@ -108,18 +108,32 @@ class MAGNUM_GL_EXPORT Extension {
@ brief Magnum OpenGL context
Provides access to OpenGL version and extension information and manages
Magnum ' s internal OpenGL state tracker . An instance available through
@ ref Context : : current ( ) is automatically created during construction of
` Platform : : * Application ` classes and you can safely assume the instance is
available during the whole ` * Application ` lifetime . It ' s also possible to
create the context without using any ` * Application ` class using the
Magnum ' s internal OpenGL state tracker .
@ section GL - Context - usage Creating a context
In order to use any Magnum OpenGL functionality , an instance of this class has
to exist and be made current . If you use any ` Platform : : * Application ` classes ,
an instance available through @ ref Context : : current ( ) is automatically created
during construction ( or after @ ref Platform : : Sdl2Application : : create ( ) " Platform::*Application::create() "
/ @ relativeref { Platform : : Sdl2Application , tryCreate ( ) } and you can safely assume
the instance is available during the whole ` * Application ` lifetime . It ' s also
possible to create the context without using any ` * Application ` class using the
@ ref Platform : : GLContext subclass , see @ ref platform for more information .
@ section GL - Context - command - line Command - line options
Various options can be passed using the @ ref Configuration class , which is then
extended by various
@ ref Platform : : Sdl2Application : : GLConfiguration " Platform::*Application::GLConfiguration "
and @ ref Platform : : WindowlessEglContext : : Configuration " Platform::Windowless*Application::Configuration "
subclasses .
The context is configurable through command - line options , that are passed
either from the ` Platform : : * Application ` classes or from the
@ ref Platform : : GLContext class . Usage :
@ subsection GL - Context - usage - command - line Command - line options
In addition to the @ ref Configuration , the context is configurable through
command - line options , that are passed either from the ` Platform : : * Application `
classes or from the @ ref Platform : : GLContext class . In case an option is set in
both the @ ref Configuration and on command - line / environment , the two are
combined together - - - flags ORed together , lists joined . Usage :
@ code { . sh }
< application > [ - - magnum - help ] [ - - magnum - disable - workarounds LIST ]
@ -134,20 +148,23 @@ Arguments:
- ` - - magnum - help ` - - - display this help message and exit
- ` - - magnum - disable - workarounds LIST ` - - - driver workarounds to disable ( see
@ ref opengl - workarounds for detailed info ) ( environment :
` MAGNUM_DISABLE_WORKAROUNDS ` )
` MAGNUM_DISABLE_WORKAROUNDS ` ) . Corresponds to
@ ref Configuration : : addDisabledWorkarounds ( ) .
- ` - - magnum - disable - extensions LIST ` - - - API extensions to disable
( environment : ` MAGNUM_DISABLE_EXTENSIONS ` )
( environment : ` MAGNUM_DISABLE_EXTENSIONS ` ) . Corresponds to
@ ref Configuration : : addDisabledExtensions ( ) .
- ` - - magnum - gpu - validation off | on ` - - - GPU validation using
@ gl_extension { KHR , debug } , if present ( environment :
` MAGNUM_GPU_VALIDATION ` ) ( default : ` off ` ) . This sets up @ ref DebugOutput
callbacks and also causes
@ ref Platform : : Sdl2Application : : GLConfiguration : : Flag : : Debug " GLConfiguration::Flag::Debug "
to be enabled for context creation for both windowed and windowless
applications on supported platforms
applications on supported platforms . Corresponds to
@ ref Configuration : : Flag : : GpuValidation .
- ` - - magnum - log default | quiet | verbose ` - - - console logging
( environment : ` MAGNUM_LOG ` ) ( default : ` default ` ) . If you need to suppress
the engine startup log from code , the recommended way is to redirect
@ ref Utility - Debug - scoped - output " debug output to null " during context creation .
( environment : ` MAGNUM_LOG ` ) ( default : ` default ` ) . Corresponds to
@ ref Configuration : : Flag : : QuietLog and
@ relativeref { Configuration : : Flag , VerboseLog } .
Note that all options are prefixed with ` - - magnum - ` to avoid conflicts with
options passed to the application itself . Options that don ' t have this prefix
@ -158,15 +175,7 @@ Particular application implementations add more options for DPI scaling or
GPU selection , see @ ref Platform : : Sdl2Application , @ ref Platform : : GlfwApplication
and @ ref Platform : : WindowlessEglApplication for details .
