xash3d-fwgs/ref/gl/gl_opengl.c

#include "gl_local.h"
#if XASH_GL4ES
#include "gl4es/include/gl4esinit.h"
#include "gl4es/include/gl4eshint.h"
#endif // XASH_GL4ES

CVAR_DEFINE( gl_extensions, "gl_allow_extensions", "1", FCVAR_GLCONFIG|FCVAR_READ_ONLY, "allow gl_extensions" );
CVAR_DEFINE( gl_texture_anisotropy, "gl_anisotropy", "8", FCVAR_GLCONFIG, "textures anisotropic filter" );
CVAR_DEFINE_AUTO( gl_texture_lodbias, "0.0", FCVAR_GLCONFIG, "LOD bias for mipmapped textures (perfomance|quality)" );
CVAR_DEFINE_AUTO( gl_texture_nearest, "0", FCVAR_GLCONFIG, "disable texture filter" );
CVAR_DEFINE_AUTO( gl_lightmap_nearest, "0", FCVAR_GLCONFIG, "disable lightmap filter" );
CVAR_DEFINE_AUTO( gl_keeptjunctions, "1", FCVAR_GLCONFIG, "removing tjuncs causes blinking pixels" );
CVAR_DEFINE_AUTO( gl_check_errors, "1", FCVAR_GLCONFIG, "ignore video engine errors" );
CVAR_DEFINE_AUTO( gl_polyoffset, "2.0", FCVAR_GLCONFIG, "polygon offset for decals" );
CVAR_DEFINE_AUTO( gl_wireframe, "0", FCVAR_GLCONFIG|FCVAR_SPONLY, "show wireframe overlay" );
CVAR_DEFINE_AUTO( gl_finish, "0", FCVAR_GLCONFIG, "use glFinish instead of glFlush" );
CVAR_DEFINE_AUTO( gl_nosort, "0", FCVAR_GLCONFIG, "disable sorting of translucent surfaces" );
CVAR_DEFINE_AUTO( gl_test, "0", 0, "engine developer cvar for quick testing new features" );
CVAR_DEFINE_AUTO( gl_msaa, "1", FCVAR_GLCONFIG, "enable or disable multisample anti-aliasing" );
CVAR_DEFINE_AUTO( gl_stencilbits, "8", FCVAR_GLCONFIG|FCVAR_READ_ONLY, "pixelformat stencil bits (0 - auto)" );
CVAR_DEFINE_AUTO( r_lighting_extended, "1", FCVAR_GLCONFIG, "allow to get lighting from world and bmodels" );
CVAR_DEFINE_AUTO( r_lighting_ambient, "0.3", FCVAR_GLCONFIG, "map ambient lighting scale" );
CVAR_DEFINE_AUTO( r_detailtextures, "1", FCVAR_ARCHIVE, "enable detail textures support" );
CVAR_DEFINE_AUTO( r_novis, "0", 0, "ignore vis information (perfomance test)" );
CVAR_DEFINE_AUTO( r_nocull, "0", 0, "ignore frustrum culling (perfomance test)" );
CVAR_DEFINE_AUTO( r_lockpvs, "0", FCVAR_CHEAT, "lockpvs area at current point (pvs test)" );
CVAR_DEFINE_AUTO( r_lockfrustum, "0", FCVAR_CHEAT, "lock frustrum area at current point (cull test)" );
CVAR_DEFINE_AUTO( r_traceglow, "1", FCVAR_GLCONFIG, "cull flares behind models" );
CVAR_DEFINE_AUTO( gl_round_down, "2", FCVAR_GLCONFIG|FCVAR_READ_ONLY, "round texture sizes to nearest POT value" );
CVAR_DEFINE( r_vbo, "gl_vbo", "0", FCVAR_ARCHIVE, "draw world using VBO (known to be glitchy)" );
CVAR_DEFINE( r_vbo_dlightmode, "gl_vbo_dlightmode", "1", FCVAR_ARCHIVE, "vbo dlight rendering mode (0-1)" );

DEFINE_ENGINE_SHARED_CVAR_LIST()

poolhandle_t r_temppool;

gl_globals_t	tr;
glconfig_t	glConfig;
glstate_t	glState;
glwstate_t	glw_state;

#ifdef XASH_GL_STATIC
#define GL_CALL( x ) #x, NULL
#else
#define GL_CALL( x ) #x, (void**)&p##x
#endif
static dllfunc_t opengl_110funcs[] =
{
	{ GL_CALL( glClearColor ) },
	{ GL_CALL( glClear ) },
	{ GL_CALL( glAlphaFunc ) },
	{ GL_CALL( glBlendFunc ) },
	{ GL_CALL( glCullFace ) },
	{ GL_CALL( glDrawBuffer ) },
	{ GL_CALL( glReadBuffer ) },
	{ GL_CALL( glAccum ) },
	{ GL_CALL( glEnable ) },
	{ GL_CALL( glDisable ) },
	{ GL_CALL( glEnableClientState ) },
	{ GL_CALL( glDisableClientState ) },
	{ GL_CALL( glGetBooleanv ) },
	{ GL_CALL( glGetDoublev ) },
	{ GL_CALL( glGetFloatv ) },
	{ GL_CALL( glGetIntegerv ) },
	{ GL_CALL( glGetError ) },
	{ GL_CALL( glGetString ) },
	{ GL_CALL( glFinish ) },
	{ GL_CALL( glFlush ) },
	{ GL_CALL( glClearDepth ) },
	{ GL_CALL( glDepthFunc ) },
	{ GL_CALL( glDepthMask ) },
	{ GL_CALL( glDepthRange ) },
	{ GL_CALL( glFrontFace ) },
	{ GL_CALL( glDrawElements ) },
	{ GL_CALL( glDrawArrays ) },
	{ GL_CALL( glColorMask ) },
	{ GL_CALL( glIndexPointer ) },
	{ GL_CALL( glVertexPointer ) },
	{ GL_CALL( glNormalPointer ) },
	{ GL_CALL( glColorPointer ) },
	{ GL_CALL( glTexCoordPointer ) },
	{ GL_CALL( glArrayElement ) },
	{ GL_CALL( glColor3f ) },
	{ GL_CALL( glColor3fv ) },
	{ GL_CALL( glColor4f ) },
	{ GL_CALL( glColor4fv ) },
	{ GL_CALL( glColor3ub ) },
	{ GL_CALL( glColor4ub ) },
	{ GL_CALL( glColor4ubv ) },
	{ GL_CALL( glTexCoord1f ) },
	{ GL_CALL( glTexCoord2f ) },
	{ GL_CALL( glTexCoord3f ) },
	{ GL_CALL( glTexCoord4f ) },
	{ GL_CALL( glTexCoord1fv ) },
	{ GL_CALL( glTexCoord2fv ) },
	{ GL_CALL( glTexCoord3fv ) },
	{ GL_CALL( glTexCoord4fv ) },
	{ GL_CALL( glTexGenf ) },
	{ GL_CALL( glTexGenfv ) },
	{ GL_CALL( glTexGeni ) },
	{ GL_CALL( glVertex2f ) },
	{ GL_CALL( glVertex3f ) },
	{ GL_CALL( glVertex3fv ) },
	{ GL_CALL( glNormal3f ) },
	{ GL_CALL( glNormal3fv ) },
	{ GL_CALL( glBegin ) },
	{ GL_CALL( glEnd ) },
	{ GL_CALL( glLineWidth ) },
	{ GL_CALL( glPointSize ) },
	{ GL_CALL( glMatrixMode ) },
	{ GL_CALL( glOrtho ) },
	{ GL_CALL( glRasterPos2f ) },
	{ GL_CALL( glFrustum ) },
	{ GL_CALL( glViewport ) },
	{ GL_CALL( glPushMatrix ) },
	{ GL_CALL( glPopMatrix ) },
	{ GL_CALL( glPushAttrib ) },
	{ GL_CALL( glPopAttrib ) },
	{ GL_CALL( glLoadIdentity ) },
	{ GL_CALL( glLoadMatrixd ) },
	{ GL_CALL( glLoadMatrixf ) },
	{ GL_CALL( glMultMatrixd ) },
	{ GL_CALL( glMultMatrixf ) },
	{ GL_CALL( glRotated ) },
	{ GL_CALL( glRotatef ) },
	{ GL_CALL( glScaled ) },
	{ GL_CALL( glScalef ) },
	{ GL_CALL( glTranslated ) },
	{ GL_CALL( glTranslatef ) },
	{ GL_CALL( glReadPixels ) },
	{ GL_CALL( glDrawPixels ) },
	{ GL_CALL( glStencilFunc ) },
	{ GL_CALL( glStencilMask ) },
	{ GL_CALL( glStencilOp ) },
	{ GL_CALL( glClearStencil ) },
	{ GL_CALL( glIsEnabled ) },
	{ GL_CALL( glIsList ) },
	{ GL_CALL( glIsTexture ) },
	{ GL_CALL( glTexEnvf ) },
	{ GL_CALL( glTexEnvfv ) },
	{ GL_CALL( glTexEnvi ) },
	{ GL_CALL( glTexParameterf ) },
	{ GL_CALL( glTexParameterfv ) },
	{ GL_CALL( glTexParameteri ) },
	{ GL_CALL( glHint ) },
	{ GL_CALL( glPixelStoref ) },
	{ GL_CALL( glPixelStorei ) },
	{ GL_CALL( glGenTextures ) },
	{ GL_CALL( glDeleteTextures ) },
	{ GL_CALL( glBindTexture ) },
	{ GL_CALL( glTexImage1D ) },
	{ GL_CALL( glTexImage2D ) },
	{ GL_CALL( glTexSubImage1D ) },
	{ GL_CALL( glTexSubImage2D ) },
	{ GL_CALL( glCopyTexImage1D ) },
	{ GL_CALL( glCopyTexImage2D ) },
	{ GL_CALL( glCopyTexSubImage1D ) },
	{ GL_CALL( glCopyTexSubImage2D ) },
	{ GL_CALL( glScissor ) },
	{ GL_CALL( glGetTexImage ) },
	{ GL_CALL( glGetTexEnviv ) },
	{ GL_CALL( glPolygonOffset ) },
	{ GL_CALL( glPolygonMode ) },
	{ GL_CALL( glPolygonStipple ) },
	{ GL_CALL( glClipPlane ) },
	{ GL_CALL( glGetClipPlane ) },
	{ GL_CALL( glShadeModel ) },
	{ GL_CALL( glGetTexLevelParameteriv ) },
	{ GL_CALL( glGetTexLevelParameterfv ) },
	{ GL_CALL( glFogfv ) },
	{ GL_CALL( glFogf ) },
	{ GL_CALL( glFogi ) },
	{ NULL					, NULL }
};

