Intro to NeL Coding: Hello World¶

A very minimal client example can be created that will print the text "Hello, World!" in the upper left of the screen. The program expects to be run from the Snowballs bin directory (it needs a font from the data directory, as well as a bunch of the DLL's / NeL libraries.)

 1#include <nel/misc/types_nl.h>
 2#include <nel/3d/u_driver.h>
 3#include <nel/3d/u_text_context.h>
 4
 5using namespace std;
 6using namespace NLMISC;
 7using namespace NL3D;
 8
 9// The 3d driver
10UDriver        *Driver = NULL;
11// This variable is used to display text on the screen
12UTextContext   *TextContext = NULL;
13// true if you want to exit the main loop
14bool            NeedExit = false;
15
16int main(int argc, char **argv)
17{
18    // Create a driver
19    Driver = UDriver::createDriver();
20    nlassert(Driver);
21
22    // Create the window with config file values
23    Driver->setDisplay (UDriver::CMode(640, 480, 32));
24
25    // Create a Text context for later text rendering
26    TextContext = Driver->createTextContext ("data/n019003l.pfb");
27    nlassert(TextContext);
28
29    while ((!NeedExit) && Driver->isActive())
30    {
31        // Clear all buffers
32        Driver->clearBuffers (CRGBA (0, 0, 0));
33
34        // Display a text on the screen
35        TextContext->setHotSpot (UTextContext::TopLeft);
36        TextContext->setColor (CRGBA(255, 255, 255, 255));
37        TextContext->setFontSize (14);
38        TextContext->printfAt (0.01f, 0.99f, "Hello, World!");
39
40        // Swap 3d buffers
41        Driver->swapBuffers ();
42
43        // Pump user input messages
44        Driver->EventServer.pump();
45
46        // Manage the keyboard
47        if (Driver->AsyncListener.isKeyDown (KeySHIFT)
48            && Driver->AsyncListener.isKeyDown (KeyESCAPE))
49        {
50            // Shift Escape -> quit
51            NeedExit = true;
52        }
53    }
54}