Including OpenGL 3.2 in Zack Zero

Next week, we will release Zack Zero on Steam.
Those months, we have been working improving the game. About the engine, we have improved the graphics engine to support OpenGL 3.2 ‘core profile’ but keeping the OpenGL 2.1 path for cards with less capabilities (OpenGL 3.2 is supported from the NVIDIA 8xxx, the first one, the 8800 was relesead in late 2006. But there are laptops whose manufacturers do not update drivers, and Intel chips for which there are no drivers for OpenGL 3.2 on Windows. Curiously in OSX the same chipset has OpenGL 3.2 drivers).
The main motivation to include OpenGL 3.2 was to solve some problems we had with the OpenGL 2.1 path in some notebooks with ATI graphics chip. In some combination of drivers / graphics chip, the game texts did not appear. This happened because the font textures are single channel textures and in some combinations of ATI they work as ALPHA textures and in others they work as RED textures. In OpenGL 3.2, ALPHA textures are deprecated so I can only use GL_RED for them and it works properly in those machines. In addition, the code is cleaner and it shows gains in performance over previous versions.
Also, I was porting the game to OSX. And OSX has OpenGL 3.2 (only the ‘core profile’  implementation) and although I did the first port using the OpenGL 2.1 path (the same implementation of the first PC version that was released in Spain and in Germany, it made sense to clean up the code and leave only the 3.2 path that all the Macs, with recent OSX, have).
Moreover, as there are two paths and there are two sets of shaders. And as it is assumed that the cards that support OpenGL 3.2 are more powerful (although this doesn’t has to be true as there are recent low end graphic cards that are really bad), OpenGL 3.2 shaders have slight improvements that result in better image quality.
And, to my horror, I discovered that there was a bug (mine) in the calculation of fog that could even produce a clear cut where fog starts. It is clearly seen in many places: in the first part of the cave, when the ship is at the end of the first phase, … Now it looks perfect ;)

There are two images of the game: the first one is a screenshot of the original PS3 version. The second is from the current PC version:

One Comment
  1. Pablo Ruiz

    Hola Carlos, me encanta el cuidado y el cariño extra con el que estaís puliendo el juego. En PS3 ya era genial, pero para los amantes del PC entre lo que me encuentro es todavía mejor!!! Espero que el público de Steam sepa valorarlo y sea todo un éxito!!!

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