This did not have any real impact, as the excess bytes were written into the next buffer, which was then immediately "fixed up" during the following copy call with the correct data, but could cause a crash and other nasty things if someone would reorder the class members or insert something in between.
Consolidated audio processing code into the PCM class, removing the BeatDetect class in the process. Beat detection now uses the same algorithm as Milkdrop, passing the proper relative bass/mid/treb values to presets. Makes many presets look less jumpy/flickering, as the values are now (smoothly) alternating around 1.0.
Updating frame audio is now done in a function that must specifically be called. Any subsequent calls to GetFrameAudioData() will then return the exact same copy of the audio data. As of now with the exception that new waveform data may be passed in via a separate thread, which will then be returned and might not match the spectrum data. Will fix that in a later commit.
Removed the previous FFT algorithm, now using a modernized version of the original Milkdrop FFT transform which also has both an equalizer and frequency envelope, making it slightly more sophisticated.
Modernization mainly included replacing raw pointer arrays with std::vector and using STL types/functions for the calculation, specifically std::complex as the FFT heavily uses these numbers. This makes the code more compact and readable.
Manually tested both original and modernized versions of the class to test if the algorithm still returns the exact same results, which is the case.
Moved per-pixel mesh texture coordinate calculations into the vertex shader. This is probably more performant than the SSE2 code in the old PresetFrameIO class, as the GPU is better at running this stuff in parallel.
All the texture management also needs some refactoring, so now that I've already broken everything, I can just do it as well.
Requires a general rewrite of the Milkdrop preset code. Previous implementation was tightly integrated into the code parser, so reusing this code wasn't possible. Additional refactoring was done, finished converting custom wave/shape implementations to use the new expression parser code.
