Add support for floating point textures to OpenGL

Created by: AmnonOwed

I'm packing data in a texture (PImage) to send to a fragment shader. I'm running into the limitations of the 32bit RGBA format that seems to be the default for every texture in Processing. It's causing banding effects in my output. Switching to floating point textures will most likely solve these problems, because of the increased accuracy.

I have searched high and low (all the forums, the source code, the issue list), but I cannot find a way to use floating points textures in Processing. Is this possible? If not, I would like to post this issue as a feature request.

まず、Processing の PImage テクスチャがどのように作成され、OpenGL パスを通じて fragment shader に渡されるかを追跡します。対応すべき浮動小数点テクスチャ形式と、サポート対象ハードウェアの制約を特定します。現在の 32-bit RGBA 制限なしで浮動小数点テクスチャを使用する、文書化およびテスト済みの方法があれば完了とします。