llgl.cpp

void rotate_quat(LLQuaternion& rotation)
{
	F32 angle_radians, x, y, z;
	rotation.getAngleAxis(&angle_radians, &x, &y, &z);
	gGL.rotatef(angle_radians * RAD_TO_DEG, x, y, z);
}

void flush_glerror()
{
	glGetError();
}

//this function outputs gl error to the log file, does not crash the code.
void log_glerror()
{
	if (LL_UNLIKELY(!gGLManager.mInited))
	{
		return ;
	}
	//  Create or update texture to be used with this data 
	GLenum error = glGetError();
	while (LL_UNLIKELY(error))
	{
		GLubyte const * gl_error_msg = gluErrorString(error);
		if (NULL != gl_error_msg)
		{
			LL_WARNS() << "GL Error: " << error << " GL Error String: " << gl_error_msg << LL_ENDL ;			
		}
		else
		{
			// gluErrorString returns NULL for some extensions' error codes.
			// you'll probably have to grep for the number in glext.h.
			LL_WARNS() << "GL Error: UNKNOWN 0x" << std::hex << error << std::dec << LL_ENDL;
		}
		error = glGetError();
	}
}

void do_assert_glerror()
{
	//  Create or update texture to be used with this data 
	GLenum error = glGetError();
	BOOL quit = FALSE;
	while (LL_UNLIKELY(error))
	{
		quit = TRUE;
		GLubyte const * gl_error_msg = gluErrorString(error);
		if (NULL != gl_error_msg)
		{
			LL_WARNS("RenderState") << "GL Error:" << error<< LL_ENDL;
			LL_WARNS("RenderState") << "GL Error String:" << gl_error_msg << LL_ENDL;

			if (gDebugSession)
			{
				gFailLog << "GL Error:" << gl_error_msg << std::endl;
			}
		}
		else
		{
			// gluErrorString returns NULL for some extensions' error codes.
			// you'll probably have to grep for the number in glext.h.
			LL_WARNS("RenderState") << "GL Error: UNKNOWN 0x" << std::hex << error << std::dec << LL_ENDL;

			if (gDebugSession)
			{
				gFailLog << "GL Error: UNKNOWN 0x" << std::hex << error << std::dec << std::endl;
			}
		}
		error = glGetError();
	}

	if (quit)
	{
		if (gDebugSession)
		{
			ll_fail("assert_glerror failed");
		}
		else
		{
			LL_ERRS() << "One or more unhandled GL errors." << LL_ENDL;
		}
	}
}

void assert_glerror()
{
/*	if (!gGLActive)
	{
		//LL_WARNS() << "GL used while not active!" << LL_ENDL;

		if (gDebugSession)
		{
			//ll_fail("GL used while not active");
		}
	}
*/

	if (!gDebugGL) 
	{
		//funny looking if for branch prediction -- gDebugGL is almost always false and assert_glerror is called often
	}
	else
	{
		do_assert_glerror();
	}
}
	

void clear_glerror()
{
	glGetError();
	glGetError();
}

///////////////////////////////////////////////////////////////
//
// LLGLState
//

// Static members
absl::flat_hash_map<LLGLenum, LLGLboolean> LLGLState::sStateMap;

GLboolean LLGLDepthTest::sDepthEnabled = GL_FALSE; // OpenGL default
GLenum LLGLDepthTest::sDepthFunc = GL_LESS; // OpenGL default
GLboolean LLGLDepthTest::sWriteEnabled = GL_TRUE; // OpenGL default

//static
void LLGLState::initClass() 
{
	sStateMap[GL_DITHER] = GL_TRUE;
	// sStateMap[GL_TEXTURE_2D] = GL_TRUE;
	
	//make sure multisample defaults to disabled
	sStateMap[GL_MULTISAMPLE] = GL_FALSE;
	glDisable(GL_MULTISAMPLE);
}

