManager::initWGL(HDC dc)
{
	mHasPBuffer = FALSE;

	if (!epoxy_has_wgl_extension(dc, "WGL_ARB_pixel_format"))
	{
		LL_WARNS("RenderInit") << "No ARB pixel format extensions" << LL_ENDL;
	}

	if (epoxy_has_wgl_extension(dc, "WGL_ARB_create_context"))
	{
		//GLH_EXT_NAME(wglCreateContextAttribsARB) = (PFNWGLCREATECONTEXTATTRIBSARBPROC)GLH_EXT_GET_PROC_ADDRESS("wglCreateContextAttribsARB");
	}
	else
	{
		LL_WARNS("RenderInit") << "No ARB create context extensions" << LL_ENDL;
	}

	// For retreiving information per AMD adapter, 
	// because we can't trust curently selected/default one when there are multiple
	mHasAMDAssociations = epoxy_has_wgl_extension(dc, "WGL_AMD_gpu_association");
	if (mHasAMDAssociations)
	{
		//GLH_EXT_NAME(wglGetGPUIDsAMD) = (PFNWGLGETGPUIDSAMDPROC)GLH_EXT_GET_PROC_ADDRESS("wglGetGPUIDsAMD");
		//GLH_EXT_NAME(wglGetGPUInfoAMD) = (PFNWGLGETGPUINFOAMDPROC)GLH_EXT_GET_PROC_ADDRESS("wglGetGPUInfoAMD");
	}

	if (epoxy_has_wgl_extension(dc, "WGL_EXT_swap_control"))
	{
        //GLH_EXT_NAME(wglSwapIntervalEXT) = (PFNWGLSWAPINTERVALEXTPROC)GLH_EXT_GET_PROC_ADDRESS("wglSwapIntervalEXT");
	}

	if( !epoxy_has_wgl_extension(dc, "WGL_ARB_pbuffer") )
	{
		LL_WARNS("RenderInit") << "No ARB WGL PBuffer extensions" << LL_ENDL;
	}

	if( !epoxy_has_wgl_extension(dc, "WGL_ARB_render_texture") )
	{
		LL_WARNS("RenderInit") << "No ARB WGL render texture extensions" << LL_ENDL;
	}

	mHasPBuffer = epoxy_has_wgl_extension(dc, "WGL_ARB_pbuffer") &&
					epoxy_has_wgl_extension(dc, "WGL_ARB_render_texture") &&
					epoxy_has_wgl_extension(dc, "WGL_ARB_pixel_format");
}
#endif

// return false if unable (or unwilling due to old drivers) to init GL
bool LLGLManager::initGL()
{
	if (mInited)
	{
		LL_ERRS("RenderInit") << "Calling init on LLGLManager after already initialized!" << LL_ENDL;
	}
	
	stop_glerror();

	// Extract video card strings and convert to upper case to
	// work around driver-to-driver variation in capitalization.
	mGLVendor = ll_safe_string((const char *)glGetString(GL_VENDOR));
	LLStringUtil::toUpper(mGLVendor);

	mGLRenderer = ll_safe_string((const char *)glGetString(GL_RENDERER));
	LLStringUtil::toUpper(mGLRenderer);

	parse_gl_version( &mDriverVersionMajor, 
		&mDriverVersionMinor, 
		&mDriverVersionRelease, 
		&mDriverVersionVendorString,
		&mGLVersionString);

	mGLVersion = mDriverVersionMajor + mDriverVersionMinor * .1f;

	if (mGLVersion >= 2.f)
	{
		parse_glsl_version(mGLSLVersionMajor, mGLSLVersionMinor);

#if LL_DARWIN
		//never use GLSL greater than 1.20 on OSX
		if (mGLSLVersionMajor > 1 || mGLSLVersionMinor >= 30)
		{
			mGLSLVersionMajor = 1;
			mGLSLVersionMinor = 20;
		}
#endif
	}

	if (mGLVersion >= 2.1f && LLImageGL::sCompressTextures)
	{ //use texture compression
		glHint(GL_TEXTURE_COMPRESSION_HINT, GL_NICEST);
	}
	else
	{ //GL version is < 3.0, always disable texture compression
		LLImageGL::sCompressTextures = false;
	}
	
