Design of a 2D Graphics Engine

By Joe Hallahan

What is an Engine?

Software engine: core of the program Internal as opposed to visible

Others (physics, database) excel at one task only, “software engine” is more general

Emphasis on graphics

Benefits

Reusable, safe

Framework for program – everything else is specific/detail work

Purpose

To create an engine using C++, OpenGL, and SDL that can simplify the process required for creating a graphical application by rendering graphics automatically and providing support for other general functions

Design - Tools

C++ Fast, efficient

SDL Free Makes many functions easier Works well with OpenGL Cross-platform

Design - Tools

OpenGL 2D and 3D support Can be hard to learn/use Free, supported on most systems Really really fast

Design - Structure

Engine.h contains declarations of variables, functions, classes, also includes external libraries

Engine.cpp defines everything declared in Engine.h

A third program can be used to test the engine, all that is really necessary is the main() method

Problems to Overcome

Data structure– Array used– Holds Shapes– Only holds up to 100 objects

Testing

#include "Engine.h"

int main(int argc, char* argv[]){

Engine e;

e.run();

return 0;

}

Testing

Testing / Analysis

3 test programs Simple Test

Bare minimum – no external program, just a main method Pong

Game, familiar Simple, controls supported through SDL

Engine Demo Colors Collisions

Conclusion

Engine works correctly Performance mainly hardware dependent,

should be about as efficient as a normal program made without using engine

No performance loss

Expandability

3D support Sound More inputs More performance tweaks Better collision detection

Will hurt performance in most cases Specialization

Bibliography• -Development of a 3D Graphics Engine (Kassing)• -Modular Architecture for Computer Game

Design (McNeill)• -Multi-threaded Game Engine (Tulip, Bekkema,

Nesbitt)• -Interactive 3D Geometry in OpenGL (Welsh)• -FROG: The Fast \& Realistic OPENGL

Displayer• -Simple and rapid collision detection using

multiple viewing volumes (Fan, Wan, Gao)