static dllfunc_t debugoutputfuncs[] =
{
	{ GL_CALL( glDebugMessageControlARB ) },
	{ GL_CALL( glDebugMessageInsertARB ) },
	{ GL_CALL( glDebugMessageCallbackARB ) },
	{ GL_CALL( glGetDebugMessageLogARB ) },
	{ NULL					, NULL }
};

static dllfunc_t multitexturefuncs[] =
{
	{ GL_CALL( glMultiTexCoord1f ) },
	{ GL_CALL( glMultiTexCoord2f ) },
	{ GL_CALL( glMultiTexCoord3f ) },
	{ GL_CALL( glMultiTexCoord4f ) },
	{ GL_CALL( glActiveTexture ) },
	{ GL_CALL( glActiveTextureARB ) },
	{ GL_CALL( glClientActiveTexture ) },
	{ GL_CALL( glClientActiveTextureARB ) },
	{ NULL					, NULL }
};

static dllfunc_t texture3dextfuncs[] =
{
	{ GL_CALL( glTexImage3D ) },
	{ GL_CALL( glTexSubImage3D ) },
	{ GL_CALL( glCopyTexSubImage3D ) },
	{ NULL					, NULL }
};

static dllfunc_t texturecompressionfuncs[] =
{
	{ GL_CALL( glCompressedTexImage3DARB ) },
	{ GL_CALL( glCompressedTexImage2DARB ) },
	{ GL_CALL( glCompressedTexImage1DARB ) },
	{ GL_CALL( glCompressedTexSubImage3DARB ) },
	{ GL_CALL( glCompressedTexSubImage2DARB ) },
	{ GL_CALL( glCompressedTexSubImage1DARB ) },
	{ GL_CALL( glGetCompressedTexImage ) },
	{ NULL					, NULL }
};

static dllfunc_t vbofuncs[] =
{
	{ GL_CALL( glBindBufferARB ) },
	{ GL_CALL( glDeleteBuffersARB ) },
	{ GL_CALL( glGenBuffersARB ) },
	{ GL_CALL( glIsBufferARB ) },
	{ GL_CALL( glMapBufferARB ) },
	{ GL_CALL( glUnmapBufferARB ) }, // ,
	{ GL_CALL( glBufferDataARB ) },
	{ GL_CALL( glBufferSubDataARB ) },
	{ NULL, NULL }
};

static dllfunc_t multisampletexfuncs[] =
{
	{ GL_CALL(glTexImage2DMultisample) },
	{ NULL, NULL }
};

static dllfunc_t drawrangeelementsfuncs[] =
{
{ GL_CALL( glDrawRangeElements ) },
{ NULL, NULL }
};

static dllfunc_t drawrangeelementsextfuncs[] =
{
{ GL_CALL( glDrawRangeElementsEXT ) },
{ NULL, NULL }
};

#ifndef XASH_GL_STATIC
static dllfunc_t shaderobjectsfuncs[] =
{
	{ GL_CALL( glDeleteObjectARB ) },
	{ GL_CALL( glGetHandleARB ) },
	{ GL_CALL( glDetachObjectARB ) },
	{ GL_CALL( glCreateShaderObjectARB ) },
	{ GL_CALL( glShaderSourceARB ) },
	{ GL_CALL( glCompileShaderARB ) },
	{ GL_CALL( glCreateProgramObjectARB ) },
	{ GL_CALL( glAttachObjectARB ) },
	{ GL_CALL( glLinkProgramARB ) },
	{ GL_CALL( glUseProgramObjectARB ) },
	{ GL_CALL( glValidateProgramARB ) },
	{ GL_CALL( glUniform1fARB ) },
	{ GL_CALL( glUniform2fARB ) },
	{ GL_CALL( glUniform3fARB ) },
	{ GL_CALL( glUniform4fARB ) },
	{ GL_CALL( glUniform1iARB ) },
	{ GL_CALL( glUniform2iARB ) },
	{ GL_CALL( glUniform3iARB ) },
	{ GL_CALL( glUniform4iARB ) },
	{ GL_CALL( glUniform1fvARB ) },
	{ GL_CALL( glUniform2fvARB ) },
	{ GL_CALL( glUniform3fvARB ) },
	{ GL_CALL( glUniform4fvARB ) },
	{ GL_CALL( glUniform1ivARB ) },
	{ GL_CALL( glUniform2ivARB ) },
	{ GL_CALL( glUniform3ivARB ) },
	{ GL_CALL( glUniform4ivARB ) },
	{ GL_CALL( glUniformMatrix2fvARB ) },
	{ GL_CALL( glUniformMatrix3fvARB ) },
	{ GL_CALL( glUniformMatrix4fvARB ) },
	{ GL_CALL( glGetObjectParameterfvARB ) },
	{ GL_CALL( glGetObjectParameterivARB ) },
	{ GL_CALL( glGetInfoLogARB ) },
	{ GL_CALL( glGetAttachedObjectsARB ) },
	{ GL_CALL( glGetUniformLocationARB ) },
	{ GL_CALL( glGetActiveUniformARB ) },
	{ GL_CALL( glGetUniformfvARB ) },
	{ GL_CALL( glGetUniformivARB ) },
	{ GL_CALL( glGetShaderSourceARB ) },
	{ GL_CALL( glVertexAttribPointerARB ) },
	{ GL_CALL( glEnableVertexAttribArrayARB ) },
	{ GL_CALL( glDisableVertexAttribArrayARB ) },
	{ GL_CALL( glBindAttribLocationARB ) },
	{ GL_CALL( glGetActiveAttribARB ) },
	{ GL_CALL( glGetAttribLocationARB ) },
	{ GL_CALL( glVertexAttrib2fARB ) },
	{ GL_CALL( glVertexAttrib2fvARB ) },
//	{ GL_CALL( glVertexAttrib3fv ) },
//	{ GL_CALL( glVertexAttrib4f ) },
//	{ GL_CALL( glVertexAttrib4fv ) },
//	{ GL_CALL( glVertexAttrib4ubv ) },
{ NULL, NULL }
};

