| | 1 | = Manual = |
| | 2 | |
| | 3 | == How to use Kernel/Task subsystem == |
| | 4 | |
| | 5 | Most of the games has got a main-loop. During the execution of one cycle of the loop a game engine has to perfrom a lot of tasks, e.g. checking user input, rendering, physic update and so on. [[BR]] |
| | 6 | nrEngine's Kernel/Task subsystems provides a simple but powerfull interface to manage the main loop. The engine does contains a '''Kernel''' which runs in the background of the engine. A '''Task''' can be bound to the kernel, so that it gets updated every cycle. A task can be any user derived class which has to perform repetitive jobs, e.g. check for user input or stream data from the disk. [[BR]] |
| | 7 | Moreover a task can get a specific order number or it can depend on another task. Hence the engine does provide a simple graph based task execution system. The functionality of the nrEngine's kernel is similar to the operating system's one, but in a very simple form. [[BR]] |
| | 8 | And finally a task can be shifted to a thread, so that it executes in parallel to the main application. |
| | 9 | |
| | 10 | The following code show you how to use the engine's kernel subsystem for a simple managment of tasks in your application/game: |
| | 11 | {{{ |
| | 12 | #include <nrEngine/nrEngine.h> |
| | 13 | |
| | 14 | using namespace nrEngine; |
| | 15 | |
| | 16 | //! This is a simpel task performing sound output |
| | 17 | class SoundTask : public ITask |
| | 18 | { |
| | 19 | public: |
| | 20 | |
| | 21 | SoundTask(); |
| | 22 | ~SoundTask(); |
| | 23 | |
| | 24 | //! This method will be called when the task stops |
| | 25 | Result stopTask(); |
| | 26 | |
| | 27 | //! Task was added to the kernel, so initilize it |
| | 28 | Result onAddTask(); |
| | 29 | |
| | 30 | //! This is called every cycle, so that SoundTask can react on it |
| | 31 | Result updateTask(); |
| | 32 | |
| | 33 | ... |
| | 34 | }; |
| | 35 | |
| | 36 | void main() |
| | 37 | { |
| | 38 | // Initialize engine |
| | 39 | ... |
| | 40 | |
| | 41 | |
| | 42 | // Add the sound task to the kernel with a low order number |
| | 43 | Engine::sKernel()->AddTask(new SoundTask(), ORDER_LOW); |
| | 44 | |
| | 45 | // Executes engine's kernel, hence execute all tasks which are in the kernel |
| | 46 | // The function returns if there are no more tasks in the kernel (i.e. if all tasks stops) |
| | 47 | Engine::sKernel()->Execute(); |
| | 48 | } |
| | 49 | }}} |
| | 50 | |
| | 51 | See also: ["ManualPage"] |