//static
void LLGLState::restoreGL()
{
	sStateMap.clear();
	initClass();
}

//static
// Really shouldn't be needed, but seems we sometimes do.
void LLGLState::resetTextureStates()
{
	gGL.flush();
	GLint maxTextureUnits;
	
	glGetIntegerv(GL_MAX_TEXTURE_UNITS, &maxTextureUnits);
	for (S32 j = maxTextureUnits-1; j >=0; j--)
	{
		gGL.getTexUnit(j)->activate();
		glClientActiveTexture(GL_TEXTURE0+j);
		j == 0 ? gGL.getTexUnit(j)->enable(LLTexUnit::TT_TEXTURE) : gGL.getTexUnit(j)->disable();
	}
}

void LLGLState::dumpStates() 
{
	LL_INFOS("RenderState") << "GL States:" << LL_ENDL;
	for (const auto& state_pair : sStateMap)
	{
		LL_INFOS("RenderState") << llformat(" 0x%04x : %s",(S32)state_pair.first, state_pair.second?"TRUE":"FALSE") << LL_ENDL;
	}
}

void LLGLState::checkStates(const std::string& msg)  
{
	if (!gDebugGL)
	{
		return;
	}

	stop_glerror();

	GLint src;
	GLint dst;
	glGetIntegerv(GL_BLEND_SRC, &src);
	glGetIntegerv(GL_BLEND_DST, &dst);
	
	stop_glerror();

	BOOL error = FALSE;

	if (src != GL_SRC_ALPHA || dst != GL_ONE_MINUS_SRC_ALPHA)
	{
		if (gDebugSession)
		{
			gFailLog << "Blend function corrupted: " << std::hex << src << " " << std::hex << dst << "  " << msg << std::dec << std::endl;
			error = TRUE;
		}
		else
		{
			LL_GL_ERRS << "Blend function corrupted: " << std::hex << src << " " << std::hex << dst << "  " << msg << std::dec << LL_ENDL;
		}
	}
	
	for (auto iter = sStateMap.begin();
		 iter != sStateMap.end(); ++iter)
	{
		LLGLenum state = iter->first;
		LLGLboolean cur_state = iter->second;
		stop_glerror();
		LLGLboolean gl_state = glIsEnabled(state);
		stop_glerror();
		if(cur_state != gl_state)
		{
			dumpStates();
			if (gDebugSession)
			{
				gFailLog << llformat("LLGLState error. State: 0x%04x",state) << std::endl;
				error = TRUE;
			}
			else
			{
				LL_GL_ERRS << llformat("LLGLState error. State: 0x%04x",state) << LL_ENDL;
			}
		}
	}
	
	if (error)
	{
		ll_fail("LLGLState::checkStates failed.");
	}
	stop_glerror();
}

void LLGLState::checkTextureChannels(const std::string& msg)
{
#if 0
	if (!gDebugGL)
	{
		return;
	}
	stop_glerror();

	GLint activeTexture;
	glGetIntegerv(GL_ACTIVE_TEXTURE, &activeTexture);
	stop_glerror();

	BOOL error = FALSE;

	if (activeTexture == GL_TEXTURE0)
	{
		GLint tex_env_mode = 0;

		glGetTexEnviv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, &tex_env_mode);
		stop_glerror();

		if (tex_env_mode != GL_MODULATE)
		{
			error = TRUE;
			LL_WARNS("RenderState") << "GL_TEXTURE_ENV_MODE invalid: " << std::hex << tex_env_mode << std::dec << LL_ENDL;
			if (gDebugSession)
			{
				gFailLog << "GL_TEXTURE_ENV_MODE invalid: " << std::hex << tex_env_mode << std::dec << std::endl;
			}
		}
	}

	static const char* label[] =
	{
		"GL_TEXTURE_2D",
		"GL_TEXTURE_COORD_ARRAY",
		"GL_TEXTURE_1D",
		"GL_TEXTURE_CUBE_MAP",
		"GL_TEXTURE_GEN_S",
		"GL_TEXTURE_GEN_T",
		"GL_TEXTURE_GEN_Q",
		"GL_TEXTURE_GEN_R",
		"GL_TEXTURE_RECTANGLE",
		"GL_TEXTURE_2D_MULTISAMPLE"
	};

	static GLint value[] =
	{
		GL_TEXTURE_2D,
		GL_TEXTURE_COORD_ARRAY,
		GL_TEXTURE_1D,
		GL_TEXTURE_CUBE_MAP,
		GL_TEXTURE_GEN_S,
		GL_TEXTURE_GEN_T,
		GL_TEXTURE_GEN_Q,
		GL_TEXTURE_GEN_R,
		GL_TEXTURE_RECTANGLE,
		GL_TEXTURE_2D_MULTISAMPLE
	};

