Question

In your initial discussion post, briefly compare OpenGL to its competitor. What do they have in common, and how are they different? Next, explain why OpenGL may have a competitive advantage.

Answer 1

The competition between OpenGL and DirectX is possibly as well known.
Perhaps the most obvious difference is that DirectX, as opposed to OpenGL, is more than just a graphics API. DirectX contains tools to deal with such components of a game as sound, music, input, networking, and multimedia. On the other hand, OpenGL is strictly a graphics API. So what aspect of OpenGL sets it apart from the DirectX graphics component?

Well, first things first: both APIs rely on the use of the traditional graphics pipeline. This is the same pipeline that has been used in computer games since the early days of computer graphics. Although it has been modified in slight ways to adapt with advancements in hardware, the basic idea remains intact.

Both OpenGL and DirectX describe vertices as a set of data consisting of coordinates in space that define the vertex location and any other vertex related data. Graphics primitives, such as points, lines, and triangles, are defined as an ordered set of vertices. There is a difference in how each API handles how vertices are combined to form primitive.

List of APIs in OpenGL and DirectX:

Advantages of using OpenGL

Given that OpenGL has less vendor support, is no longer used in games, is being actively attacked by Microsoft, and has no marketing momentum, why should we still use it? Wouldn't it be more profitable to ditch it and use DirectX like everyone else? No, because in reality, OpenGL is more powerful than DirectX, supports more platforms, and is essential for the future of games.

1. OpenGL is more powerful than DirectX

It's common knowledge that OpenGL has faster draw calls than DirectX, and it has first access to new GPU features via vendor extensions. OpenGL gives you direct access to all new graphics features on all platforms, while DirectX only provides occasional snapshots of them on their newest versions of Windows. The tesselation technology that Microsoft is heavily promoting for DirectX 11has been an OpenGL extension for three years. It has even been possible for years before that, using fast instancing and vertex-texture-fetch. I don't know what new technologies will be exposed in the next couple years, I know they will be available first in OpenGL.

Microsoft has worked hard on DirectX 10 and 11, and they're now about as fast as OpenGL, and support almost as many features. However, there's one big problem: they don't work on Windows XP! Half of PC gamers still use XP, so using DirectX 10 or 11 is not really a viable option. If you really care about having the best possible graphics, and delivering them to as many gamers as possible, there's no choice but OpenGL.

2. OpenGL is cross-platform

When we talk to major game developers, we hear that supporting Mac and Linux is a waste of time. Blizzard always releases Mac versions of their games simultaneously, and they're one of the most successful game companies in the world! If they're doing something in a different way from everyone else, then their way is probably right.

3. OpenGL is better for the future of games

OpenGL is a non-profit open standard created to allow users on any platform to experience the highest quality graphics that their hardware can provide. Its use is being crushed by a monopolistic attack from a monolithic corporate giant trying to dominate an industry that is too young to protect itself. As Direct3D becomes the only gaming graphics API supported on Windows, Microsoft is gaining a stranglehold on PC gaming.