@ section GL - Context - multithreading Thread safety
If Corrade is compiled with @ ref CORRADE_BUILD_MULTITHREADED ( the default ) , the
@ ref hasCurrent ( ) and @ ref current ( ) accessors are thread - local , matching the
OpenGL context thread locality . This might cause some performance penalties - - -
if you are sure that you never need to have multiple independent thread - local
Magnum context , build Corrade with the option disabled .
@ section GL - Context - multiple Using multiple OpenGL contexts
@ subsection GL - Context - usage - multiple Using multiple OpenGL contexts
By default , Magnum assumes you have one OpenGL context active at all times , and
all state tracking is done by the @ ref Context instance that ' s associated with
@ -187,9 +196,19 @@ Once all needed instances are created, switch between them right after making
the underlying GL context current :
@ snippet MagnumGL - framebuffer . cpp Context - makeCurrent
@ section GL - Context - multithreading Thread safety
If Corrade is compiled with @ ref CORRADE_BUILD_MULTITHREADED ( the default ) , the
@ ref hasCurrent ( ) and @ ref current ( ) accessors are thread - local , matching the
OpenGL context thread locality . This might cause some performance penalties - - -
if you are sure that you never need to have multiple independent thread - local
Magnum context , build Corrade with the option disabled .
*/
class MAGNUM_GL_EXPORT Context {
public :
class Configuration ;
# ifndef MAGNUM_TARGET_WEBGL
/**
* @ brief Context flag
@ -204,7 +223,8 @@ class MAGNUM_GL_EXPORT Context {
* Debug context . Enabled automatically by @ ref Platform windowed
* and windowless application implementations if the
* ` - - magnum - gpu - validation `
* @ ref GL - Context - command - line " command-line option " is present .
* @ ref GL - Context - usage - command - line " command-line option " is
* present .
* @ requires_gl43 Extension @ gl_extension { KHR , debug }
* @ requires_gles32 Extension @ gl_extension { ANDROID , extension_pack_es31a } /
* @ gl_extension { KHR , debug }
@ -485,7 +505,7 @@ class MAGNUM_GL_EXPORT Context {
* @ m_since { 2019 , 10 }
*
* To be used when you need to manage multiple OpenGL contexts . See
* @ ref GL - Context - multiple for more information .
* @ ref GL - Context - usage - multiple for more information .
*/
static void makeCurrent ( Context * context ) ;
@ -693,8 +713,10 @@ class MAGNUM_GL_EXPORT Context {
* @ brief Whether given extension is disabled
*
* Can be used for detecting driver bug workarounds . Disabled
* extensions return ` false ` in @ ref isExtensionSupported ( ) even if
* they are advertised as being supported by the driver .
* extensions return @ cpp false @ ce in @ ref isExtensionSupported ( ) even
* if they are advertised as being supported by the driver .
* @ see @ ref Configuration : : addDisabledExtensions ( ) ,
* @ ref GL - Context - usage - command - line
*/
template < class E > bool isExtensionDisabled ( ) const {
return isExtensionDisabled < E > ( version ( ) ) ;
@ -705,6 +727,8 @@ class MAGNUM_GL_EXPORT Context {
*
* Similar to above , but can also check for extensions which are
* disabled only for particular versions .
* @ see @ ref Configuration : : addDisabledExtensions ( ) ,
* @ ref GL - Context - usage - command - line
*/
template < class E > bool isExtensionDisabled ( Version version ) const {
static_assert ( Implementation : : IsExtension < E > : : value , " expected an OpenGL extension " ) ;
@ -717,8 +741,11 @@ class MAGNUM_GL_EXPORT Context {
* @ brief Whether given extension is disabled
*
* Can be used e . g . for listing extensions available on current
* hardware , but for general usage prefer @ ref isExtensionDisabled ( ) const ,
* as it does most operations in compile time .
* hardware , but for general usage prefer
* @ ref isExtensionDisabled ( ) const , as it does most operations at
* compile time .