	GLint stackDepth = 0;

	glh::matrix4f mat;
	glh::matrix4f identity;
	identity.identity();

	for (GLint i = 1; i < gGLManager.mNumTextureUnits; i++)
	{
		gGL.getTexUnit(i)->activate();

		if (i < gGLManager.mNumTextureUnits)
		{
			glClientActiveTexture(GL_TEXTURE0+i);
			stop_glerror();
			glGetIntegerv(GL_TEXTURE_STACK_DEPTH, &stackDepth);
			stop_glerror();

			if (stackDepth != 1)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "Texture matrix stack corrupted." << LL_ENDL;

				if (gDebugSession)
				{
					gFailLog << "Texture matrix stack corrupted." << std::endl;
				}
			}

			glGetFloatv(GL_TEXTURE_MATRIX, (GLfloat*) mat.m);
			stop_glerror();

			if (mat != identity)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "Texture matrix in channel " << i << " corrupt." << LL_ENDL;
				if (gDebugSession)
				{
					gFailLog << "Texture matrix in channel " << i << " corrupt." << std::endl;
				}
			}
				
			for (S32 j = (i == 0 ? 1 : 0); 
				j < 9; j++)
			{
				if (j == 8 && !gGLManager.mHasTextureRectangle ||
					j == 9 && !gGLManager.mHasTextureMultisample)
				{
					continue;
				}
				
				if (glIsEnabled(value[j]))
				{
					error = TRUE;
					LL_WARNS("RenderState") << "Texture channel " << i << " still has " << label[j] << " enabled." << LL_ENDL;
					if (gDebugSession)
					{
						gFailLog << "Texture channel " << i << " still has " << label[j] << " enabled." << std::endl;
					}
				}
				stop_glerror();
			}

			glGetFloatv(GL_TEXTURE_MATRIX, mat.m);
			stop_glerror();

			if (mat != identity)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "Texture matrix " << i << " is not identity." << LL_ENDL;
				if (gDebugSession)
				{
					gFailLog << "Texture matrix " << i << " is not identity." << std::endl;
				}
			}
		}

		{
			GLint tex = 0;
			stop_glerror();
			glGetIntegerv(GL_TEXTURE_BINDING_2D, &tex);
			stop_glerror();

			if (tex != 0)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "Texture channel " << i << " still has texture " << tex << " bound." << LL_ENDL;

				if (gDebugSession)
				{
					gFailLog << "Texture channel " << i << " still has texture " << tex << " bound." << std::endl;
				}
			}
		}
	}

	stop_glerror();
	gGL.getTexUnit(0)->activate();
	glClientActiveTexture(GL_TEXTURE0);
	stop_glerror();

	if (error)
	{
		if (gDebugSession)
		{
			ll_fail("LLGLState::checkTextureChannels failed.");
		}
		else
		{
			LL_GL_ERRS << "GL texture state corruption detected.  " << msg << LL_ENDL;
		}
	}
#endif
}

void LLGLState::checkClientArrays(const std::string& msg, U32 data_mask)
{
	if (!gDebugGL || LLGLSLShader::sNoFixedFunction)
	{
		return;
	}

	stop_glerror();
	BOOL error = FALSE;

	GLint active_texture;
	glGetIntegerv(GL_CLIENT_ACTIVE_TEXTURE, &active_texture);

	if (active_texture != GL_TEXTURE0)
	{
		LL_WARNS() << "Client active texture corrupted: " << active_texture << LL_ENDL;
		if (gDebugSession)
		{
			gFailLog << "Client active texture corrupted: " << active_texture << std::endl;
		}
		error = TRUE;
	}