	// Trailing space necessary to keep "nVidia Corpor_ati_on" cards
	// from being recognized as ATI.
	if (mGLVendor.substr(0,4) == "ATI ")
	{
		mGLVendorShort = "ATI";
		// *TODO: Fix this?
		mIsATI = TRUE;

#if LL_WINDOWS && !LL_MESA_HEADLESS
		if (mDriverVersionRelease < 3842)
		{
			mATIOffsetVerticalLines = TRUE;
		}
#endif // LL_WINDOWS

#if (LL_WINDOWS || LL_LINUX) && !LL_MESA_HEADLESS
		// count any pre OpenGL 3.0 implementation as an old driver
		if (mGLVersion < 3.f) 
		{
			mATIOldDriver = TRUE;
		}
#endif // (LL_WINDOWS || LL_LINUX) && !LL_MESA_HEADLESS
	}
	else if (mGLVendor.find("NVIDIA ") != std::string::npos)
	{
		mGLVendorShort = "NVIDIA";
		mIsNVIDIA = TRUE;
		if (   mGLRenderer.find("GEFORCE4 MX") != std::string::npos
			|| mGLRenderer.find("GEFORCE2") != std::string::npos
			|| mGLRenderer.find("GEFORCE 2") != std::string::npos
			|| mGLRenderer.find("GEFORCE4 460 GO") != std::string::npos
			|| mGLRenderer.find("GEFORCE4 440 GO") != std::string::npos
			|| mGLRenderer.find("GEFORCE4 420 GO") != std::string::npos)
		{
			mIsGF2or4MX = TRUE;
		}
		else if (mGLRenderer.find("GEFORCE FX") != std::string::npos
				 || mGLRenderer.find("QUADRO FX") != std::string::npos
				 || mGLRenderer.find("NV34") != std::string::npos)
		{
			mIsGFFX = TRUE;
		}
		else if(mGLRenderer.find("GEFORCE3") != std::string::npos)
		{
			mIsGF3 = TRUE;
		}
#if LL_DARWIN
		else if ((mGLRenderer.find("9400M") != std::string::npos)
			  || (mGLRenderer.find("9600M") != std::string::npos)
			  || (mGLRenderer.find("9800M") != std::string::npos))
		{
			mIsMobileGF = TRUE;
		}
#endif

	}
	else if (mGLVendor.find("INTEL") != std::string::npos
#if LL_LINUX
		 // The Mesa-based drivers put this in the Renderer string,
		 // not the Vendor string.
		 || mGLRenderer.find("INTEL") != std::string::npos
#endif //LL_LINUX
		 )
	{
		mGLVendorShort = "INTEL";
		mIsIntel = TRUE;
	}
	else
	{
		mGLVendorShort = "MISC";
	}
	
	stop_glerror();
	// This is called here because it depends on the setting of mIsGF2or4MX, and sets up mHasMultitexture.
	initExtensions();
	stop_glerror();

	if (mVRAM == 0)
	{
		S32 old_vram = mVRAM;
	mVRAM = 0;

#if LL_WINDOWS
	if (mHasAMDAssociations)
	{
		GLuint gl_gpus_count = wglGetGPUIDsAMD(0, 0);
		if (gl_gpus_count > 0)
		{
			GLuint* ids = new GLuint[gl_gpus_count];
			wglGetGPUIDsAMD(gl_gpus_count, ids);

			GLuint mem_mb = 0;
			for (U32 i = 0; i < gl_gpus_count; i++)
			{
				wglGetGPUInfoAMD(ids[i],
					WGL_GPU_RAM_AMD,
					GL_UNSIGNED_INT,
					sizeof(GLuint),
					&mem_mb);
				if (mVRAM < mem_mb)
				{
					// basically pick the best AMD and trust driver/OS to know to switch
					mVRAM = mem_mb;
				}
			}
		}
		if (mVRAM != 0)
		{
			LL_WARNS("RenderInit") << "VRAM Detected (AMDAssociations):" << mVRAM << LL_ENDL;
		}
	}
#endif

	if (mHasATIMemInfo && mVRAM == 0)
	{ //ask the gl how much vram is free at startup and attempt to use no more than half of that
		S32 meminfo[4];
		glGetIntegerv(GL_TEXTURE_FREE_MEMORY_ATI, meminfo);

		mVRAM = meminfo[0] / 1024;
		LL_WARNS("RenderInit") << "VRAM Detected (ATIMemInfo):" << mVRAM << LL_ENDL;
	}

	if (mHasNVXMemInfo && mVRAM == 0)
	{
		S32 dedicated_memory;
		glGetIntegerv(GL_GPU_MEMORY_INFO_DEDICATED_VIDMEM_NVX, &dedicated_memory);
		mVRAM = dedicated_memory/1024;
		LL_WARNS("RenderInit") << "VRAM Detected (NVXMemInfo):" << mVRAM << LL_ENDL;
	}