* @ see @ ref Configuration : : addDisabledExtensions ( ) ,
* @ ref GL - Context - usage - command - line
*/
bool isExtensionDisabled ( const Extension & extension ) const {
return isVersionSupported ( extension . requiredVersion ( ) ) & & ! isVersionSupported ( _extensionRequiredVersion [ extension . index ( ) ] ) ;
@ -786,8 +813,8 @@ class MAGNUM_GL_EXPORT Context {
explicit Context ( NoCreateT , Utility : : Arguments & & args , Int argc , const char * * argv , void functionLoader ( Context & ) ) : Context { NoCreate , args , argc , argv , functionLoader } { }
explicit Context ( NoCreateT , Utility : : Arguments & args , Int argc , const char * * argv , void functionLoader ( Context & ) ) ;
bool tryCreate ( ) ;
void create ( ) ;
bool tryCreate ( const Configuration & configuration ) ;
void create ( const Configuration & configuration ) ;
private :
# ifndef DOXYGEN_GENERATING_OUTPUT /* https://bugzilla.gnome.org/show_bug.cgi?id=776986 */
@ -847,6 +874,206 @@ MAGNUM_GL_EXPORT Debug& operator<<(Debug& debug, Context::DetectedDriver value);
/** @debugoperatorclassenum{Context,Context::DetectedDrivers} */
MAGNUM_GL_EXPORT Debug & operator < < ( Debug & debug , Context : : DetectedDrivers value ) ;
/**
@ brief Configuration
@ m_since_latest
Affects how Magnum ' s context creation behaves . See @ ref GL - Context - usage for
more information .
@ see @ ref Platform : : GLContext : : GLContext ( ) ,
@ ref Platform : : GLContext : : create ( ) ,
@ ref Platform : : GLContext : : tryCreate ( )
*/
class MAGNUM_GL_EXPORT Context : : Configuration {
public :
/**
* @ brief Context setup flag
*
* Flags affecting the actual GL context are merged with this enum in
* @ ref Platform : : Sdl2Application : : GLConfiguration : : Flag " Platform::*Application::GLConfiguration::Flag "
* and @ ref Platform : : WindowlessEglContext : : Configuration : : Flag " Platform::Windowless*Application::Configuration::Flag "
* and after context creation available through @ ref Context : : Flag /
* @ ref Context : : flags ( ) .
* @ see @ ref Flags , @ ref setFlags ( )
*/
enum class Flag : UnsignedLong {
/* Keeping the 32-bit range reserved for actual GL context flags */
/**
* Print only warnings and errors instead of the usual startup log
* listing used extensions and workarounds . Ignored if
* @ ref Flag : : VerboseLog is set .
*
* Corresponds to the ` - - magnum - log quiet `
* @ ref GL - Context - usage - command - line " command-line option " .
*/
QuietLog = 1ull < < 61 ,
/**
* Print additional information on startup in addition to the usual
* startup log that lists used extensions and workarounds . Has a
* precedence over @ ref Flag : : QuietLog .
*
* Corresponds to the ` - - magnum - log verbose `
* @ ref GL - Context - usage - command - line " command-line option " .
*/
VerboseLog = 1ull < < 62 ,
/**
* Enable GPU validation , if available .
*
* Corresponds to the ` - - magnum - gou - validation on `
* @ ref GL - Context - usage - command - line " command-line option " .
*/
GpuValidation = 1ull < < 63
} ;
/**
* @ brief Context setup flags
*
* @ see @ ref setFlags ( ) , @ ref GL : : Context : : Flags
*/
typedef Containers : : EnumSet < Flag > Flags ;
/*implicit*/ Configuration ( ) ;
/** @brief Copy constructor */
/* The class has to be copyable in order to make command-line and
configuration options easy to merge in application implementations
- - these make a mutable copy and add what arrived via command line */
Configuration ( const Configuration & other ) ;
/** @brief Move constructor */
Configuration ( Configuration & & ) noexcept ;
~ Configuration ( ) ;
/** @brief Copy constructor */
Configuration & operator = ( const Configuration & other ) ;
/** @brief Move assignment */
Configuration & operator = ( Configuration & & ) noexcept ;
/** @brief Context setup flags */
Flags flags ( ) const { return _flags ; }
/**
* @ brief Set context setup flags
* @ return Reference to self ( for method chaining )
*
* By default no flags are set . Note that subclasses might have
* different flag defaults , see their documentation for more
* information . To avoid clearing default flags by accident , prefer to
* use @ ref addFlags ( ) and @ ref clearFlags ( ) instead .