static dllfunc_t shaderobjectsfuncs_gles[] =
{
	{ "glDeleteShader"             , (void **)&pglDeleteObjectARB },
	//{ "glGetHandleARB"                , (void **)&pglGetHandleARB },
	{ "glDetachShader"             , (void **)&pglDetachObjectARB },
	{ "glCreateShader"       , (void **)&pglCreateShaderObjectARB },
	{ "glShaderSource"             , (void **)&pglShaderSourceARB },
	{ "glCompileShader"            , (void **)&pglCompileShaderARB },
	{ "glCreateProgram"      , (void **)&pglCreateProgramObjectARB },
	{ "glAttachShader"             , (void **)&pglAttachObjectARB },
	{ "glLinkProgram"              , (void **)&pglLinkProgramARB },
	{ "glUseProgram"         , (void **)&pglUseProgramObjectARB },
	{ "glValidateProgram"          , (void **)&pglValidateProgramARB },
	{ "glUniform1f"                , (void **)&pglUniform1fARB },
	{ "glUniform2f"                , (void **)&pglUniform2fARB },
	{ "glUniform3f"                , (void **)&pglUniform3fARB },
	{ "glUniform4f"                , (void **)&pglUniform4fARB },
	{ "glUniform1i"                , (void **)&pglUniform1iARB },
	{ "glUniform2i"                , (void **)&pglUniform2iARB },
	{ "glUniform3i"                , (void **)&pglUniform3iARB },
	{ "glUniform4i"                , (void **)&pglUniform4iARB },
	{ "glUniform1f"               , (void **)&pglUniform1fvARB },
	{ "glUniform2fv"               , (void **)&pglUniform2fvARB },
	{ "glUniform3fv"               , (void **)&pglUniform3fvARB },
	{ "glUniform4fv"               , (void **)&pglUniform4fvARB },
	{ "glUniform1iv"               , (void **)&pglUniform1ivARB },
	{ "glUniform2iv"               , (void **)&pglUniform2ivARB },
	{ "glUniform3iv"               , (void **)&pglUniform3ivARB },
	{ "glUniform4iv"               , (void **)&pglUniform4ivARB },
	{ "glUniformMatrix2fv"         , (void **)&pglUniformMatrix2fvARB },
	{ "glUniformMatrix3fv"         , (void **)&pglUniformMatrix3fvARB },
	{ "glUniformMatrix4fv"         , (void **)&pglUniformMatrix4fvARB },
	{ "glGetShaderfv"     , (void **)&pglGetObjectParameterfvARB },
	{ "glGetShaderiv"     , (void **)&pglGetObjectParameterivARB },
	{ "glGetShaderInfoLog"               , (void **)&pglGetInfoLogARB },
	{ "glGetAttachedObjects"       , (void **)&pglGetAttachedObjectsARB },
	{ "glGetUniformLocation"       , (void **)&pglGetUniformLocationARB },
	{ "glGetActiveUniform"         , (void **)&pglGetActiveUniformARB },
	{ "glGetUniformfv"             , (void **)&pglGetUniformfvARB },
	{ "glGetUniformiv"             , (void **)&pglGetUniformivARB },
	{ "glGetShaderSource"          , (void **)&pglGetShaderSourceARB },
	{ "glVertexAttribPointer"      , (void **)&pglVertexAttribPointerARB },
	{ "glEnableVertexAttribArray"  , (void **)&pglEnableVertexAttribArrayARB },
	{ "glDisableVertexAttribArray" , (void **)&pglDisableVertexAttribArrayARB },
	{ "glBindAttribLocation"       , (void **)&pglBindAttribLocationARB },
	{ "glGetActiveAttrib"          , (void **)&pglGetActiveAttribARB },
	{ "glGetAttribLocation"        , (void **)&pglGetAttribLocationARB },
	{ "glVertexAttrib2f"              , (void **)&pglVertexAttrib2fARB },
	{ "glVertexAttrib2fv"             , (void **)&pglVertexAttrib2fvARB },
	{ "glVertexAttrib3fv"             , (void **)&pglVertexAttrib3fvARB },
	//{ "glVertexAttrib4f"              , (void **)&pglVertexAttrib4fARB },
	//{ "glVertexAttrib4fv"             , (void **)&pglVertexAttrib4fvARB },
	//{ "glVertexAttrib4ubv"            , (void **)&pglVertexAttrib4ubvARB },
{ NULL, NULL }
};

static dllfunc_t vaofuncs[] =
{
{ "glBindVertexArray"    , (void **)&pglBindVertexArray },
{ "glDeleteVertexArrays" , (void **)&pglDeleteVertexArrays },
{ "glGenVertexArrays"    , (void **)&pglGenVertexArrays },
{ "glIsVertexArray"      , (void **)&pglIsVertexArray },
{ NULL, NULL }
};
#endif

/*
========================
DebugCallback

For ARB_debug_output
========================
*/
static void APIENTRY GL_DebugOutput( GLuint source, GLuint type, GLuint id, GLuint severity, GLint length, const GLcharARB *message, GLvoid *userParam )
{
	switch( type )
	{
	case GL_DEBUG_TYPE_ERROR_ARB:
		gEngfuncs.Con_Printf( S_OPENGL_ERROR "%s\n", message );
		break;
	case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR_ARB:
	case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR_ARB:
		gEngfuncs.Con_Printf( S_OPENGL_WARN "%s\n", message );
		break;
	case GL_DEBUG_TYPE_PORTABILITY_ARB:
		gEngfuncs.Con_Reportf( S_OPENGL_WARN "%s\n", message );
		break;
	case GL_DEBUG_TYPE_PERFORMANCE_ARB:
	case GL_DEBUG_TYPE_OTHER_ARB:
	default:
		gEngfuncs.Con_Printf( S_OPENGL_NOTE "%s\n", message );
		break;
	}
}

/*
=================
GL_SetExtension
=================
*/
void GL_SetExtension( int r_ext, int enable )
{
	if( r_ext >= 0 && r_ext < GL_EXTCOUNT )
		glConfig.extension[r_ext] = enable ? GL_TRUE : GL_FALSE;
	else gEngfuncs.Con_Printf( S_ERROR "GL_SetExtension: invalid extension %d\n", r_ext );
}

/*
=================
GL_Support
=================
*/
qboolean GL_Support( int r_ext )
{
	if( r_ext >= 0 && r_ext < GL_EXTCOUNT )
		return glConfig.extension[r_ext] ? true : false;
	gEngfuncs.Con_Printf( S_ERROR "GL_Support: invalid extension %d\n", r_ext );

	return false;
}

/*
=================
GL_MaxTextureUnits
=================
*/
int GL_MaxTextureUnits( void )
{
	if( GL_Support( GL_SHADER_GLSL100_EXT ))
		return Q_min( Q_max( glConfig.max_texture_coords, glConfig.max_teximage_units ), MAX_TEXTURE_UNITS );
	return glConfig.max_texture_units;
}

