Magnum::Platform::GlfwApplication class

GLFW application.

Bootstrap application
General usage
DPI awareness
Reference

Application using the GLFW toolkit. Supports keyboard and mouse handling with support for changing cursor and mouse tracking and warping.

This application library is available on all platforms where GLFW is ported. It depends on the GLFW library and is built if WITH_GLFWAPPLICATION is enabled when building Magnum.

Bootstrap application

Fully contained base application using GlfwApplication along with CMake setup is available in base-glfw 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

In order to use this library from CMake, you need to copy FindGLFW.cmake from the modules directory in Magnum source to the modules/ dir in your project (so it is able to find the GLFW library). Request the GlfwApplication component of the Magnum package and link to the Magnum::GlfwApplication target:

find_package(Magnum REQUIRED GlfwApplication)

# ...
target_link_libraries(your-app Magnum::GlfwApplication)

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

In C++ code you need to implement at least drawEvent() to be able to draw on the screen. The subclass can be then used directly in main() — see convenience macro MAGNUM_GLFWAPPLICATION_MAIN(). See Platform support for more information.

class MyApplication: public Platform::GlfwApplication {
    // implement required methods...
};
MAGNUM_GLFWAPPLICATION_MAIN(MyApplication)

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

DPI awareness

DPI awareness behavior is consistent with Sdl2Application except that iOS or Emscripten specifics don't apply here. See its DPI awareness documentation for more information.

Public types

struct Arguments: Application arguments.
class Configuration: Configuration.
class GLConfiguration: OpenGL context configuration.
class InputEvent: Base for input events.
class KeyEvent: Key event.
class MouseEvent: Mouse event.
class MouseMoveEvent: Mouse move event.
class MouseScrollEvent: Mouse scroll event.
class TextInputEvent: Text input event.
class ViewportEvent: Viewport event.

Constructors, destructors, conversion operators

GlfwApplication(const Arguments& arguments, const Configuration& configuration, const GLConfiguration& glConfiguration) explicit: Construct with given configuration for OpenGL context.
GlfwApplication(const Arguments& arguments, const Configuration& configuration) explicit: Construct with given configuration.
GlfwApplication(const Arguments& arguments) explicit: Construct with default configuration.
GlfwApplication(const Arguments& arguments, NoCreateT) explicit: Construct without creating a window.
GlfwApplication(const Arguments& arguments, std::nullptr_t) deprecated explicit: Construct without creating a window.
GlfwApplication(const GlfwApplication&) deleted: Copying is not allowed.
GlfwApplication(GlfwApplication&&) deleted: Moving is not allowed.

Public functions

auto operator=(const GlfwApplication&) -> GlfwApplication& deleted: Copying is not allowed.
auto operator=(GlfwApplication&&) -> GlfwApplication& deleted: Moving is not allowed.
auto exec() -> int: Execute main loop.
void exit(): Exit application main loop.
auto window() -> GLFWwindow*: Underlying window handle.

Protected functions

void create(const Configuration& configuration, const GLConfiguration& glConfiguration): Create a window with given configuration for OpenGL context.
void create(const Configuration& configuration): Create a window with given configuration.
void create(): Create a window with default configuration and OpenGL context.
void createContext(const Configuration& configuration) deprecated: Create a window with given configuration for OpenGL context.
void createContext() deprecated: Create a window with default configuration and OpenGL context.
auto tryCreate(const Configuration& configuration, const GLConfiguration& glConfiguration) -> bool: Try to create context with given configuration for OpenGL context.
auto tryCreate(const Configuration& configuration) -> bool: Try to create context with given configuration.
auto tryCreateContext(const Configuration& configuration) -> bool deprecated: Try to create context with given configuration for OpenGL context.

Screen handling

auto windowSize() const -> Vector2i: Window size.
auto framebufferSize() const -> Vector2i: Framebuffer size.
auto dpiScaling() const -> Vector2: DPI scaling.
auto dpiScaling(const Configuration& configuration) const -> Vector2: DPI scaling for given configuration.
void swapBuffers(): Swap buffers.
void setSwapInterval(Int interval): Set swap interval.
void redraw(): Redraw immediately.
void viewportEvent(ViewportEvent& event) protected virtual: Viewport event.
void viewportEvent(const Vector2i& size) deprecated protected virtual: Viewport event.
void drawEvent() protected pure virtual: Draw event.

Keyboard handling

void keyPressEvent(KeyEvent& event) protected virtual: Key press event.
void keyReleaseEvent(KeyEvent& event) protected virtual: Key release event.