#if LL_WINDOWS
	if (mVRAM < 256)
	{
		// Something likely went wrong using the above extensions
		// try WMI first and fall back to old method (from dxdiag) if all else fails
		// Function will check all GPUs WMI knows of and will pick up the one with most
		// memory. We need to check all GPUs because system can switch active GPU to
		// weaker one, to preserve power when not under load.
		S32 mem = LLDXHardware::getMBVideoMemoryViaDXGI();
		if (mem != 0)
		{
			mVRAM = mem;
			LL_WARNS("RenderInit") << "VRAM Detected (WMI):" << mVRAM<< LL_ENDL;
		}
	}
#endif

	if (mVRAM < 256 && old_vram > 0)
	{
		// fall back to old method
		// Note: on Windows value will be from LLDXHardware.
		// Either received via dxdiag or via WMI by id from dxdiag.
		mVRAM = old_vram;
	}

		else
		{
			LL_INFOS("RenderInit") << "Detected VRAM from GL: " << mVRAM << LL_ENDL;
		}
	}
	else
	{
		LL_INFOS("RenderInit") << "Using VRAM value from OS: " << mVRAM << LL_ENDL;
	}

	stop_glerror();

	if (mHasFragmentShader)
	{
		GLint num_tex_image_units;
		glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &num_tex_image_units);
		mNumTextureImageUnits = llmin(num_tex_image_units, 32);
	}

	LL_INFOS() << "NUM TEX IMAGE UNITS: " << mNumTextureImageUnits << LL_ENDL;

	if (LLRender::sGLCoreProfile)
	{
		mNumTextureUnits = llmin(mNumTextureImageUnits, MAX_GL_TEXTURE_UNITS);
	}
	else if (mHasMultitexture)
	{
		GLint num_tex_units;		
		glGetIntegerv(GL_MAX_TEXTURE_UNITS, &num_tex_units);
		mNumTextureUnits = llmin(num_tex_units, (GLint)MAX_GL_TEXTURE_UNITS);
		if (mIsIntel)
		{
			mNumTextureUnits = llmin(mNumTextureUnits, 2);
		}
	}
	else
	{
		mHasRequirements = FALSE;

		// We don't support cards that don't support the GL_ARB_multitexture extension
		LL_WARNS("RenderInit") << "GL Drivers do not support GL_ARB_multitexture" << LL_ENDL;
		return false;
	}
	
	stop_glerror();

	if (mHasTextureMultisample)
	{
		glGetIntegerv(GL_MAX_COLOR_TEXTURE_SAMPLES, &mMaxColorTextureSamples);
		glGetIntegerv(GL_MAX_DEPTH_TEXTURE_SAMPLES, &mMaxDepthTextureSamples);
		glGetIntegerv(GL_MAX_INTEGER_SAMPLES, &mMaxIntegerSamples);
		glGetIntegerv(GL_MAX_SAMPLE_MASK_WORDS, &mMaxSampleMaskWords);
	}

	stop_glerror();

	if (mHasDebugOutput && gDebugGL)
	{ //setup debug output callback
		glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DEBUG_SEVERITY_LOW, 0, NULL, GL_TRUE);
		glDebugMessageCallback((GLDEBUGPROC) gl_debug_callback, NULL);
		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
	}

	stop_glerror();