/*
=================
GL_CheckExtension
=================
*/
qboolean GL_CheckExtension( const char *name, const dllfunc_t *funcs, const char *cvarname, int r_ext )
{
	const dllfunc_t	*func;
	cvar_t		*parm = NULL;
	const char	*extensions_string;
	char		desc[MAX_VA_STRING];

	gEngfuncs.Con_Reportf( "GL_CheckExtension: %s ", name );
	GL_SetExtension( r_ext, true );

	if( cvarname )
	{
		// system config disable extensions
		Q_snprintf( desc, sizeof( desc ), CVAR_GLCONFIG_DESCRIPTION, name );
		parm = gEngfuncs.Cvar_Get( cvarname, "1", FCVAR_GLCONFIG|FCVAR_READ_ONLY, desc );
	}

	if(( parm && !parm->value ) || ( !gl_extensions.value && r_ext != GL_OPENGL_110 ))
	{
		gEngfuncs.Con_Reportf( "- disabled\n" );
		GL_SetExtension( r_ext, false );
		return false; // nothing to process at
	}

	extensions_string = glConfig.extensions_string;

	if(( name[2] == '_' || name[3] == '_' ) && !Q_strstr( extensions_string, name ) && glConfig.context != CONTEXT_TYPE_GL_CORE)
	{
		GL_SetExtension( r_ext, false );	// update render info
		gEngfuncs.Con_Reportf( "- ^1failed\n" );
		return false;
	}

#ifndef XASH_GL_STATIC
	// clear exports
	for( func = funcs; func && func->name; func++ )
		*func->func = NULL;

	for( func = funcs; func && func->name; func++ )
	{
		// functions are cleared before all the extensions are evaluated
		if((*func->func = (void *)gEngfuncs.GL_GetProcAddress( func->name )) == NULL )
		{
			// one or more functions are invalid, extension will be disabled
			GL_SetExtension( r_ext, false );
		}
	}
#endif

	if( GL_Support( r_ext ))
	{
		gEngfuncs.Con_Reportf( "- ^2enabled\n" );
		return true;
	}

	gEngfuncs.Con_Reportf( "- ^1failed\n" );
	return false;
}

/*
==============
GL_GetProcAddress

defined just for nanogl/glwes, so it don't link to SDL2 directly, nor use dlsym
==============
*/
void GAME_EXPORT *GL_GetProcAddress( const char *name )
{
	return gEngfuncs.GL_GetProcAddress( name );
}

/*
===============
GL_SetDefaultTexState
===============
*/
static void GL_SetDefaultTexState( void )
{

	int	i;

	memset( glState.currentTextures, -1, MAX_TEXTURE_UNITS * sizeof( *glState.currentTextures ));
	memset( glState.texCoordArrayMode, 0, MAX_TEXTURE_UNITS * sizeof( *glState.texCoordArrayMode ));
	memset( glState.genSTEnabled, 0, MAX_TEXTURE_UNITS * sizeof( *glState.genSTEnabled ));

	for( i = 0; i < MAX_TEXTURE_UNITS; i++ )
	{
		glState.currentTextureTargets[i] = GL_NONE;
		glState.texIdentityMatrix[i] = true;
	}
}

/*
===============
GL_SetDefaultState
===============
*/
static void GL_SetDefaultState( void )
{
	memset( &glState, 0, sizeof( glState ));
	GL_SetDefaultTexState ();

	// init draw stack
	tr.draw_list = &tr.draw_stack[0];
	tr.draw_stack_pos = 0;
}

/*
===============
GL_SetDefaults
===============
*/
static void GL_SetDefaults( void )
{
	pglFinish();

	pglClearColor( 0.5f, 0.5f, 0.5f, 1.0f );

	pglDisable( GL_DEPTH_TEST );
	pglDisable( GL_CULL_FACE );
	pglDisable( GL_SCISSOR_TEST );
	pglDepthFunc( GL_LEQUAL );
	pglColor4f( 1.0f, 1.0f, 1.0f, 1.0f );

	if( glState.stencilEnabled )
	{
		pglDisable( GL_STENCIL_TEST );
		pglStencilMask( ( GLuint ) ~0 );
		pglStencilFunc( GL_EQUAL, 0, ~0 );
		pglStencilOp( GL_KEEP, GL_INCR, GL_INCR );
	}

	pglPolygonMode( GL_FRONT_AND_BACK, GL_FILL );
	pglPolygonOffset( -1.0f, -2.0f );

	GL_CleanupAllTextureUnits();

	pglDisable( GL_BLEND );
	pglDisable( GL_ALPHA_TEST );
	pglDisable( GL_POLYGON_OFFSET_FILL );
	pglAlphaFunc( GL_GREATER, DEFAULT_ALPHATEST );
	pglEnable( GL_TEXTURE_2D );
	pglShadeModel( GL_SMOOTH );
	pglFrontFace( GL_CCW );

	pglPointSize( 1.2f );
	pglLineWidth( 1.2f );

	GL_Cull( GL_NONE );
}


/*
=================
R_RenderInfo_f
=================
*/
void R_RenderInfo_f( void )
{
	gEngfuncs.Con_Printf( "\n" );
	gEngfuncs.Con_Printf( "GL_VENDOR: %s\n", glConfig.vendor_string );
	gEngfuncs.Con_Printf( "GL_RENDERER: %s\n", glConfig.renderer_string );
	gEngfuncs.Con_Printf( "GL_VERSION: %s\n", glConfig.version_string );

	// don't spam about extensions
	gEngfuncs.Con_Reportf( "GL_EXTENSIONS: %s\n", glConfig.extensions_string );

	if( glConfig.wrapper == GLES_WRAPPER_GL4ES )
	{
		const char *vendor = (const char *)pglGetString( GL_VENDOR | 0x10000 );
		const char *renderer = (const char *)pglGetString( GL_RENDERER | 0x10000 );
		const char *version = (const char *)pglGetString( GL_VERSION | 0x10000 );
		const char *extensions = (const char *)pglGetString( GL_EXTENSIONS | 0x10000 );

		if( vendor )
			gEngfuncs.Con_Printf( "GL4ES_VENDOR: %s\n", vendor );
		if( renderer )
			gEngfuncs.Con_Printf( "GL4ES_RENDERER: %s\n", renderer );
		if( version )
			gEngfuncs.Con_Printf( "GL4ES_VERSION: %s\n", version );
		if( extensions )
			gEngfuncs.Con_Reportf( "GL4ES_EXTENSIONS: %s\n", extensions );

	}


	gEngfuncs.Con_Printf( "GL_MAX_TEXTURE_SIZE: %i\n", glConfig.max_2d_texture_size );

	if( GL_Support( GL_ARB_MULTITEXTURE ))
		gEngfuncs.Con_Printf( "GL_MAX_TEXTURE_UNITS_ARB: %i\n", glConfig.max_texture_units );
	if( GL_Support( GL_TEXTURE_CUBEMAP_EXT ))
		gEngfuncs.Con_Printf( "GL_MAX_CUBE_MAP_TEXTURE_SIZE_ARB: %i\n", glConfig.max_cubemap_size );
	if( GL_Support( GL_ANISOTROPY_EXT ))
		gEngfuncs.Con_Printf( "GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT: %.1f\n", glConfig.max_texture_anisotropy );
	if( GL_Support( GL_TEXTURE_2D_RECT_EXT ))
		gEngfuncs.Con_Printf( "GL_MAX_RECTANGLE_TEXTURE_SIZE: %i\n", glConfig.max_2d_rectangle_size );
	if( GL_Support( GL_TEXTURE_ARRAY_EXT ))
		gEngfuncs.Con_Printf( "GL_MAX_ARRAY_TEXTURE_LAYERS_EXT: %i\n", glConfig.max_2d_texture_layers );
	if( GL_Support( GL_SHADER_GLSL100_EXT ))
	{
		gEngfuncs.Con_Printf( "GL_MAX_TEXTURE_COORDS_ARB: %i\n", glConfig.max_texture_coords );
		gEngfuncs.Con_Printf( "GL_MAX_TEXTURE_IMAGE_UNITS_ARB: %i\n", glConfig.max_teximage_units );
		gEngfuncs.Con_Printf( "GL_MAX_VERTEX_UNIFORM_COMPONENTS_ARB: %i\n", glConfig.max_vertex_uniforms );
		gEngfuncs.Con_Printf( "GL_MAX_VERTEX_ATTRIBS_ARB: %i\n", glConfig.max_vertex_attribs );
	}

	gEngfuncs.Con_Printf( "\n" );
	gEngfuncs.Con_Printf( "MODE: %ix%i\n", gpGlobals->width, gpGlobals->height );
	gEngfuncs.Con_Printf( "\n" );
	gEngfuncs.Con_Printf( "VERTICAL SYNC: %s\n", gl_vsync->value ? "enabled" : "disabled" );
	gEngfuncs.Con_Printf( "Color %d bits, Alpha %d bits, Depth %d bits, Stencil %d bits\n", glConfig.color_bits,
		glConfig.alpha_bits, glConfig.depth_bits, glConfig.stencil_bits );
}

