Magnum::Platform::WindowlessWglApplication class
#include <Magnum/Platform/WindowlessWglApplication.h>

Windowless WGL application.

Application for offscreen rendering using WindowlessWglContext. This application library is available on desktop OpenGL on Windows.

Bootstrap application

Fully contained windowless application using WindowlessWglApplication along with CMake setup is available in windowless branch of Magnum Bootstrap repository, download it as tar.gz or zip file. After extracting the downloaded archive you can build and run the application with these four commands:

mkdir build && cd build
cmake ..
cmake --build .
./src/MyApplication # or ./src/Debug/MyApplication

See Usage with CMake for more information.

General usage

This application library is built if MAGNUM_WITH_WINDOWLESSWGLAPPLICATION is enabled when building Magnum. To use this library from CMake, request the WindowlessWglApplication component of the Magnum package and link to the Magnum::WindowlessWglApplication target:

find_package(Magnum REQUIRED)
if(CORRADE_TARGET_WINDOWS)
    find_package(Magnum REQUIRED WindowlessWglApplication)
endif()

# ...
if(CORRADE_TARGET_WINDOWS)
    target_link_libraries(your-app PRIVATE Magnum::WindowlessWglApplication)
endif()

Additionally, if you're using Magnum as a CMake subproject, do the following before calling find_package() to ensure it's enabled, as the library is not built by default:

set(MAGNUM_WITH_WINDOWLESSWGLAPPLICATION ON CACHE BOOL "" FORCE)
add_subdirectory(magnum EXCLUDE_FROM_ALL)

If no other application is requested, you can also use the generic Magnum::WindowlessApplication alias to simplify porting. Again, see Downloading and building and Usage with CMake for more information.

Place your code into exec(). The subclass can be then used in main() function using MAGNUM_WINDOWLESSWGLAPPLICATION_MAIN() macro. See Platform support for more information.

class MyApplication: public Platform::WindowlessWglApplication {
    // implement required methods...
};
MAGNUM_WINDOWLESSWGLAPPLICATION_MAIN(MyApplication)

If no other application header is included, this class is also aliased to Platform::WindowlessApplication and the macro is aliased to MAGNUM_WINDOWLESSAPPLICATION_MAIN() to simplify porting.

Public types

struct Arguments: Application arguments.
using Configuration = WindowlessWglContext::Configuration: Configuration.

Constructors, destructors, conversion operators

WindowlessWglApplication(const Arguments& arguments, const Configuration& configuration = Configuration{}) explicit: Default constructor.
WindowlessWglApplication(const Arguments& arguments, NoCreateT) explicit: Constructor.
WindowlessWglApplication(const WindowlessWglApplication&) deleted: Copying is not allowed.
WindowlessWglApplication(WindowlessWglApplication&&) deleted: Moving is not allowed.

Public functions

auto operator=(const WindowlessWglApplication&) -> WindowlessWglApplication& deleted: Copying is not allowed.
auto operator=(WindowlessWglApplication&&) -> WindowlessWglApplication& deleted: Moving is not allowed.
auto exec() -> int pure virtual: Execute application.
auto glContext() -> HGLRC new in 2020.06: Underlying OpenGL context.

Protected functions

void createContext(const Configuration& configuration = Configuration()): Create context with given configuration.
auto tryCreateContext(const Configuration& configuration) -> bool: Try to create context with given configuration.

Typedef documentation

typedef WindowlessWglContext::Configuration Magnum::Platform::WindowlessWglApplication::Configuration

Configuration.

Function documentation

Magnum::Platform::WindowlessWglApplication::WindowlessWglApplication(const Arguments& arguments, const Configuration& configuration = Configuration{}) explicit

Default constructor.

Parameters
arguments	Application arguments
configuration	Configuration

Creates application with default or user-specified configuration. See Configuration for more information. The program exits if the context cannot be created, see tryCreateContext() for an alternative.

Magnum::Platform::WindowlessWglApplication::WindowlessWglApplication(const Arguments& arguments, NoCreateT) explicit

Constructor.

Parameters
arguments	Application arguments

Unlike above, the context is not created and must be created later with createContext() or tryCreateContext().

int Magnum::Platform::WindowlessWglApplication::exec() pure virtual

Execute application.

Returns	Value for returning from `main()`

See MAGNUM_WINDOWLESSWGLAPPLICATION_MAIN() for usage information.

HGLRC Magnum::Platform::WindowlessWglApplication::glContext() new in 2020.06

Underlying OpenGL context.

Use in case you need to call WGL functionality directly or in order to create a shared context. Returns nullptr in case the context was not created yet.

void Magnum::Platform::WindowlessWglApplication::createContext(const Configuration& configuration = Configuration()) protected

Create context with given configuration.

Must be called if and only if the context wasn't created by the constructor itself. Error message is printed and the program exits if the context cannot be created, see tryCreateContext() for an alternative.

bool Magnum::Platform::WindowlessWglApplication::tryCreateContext(const Configuration& configuration) protected

Try to create context with given configuration.

Unlike createContext() returns false if the context cannot be created, true otherwise.