	/*glGetIntegerv(GL_ACTIVE_TEXTURE, &active_texture);
	if (active_texture != GL_TEXTURE0)
	{
		LL_WARNS() << "Active texture corrupted: " << active_texture << LL_ENDL;
		if (gDebugSession)
		{
			gFailLog << "Active texture corrupted: " << active_texture << std::endl;
		}
		error = TRUE;
	}*/

	static const char* label[] =
	{
		"GL_VERTEX_ARRAY",
		"GL_NORMAL_ARRAY",
		"GL_COLOR_ARRAY",
		"GL_TEXTURE_COORD_ARRAY"
	};

	static GLint value[] =
	{
		GL_VERTEX_ARRAY,
		GL_NORMAL_ARRAY,
		GL_COLOR_ARRAY,
		GL_TEXTURE_COORD_ARRAY
	};

	static const U32 mask[] = 
	{ //copied from llvertexbuffer.h
		0x0001, //MAP_VERTEX,
		0x0002, //MAP_NORMAL,
		0x0010, //MAP_COLOR,
		0x0004, //MAP_TEXCOORD
	};


	for (S32 j = 1; j < 4; j++)
	{
		if (glIsEnabled(value[j]))
		{
			if (!(mask[j] & data_mask))
			{
				error = TRUE;
				LL_WARNS("RenderState") << "GL still has " << label[j] << " enabled." << LL_ENDL;
				if (gDebugSession)
				{
					gFailLog << "GL still has " << label[j] << " enabled." << std::endl;
				}
			}
		}
		else
		{
			if (mask[j] & data_mask)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "GL does not have " << label[j] << " enabled." << LL_ENDL;
				if (gDebugSession)
				{
					gFailLog << "GL does not have " << label[j] << " enabled." << std::endl;
				}
			}
		}
	}

	glClientActiveTexture(GL_TEXTURE1);
	gGL.getTexUnit(1)->activate();
	if (glIsEnabled(GL_TEXTURE_COORD_ARRAY))
	{
		if (!(data_mask & 0x0008))
		{
			error = TRUE;
			LL_WARNS("RenderState") << "GL still has GL_TEXTURE_COORD_ARRAY enabled on channel 1." << LL_ENDL;
			if (gDebugSession)
			{
				gFailLog << "GL still has GL_TEXTURE_COORD_ARRAY enabled on channel 1." << std::endl;
			}
		}
	}
	else
	{
		if (data_mask & 0x0008)
		{
			error = TRUE;
			LL_WARNS("RenderState") << "GL does not have GL_TEXTURE_COORD_ARRAY enabled on channel 1." << LL_ENDL;
			if (gDebugSession)
			{
				gFailLog << "GL does not have GL_TEXTURE_COORD_ARRAY enabled on channel 1." << std::endl;
			}
		}
	}

	/*if (glIsEnabled(GL_TEXTURE_2D))
	{
		if (!(data_mask & 0x0008))
		{
			error = TRUE;
			LL_WARNS("RenderState") << "GL still has GL_TEXTURE_2D enabled on channel 1." << LL_ENDL;
			if (gDebugSession)
			{
				gFailLog << "GL still has GL_TEXTURE_2D enabled on channel 1." << std::endl;
			}
		}
	}
	else
	{
		if (data_mask & 0x0008)
		{
			error = TRUE;
			LL_WARNS("RenderState") << "GL does not have GL_TEXTURE_2D enabled on channel 1." << LL_ENDL;
			if (gDebugSession)
			{
				gFailLog << "GL does not have GL_TEXTURE_2D enabled on channel 1." << std::endl;
			}
		}
	}*/

	glClientActiveTexture(GL_TEXTURE0);
	gGL.getTexUnit(0)->activate();