	//HACK always disable texture multisample, use FXAA instead
	mHasTextureMultisample = FALSE;
#if LL_WINDOWS
	if (mIsATI)
	{ //using multisample textures on ATI results in black screen for some reason
		mHasTextureMultisample = FALSE;
	}


	if (mIsIntel && mGLVersion <= 3.f)
	{ //never try to use framebuffer objects on older intel drivers (crashy)
		mHasFramebufferObject = FALSE;
	}
#endif

	if (mHasFramebufferObject)
	{
		glGetIntegerv(GL_MAX_SAMPLES, &mMaxSamples);
	}

	stop_glerror();
	
	setToDebugGPU();

	stop_glerror();

	initGLStates();

	stop_glerror();

	return true;
}

void LLGLManager::setToDebugGPU()
{
	//"MOBILE INTEL(R) 965 EXPRESS CHIP", 
	if (mGLRenderer.find("INTEL") != std::string::npos && mGLRenderer.find("965") != std::string::npos)
	{
		mDebugGPU = TRUE ;
	}

	return ;
}

void LLGLManager::getGLInfo(LLSD& info)
{
	if (gHeadlessClient)
	{
		info["GLInfo"]["GLVendor"] = HEADLESS_VENDOR_STRING;
		info["GLInfo"]["GLRenderer"] = HEADLESS_RENDERER_STRING;
		info["GLInfo"]["GLVersion"] = HEADLESS_VERSION_STRING;
		return;
	}
	else
	{
		info["GLInfo"]["GLVendor"] = ll_safe_string((const char *)glGetString(GL_VENDOR));
		info["GLInfo"]["GLRenderer"] = ll_safe_string((const char *)glGetString(GL_RENDERER));
		info["GLInfo"]["GLVersion"] = ll_safe_string((const char *)glGetString(GL_VERSION));
	}

#if !LL_MESA_HEADLESS
#if !LL_DARWIN
    if (mGLVersion >= 3.0f && glGetStringi) {
        std::vector<std::string> gl_extension_str_vec;
        GLint n, i;
        glGetIntegerv(GL_NUM_EXTENSIONS, &n);
        for (i = 0; i < n; i++) {
            std::string exten = ll_safe_string((const char *) glGetStringi(GL_EXTENSIONS, i));
            if (!exten.empty())
                info["GLInfo"]["GLExtensions"].append(exten);
        }
    } else
#endif
    {
        std::string all_exts = ll_safe_string((const char *) glGetString(GL_EXTENSIONS));
        boost::char_separator<char> sep(" ");
        boost::tokenizer<boost::char_separator<char> > tok(all_exts, sep);
        for (boost::tokenizer<boost::char_separator<char> >::iterator i = tok.begin(); i != tok.end(); ++i) {
            info["GLInfo"]["GLExtensions"].append(*i);
        }
    }
#endif
}

std::string LLGLManager::getGLInfoString()
{
	std::string info_str;

	if (gHeadlessClient)
	{
		info_str += std::string("GL_VENDOR      ") + HEADLESS_VENDOR_STRING + std::string("\n");
		info_str += std::string("GL_RENDERER    ") + HEADLESS_RENDERER_STRING + std::string("\n");
		info_str += std::string("GL_VERSION     ") + HEADLESS_VERSION_STRING + std::string("\n");
	}
	else
	{
		info_str += std::string("GL_VENDOR      ") + ll_safe_string((const char *)glGetString(GL_VENDOR)) + std::string("\n");
		info_str += std::string("GL_RENDERER    ") + ll_safe_string((const char *)glGetString(GL_RENDERER)) + std::string("\n");
		info_str += std::string("GL_VERSION     ") + ll_safe_string((const char *)glGetString(GL_VERSION)) + std::string("\n");
	}

#if !LL_MESA_HEADLESS
#if !LL_DARWIN
    if (mGLVersion >= 3.0f && glGetStringi) {
        std::stringstream gl_extension_strstrm;
        GLint n, i;
        glGetIntegerv(GL_NUM_EXTENSIONS, &n);
        for (i = 0; i < n; i++) {
            std::string exten = ll_safe_string((const char *) glGetStringi(GL_EXTENSIONS, i));
            if (!exten.empty() && i != n)
                gl_extension_strstrm << exten << "\n";
        }
        info_str += std::string("GL_EXTENSIONS:\n") + gl_extension_strstrm.str() + std::string("\n");
    } else
#endif
    {
        std::string all_exts = ll_safe_string((const char *) glGetString(GL_EXTENSIONS));
        LLStringUtil::replaceChar(all_exts, ' ', '\n');
        info_str += std::string("GL_EXTENSIONS:\n") + all_exts + std::string("\n");
    }
#endif

