llgl.cpp

	if (mState)
	{
		mWasEnabled = sStateMap[state];
		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::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()
{
	if (mApply)
	{
		gGL.matrixMode(LLRender::MM_PROJECTION);
		gGL.popMatrix();
		gGL.matrixMode(LLRender::MM_MODELVIEW);
	}
}

LLGLNamePool::LLGLNamePool()
{
}

LLGLNamePool::~LLGLNamePool()
{
}

void LLGLNamePool::upkeep()
{
	std::sort(mNameList.begin(), mNameList.end(), CompareUsed());
}

void LLGLNamePool::cleanup()
{
	for (name_list_t::iterator iter = mNameList.begin(); iter != mNameList.end(); ++iter)
	{
		releaseName(iter->name);
	}

	mNameList.clear();
}

GLuint LLGLNamePool::allocate()
{
#if LL_GL_NAME_POOLING
	for (name_list_t::iterator iter = mNameList.begin(); iter != mNameList.end(); ++iter)
	{
		if (!iter->used)
		{
			iter->used = TRUE;
			return iter->name;
		}
	}

	NameEntry entry;
	entry.name = allocateName();
	entry.used = TRUE;
	mNameList.push_back(entry);

	return entry.name;
#else
	return allocateName();
#endif
}

void LLGLNamePool::release(GLuint name)
{
#if LL_GL_NAME_POOLING
	for (name_list_t::iterator iter = mNameList.begin(); iter != mNameList.end(); ++iter)
	{
		if (iter->name == name)
		{
			if (iter->used)
			{
				iter->used = FALSE;
				return;
			}
			else
			{
				llerrs << "Attempted to release a pooled name that is not in use!" << llendl;
			}
		}
	}
	llerrs << "Attempted to release a non pooled name!" << llendl;
#else
	releaseName(name);
#endif
}

//static
void LLGLNamePool::upkeepPools()
{
	for (tracker_t::instance_iter iter = beginInstances(); iter != endInstances(); ++iter)
	{
		LLGLNamePool & pool = *iter;
		pool.upkeep();
	}
}

//static
void LLGLNamePool::cleanupPools()
{
	for (tracker_t::instance_iter iter = beginInstances(); iter != endInstances(); ++iter)
	{
		LLGLNamePool & pool = *iter;
		pool.cleanup();
	}
}

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 P, U32 layer)
{

	F32 depth = 0.99999f - 0.0001f * layer;

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

	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.pushMatrix();
	gGL.loadMatrix(P.m);
	gGL.matrixMode(LLRender::MM_MODELVIEW);
}

LLGLSquashToFarClip::~LLGLSquashToFarClip()
{
	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.popMatrix();
	gGL.matrixMode(LLRender::MM_MODELVIEW);
}


	
LLGLSyncFence::LLGLSyncFence()
{
#ifdef GL_ARB_sync
	mSync = 0;
#endif
}

LLGLSyncFence::~LLGLSyncFence()
{
#ifdef GL_ARB_sync
	if (mSync)
	{
		glDeleteSync(mSync);
	}
#endif
}

void LLGLSyncFence::placeFence()
{
#ifdef GL_ARB_sync
	if (mSync)
	{
		glDeleteSync(mSync);
	}
	mSync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
#endif
}

bool LLGLSyncFence::isCompleted()
{
	bool ret = true;
#ifdef GL_ARB_sync
	if (mSync)
	{
		GLenum status = glClientWaitSync(mSync, 0, 1);
		if (status == GL_TIMEOUT_EXPIRED)
		{
			ret = false;
		}
	}
#endif
	return ret;
}

void LLGLSyncFence::wait()
{
#ifdef GL_ARB_sync
	if (mSync)
	{
		while (glClientWaitSync(mSync, 0, FENCE_WAIT_TIME_NANOSECONDS) == GL_TIMEOUT_EXPIRED)
		{ //track the number of times we've waited here
			static S32 waits = 0;
			waits++;
		}
	}
#endif
}