#ifdef XASH_GLES
void GL_InitExtensionsGLES( void )
{
	int extid;

	// intialize wrapper type
#ifdef XASH_NANOGL
	glConfig.context = CONTEXT_TYPE_GLES_1_X;
	glConfig.wrapper = GLES_WRAPPER_NANOGL;
#elif defined( XASH_WES )
	glConfig.context = CONTEXT_TYPE_GLES_2_X;
	glConfig.wrapper = GLES_WRAPPER_WES;
#elif defined( XASH_GLES3COMPAT )
	glConfig.context = CONTEXT_TYPE_GLES_2_X;
	glConfig.wrapper = GLES_WRAPPER_NONE;
#else

#error "unknown gles wrapper"
#endif

	glConfig.hardware_type = GLHW_GENERIC;

	for( extid = GL_OPENGL_110 + 1; extid < GL_EXTCOUNT; extid++ )
	{
		switch( extid )
		{
		case GL_ARB_VERTEX_BUFFER_OBJECT_EXT:
			GL_CheckExtension( "vertex_buffer_object", vbofuncs, "gl_vertex_buffer_object", extid );
			break;
		case GL_ARB_MULTITEXTURE:
			GL_CheckExtension( "multitexture", multitexturefuncs, "gl_arb_multitexture", GL_ARB_MULTITEXTURE );
			//GL_SetExtension( extid, true ); // required to be supported by wrapper

			pglGetIntegerv( GL_MAX_TEXTURE_UNITS_ARB, &glConfig.max_texture_units );
			if( glConfig.max_texture_units <= 1 )
				pglGetIntegerv( GL_MAX_TEXTURE_IMAGE_UNITS_ARB, &glConfig.max_texture_units );
			if( glConfig.max_texture_units <= 1 )
			{
				GL_SetExtension( extid, false );
				glConfig.max_texture_units = 1;
			}

			glConfig.max_texture_coords = glConfig.max_teximage_units = glConfig.max_texture_units;
			break;
		case GL_TEXTURE_CUBEMAP_EXT:
			if( GL_CheckExtension( "GL_OES_texture_cube_map", NULL, "gl_texture_cubemap", extid ))
				pglGetIntegerv( GL_MAX_CUBE_MAP_TEXTURE_SIZE_ARB, &glConfig.max_cubemap_size );
			break;
		case GL_ANISOTROPY_EXT:
			glConfig.max_texture_anisotropy = 0.0f;
			if( GL_CheckExtension( "GL_EXT_texture_filter_anisotropic", NULL, "gl_ext_anisotropic_filter", extid ))
				pglGetFloatv( GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &glConfig.max_texture_anisotropy );
			break;
		case GL_TEXTURE_LOD_BIAS:
			if( GL_CheckExtension( "GL_EXT_texture_lod_bias", NULL, "gl_texture_mipmap_biasing", extid ))
				pglGetFloatv( GL_MAX_TEXTURE_LOD_BIAS_EXT, &glConfig.max_texture_lod_bias );
			break;
		case GL_ARB_TEXTURE_NPOT_EXT:
			GL_CheckExtension( "GL_OES_texture_npot", NULL, "gl_texture_npot", extid );
			break;
#ifndef XASH_GL_STATIC
		case GL_SHADER_OBJECTS_EXT:
			GL_CheckExtension( "ES2 Shaders", shaderobjectsfuncs_gles, "gl_shaderobjects", extid );
			break;
		case GL_ARB_VERTEX_ARRAY_OBJECT_EXT:
			GL_CheckExtension( "vertex_array_object", vaofuncs, "gl_vertex_array_object", extid );
			break;
		case GL_DRAW_RANGEELEMENTS_EXT:
			GL_CheckExtension( "draw_range_elements", drawrangeelementsfuncs, "gl_drawrangeelements", extid );
			break;
#endif
		case GL_DEBUG_OUTPUT:
			if( glw_state.extended )
				GL_CheckExtension( "GL_KHR_debug", NULL, NULL, extid );
			break;
		// case GL_TEXTURE_COMPRESSION_EXT: NOPE
		// case GL_SHADER_GLSL100_EXT: NOPE
		// case GL_TEXTURE_2D_RECT_EXT: NOPE
		// case GL_TEXTURE_ARRAY_EXT: NOPE
		// case GL_TEXTURE_3D_EXT: NOPE
		// case GL_CLAMPTOEDGE_EXT: NOPE
		// case GL_CLAMP_TEXBORDER_EXT: NOPE
		// case GL_ARB_TEXTURE_FLOAT_EXT: NOPE
		// case GL_ARB_DEPTH_FLOAT_EXT: NOPE
		// case GL_ARB_SEAMLESS_CUBEMAP: NOPE
		// case GL_EXT_GPU_SHADER4: NOPE
		// case GL_DEPTH_TEXTURE: NOPE
		// case GL_DRAWRANGEELEMENTS_EXT: NOPE
		default:
			GL_SetExtension( extid, false );
		}
	}
#ifndef XASH_GL_STATIC
	GL2_ShimInit();
#endif
}
#else
void GL_InitExtensionsBigGL( void )
{
	// intialize wrapper type
	glConfig.context = gEngfuncs.Sys_CheckParm( "-glcore" )? CONTEXT_TYPE_GL_CORE : CONTEXT_TYPE_GL;
	glConfig.wrapper = GLES_WRAPPER_NONE;

	if( Q_stristr( glConfig.renderer_string, "geforce" ))
		glConfig.hardware_type = GLHW_NVIDIA;
	else if( Q_stristr( glConfig.renderer_string, "quadro fx" ))
		glConfig.hardware_type = GLHW_NVIDIA;
	else if( Q_stristr(glConfig.renderer_string, "rv770" ))
		glConfig.hardware_type = GLHW_RADEON;
	else if( Q_stristr(glConfig.renderer_string, "radeon hd" ))
		glConfig.hardware_type = GLHW_RADEON;
	else if( Q_stristr( glConfig.renderer_string, "eah4850" ) || Q_stristr( glConfig.renderer_string, "eah4870" ))
		glConfig.hardware_type = GLHW_RADEON;
	else if( Q_stristr( glConfig.renderer_string, "radeon" ))
		glConfig.hardware_type = GLHW_RADEON;
	else if( Q_stristr( glConfig.renderer_string, "intel" ))
		glConfig.hardware_type = GLHW_INTEL;
	else glConfig.hardware_type = GLHW_GENERIC;

	// gl4es may be used system-wide
	if( Q_stristr( glConfig.renderer_string, "gl4es" ))
	{
		const char *vendor = (const char *)pglGetString( GL_VENDOR | 0x10000 );
		const char *renderer = (const char *)pglGetString( GL_RENDERER | 0x10000 );
		const char *version = (const char *)pglGetString( GL_VERSION | 0x10000 );
		const char *extensions = (const char *)pglGetString( GL_EXTENSIONS | 0x10000 );
		glConfig.wrapper = GLES_WRAPPER_GL4ES;
	}

	// multitexture
	glConfig.max_texture_units = glConfig.max_texture_coords = glConfig.max_teximage_units = 1;
	if( GL_CheckExtension( "GL_ARB_multitexture", multitexturefuncs, "gl_arb_multitexture", GL_ARB_MULTITEXTURE ))
	{
		pglGetIntegerv( GL_MAX_TEXTURE_UNITS_ARB, &glConfig.max_texture_units );
	}

	if( glConfig.max_texture_units == 1 )
		GL_SetExtension( GL_ARB_MULTITEXTURE, false );