Mouse handling

void warpCursor(const Vector2i& position): Warp mouse cursor to given coordinates.
void mousePressEvent(MouseEvent& event) protected virtual: Mouse press event.
void mouseReleaseEvent(MouseEvent& event) protected virtual: Mouse release event.
void mouseMoveEvent(MouseMoveEvent& event) protected virtual: Mouse move event.
void mouseScrollEvent(MouseScrollEvent& event) protected virtual: Mouse scroll event.

Text input handling

auto isTextInputActive() const -> bool: Whether text input is active.
void startTextInput(): Start text input.
void stopTextInput(): Stop text input.
void textInputEvent(TextInputEvent& event) protected virtual: Text input event.

Function documentation

Magnum::Platform::GlfwApplication::GlfwApplication(const Arguments& arguments, const Configuration& configuration, const GLConfiguration& glConfiguration) explicit

Construct with given configuration for OpenGL context.

Parameters
arguments	Application arguments
configuration	Application configuration
glConfiguration	OpenGL context configuration

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

Magnum::Platform::GlfwApplication::GlfwApplication(const Arguments& arguments, const Configuration& configuration) explicit

Construct with given configuration.

If Configuration::WindowFlag::Contextless is present or Magnum was not built with MAGNUM_TARGET_GL, this creates a window without any GPU context attached, leaving that part on the user.

If none of the flags is present and Magnum was built with MAGNUM_TARGET_GL, this is equivalent to calling GlfwApplication(const Arguments&, const Configuration&, const GLConfiguration&) with default-constructed GLConfiguration.

See also Enabling or disabling features for more information.

Magnum::Platform::GlfwApplication::GlfwApplication(const Arguments& arguments) explicit

Construct with default configuration.

Equivalent to calling GlfwApplication(const Arguments&, const Configuration&) with default-constructed Configuration.

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

Construct without creating a window.

Parameters
arguments	Application arguments

Unlike above, the window is not created and must be created later with create() or tryCreate().

Magnum::Platform::GlfwApplication::GlfwApplication(const Arguments& arguments, std::nullptr_t) explicit

Construct without creating a window.

int Magnum::Platform::GlfwApplication::exec()

Execute main loop.

Returns	Value for returning from `main()`

See MAGNUM_GLFWAPPLICATION_MAIN() for usage information.

GLFWwindow* Magnum::Platform::GlfwApplication::window()

Underlying window handle.

Use in case you need to call GLFW functionality directly.

void Magnum::Platform::GlfwApplication::create(const Configuration& configuration, const GLConfiguration& glConfiguration) protected

Create a window with given configuration for OpenGL context.

Parameters
configuration	Application configuration
glConfiguration	OpenGL context configuration

Must be called only if the context wasn't created by the constructor itself, i.e. when passing NoCreate to it. Error message is printed and the program exits if the context cannot be created, see tryCreate() for an alternative.

On desktop GL, if version is not specified in glConfiguration, the application first tries to create core context (OpenGL 3.2+) and if that fails, falls back to compatibility OpenGL 2.1 context.

void Magnum::Platform::GlfwApplication::create(const Configuration& configuration) protected

Create a window with given configuration.

If Configuration::WindowFlag::Contextless is present or Magnum was not built with MAGNUM_TARGET_GL, this creates a window without any GPU context attached, leaving that part on the user.

If none of the flags is present and Magnum was built with MAGNUM_TARGET_GL, this is equivalent to calling create(const Configuration&, const GLConfiguration&) with default-constructed GLConfiguration.

See also Enabling or disabling features for more information.

void Magnum::Platform::GlfwApplication::create() protected

Create a window with default configuration and OpenGL context.

Equivalent to calling create(const Configuration&) with default-constructed Configuration.

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

Create a window with given configuration for OpenGL context.

void Magnum::Platform::GlfwApplication::createContext() protected

Create a window with default configuration and OpenGL context.

bool Magnum::Platform::GlfwApplication::tryCreate(const Configuration& configuration, const GLConfiguration& glConfiguration) protected

Try to create context with given configuration for OpenGL context.

Unlike create(const Configuration&, const GLConfiguration&) returns false if the context cannot be created, true otherwise.

bool Magnum::Platform::GlfwApplication::tryCreate(const Configuration& configuration) protected

Try to create context with given configuration.

Unlike create(const Configuration&) returns false if the context cannot be created, true otherwise.

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

Try to create context with given configuration for OpenGL context.

