| 12 | | == Getting started == |
| 13 | | |
| 14 | | A following code snippet shows you how to start working with the engine. It will initialize the engine singleton and setup basic logging capabilities. |
| 15 | | |
| 16 | | {{{ |
| 17 | | #include <nrEngine/nrEngine.h> |
| 18 | | |
| 19 | | void main() |
| 20 | | { |
| 21 | | // initialize logging |
| 22 | | Engine::instance()->initializeLog("log/"); |
| 23 | | Engine::sLog()->setLevel(Log::LL_WARNING); |
| 24 | | |
| 25 | | // initialize essential parts of the engine |
| 26 | | Engine::instance()->initializeEngine(); |
| 27 | | |
| 28 | | |
| 29 | | .... |
| 30 | | |
| 31 | | |
| 32 | | // release the engine and free memory |
| 33 | | Engine::release(); |
| 34 | | } |
| 35 | | }}} |
| 36 | | |
| 37 | | Note: You do not have to initialize logging at all. However this helps to determine errors and to debug the engine integration into your application. I would suggest to enable logging during the development of your software (e.g. with level=LL_DEBUG) and to disable it in the release version. |
| 38 | | |
| 39 | | |
| 40 | | == How to use Kernel/Task subsystem == |
| 41 | | |
| 42 | | 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]] |
| 43 | | 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]] |
| 44 | | 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]] |
| 45 | | And finally a task can be shifted to a thread, so that it executes in parallel to the main application. |
| 46 | | |
| 47 | | The following code show you how to use the engine's kernel subsystem for a simple managment of tasks in your application/game: |
| 48 | | {{{ |
| 49 | | #include <nrEngine/nrEngine.h> |
| 50 | | |
| 51 | | using namespace nrEngine; |
| 52 | | |
| 53 | | //! This is a simpel task performing sound output |
| 54 | | class SoundTask : public ITask |
| 55 | | { |
| 56 | | public: |
| 57 | | |
| 58 | | SoundTask(); |
| 59 | | ~SoundTask(); |
| 60 | | |
| 61 | | //! This method will be called when the task stops |
| 62 | | Result stopTask(); |
| 63 | | |
| 64 | | //! Task was added to the kernel, so initilize it |
| 65 | | Result onAddTask(); |
| 66 | | |
| 67 | | //! This is called every cycle, so that SoundTask can react on it |
| 68 | | Result updateTask(); |
| 69 | | |
| 70 | | ... |
| 71 | | }; |
| 72 | | |
| 73 | | void main() |
| 74 | | { |
| 75 | | // Initialize engine |
| 76 | | ... |
| 77 | | |
| 78 | | |
| 79 | | // Add the sound task to the kernel with a low order number |
| 80 | | Engine::sKernel()->AddTask(new SoundTask(), ORDER_LOW); |
| 81 | | |
| 82 | | // Executes engine's kernel, hence execute all tasks which are in the kernel |
| 83 | | // The function returns if there are no more tasks in the kernel (i.e. if all tasks stops) |
| 84 | | Engine::sKernel()->Execute(); |
| 85 | | } |
| 86 | | }}} |
| 87 | | |
