I have heard often people speaking about engines
(tile engine, particle engine etc.) and I never really understood what they are good for because if I want to write a game with particles or tiles I simply write it without bothering with engines, gears, tires etc.

An Engine in this case would simply be a specific section of your code, or a module. Say you have a tile 'engine' it is passed the map data and draws the tiles to fill the view on the screen.

An Engine may be tied in very close to the game code, meaning it can't easily be used for other games. Or it can be actually quite seperate from the rest of the game, although this involves more work when writing the engine.

Either way it is still classed as an Engine, because it's a section of code which does a very specific and important role.

Yeah I tend to agree - you're better off starting from scratch with most games rather than trying to work within the limits of someone else's tile engine or something.

Although, for example, if you were to write a new 3D engine for every 3D game you made you would have to be completely and utterly insane. In fact you have to be insane to write your own 3D engine at all (talking from experience) when you can just use OpenGL.

I was going to start a new thread but I can kill two birds with one stone here...

Here is an example of my tile engine...mind you I"m a budding programmer and theres probably a million better ways to do this... but here it goes...

void draw_map(BITMAP *bmp,int MapX,int MapY){

  for (int i = 0; i < MapX; i ++){
        for(int j = 0; j < MapY; j++){
      if(Map1<i>[j] == 0){
           draw_sprite((BITMAP *) bmp,tiles[0],(i * 32) - 32,(j * 32) - 32);
      }
      else;
    }
  }
}

I want 'Map1' to be a variable passed to the function so I can use it for several different maps.. I looked in both my C++ books (complete idiots guide to C++ and C++ in 24 hours) but I couldnt find any good examples of passing pointers into functions in the way I need to do it...

How could I do this?

Ok cool deal.. forgive the dumb question but why the double ** ... Pointers is something I'm not completly developed with yet... Should I first declare *map1 before I pass it as a function argument... Also I assume I'll have to reference Map1[][] with a pointer in order for it to work right?

or just use a 1-d array and access elements by doing array[x + y * width]. Saves you a heckload of trouble.

Even better, wrap it all in a class, and have it do the allocating/freeing, then just provide accessor functions like getTile(int x, int y).

Marcello

it's not difficult to do

Map::Map(int _width, int _height) width(_width), height(_height) {
  array = new int[width * height];
}
Map::~Map() {
  delete [] array;
}

I think the word 'engine' is pretty abused in amateur/indie gamedev circles. But since its not really defined anywhere you can't complain when people misuse it. I think using the word 'tile engine' to talk about a function to draw a tile map is a little (ok alot) overboard.

Personally, I have this idea that out there somewhere floating around in space is a 'perfect game engine' design. By perfect I mean easy to use, powerful, and implemented in very little code. But not general purpose. Although a sidescrolling platformer and fps have some things in common, they also have a lot of things in difference. I think I have a really good design, I just need to implement it.

I just would hate to see a 3D matrix engine:o. I've been wanting to do 3D programming but I've seen how hard the 3D rendering logic and I've not tried it yet. I want to do a few 2D games before I go to 3D and I've completed 1 lame text game but I've not done graphics yet. I've got a 2D project going now but I've not started working on the graphics or the engines yet I'm only fleshing it out on paper.

I have several sources to look at myself that probably wouldn't have helped you.

• C/C++ Programmer's Reference

• Teach Yourself C++ in 24 Hours

• C++ for DUMMIES

• Teach Yourself C++ in 21 Days

• C++ Primer

• Game Coding Complete

• Teach Yourself Game Programming in 24 Hours

• Tricks of the Windows Game Programming Gurus

• Tricks of the 3D Game Programming Gurus

Then I have a few miscellaneous books.

• Game Design Secrets of the Sages

• GMAX Bible

• Red Hat Linux For DUMMIES

I would define an engine as one or more functions or code pieces used for one big purpose. Not a particle engine, texture engine or backround engine. Those are just single functions. Together, however, they are a graphics engine. I have one engine in my game DFD. I call it the DFD engine.

I prefer to consider the term "engine" to be for large-scale programs that serve a bunch of tasks. The term for smaller pieces of code that only do one specific thing (GUI, tilemap, particle) should be "system", not "engine".

Game = (Levels+Art) + Engine.

OR:

Program = Data + Code.

A good game has levels, which are a bunch of data, and an engine that interprets the data. An engine may be subdivided into a graphics part, a logic part, a sound part, a network part, and so on, and all these parts are "engines" by themselves.
The word "engine", then, serves the only purpose to talk about a part of the game that is level-independent, and very likely also artwork-independent.