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+ Irrlicht 3D Engine
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+A tutorial by Max Winkel.
+In this tutorial we'll learn how to use splitscreen (e.g. for racing-games) with Irrlicht. We'll create a viewport divided into 4 parts, with 3 fixed cameras and one user-controlled.
+Ok, let's start with the headers (I think there's nothing to say about it)
+#include <irrlicht.h> +#include "driverChoice.h" + +#ifdef _MSC_VER +#pragma comment(lib, "Irrlicht.lib") +#endif + +//Namespaces for the engine +using namespace irr; +using namespace core; +using namespace video; +using namespace scene; +
Now we'll define the resolution in a constant for use in initializing the device and setting up the viewport. In addition we set up a global variable saying splitscreen is active or not.
+//Resolution +const int ResX=800; +const int ResY=600; +const bool fullScreen=false; + +//Use SplitScreen? +bool SplitScreen=true; +
Now we need four pointers to our cameras which are created later:
+//cameras
+ICameraSceneNode *camera[4]={0,0,0,0};
+In our event-receiver we switch the SplitScreen-variable, whenever the user press the S-key. All other events are sent to the FPS camera.
+class MyEventReceiver : public IEventReceiver +{ + public: + virtual bool OnEvent(const SEvent& event) + { + //Key S enables/disables SplitScreen + if (event.EventType == irr::EET_KEY_INPUT_EVENT && + event.KeyInput.Key == KEY_KEY_S && event.KeyInput.PressedDown) + { + SplitScreen = !SplitScreen; + return true; + } + //Send all other events to camera4 + if (camera[3]) + return camera[3]->OnEvent(event); + return false; + } +}; +
Ok, now the main-function: First, we initialize the device, get the SourceManager and VideoDriver, load an animated mesh from .md2 and a map from .pk3. Because that's old stuff, I won't explain every step. Just take care of the maps position.
+int main() +{ + // ask user for driver + video::E_DRIVER_TYPE driverType=driverChoiceConsole(); + if (driverType==video::EDT_COUNT) + return 1; + + //Instance of the EventReceiver + MyEventReceiver receiver; + + //Initialise the engine + IrrlichtDevice *device = createDevice(driverType, + dimension2du(ResX,ResY), 32, fullScreen, + false, false, &receiver); + if (!device) + return 1; + + ISceneManager *smgr = device->getSceneManager(); + IVideoDriver *driver = device->getVideoDriver(); + + //Load model + IAnimatedMesh *model = smgr->getMesh("../../media/sydney.md2"); + if (!model) + return 1; + IAnimatedMeshSceneNode *model_node = smgr->addAnimatedMeshSceneNode(model); + //Load texture + if (model_node) + { + ITexture *texture = driver->getTexture("../../media/sydney.bmp"); + model_node->setMaterialTexture(0,texture); + model_node->setMD2Animation(scene::EMAT_RUN); + //Disable lighting (we've got no light) + model_node->setMaterialFlag(EMF_LIGHTING,false); + } + + //Load map + device->getFileSystem()->addFileArchive("../../media/map-20kdm2.pk3"); + IAnimatedMesh *map = smgr->getMesh("20kdm2.bsp"); + if (map) + { + ISceneNode *map_node = smgr->addOctreeSceneNode(map->getMesh(0)); + //Set position + map_node->setPosition(vector3df(-850,-220,-850)); + } +
Now we create our four cameras. One is looking at the model from the front, one from the top and one from the side. In addition there's a FPS-camera which can be controlled by the user.
+// Create 3 fixed and one user-controlled cameras + //Front + camera[0] = smgr->addCameraSceneNode(0, vector3df(50,0,0), vector3df(0,0,0)); + //Top + camera[1] = smgr->addCameraSceneNode(0, vector3df(0,50,0), vector3df(0,0,0)); + //Left + camera[2] = smgr->addCameraSceneNode(0, vector3df(0,0,50), vector3df(0,0,0)); + //User-controlled + camera[3] = smgr->addCameraSceneNodeFPS(); + // don't start at sydney's position + if (camera[3]) + camera[3]->setPosition(core::vector3df(-50,0,-50)); +
Create a variable for counting the fps and hide the mouse:
+//Hide mouse + device->getCursorControl()->setVisible(false); + //We want to count the fps + int lastFPS = -1; +
There wasn't much new stuff - till now! Only by defining four cameras, the game won't be splitscreen. To do this you need several steps:
+Sounds a little complicated, but you'll see it isn't:
+while(device->run()) + { + //Set the viewpoint to the whole screen and begin scene + driver->setViewPort(rect<s32>(0,0,ResX,ResY)); + driver->beginScene(true,true,SColor(255,100,100,100)); + //If SplitScreen is used + if (SplitScreen) + { + //Activate camera1 + smgr->setActiveCamera(camera[0]); + //Set viewpoint to the first quarter (left top) + driver->setViewPort(rect<s32>(0,0,ResX/2,ResY/2)); + //Draw scene + smgr->drawAll(); + //Activate camera2 + smgr->setActiveCamera(camera[1]); + //Set viewpoint to the second quarter (right top) + driver->setViewPort(rect<s32>(ResX/2,0,ResX,ResY/2)); + //Draw scene + smgr->drawAll(); + //Activate camera3 + smgr->setActiveCamera(camera[2]); + //Set viewpoint to the third quarter (left bottom) + driver->setViewPort(rect<s32>(0,ResY/2,ResX/2,ResY)); + //Draw scene + smgr->drawAll(); + //Set viewport the last quarter (right bottom) + driver->setViewPort(rect<s32>(ResX/2,ResY/2,ResX,ResY)); + } + //Activate camera4 + smgr->setActiveCamera(camera[3]); + //Draw scene + smgr->drawAll(); + driver->endScene(); +
As you can probably see, the image is rendered for every viewport separately. That means, that you'll loose much performance. Ok, if you're asking "How do I have to set the viewport + to get this or that screen?", don't panic. It's really easy: In the rect-function you define 4 coordinates:
+That means, if you want to split the screen into 2 viewports you would give the following coordinates:
+If you didn't fully understand, just play around with the example to check out what happens.
+Now we just view the current fps and shut down the engine, when the user wants to:
+//Get and show fps + if (driver->getFPS() != lastFPS) + { + lastFPS = driver->getFPS(); + core::stringw tmp = L"Irrlicht SplitScreen-Example (FPS: "; + tmp += lastFPS; + tmp += ")"; + device->setWindowCaption(tmp.c_str()); + } + } + //Delete device + device->drop(); + return 0; +} +
That's it! Just compile and play around with the program. Note: With the S-Key you can switch between using splitscreen and not.
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