    return info_str;
}

void LLGLManager::printGLInfoString()
{
	if (gHeadlessClient)
	{
		LL_INFOS("RenderInit") << "GL_VENDOR:     " << HEADLESS_VENDOR_STRING << LL_ENDL;
		LL_INFOS("RenderInit") << "GL_RENDERER:   " << HEADLESS_RENDERER_STRING << LL_ENDL;
		LL_INFOS("RenderInit") << "GL_VERSION:    " << HEADLESS_VERSION_STRING << LL_ENDL;
	}
	else
	{
		LL_INFOS("RenderInit") << "GL_VENDOR:     " << ll_safe_string((const char *)glGetString(GL_VENDOR)) << LL_ENDL;
		LL_INFOS("RenderInit") << "GL_RENDERER:   " << ll_safe_string((const char *)glGetString(GL_RENDERER)) << LL_ENDL;
		LL_INFOS("RenderInit") << "GL_VERSION:    " << ll_safe_string((const char *)glGetString(GL_VERSION)) << LL_ENDL;
	}

#if !LL_MESA_HEADLESS
#if !LL_DARWIN
    if (mGLVersion >= 3.0f && glGetStringi) {
        std::stringstream gl_extension_strstrm;
        GLint n, i;
        glGetIntegerv(GL_NUM_EXTENSIONS, &n);
        for (i = 0; i < n; i++) {
            std::string exten = ll_safe_string((const char *) glGetStringi(GL_EXTENSIONS, i));
            if (!exten.empty() && i != n)
                gl_extension_strstrm << exten << "\n";
        }
        LL_INFOS("RenderInit") << "GL_EXTENSIONS:\n" << gl_extension_strstrm.str() << LL_ENDL;
    }
    else
#endif
    {
        std::string all_exts = ll_safe_string((const char *) glGetString(GL_EXTENSIONS));
        LLStringUtil::replaceChar(all_exts, ' ', '\n');
        LL_INFOS("RenderInit") << "GL_EXTENSIONS:\n" << all_exts << LL_ENDL;
    }
#endif
}

std::string LLGLManager::getRawGLString()
{
	std::string gl_string;
	if (gHeadlessClient)
	{
		gl_string = HEADLESS_VENDOR_STRING + " " + HEADLESS_RENDERER_STRING;
	}
	else
	{
		gl_string = ll_safe_string((char*)glGetString(GL_VENDOR)) + " " + ll_safe_string((char*)glGetString(GL_RENDERER));
	}
	return gl_string;
}

void LLGLManager::shutdownGL()
{
	if (mInited)
	{
		glFinish();
		stop_glerror();
		mInited = FALSE;
	}
}

// these are used to turn software blending on. They appear in the Debug/Avatar menu
// presence of vertex skinning/blending or vertex programs will set these to FALSE by default.

void LLGLManager::initExtensions()
{
#if LL_MESA_HEADLESS
# ifdef GL_ARB_multitexture
	mHasMultitexture = TRUE;
# else
	mHasMultitexture = FALSE;
# endif // GL_ARB_multitexture
# ifdef GL_ARB_texture_env_combine
	mHasARBEnvCombine = TRUE;	
# else
	mHasARBEnvCombine = FALSE;
# endif // GL_ARB_texture_env_combine
# ifdef GL_ARB_texture_compression
	mHasCompressedTextures = TRUE;
# else
	mHasCompressedTextures = FALSE;
# endif // GL_ARB_texture_compression
# ifdef GL_ARB_vertex_buffer_object
	mHasVertexBufferObject = TRUE;
# else
	mHasVertexBufferObject = FALSE;
# endif // GL_ARB_vertex_buffer_object
# ifdef GL_EXT_framebuffer_object
	mHasFramebufferObject = TRUE;
# else
	mHasFramebufferObject = FALSE;
# endif // GL_EXT_framebuffer_object
# ifdef GL_ARB_draw_buffers
	mHasDrawBuffers = TRUE;
#else
	mHasDrawBuffers = FALSE;
# endif // GL_ARB_draw_buffers
# if defined(GL_NV_depth_clamp) || defined(GL_ARB_depth_clamp)
	mHasDepthClamp = TRUE;
#else
	mHasDepthClamp = FALSE;
#endif // defined(GL_NV_depth_clamp) || defined(GL_ARB_depth_clamp)
# if GL_EXT_blend_func_separate
	mHasBlendFuncSeparate = TRUE;
#else
	mHasBlendFuncSeparate = FALSE;
# endif // GL_EXT_blend_func_separate
	mHasMipMapGeneration = FALSE;
	mHasSeparateSpecularColor = FALSE;
	mHasAnisotropic = FALSE;
	mHasCubeMap = FALSE;
	mHasOcclusionQuery = FALSE;
	mHasPointParameters = FALSE;
	mHasShaderObjects = FALSE;
	mHasVertexShader = FALSE;
	mHasFragmentShader = FALSE;
	mHasTextureRectangle = FALSE;
#else // LL_MESA_HEADLESS
	mHasMultitexture = mGLVersion >= 1.3f || epoxy_has_gl_extension("GL_ARB_multitexture");
	mHasATIMemInfo = epoxy_has_gl_extension("GL_ATI_meminfo"); //Basic AMD method, also see mHasAMDAssociations
	mHasNVXMemInfo = epoxy_has_gl_extension("GL_NVX_gpu_memory_info");
	mHasSeparateSpecularColor = mGLVersion >= 1.2f || epoxy_has_gl_extension("GL_EXT_separate_specular_color");
	mHasAnisotropic = mGLVersion >= 4.6f || epoxy_has_gl_extension("GL_EXT_texture_filter_anisotropic");