	// 3d texture support
	if( GL_CheckExtension( "GL_EXT_texture3D", texture3dextfuncs, "gl_texture_3d", GL_TEXTURE_3D_EXT ))
	{
		pglGetIntegerv( GL_MAX_3D_TEXTURE_SIZE, &glConfig.max_3d_texture_size );

		if( glConfig.max_3d_texture_size < 32 )
		{
			GL_SetExtension( GL_TEXTURE_3D_EXT, false );
			gEngfuncs.Con_Printf( S_ERROR "GL_EXT_texture3D reported bogus GL_MAX_3D_TEXTURE_SIZE, disabled\n" );
		}
	}

	// 2d texture array support
	if( GL_CheckExtension( "GL_EXT_texture_array", texture3dextfuncs, "gl_texture_2d_array", GL_TEXTURE_ARRAY_EXT ))
		pglGetIntegerv( GL_MAX_ARRAY_TEXTURE_LAYERS_EXT, &glConfig.max_2d_texture_layers );

	// cubemaps support
	if( GL_CheckExtension( "GL_ARB_texture_cube_map", NULL, "gl_texture_cubemap", GL_TEXTURE_CUBEMAP_EXT ))
	{
		pglGetIntegerv( GL_MAX_CUBE_MAP_TEXTURE_SIZE_ARB, &glConfig.max_cubemap_size );

		// check for seamless cubemaps too
		GL_CheckExtension( "GL_ARB_seamless_cube_map", NULL, "gl_texture_cubemap_seamless", GL_ARB_SEAMLESS_CUBEMAP );
	}

	GL_CheckExtension( "GL_ARB_texture_non_power_of_two", NULL, "gl_texture_npot", GL_ARB_TEXTURE_NPOT_EXT );
	GL_CheckExtension( "GL_ARB_texture_compression", texturecompressionfuncs, "gl_texture_dxt_compression", GL_TEXTURE_COMPRESSION_EXT );
	if( !GL_CheckExtension( "GL_EXT_texture_edge_clamp", NULL, "gl_clamp_to_edge", GL_CLAMPTOEDGE_EXT ))
		GL_CheckExtension( "GL_SGIS_texture_edge_clamp", NULL, "gl_clamp_to_edge", GL_CLAMPTOEDGE_EXT );

	glConfig.max_texture_anisotropy = 0.0f;
	if( GL_CheckExtension( "GL_EXT_texture_filter_anisotropic", NULL, "gl_texture_anisotropic_filter", GL_ANISOTROPY_EXT ))
		pglGetFloatv( GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &glConfig.max_texture_anisotropy );

#if XASH_WIN32 // Win32 only drivers?
	// g-cont. because lodbias it too glitchy on Intel's cards
	if( glConfig.hardware_type != GLHW_INTEL )
#endif
	{
		if( GL_CheckExtension( "GL_EXT_texture_lod_bias", NULL, "gl_texture_mipmap_biasing", GL_TEXTURE_LOD_BIAS ))
			pglGetFloatv( GL_MAX_TEXTURE_LOD_BIAS_EXT, &glConfig.max_texture_lod_bias );
	}

	GL_CheckExtension( "GL_ARB_texture_border_clamp", NULL, NULL, GL_CLAMP_TEXBORDER_EXT );

	GL_CheckExtension( "GL_ARB_depth_texture", NULL, NULL, GL_DEPTH_TEXTURE );
	GL_CheckExtension( "GL_ARB_texture_float", NULL, "gl_texture_float", GL_ARB_TEXTURE_FLOAT_EXT );
	GL_CheckExtension( "GL_ARB_depth_buffer_float", NULL, "gl_texture_depth_float", GL_ARB_DEPTH_FLOAT_EXT );
	GL_CheckExtension( "GL_EXT_gpu_shader4", NULL, NULL, GL_EXT_GPU_SHADER4 ); // don't confuse users
	GL_CheckExtension( "GL_ARB_vertex_buffer_object", vbofuncs, "gl_vertex_buffer_object", GL_ARB_VERTEX_BUFFER_OBJECT_EXT );
	GL_CheckExtension( "GL_ARB_texture_multisample", multisampletexfuncs, "gl_texture_multisample", GL_TEXTURE_MULTISAMPLE );
	GL_CheckExtension( "GL_ARB_texture_compression_bptc", NULL, "gl_texture_bptc_compression", GL_ARB_TEXTURE_COMPRESSION_BPTC );
#ifndef XASH_GL_STATIC
	if(glConfig.context == CONTEXT_TYPE_GL_CORE )
		GL_CheckExtension( "shader_objects", shaderobjectsfuncs_gles, "gl_shaderobjects", GL_SHADER_OBJECTS_EXT );
	else
		GL_CheckExtension( "GL_ARB_shader_objects", shaderobjectsfuncs, "gl_shaderobjects", GL_SHADER_OBJECTS_EXT );
	GL_CheckExtension( "GL_ARB_vertex_array_object", vaofuncs, "gl_vertex_array_object", GL_ARB_VERTEX_ARRAY_OBJECT_EXT );
#endif
	if( GL_CheckExtension( "GL_ARB_shading_language_100", NULL, NULL, GL_SHADER_GLSL100_EXT ))
	{
		pglGetIntegerv( GL_MAX_TEXTURE_COORDS_ARB, &glConfig.max_texture_coords );
		pglGetIntegerv( GL_MAX_TEXTURE_IMAGE_UNITS_ARB, &glConfig.max_teximage_units );

		// check for hardware skinning
		pglGetIntegerv( GL_MAX_VERTEX_UNIFORM_COMPONENTS_ARB, &glConfig.max_vertex_uniforms );
		pglGetIntegerv( GL_MAX_VERTEX_ATTRIBS_ARB, &glConfig.max_vertex_attribs );

#if XASH_WIN32 // Win32 only drivers?
		if( glConfig.hardware_type == GLHW_RADEON && glConfig.max_vertex_uniforms > 512 )
			glConfig.max_vertex_uniforms /= 4; // radeon returns not correct info
#endif
	}
	else
	{
		// just get from multitexturing
		glConfig.max_texture_coords = glConfig.max_teximage_units = glConfig.max_texture_units;
	}

	// rectangle textures support
	GL_CheckExtension( "GL_ARB_texture_rectangle", NULL, "gl_texture_rectangle", GL_TEXTURE_2D_RECT_EXT );

	if( !GL_CheckExtension( "glDrawRangeElements", drawrangeelementsfuncs, "gl_drawrangeelements", GL_DRAW_RANGEELEMENTS_EXT ) )
	{
		if( GL_CheckExtension( "glDrawRangeElementsEXT", drawrangeelementsextfuncs,
			"gl_drawrangelements", GL_DRAW_RANGEELEMENTS_EXT ) )
		{
#ifndef XASH_GL_STATIC
			pglDrawRangeElements = pglDrawRangeElementsEXT;
#endif
		}
	}

	// this won't work without extended context
	if( glw_state.extended )
		GL_CheckExtension( "GL_ARB_debug_output", debugoutputfuncs, "gl_debug_output", GL_DEBUG_OUTPUT );

#if XASH_PSVITA
	// not all GL1.1 functions are implemented in vitaGL, but there's enough
	GL_SetExtension( GL_OPENGL_110, true );
	// init our immediate mode override
	VGL_ShimInit();
#endif
#if !defined(XASH_GLES) && !defined(XASH_GL_STATIC)
	if( gEngfuncs.Sys_CheckParm("-gl2shim") )
		GL2_ShimInit();
#endif
}
#endif

void GL_InitExtensions( void )
{
	char value[MAX_VA_STRING];

	GL_OnContextCreated();

	// initialize gl extensions
	GL_CheckExtension( "OpenGL 1.1.0", opengl_110funcs, NULL, GL_OPENGL_110 );

	// get our various GL strings
	glConfig.vendor_string = (const char *)pglGetString( GL_VENDOR );
	glConfig.renderer_string = (const char *)pglGetString( GL_RENDERER );
	glConfig.version_string = (const char *)pglGetString( GL_VERSION );
	glConfig.extensions_string = (const char *)pglGetString( GL_EXTENSIONS );
	gEngfuncs.Con_Reportf( "^3Video^7: %s\n", glConfig.renderer_string );