Vector2i Magnum::Platform::GlfwApplication::windowSize() const

Window size.

Window size to which all input event coordinates can be related. Note that, especially on HiDPI systems, it may be different from framebufferSize(). Expects that a window is already created. See DPI awareness for more information.

Vector2i Magnum::Platform::GlfwApplication::framebufferSize() const

Framebuffer size.

Size of the default framebuffer. Note that, especially on HiDPI systems, it may be different from windowSize(). Expects that a window is already created. See DPI awareness for more information.

Vector2 Magnum::Platform::GlfwApplication::dpiScaling() const

DPI scaling.

How the content should be scaled relative to system defaults for given windowSize(). If a window is not created yet, returns zero vector, use dpiScaling(const Configuration&) const for calculating a value independently. See DPI awareness for more information.

Vector2 Magnum::Platform::GlfwApplication::dpiScaling(const Configuration& configuration) const

DPI scaling for given configuration.

Calculates DPI scaling that would be used when creating a window with given configuration. Takes into account DPI scaling policy and custom scaling specified on the command-line. See DPI awareness for more information.

void Magnum::Platform::GlfwApplication::swapBuffers()

Swap buffers.

Paints currently rendered framebuffer on screen.

void Magnum::Platform::GlfwApplication::setSwapInterval(Int interval)

Set swap interval.

Set 0 for no VSync, 1 for enabled VSync. Some platforms support -1 for late swap tearing. Default is driver-dependent.

void Magnum::Platform::GlfwApplication::redraw()

Redraw immediately.

Marks the window for redrawing, resulting in call to drawEvent() in the next iteration. You can call it from drawEvent() itself to redraw immediately without waiting for user input.

void Magnum::Platform::GlfwApplication::viewportEvent(ViewportEvent& event) virtual protected

Viewport event.

Called when window size changes. The default implementation does nothing. If you want to respond to size changes, you should pass the new size to GL::DefaultFramebuffer::setViewport() (if using OpenGL) and possibly elsewhere (to SceneGraph::Camera::setViewport(), other framebuffers...).

Note that this function might not get called at all if the window size doesn't change. You should configure the initial state of your cameras, framebuffers etc. in application constructor rather than relying on this function to be called. Size of the window can be retrieved using windowSize(), size of the backing framebuffer via framebufferSize() and DPI scaling using dpiScaling(). See DPI awareness for detailed info about these values.

void Magnum::Platform::GlfwApplication::viewportEvent(const Vector2i& size) virtual protected

Viewport event.

void Magnum::Platform::GlfwApplication::drawEvent() pure virtual protected

Draw event.

Called when the screen is redrawn. You should clean the framebuffer using GL::DefaultFramebuffer::clear() (if using OpenGL) and then add your own drawing functions. After drawing is finished, call swapBuffers(). If you want to draw immediately again, call also redraw().

void Magnum::Platform::GlfwApplication::keyPressEvent(KeyEvent& event) virtual protected

Key press event.

Called when an key is pressed. Default implementation does nothing.

void Magnum::Platform::GlfwApplication::keyReleaseEvent(KeyEvent& event) virtual protected

Key release event.

Called when an key is released. Default implementation does nothing.

void Magnum::Platform::GlfwApplication::mousePressEvent(MouseEvent& event) virtual protected

Mouse press event.

Called when mouse button is pressed. Default implementation does nothing.

void Magnum::Platform::GlfwApplication::mouseReleaseEvent(MouseEvent& event) virtual protected

Mouse release event.

Called when mouse button is released. Default implementation does nothing.

void Magnum::Platform::GlfwApplication::mouseMoveEvent(MouseMoveEvent& event) virtual protected

Mouse move event.

Called when any mouse button is pressed and mouse is moved. Default implementation does nothing.

void Magnum::Platform::GlfwApplication::mouseScrollEvent(MouseScrollEvent& event) virtual protected

Mouse scroll event.

Called when a scrolling device is used (mouse wheel or scrolling area on a touchpad). Default implementation does nothing.

bool Magnum::Platform::GlfwApplication::isTextInputActive() const

Whether text input is active.

If text input is active, text input events go to textInputEvent().

void Magnum::Platform::GlfwApplication::startTextInput()

Start text input.

Starts text input that will go to textInputEvent().

void Magnum::Platform::GlfwApplication::stopTextInput()

Stop text input.

Stops text input that went to textInputEvent().

void Magnum::Platform::GlfwApplication::textInputEvent(TextInputEvent& event) virtual protected

Text input event.

Called when text input is active and the text is being input.