	mHasCubeMap = mGLVersion >= 1.3f || epoxy_has_gl_extension("GL_ARB_texture_cube_map");
	mHasARBEnvCombine = mGLVersion >= 1.3f || epoxy_has_gl_extension("GL_ARB_texture_env_combine");
	mHasCompressedTextures = mGLVersion >= 1.3f || epoxy_has_gl_extension("GL_ARB_texture_compression");
	mHasOcclusionQuery = mGLVersion >= 1.5f || epoxy_has_gl_extension("GL_ARB_occlusion_query");
	mHasTimerQuery = mGLVersion >= 3.3f || epoxy_has_gl_extension("GL_ARB_timer_query");
	mHasOcclusionQuery2 = mGLVersion >= 3.3f || epoxy_has_gl_extension("GL_ARB_occlusion_query2");
	mHasVertexBufferObject = mGLVersion >= 1.5f || epoxy_has_gl_extension("GL_ARB_vertex_buffer_object");
	mHasVertexArrayObject = mGLVersion >= 3.0f || epoxy_has_gl_extension("GL_ARB_vertex_array_object");
	mHasSync = mGLVersion >= 3.2f || epoxy_has_gl_extension("GL_ARB_sync");
	mHasMapBufferRange = mGLVersion >= 3.0f || epoxy_has_gl_extension("GL_ARB_map_buffer_range");
	mHasFlushBufferRange = epoxy_has_gl_extension("GL_APPLE_flush_buffer_range");
	mHasDepthClamp = mGLVersion >= 3.2f || (epoxy_has_gl_extension("GL_ARB_depth_clamp") || epoxy_has_gl_extension("GL_NV_depth_clamp"));
	// mask out FBO support when packed_depth_stencil isn't there 'cause we need it for LLRenderTarget -Brad
#ifdef GL_ARB_framebuffer_object
	mHasFramebufferObject = mGLVersion >= 3.0f || epoxy_has_gl_extension("GL_ARB_framebuffer_object");
#else
	mHasFramebufferObject = mGLVersion >= 3.0f || (epoxy_has_gl_extension("GL_EXT_framebuffer_object") &&
		epoxy_has_gl_extension("GL_EXT_framebuffer_blit") &&
		epoxy_has_gl_extension("GL_EXT_framebuffer_multisample") &&
		epoxy_has_gl_extension("GL_EXT_packed_depth_stencil"));
#endif
#ifdef GL_EXT_texture_sRGB
	mHassRGBTexture = mGLVersion >= 2.1f || epoxy_has_gl_extension("GL_EXT_texture_sRGB");
#endif

#ifdef GL_ARB_framebuffer_sRGB
	mHassRGBFramebuffer = mGLVersion >= 3.0f || epoxy_has_gl_extension("GL_ARB_framebuffer_sRGB");
#else
	mHassRGBFramebuffer = mGLVersion >= 3.0f || epoxy_has_gl_extension("GL_EXT_framebuffer_sRGB");
#endif