	if (gGLManager.mHasVertexShader && LLGLSLShader::sNoFixedFunction)
	{	//make sure vertex attribs are all disabled
		GLint count;
		glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &count);
		for (GLint i = 0; i < count; i++)
		{
			GLint enabled;
			glGetVertexAttribiv((GLuint) i, GL_VERTEX_ATTRIB_ARRAY_ENABLED, &enabled);
			if (enabled)
			{
				error = TRUE;
				LL_WARNS("RenderState") << "GL still has vertex attrib array " << i << " enabled." << LL_ENDL;
				if (gDebugSession)
				{
					gFailLog <<  "GL still has vertex attrib array " << i << " enabled." << std::endl;
				}
			}
		}
	}

	if (error)
	{
		if (gDebugSession)
		{
			ll_fail("LLGLState::checkClientArrays failed.");
		}
		else
		{
			LL_GL_ERRS << "GL client array corruption detected.  " << msg << LL_ENDL;
		}
	}
}

///////////////////////////////////////////////////////////////////////

LLGLState::LLGLState(LLGLenum state, S32 enabled) :
	mState(state), mWasEnabled(FALSE), mIsEnabled(FALSE)
{
	if (LLGLSLShader::sNoFixedFunction)
	{ //always ignore state that's deprecated post GL 3.0
		switch (state)
		{
			case GL_ALPHA_TEST:
			case GL_NORMALIZE:
			case GL_TEXTURE_GEN_R:
			case GL_TEXTURE_GEN_S:
			case GL_TEXTURE_GEN_T:
			case GL_TEXTURE_GEN_Q:
			case GL_LIGHTING:
			case GL_COLOR_MATERIAL:
			case GL_FOG:
			case GL_LINE_STIPPLE:
			case GL_POLYGON_STIPPLE:
				mState = 0;
				break;
		}
	}

	stop_glerror();
	if (mState)
	{
		mWasEnabled = sStateMap[state];
        // we can't actually assert on this as queued changes to state are not reflected by glIsEnabled
		//llassert(mWasEnabled == glIsEnabled(state));
		setEnabled(enabled);
		stop_glerror();
	}
}

void LLGLState::setEnabled(S32 enabled)
{
	if (!mState)
	{
		return;
	}
	if (enabled == CURRENT_STATE)
	{
		enabled = sStateMap[mState] == GL_TRUE ? TRUE : FALSE;
	}
	else if (enabled == TRUE && sStateMap[mState] != GL_TRUE)
	{
		gGL.flush();
		glEnable(mState);
		sStateMap[mState] = GL_TRUE;
	}
	else if (enabled == FALSE && sStateMap[mState] != GL_FALSE)
	{
		gGL.flush();
		glDisable(mState);
		sStateMap[mState] = GL_FALSE;
	}
	mIsEnabled = enabled;
}

LLGLState::~LLGLState() 
{
	stop_glerror();
	if (mState)
	{
		if (gDebugGL)
		{
			if (!gDebugSession)
			{
				llassert_always(sStateMap[mState] == glIsEnabled(mState));
			}
			else
			{
				if (sStateMap[mState] != glIsEnabled(mState))
				{
					ll_fail("GL enabled state does not match expected");
				}
			}
		}

		if (mIsEnabled != mWasEnabled)
		{
			gGL.flush();
			if (mWasEnabled)
			{
				glEnable(mState);
				sStateMap[mState] = GL_TRUE;
			}
			else
			{
				glDisable(mState);
				sStateMap[mState] = GL_FALSE;
			}
		}
	}
	stop_glerror();
}

////////////////////////////////////////////////////////////////////////////////

void LLGLManager::initGLStates()
{
	//gl states moved to classes in llglstates.h
	LLGLState::initClass();
}