#ifdef XASH_GLES
	GL_InitExtensionsGLES();
#else
	GL_InitExtensionsBigGL();
#endif

	pglGetIntegerv( GL_MAX_TEXTURE_SIZE, &glConfig.max_2d_texture_size );
	if( glConfig.max_2d_texture_size <= 0 ) glConfig.max_2d_texture_size = 256;
#ifndef XASH_GL4ES
	// enable gldebug if allowed
	if( GL_Support( GL_DEBUG_OUTPUT ))
	{
		if( gpGlobals->developer )
		{
			gEngfuncs.Con_Reportf( "Installing GL_DebugOutput...\n");
			pglDebugMessageCallbackARB( GL_DebugOutput, NULL );

			// force everything to happen in the main thread instead of in a separate driver thread
			pglEnable( GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB );
		}

		// enable all the low priority messages
		pglDebugMessageControlARB( GL_DONT_CARE, GL_DONT_CARE, GL_DEBUG_SEVERITY_LOW_ARB, 0, NULL, true );
	}
#endif
	if( GL_Support( GL_TEXTURE_2D_RECT_EXT ))
		pglGetIntegerv( GL_MAX_RECTANGLE_TEXTURE_SIZE_EXT, &glConfig.max_2d_rectangle_size );

	Q_snprintf( value, sizeof( value ), "%i", glConfig.max_2d_texture_size );
	gEngfuncs.Cvar_Get( "gl_max_size", value, 0, "opengl texture max dims" );
	gEngfuncs.Cvar_SetValue( "gl_anisotropy", bound( 0, gl_texture_anisotropy.value, glConfig.max_texture_anisotropy ));

	if( GL_Support( GL_TEXTURE_COMPRESSION_EXT ))
		gEngfuncs.Image_AddCmdFlags( IL_DDS_HARDWARE );

	// MCD has buffering issues
#if XASH_WIN32
	if( Q_strstr( glConfig.renderer_string, "gdi" ))
		gEngfuncs.Cvar_SetValue( "gl_finish", 1 );
#endif

	R_RenderInfo_f();

	tr.framecount = tr.visframecount = 1;
	glw_state.initialized = true;
}

void GL_ClearExtensions( void )
{
	// now all extensions are disabled
	memset( glConfig.extension, 0, sizeof( glConfig.extension ));
	glw_state.initialized = false;
#if XASH_PSVITA
	// deinit our immediate mode override
	VGL_ShimShutdown();
#endif
#if !defined(XASH_GLES) && !defined(XASH_GL_STATIC)
	GL2_ShimShutdown();
#endif
}

//=======================================================================

/*
=================
GL_InitCommands
=================
*/
void GL_InitCommands( void )
{
	RETRIEVE_ENGINE_SHARED_CVAR_LIST();

	gEngfuncs.Cvar_RegisterVariable( &r_lighting_extended );
	gEngfuncs.Cvar_RegisterVariable( &r_lighting_ambient );
	gEngfuncs.Cvar_RegisterVariable( &r_novis );
	gEngfuncs.Cvar_RegisterVariable( &r_nocull );
	gEngfuncs.Cvar_RegisterVariable( &r_detailtextures );
	gEngfuncs.Cvar_RegisterVariable( &r_lockpvs );
	gEngfuncs.Cvar_RegisterVariable( &r_lockfrustum );
	gEngfuncs.Cvar_RegisterVariable( &r_traceglow );
	gEngfuncs.Cvar_RegisterVariable( &r_studio_sort_textures );
	gEngfuncs.Cvar_RegisterVariable( &r_studio_drawelements );

	gEngfuncs.Cvar_RegisterVariable( &gl_extensions );
	gEngfuncs.Cvar_RegisterVariable( &gl_texture_nearest );
	gEngfuncs.Cvar_RegisterVariable( &gl_lightmap_nearest );
	gEngfuncs.Cvar_RegisterVariable( &gl_check_errors );
	gEngfuncs.Cvar_RegisterVariable( &gl_texture_anisotropy );
	gEngfuncs.Cvar_RegisterVariable( &gl_texture_lodbias );
	gEngfuncs.Cvar_RegisterVariable( &gl_keeptjunctions );
	gEngfuncs.Cvar_RegisterVariable( &gl_finish );
	gEngfuncs.Cvar_RegisterVariable( &gl_nosort );
	gEngfuncs.Cvar_RegisterVariable( &gl_test );
	gEngfuncs.Cvar_RegisterVariable( &gl_wireframe );
	gEngfuncs.Cvar_RegisterVariable( &gl_msaa );
	gEngfuncs.Cvar_RegisterVariable( &gl_stencilbits );
	gEngfuncs.Cvar_RegisterVariable( &gl_round_down );

	// these cvar not used by engine but some mods requires this
	gEngfuncs.Cvar_RegisterVariable( &gl_polyoffset );

	// make sure gl_vsync is checked after vid_restart
	SetBits( gl_vsync->flags, FCVAR_CHANGED );

	gEngfuncs.Cmd_AddCommand( "r_info", R_RenderInfo_f, "display renderer info" );
	gEngfuncs.Cmd_AddCommand( "timerefresh", SCR_TimeRefresh_f, "turn quickly and print rendering statistcs" );
}

/*
===============
R_CheckVBO

register VBO cvars and get default value
===============
*/
static void R_CheckVBO( void )
{
	qboolean disable = false;

	// some bad GLES1 implementations breaks dlights completely
	if( glConfig.max_texture_units < 3 )
		disable = true;

#ifdef XASH_MOBILE_PLATFORM
	// VideoCore4 drivers have a problem with mixing VBO and client arrays
	// Disable it, as there is no suitable workaround here
	if( Q_stristr( glConfig.renderer_string, "VideoCore IV" ) || Q_stristr( glConfig.renderer_string, "vc4" ) )
		disable = true;
#endif

	if( disable )
	{
		r_vbo.flags = r_vbo_dlightmode.flags = 0;
		r_vbo.string = "0";
		r_vbo_dlightmode.string = "0";
	}

	gEngfuncs.Cvar_RegisterVariable( &r_vbo );
	gEngfuncs.Cvar_RegisterVariable( &r_vbo_dlightmode );
}

/*
=================
GL_RemoveCommands
=================
*/
void GL_RemoveCommands( void )
{
	gEngfuncs.Cmd_RemoveCommand( "r_info" );
}

/*
===============
R_Init
===============
*/
qboolean R_Init( void )
{
	if( glw_state.initialized )
		return true;

	GL_InitCommands();
	GL_InitRandomTable();

	GL_SetDefaultState();

	// create the window and set up the context
	if( !gEngfuncs.R_Init_Video( REF_GL )) // request GL context
	{
		GL_RemoveCommands();
		gEngfuncs.R_Free_Video();
// Why? Host_Error again???
//		gEngfuncs.Host_Error( "Can't initialize video subsystem\nProbably driver was not installed" );
		return false;
	}

	r_temppool = Mem_AllocPool( "Render Zone" );

	GL_SetDefaults();
	R_CheckVBO();
	R_InitImages();
	R_SpriteInit();
	R_StudioInit();
	R_AliasInit();
	R_ClearDecals();
	R_ClearScene();

	return true;
}

/*
===============
R_Shutdown
===============
*/
void R_Shutdown( void )
{
	if( !glw_state.initialized )
		return;

	GL_RemoveCommands();
	R_ShutdownImages();

	Mem_FreePool( &r_temppool );

#ifdef XASH_GL4ES
	close_gl4es();
#endif // XASH_GL4ES

	// shut down OS specific OpenGL stuff like contexts, etc.
	gEngfuncs.R_Free_Video();
}

