Magnum::Timeline class

#include <Magnum/Timeline.h>

Basic usage

Construct the timeline on initialization so the instance is available for the whole lifetime of the application. Call start() after the application state is fully initialized and before the first draw event is performed.

In your draw event implementation don't forget to call nextFrame() after buffer swap. You can use previousFrameDuration() to compute animation speed. To limit application framerate you can use Platform::*Application::setSwapInterval() or Platform::*Application::setMinimalLoopPeriod(). Note that on Emscripten the framerate is governed by the browser and you can't do anything about it.

Example usage:

MyApplication::MyApplication(const Arguments& arguments):
    Platform::Application{arguments, NoCreate}
{
    …

    // Enable VSync or set minimal loop period for the application, if
    // needed/applicable ...

    _timeline.start();
}

void MyApplication::drawEvent() {
    …

    // Distance of object traveling at speed of 15 units per second
    Float distance = 15.0f*_timeline.previousFrameDuration(); 

    // Move an object, draw it ...

    swapBuffers();
    redraw();
    _timeline.nextFrame();
}

Apart from directly using the returned time values, the Timeline can also be used together with Animation::Player for a more controlled behavior. In that case, it's recommended to never call Timeline::stop() but control the player start/pause/stop state instead. See Animation::Player documentation for more information.

Constructors, destructors, conversion operators

Timeline() defaulted explicit

Constructor.

Public functions

void start()

Start the timeline.

void stop()

Stop the timeline.

void nextFrame()

Advance to next frame.

auto previousFrameTime() const -> Float

Time at previous frame in seconds.

auto previousFrameDuration() const -> Float

Duration of previous frame in seconds.

auto currentFrameTime() const -> Float new in Git master

Current time in seconds.

auto currentFrameDuration() const -> Float new in Git master

Time since the last frame in seconds.

Function documentation