////////////////////////////////////////////////////////////////////////////////

void parse_gl_version( S32* major, S32* minor, S32* release, std::string* vendor_specific, std::string* version_string )
{
	// GL_VERSION returns a null-terminated string with the format: 
	// <major>.<minor>[.<release>] [<vendor specific>]

	const char* version = (const char*) glGetString(GL_VERSION);
	*major = 0;
	*minor = 0;
	*release = 0;
	vendor_specific->assign("");

	if( !version )
	{
		return;
	}

	version_string->assign(version);

	std::string ver_copy( version );
	S32 len = (S32)strlen( version );	/* Flawfinder: ignore */
	S32 i = 0;
	S32 start;
	// Find the major version
	start = i;
	for( ; i < len; i++ )
	{
		if( '.' == version[i] )
		{
			break;
		}
	}
	std::string major_str = ver_copy.substr(start,i-start);
	LLStringUtil::convertToS32(major_str, *major);

	if( '.' == version[i] )
	{
		i++;
	}

	// Find the minor version
	start = i;
	for( ; i < len; i++ )
	{
		if( ('.' == version[i]) || isspace(version[i]) )
		{
			break;
		}
	}
	std::string minor_str = ver_copy.substr(start,i-start);
	LLStringUtil::convertToS32(minor_str, *minor);

	// Find the release number (optional)
	if( '.' == version[i] )
	{
		i++;

		start = i;
		for( ; i < len; i++ )
		{
			if( isspace(version[i]) )
			{
				break;
			}
		}

		std::string release_str = ver_copy.substr(start,i-start);
		LLStringUtil::convertToS32(release_str, *release);
	}

	// Skip over any white space
	while( version[i] && isspace( version[i] ) )
	{
		i++;
	}

	// Copy the vendor-specific string (optional)
	if( version[i] )
	{
		vendor_specific->assign( version + i );
	}
}


void parse_glsl_version(S32& major, S32& minor)
{
	// GL_SHADING_LANGUAGE_VERSION returns a null-terminated string with the format: 
	// <major>.<minor>[.<release>] [<vendor specific>]

	const char* version = (const char*) glGetString(GL_SHADING_LANGUAGE_VERSION);
	major = 0;
	minor = 0;
	
	if( !version )
	{
		return;
	}

	std::string ver_copy( version );
	S32 len = (S32)strlen( version );	/* Flawfinder: ignore */
	S32 i = 0;
	S32 start;
	// Find the major version
	start = i;
	for( ; i < len; i++ )
	{
		if( '.' == version[i] )
		{
			break;
		}
	}
	std::string major_str = ver_copy.substr(start,i-start);
	LLStringUtil::convertToS32(major_str, major);

	if( '.' == version[i] )
	{
		i++;
	}

	// Find the minor version
	start = i;
	for( ; i < len; i++ )
	{
		if( ('.' == version[i]) || isspace(version[i]) )
		{
			break;
		}
	}
	std::string minor_str = ver_copy.substr(start,i-start);
	LLStringUtil::convertToS32(minor_str, minor);
}

LLGLUserClipPlane::LLGLUserClipPlane(const LLPlane& p, const glh::matrix4f& modelview, const glh::matrix4f& projection, bool apply)
{
	mApply = apply;

	if (mApply)
	{
		mModelview = modelview;
		mProjection = projection;

		setPlane(p[0], p[1], p[2], p[3]);
	}
}

void LLGLUserClipPlane::disable()
{
    if (mApply)
	{
		gGL.matrixMode(LLRender::MM_PROJECTION);
		gGL.popMatrix();
		gGL.matrixMode(LLRender::MM_MODELVIEW);
	}
    mApply = false;
}

void LLGLUserClipPlane::setPlane(F32 a, F32 b, F32 c, F32 d)
{
	glh::matrix4f& P = mProjection;
	glh::matrix4f& M = mModelview;
    
	glh::matrix4f invtrans_MVP = (P * M).inverse().transpose();
    glh::vec4f oplane(a,b,c,d);
    glh::vec4f cplane;
    invtrans_MVP.mult_matrix_vec(oplane, cplane);

    cplane /= fabs(cplane[2]); // normalize such that depth is not scaled
    cplane[3] -= 1;

    if(cplane[2] < 0)
        cplane *= -1;

    glh::matrix4f suffix;
    suffix.set_row(2, cplane);
    glh::matrix4f newP = suffix * P;
    gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.pushMatrix();
    gGL.loadMatrix(newP.m);
	gGLObliqueProjectionInverse = LLMatrix4(newP.inverse().transpose().m);
    gGL.matrixMode(LLRender::MM_MODELVIEW);
}