#ifdef GL_EXT_texture_sRGB_decode
	mHasTexturesRGBDecode = epoxy_has_gl_extension("GL_EXT_texture_sRGB_decode");
#else
	mHasTexturesRGBDecode = epoxy_has_gl_extension("GL_ARB_texture_sRGB_decode");
#endif

	mHasMipMapGeneration = mHasFramebufferObject || mGLVersion >= 1.4f;

	mHasDrawBuffers = mGLVersion >= 2.0f || epoxy_has_gl_extension("GL_ARB_draw_buffers");
	mHasBlendFuncSeparate = mGLVersion >= 1.4f || epoxy_has_gl_extension("GL_EXT_blend_func_separate");
	mHasTextureRectangle = mGLVersion >= 3.1f || epoxy_has_gl_extension("GL_ARB_texture_rectangle");
	mHasTextureMultisample = mGLVersion >= 3.2f || epoxy_has_gl_extension("GL_ARB_texture_multisample");
	mHasDebugOutput = mGLVersion >= 4.3f || epoxy_has_gl_extension("GL_ARB_debug_output");
	mHasTransformFeedback = mGLVersion >= 4.0f ? TRUE : FALSE;
#if !LL_DARWIN
	mHasPointParameters = !mIsATI && (mGLVersion >= 1.4f || epoxy_has_gl_extension("GL_ARB_point_parameters"));
#endif
	mHasShaderObjects = mGLVersion >= 2.0f || (epoxy_has_gl_extension("GL_ARB_shader_objects") && (LLRender::sGLCoreProfile || epoxy_has_gl_extension("GL_ARB_shading_language_100")));
	mHasVertexShader = mGLVersion >= 2.0f || (epoxy_has_gl_extension("GL_ARB_vertex_program") && epoxy_has_gl_extension("GL_ARB_vertex_shader")
		&& (LLRender::sGLCoreProfile || epoxy_has_gl_extension("GL_ARB_shading_language_100")));
	mHasFragmentShader = mGLVersion >= 2.0f || (epoxy_has_gl_extension("GL_ARB_fragment_shader") && (LLRender::sGLCoreProfile || epoxy_has_gl_extension("GL_ARB_shading_language_100")));

	mHasTextureSwizzle = mGLVersion >= 3.3f || epoxy_has_gl_extension("GL_ARB_texture_swizzle");
#endif

#if LL_LINUX || LL_SOLARIS
	LL_INFOS() << "initExtensions() checking shell variables to adjust features..." << LL_ENDL;
	// Our extension support for the Linux Client is very young with some
	// potential driver gotchas, so offer a semi-secret way to turn it off.
	if (getenv("LL_GL_NOEXT"))
	{
		//mHasMultitexture = FALSE; // NEEDED!
		mHasDepthClamp = FALSE;
		mHasARBEnvCombine = FALSE;
		mHasCompressedTextures = FALSE;
		mHasVertexBufferObject = FALSE;
		mHasFramebufferObject = FALSE;
		mHasDrawBuffers = FALSE;
		mHasBlendFuncSeparate = FALSE;
		mHasMipMapGeneration = FALSE;
		mHasSeparateSpecularColor = FALSE;
		mHasAnisotropic = FALSE;
		mHasCubeMap = FALSE;
		mHasOcclusionQuery = FALSE;
		mHasPointParameters = FALSE;
		mHasShaderObjects = FALSE;
		mHasVertexShader = FALSE;
		mHasFragmentShader = FALSE;
		mHasTextureSwizzle = FALSE;
		LL_WARNS("RenderInit") << "GL extension support DISABLED via LL_GL_NOEXT" << LL_ENDL;
	}
	else if (getenv("LL_GL_BASICEXT"))	/* Flawfinder: ignore */
	{
		// This switch attempts to turn off all support for exotic
		// extensions which I believe correspond to fatal driver
		// bug reports.  This should be the default until we get a
		// proper blacklist/whitelist on Linux.
		mHasMipMapGeneration = FALSE;
		mHasAnisotropic = FALSE;
		//mHasCubeMap = FALSE; // apparently fatal on Intel 915 & similar
		//mHasOcclusionQuery = FALSE; // source of many ATI system hangs
		mHasShaderObjects = FALSE;
		mHasVertexShader = FALSE;
		mHasFragmentShader = FALSE;
		mHasBlendFuncSeparate = FALSE;
		LL_WARNS("RenderInit") << "GL extension support forced to SIMPLE level via LL_GL_BASICEXT" << LL_ENDL;
	}
	if (getenv("LL_GL_BLACKLIST"))	/* Flawfinder: ignore */
	{
		// This lets advanced troubleshooters disable specific
		// GL extensions to isolate problems with their hardware.
		// SL-28126
		const char *const blacklist = getenv("LL_GL_BLACKLIST");	/* Flawfinder: ignore */
		LL_WARNS("RenderInit") << "GL extension support partially disabled via LL_GL_BLACKLIST: " << blacklist << LL_ENDL;
		if (strchr(blacklist,'a')) mHasARBEnvCombine = FALSE;
		if (strchr(blacklist,'b')) mHasCompressedTextures = FALSE;
		if (strchr(blacklist,'c')) mHasVertexBufferObject = FALSE;
		if (strchr(blacklist,'d')) mHasMipMapGeneration = FALSE;//S
// 		if (strchr(blacklist,'f')) mHasNVVertexArrayRange = FALSE;//S
// 		if (strchr(blacklist,'g')) mHasNVFence = FALSE;//S
		if (strchr(blacklist,'h')) mHasSeparateSpecularColor = FALSE;
		if (strchr(blacklist,'i')) mHasAnisotropic = FALSE;//S
		if (strchr(blacklist,'j')) mHasCubeMap = FALSE;//S
// 		if (strchr(blacklist,'k')) mHasATIVAO = FALSE;//S
		if (strchr(blacklist,'l')) mHasOcclusionQuery = FALSE;
		if (strchr(blacklist,'m')) mHasShaderObjects = FALSE;//S
		if (strchr(blacklist,'n')) mHasVertexShader = FALSE;//S
		if (strchr(blacklist,'o')) mHasFragmentShader = FALSE;//S
		if (strchr(blacklist,'p')) mHasPointParameters = FALSE;//S
		if (strchr(blacklist,'q')) mHasFramebufferObject = FALSE;//S
		if (strchr(blacklist,'r')) mHasDrawBuffers = FALSE;//S
		if (strchr(blacklist,'s')) mHasTextureRectangle = FALSE;
		if (strchr(blacklist,'t')) mHasBlendFuncSeparate = FALSE;//S
		if (strchr(blacklist,'u')) mHasDepthClamp = FALSE;
		