*
* Particular @ ref Flag values correspond to the ` - - magnum - log ` and
* ` - - magnum - gpu - validation `
* @ ref GL - Context - usage - command - line " command-line options " .
*/
Configuration & setFlags ( Flags flags ) {
_flags = flags ;
return * this ;
}
/**
* @ brief Add context setup flags
* @ return Reference to self ( for method chaining )
*
* Unlike @ ref setFlags ( ) , ORs the flags with existing instead of
* replacing them . Useful for preserving the defaults .
* @ see @ ref clearFlags ( )
*/
Configuration & addFlags ( Flags flags ) {
_flags | = flags ;
return * this ;
}
/**
* @ brief Clear context setup flags
* @ return Reference to self ( for method chaining )
*
* Unlike @ ref setFlags ( ) , ANDs the inverse of @ p flags with existing
* instead of replacing them . Useful for removing default flags .
* @ see @ ref addFlags ( )
*/
Configuration & clearFlags ( Flags flags ) {
_flags & = ~ flags ;
return * this ;
}
/** @brief Disabled driver workarounds */
Containers : : ArrayView < const Containers : : StringView > disabledWorkarounds ( ) const ;
/**
* @ brief Add disabled driver workarounds
* @ return Reference to self ( for method chaining )
*
* Accepts strings from the list at @ ref opengl - workarounds . Unknown
* workarounds are ignored with a warning . By default no workarounds
* are disabled .
*
* Corresponds to the ` - - magnum - disable - workarounds `
* @ ref GL - Context - usage - command - line " command-line option " .
*/
Configuration & addDisabledWorkarounds ( Containers : : ArrayView < const Containers : : StringView > workarounds ) ;
/** @overload */
Configuration & addDisabledWorkarounds ( std : : initializer_list < Containers : : StringView > workarounds ) ;
/** @brief Disabled extensions */
Containers : : ArrayView < const Extension > disabledExtensions ( ) const ;
/**
* @ brief Add disabled extensions
* @ return Reference to self ( for method chaining )
*
* By default no extensions are disabled , except for those disabled by
* driver workarounds .
*
* Corresponds to the ` - - magnum - disable - extensions `
* @ ref GL - Context - usage - command - line " command-line option " .
*/
Configuration & addDisabledExtensions ( Containers : : ArrayView < const Extension > extensions ) ;
/** @overload */
Configuration & addDisabledExtensions ( std : : initializer_list < Extension > extensions ) ;
/** @overload */
template < class . . . E > Configuration & addDisabledExtensions ( ) {
static_assert ( Implementation : : IsExtension < E . . . > : : value , " expected only OpenGL extensions " ) ;
return addDisabledExtensions ( { E { } . . . } ) ;
}
private :
Flags _flags ;
Containers : : Array < Containers : : StringView > _disabledWorkarounds ;
Containers : : Array < Extension > _disabledExtensions ;
} ;
# ifndef DOXYGEN_GENERATING_OUTPUT
# define MAGNUM_GL_CONTEXT_CONFIGURATION_SUBCLASS_IMPLEMENTATION(Type) \
Type & addDisabledWorkarounds ( Containers : : ArrayView < const Containers : : StringView > workarounds ) { \
GL : : Context : : Configuration : : addDisabledWorkarounds ( workarounds ) ; \
return * this ; \
} \
Type & addDisabledWorkarounds ( std : : initializer_list < Containers : : StringView > workarounds ) { \
GL : : Context : : Configuration : : addDisabledWorkarounds ( workarounds ) ; \
return * this ; \
} \
\
Type & addDisabledExtensions ( Containers : : ArrayView < const GL : : Extension > extensions ) { \
GL : : Context : : Configuration : : addDisabledExtensions ( extensions ) ; \
return * this ; \
} \
Type & addDisabledExtensions ( std : : initializer_list < GL : : Extension > extensions ) { \
GL : : Context : : Configuration : : addDisabledExtensions ( extensions ) ; \
return * this ; \
} \
template < class . . . E > Type & addDisabledExtensions ( ) { \
GL : : Context : : Configuration : : addDisabledExtensions < E . . . > ( ) ; \
return * this ; \
}
# endif
CORRADE_ENUMSET_OPERATORS ( Context : : Configuration : : Flags )
/** @hideinitializer
@ brief Assert that given OpenGL version is supported
@ param version Version
Vladimír Vondruš
5 years ago