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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.)
Using Windows, create a console application in Visual Studio and conform to the helloworld.cpp code below. It is worth noting that if you create a windows app rather than a console app, you will have a number of problems with multiple defined symbols during linking. Make sure that run time type identification is turned on in your build settings.
On Unix systems, you can easily compile the code below with a command similar to this (assuming nel-config is within your $PATH, and pointing to a properly installed NeL):
g++ `nel-config --libs` `nel-config --cflags` helloworld.cpp -o helloworld
The Hello World code:
#include <nel/misc/types_nl.h> #include <nel/3d/u_driver.h> #include <nel/3d/u_text_context.h> using namespace std; using namespace NLMISC; using namespace NL3D; // The 3d driver UDriver *Driver = NULL; // This variable is used to display text on the screen UTextContext *TextContext = NULL; // true if you want to exit the main loop bool NeedExit = false; int main(int argc, char **argv) { // Create a driver Driver = UDriver::createDriver(); nlassert(Driver); // Create the window with config file values Driver->setDisplay (UDriver::CMode(640, 480, 32)); // Create a Text context for later text rendering TextContext = Driver->createTextContext ("data/n019003l.pfb"); nlassert(TextContext); while ((!NeedExit) && Driver->isActive()) { // Clear all buffers Driver->clearBuffers (CRGBA (0, 0, 0)); // Display a text on the screen TextContext->setHotSpot (UTextContext::TopLeft); TextContext->setColor (CRGBA(255, 255, 255, 255)); TextContext->setFontSize (14); TextContext->printfAt (0.01f, 0.99f, "Hello, World!"); // Swap 3d buffers Driver->swapBuffers (); // Pump user input messages Driver->EventServer.pump(); // Manage the keyboard if (Driver->AsyncListener.isKeyDown (KeySHIFT) && Driver->AsyncListener.isKeyDown (KeyESCAPE)) { // Shift Escape -> quit NeedExit = true; } } }