/*
=================
GL_ErrorString
convert errorcode to string
=================
*/
const char *GL_ErrorString( int err )
{
	switch( err )
	{
	case GL_STACK_OVERFLOW:
		return "GL_STACK_OVERFLOW";
	case GL_STACK_UNDERFLOW:
		return "GL_STACK_UNDERFLOW";
	case GL_INVALID_ENUM:
		return "GL_INVALID_ENUM";
	case GL_INVALID_VALUE:
		return "GL_INVALID_VALUE";
	case GL_INVALID_OPERATION:
		return "GL_INVALID_OPERATION";
	case GL_OUT_OF_MEMORY:
		return "GL_OUT_OF_MEMORY";
	default:
		return "UNKNOWN ERROR";
	}
}

/*
=================
GL_CheckForErrors
obsolete
=================
*/
void GL_CheckForErrors_( const char *filename, const int fileline )
{
	int	err;

	if( !gl_check_errors.value )
		return;

	if(( err = pglGetError( )) == GL_NO_ERROR )
		return;

	gEngfuncs.Con_Printf( S_OPENGL_ERROR "%s (at %s:%i)\n", GL_ErrorString( err ), filename, fileline );
}

void GL_SetupAttributes( int safegl )
{
	int context_flags = 0; // REFTODO!!!!!
	int samples = 0;

#ifdef XASH_GLES
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_PROFILE_MASK, REF_GL_CONTEXT_PROFILE_ES );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_EGL, 1 );
#ifdef XASH_NANOGL
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 1 );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 1 );
#elif defined( XASH_WES ) || defined( XASH_REGAL )
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 2 );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 0 );
#endif
#elif defined XASH_GL4ES
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_PROFILE_MASK, REF_GL_CONTEXT_PROFILE_ES );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_EGL, 1 );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 2 );
	gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 0 );
#else // GL1.x
	if( gEngfuncs.Sys_CheckParm( "-glcore" ))
	{
		SetBits( context_flags, FCONTEXT_CORE_PROFILE );

		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_PROFILE_MASK, REF_GL_CONTEXT_PROFILE_CORE );
		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MAJOR_VERSION, 3 );
		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_MINOR_VERSION, 3 );
	}
	else
	{
		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_PROFILE_MASK, REF_GL_CONTEXT_PROFILE_COMPATIBILITY );
	}
#endif // XASH_GLES

	if( gEngfuncs.Sys_CheckParm( "-gldebug" ) )
	{
		gEngfuncs.Con_Reportf( "Creating an extended GL context for debug...\n" );
		SetBits( context_flags, FCONTEXT_DEBUG_ARB );
		gEngfuncs.GL_SetAttribute( REF_GL_CONTEXT_FLAGS, REF_GL_CONTEXT_DEBUG_FLAG );
		glw_state.extended = true;
	}

	if( safegl > SAFE_DONTCARE )
	{
		safegl = -1; // can't retry anymore, can only shutdown engine
		return;
	}

	gEngfuncs.Con_Printf( "Trying safe opengl mode %d\n", safegl );

	if( safegl == SAFE_DONTCARE )
		return;

	gEngfuncs.GL_SetAttribute( REF_GL_DOUBLEBUFFER, 1 );

	if( safegl < SAFE_NOACC )
		gEngfuncs.GL_SetAttribute( REF_GL_ACCELERATED_VISUAL, 1 );

	gEngfuncs.Con_Printf( "bpp %d\n", gpGlobals->desktopBitsPixel );

	if( safegl < SAFE_NOSTENCIL )
		gEngfuncs.GL_SetAttribute( REF_GL_STENCIL_SIZE, gl_stencilbits.value );

	if( safegl < SAFE_NOALPHA )
		gEngfuncs.GL_SetAttribute( REF_GL_ALPHA_SIZE, 8 );

	if( safegl < SAFE_NODEPTH )
		gEngfuncs.GL_SetAttribute( REF_GL_DEPTH_SIZE, 24 );
	else
		gEngfuncs.GL_SetAttribute( REF_GL_DEPTH_SIZE, 8 );

	if( safegl < SAFE_NOCOLOR )
	{
		if( gpGlobals->desktopBitsPixel >= 24 )
		{
			gEngfuncs.GL_SetAttribute( REF_GL_RED_SIZE, 8 );
			gEngfuncs.GL_SetAttribute( REF_GL_GREEN_SIZE, 8 );
			gEngfuncs.GL_SetAttribute( REF_GL_BLUE_SIZE, 8 );
		}
		else if( gpGlobals->desktopBitsPixel >= 16 )
		{
			gEngfuncs.GL_SetAttribute( REF_GL_RED_SIZE, 5 );
			gEngfuncs.GL_SetAttribute( REF_GL_GREEN_SIZE, 6 );
			gEngfuncs.GL_SetAttribute( REF_GL_BLUE_SIZE, 5 );
		}
		else
		{
			gEngfuncs.GL_SetAttribute( REF_GL_RED_SIZE, 3 );
			gEngfuncs.GL_SetAttribute( REF_GL_GREEN_SIZE, 3 );
			gEngfuncs.GL_SetAttribute( REF_GL_BLUE_SIZE, 2 );
		}
	}

	if( safegl < SAFE_NOMSAA )
	{
		switch( (int)gEngfuncs.pfnGetCvarFloat( "gl_msaa_samples" ))
		{
		case 2:
		case 4:
		case 8:
		case 16:
			samples = gEngfuncs.pfnGetCvarFloat( "gl_msaa_samples" );
			break;
		default:
			samples = 0; // don't use, because invalid parameter is passed
		}

		if( samples )
		{
			gEngfuncs.GL_SetAttribute( REF_GL_MULTISAMPLEBUFFERS, 1 );
			gEngfuncs.GL_SetAttribute( REF_GL_MULTISAMPLESAMPLES, samples );

			glConfig.max_multisamples = samples;
		}
		else
		{
			gEngfuncs.GL_SetAttribute( REF_GL_MULTISAMPLEBUFFERS, 0 );
			gEngfuncs.GL_SetAttribute( REF_GL_MULTISAMPLESAMPLES, 0 );

			glConfig.max_multisamples = 0;
		}
	}
	else
	{
		gEngfuncs.Cvar_Set( "gl_msaa_samples", "0" );
	}
}

void wes_init( const char *gles2 );
int nanoGL_Init( void );
#ifdef XASH_GL4ES
void GL4ES_GetMainFBSize( int *width, int *height )
{
	*width = gpGlobals->width;
	*height = gpGlobals->height;
}
void *GL4ES_GetProcAddress( const char *name )
{
	if( !Q_strcmp(name, "glShadeModel") )
		// combined gles/gles2/gl implementation exports this, but it is invalid
		return NULL;
	return gEngfuncs.GL_GetProcAddress( name );
}
#endif

void GL_OnContextCreated( void )
{
	int colorBits[3];
#ifdef XASH_NANOGL
	nanoGL_Init();
#endif

	gEngfuncs.GL_GetAttribute( REF_GL_RED_SIZE, &colorBits[0] );
	gEngfuncs.GL_GetAttribute( REF_GL_GREEN_SIZE, &colorBits[1] );
	gEngfuncs.GL_GetAttribute( REF_GL_BLUE_SIZE, &colorBits[2] );
	glConfig.color_bits = colorBits[0] + colorBits[1] + colorBits[2];

	gEngfuncs.GL_GetAttribute( REF_GL_ALPHA_SIZE, &glConfig.alpha_bits );
	gEngfuncs.GL_GetAttribute( REF_GL_DEPTH_SIZE, &glConfig.depth_bits );
	gEngfuncs.GL_GetAttribute( REF_GL_STENCIL_SIZE, &glConfig.stencil_bits );
	glState.stencilEnabled = glConfig.stencil_bits ? true : false;

	gEngfuncs.GL_GetAttribute( REF_GL_MULTISAMPLESAMPLES, &glConfig.msaasamples );

#ifdef XASH_WES
	wes_init( "" );
#endif
#ifdef XASH_GL4ES
	set_getprocaddress( GL4ES_GetProcAddress );
	set_getmainfbsize( GL4ES_GetMainFBSize );
	initialize_gl4es();

	// merge glBegin/glEnd in beams and console
	pglHint( GL_BEGINEND_HINT_GL4ES, 1 );
	// dxt unpacked to 16-bit looks ugly
	pglHint( GL_AVOID16BITS_HINT_GL4ES, 1 );
#endif
}