Irrlicht Engine Tutorial

As always, I include the header files, use the irr namespace, and tell + the linker to link with the .lib file.

+ + + + +

#include <irrlicht.h>
#include <iostream>

using namespace irr;

#pragma comment(lib, "Irrlicht.lib")
+

At first, we let the user select the driver type, then start up the + engine, set a caption, and get a pointer to the video driver.

+ + + + +

int main()
{
  // let user select driver type
  video::E_DRIVER_TYPE driverType;

  printf("Please select the driver you want for this example:\n"\
		" (a) Direct3D 9.0c\n (b) Direct3D 8.1\n (c) OpenGL 1.5\n"\
		" (d) Software Renderer\n (e) Apfelbaum Software Renderer\n"\
		" (f) NullDevice\n (otherKey) exit\n\n");

   char i;
   std::cin >> i;

   switch(i)
   {
      case 'a': driverType = video::EDT_DIRECT3D9;break;
      case 'b': driverType = video::EDT_DIRECT3D8;break;
      case 'c': driverType = video::EDT_OPENGL;   break;
      case 'd': driverType = video::EDT_SOFTWARE; break;
      case 'e': driverType = video::EDT_BURNINGSVIDEO;break;
      case 'f': driverType = video::EDT_NULL;     break;
      default: return 0;
   }	

   // create device

  IrrlichtDevice *device = createDevice(driverType,
+         core::dimension2d<s32>(512, 384));

  if (device == 0)
+      return 1;
+ 
  device->setWindowCaption(L"Irrlicht Engine - 2D Graphics Demo");

  video::IVideoDriver* driver = device->getVideoDriver();

All 2d graphics in this example are put together into one texture, + 2ddemo.bmp. Because we want to draw colorkey based sprites, we need + to load this texture and tell the engine, which part of it should be + transparent based on a colorkey. In this example, we don't tell it the + color directly, we just say "Hey Irrlicht Engine, you'll find the + color I want at position (0,0) on the texture.". Instead, it would + be also possible to call driver->makeColorKeyTexture(images, + video::SColor(0,0,0,0)), to make e.g. all black pixels transparent. + Please note, that makeColorKeyTexture just creates an alpha channel + based on the color.

+ + + + +

video::ITexture* images = driver->getTexture("../../media/2ddemo.bmp");
driver->makeColorKeyTexture(images, core::position2d<s32>(0,0));

To be able to draw some text with two different fonts, we load them. + Ok, we load just one, as first font we just use the default font which + is built into the engine.
+ Also, we define two rectangles, which specify the position of the images + of the red imps (little flying creatures) in the texture.

+ + + + +

gui::IGUIFont* font = device->getGUIEnvironment()->getBuiltInFont();
gui::IGUIFont* font2 = device->getGUIEnvironment()->getFont(
+  "../../media/fonthaettenschweiler.bmp");

core::rect<s32> imp1(349,15,385,78);
+core::rect<s32> imp2(387,15,423,78);

Everything is prepared, now we can draw everything in the draw loop, + between the begin scene and end scene calls. In this example, we are + just doing 2d graphics, but it would be no problem to mix them with + 3d graphics. Just try it out, and draw some 3d vertices or set up a + scene with the scene manager and draw it.

First, we draw 3 sprites, using the alpha channel we created with makeColorKeyTexture. + The last parameter specifiys that the drawing method should use thiw alpha + channel. The parameter before the last one specifies a color, with wich + the sprite should be colored. (255,255,255,255) is full white, so the + sprite will look like the original. The third sprite is drawed colored + based on the time.

At last, we draw the Irrlicht Engine logo (without using a color or an + alpha channel) and a transparent 2d Rectangle at the position of the mouse + cursor.

// draw transparent rect under cursor + core::position2d<s32> m = device->getCursorControl()->getPosition(); + driver->draw2DRectangle(video::SColor(100,255,255,255), + core::rect<s32>(m.X-20, m.Y-20, m.X+20, m.Y+20));