LLGLUserClipPlane::~LLGLUserClipPlane()
{
	disable();
}

LLGLDepthTest::LLGLDepthTest(GLboolean depth_enabled, GLboolean write_enabled, GLenum depth_func)
: mPrevDepthEnabled(sDepthEnabled), mPrevDepthFunc(sDepthFunc), mPrevWriteEnabled(sWriteEnabled)
{
	stop_glerror();
	
	checkState();

	if (!depth_enabled)
	{ // always disable depth writes if depth testing is disabled
	  // GL spec defines this as a requirement, but some implementations allow depth writes with testing disabled
	  // The proper way to write to depth buffer with testing disabled is to enable testing and use a depth_func of GL_ALWAYS
		write_enabled = FALSE;
	}

	if (depth_enabled != sDepthEnabled)
	{
		gGL.flush();
		if (depth_enabled) glEnable(GL_DEPTH_TEST);
		else glDisable(GL_DEPTH_TEST);
		sDepthEnabled = depth_enabled;
	}
	if (depth_func != sDepthFunc)
	{
		gGL.flush();
		glDepthFunc(depth_func);
		sDepthFunc = depth_func;
	}
	if (write_enabled != sWriteEnabled)
	{
		gGL.flush();
		glDepthMask(write_enabled);
		sWriteEnabled = write_enabled;
	}
}

LLGLDepthTest::~LLGLDepthTest()
{
	checkState();
	if (sDepthEnabled != mPrevDepthEnabled )
	{
		gGL.flush();
		if (mPrevDepthEnabled) glEnable(GL_DEPTH_TEST);
		else glDisable(GL_DEPTH_TEST);
		sDepthEnabled = mPrevDepthEnabled;
	}
	if (sDepthFunc != mPrevDepthFunc)
	{
		gGL.flush();
		glDepthFunc(mPrevDepthFunc);
		sDepthFunc = mPrevDepthFunc;
	}
	if (sWriteEnabled != mPrevWriteEnabled )
	{
		gGL.flush();
		glDepthMask(mPrevWriteEnabled);
		sWriteEnabled = mPrevWriteEnabled;
	}
}

void LLGLDepthTest::checkState()
{
	if (gDebugGL)
	{
		GLint func = 0;
		GLboolean mask = FALSE;

		glGetIntegerv(GL_DEPTH_FUNC, &func);
		glGetBooleanv(GL_DEPTH_WRITEMASK, &mask);

		if (glIsEnabled(GL_DEPTH_TEST) != sDepthEnabled ||
			sWriteEnabled != mask ||
			sDepthFunc != func)
		{
			if (gDebugSession)
			{
				gFailLog << "Unexpected depth testing state." << std::endl;
			}
			else
			{
				LL_GL_ERRS << "Unexpected depth testing state." << LL_ENDL;
			}
		}
	}
}

LLGLSquashToFarClip::LLGLSquashToFarClip()
{
    glh::matrix4f proj = get_current_projection();
    setProjectionMatrix(proj, 0);
}

LLGLSquashToFarClip::LLGLSquashToFarClip(glh::matrix4f& P, U32 layer)
{
    setProjectionMatrix(P, layer);
}


void LLGLSquashToFarClip::setProjectionMatrix(glh::matrix4f& projection, U32 layer)
{

	F32 depth = 0.99999f - 0.0001f * layer;

	for (U32 i = 0; i < 4; i++)
	{
		projection.element(2, i) = projection.element(3, i) * depth;
	}

    LLRender::eMatrixMode last_matrix_mode = gGL.getMatrixMode();

	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.pushMatrix();
	gGL.loadMatrix(projection.m);

	gGL.matrixMode(last_matrix_mode);
}

LLGLSquashToFarClip::~LLGLSquashToFarClip()
{
    LLRender::eMatrixMode last_matrix_mode = gGL.getMatrixMode();

	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.popMatrix();

	gGL.matrixMode(last_matrix_mode);