	}
#endif // LL_LINUX || LL_SOLARIS
	
	if (!mHasMultitexture)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize multitexturing" << LL_ENDL;
	}
	if (!mHasMipMapGeneration)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize mipmap generation" << LL_ENDL;
	}
	if (!mHasARBEnvCombine)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_texture_env_combine" << LL_ENDL;
	}
	if (!mHasSeparateSpecularColor)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize separate specular color" << LL_ENDL;
	}
	if (!mHasAnisotropic)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize anisotropic filtering" << LL_ENDL;
	}
	if (!mHasCompressedTextures)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_texture_compression" << LL_ENDL;
	}
	if (!mHasOcclusionQuery)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_occlusion_query" << LL_ENDL;
	}
	if (!mHasOcclusionQuery2)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_occlusion_query2" << LL_ENDL;
	}
	if (!mHasPointParameters)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_point_parameters" << LL_ENDL;
	}
	if (!mHasShaderObjects)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_shader_objects" << LL_ENDL;
	}
	if (!mHasVertexShader)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_vertex_shader" << LL_ENDL;
	}
	if (!mHasFragmentShader)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_fragment_shader" << LL_ENDL;
	}
	if (!mHasBlendFuncSeparate)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_EXT_blend_func_separate" << LL_ENDL;
	}
	if (!mHasDrawBuffers)
	{
		LL_INFOS("RenderInit") << "Couldn't initialize GL_ARB_draw_buffers" << LL_ENDL;
	}

	// Disable certain things due to known bugs
//	if (mIsIntel && mHasMipMapGeneration)
//	{
//		LL_INFOS("RenderInit") << "Disabling mip-map generation for Intel GPUs" << LL_ENDL;
//		mHasMipMapGeneration = FALSE;
//	}
	
	// Misc
	glGetIntegerv(GL_MAX_ELEMENTS_VERTICES, (GLint*) &mGLMaxVertexRange);
	glGetIntegerv(GL_MAX_ELEMENTS_INDICES, (GLint*) &mGLMaxIndexRange);
	glGetIntegerv(GL_MAX_TEXTURE_SIZE, (GLint*) &mGLMaxTextureSize);


	mInited = TRUE;
}