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flashformatarraysshaderstage3d

How to write to an IndexBuffer3D with uploadFromByteArray(...)

I really don't understand what I'm doing wrong, but according to Adobe, this is how you use uploadFromByteArray(...) on an IndexBuffer3D object:

What I don't understand is which writing-method do I have to use to write the integers of my vertex-indexes? I've tried writeFloat, writeUnsignedInt, writeInt, even writeShort and all fails. I've set my ByteArray instance to ba.endian = Endian.LITTLE_ENDIAN, still no go.

I've made sure to reset my ByteArray position to 0 before I attempt to upload it to my index-buffer, but nothing shows up!

If I upload a Vector.<uint> instead, that works! So I know the problem is not with the AGAL shader.

Any ideas?

Solution

  • Nevermind, just found what I was doing wrong:

    WRONG:

    _buffer.uploadFromByteArray(_dataBytes, 0, 0, _dataBytes.length >> 2);

    I was dividing by 4 at first (bitwise-shift twice is the same) because I though the number of bytes per index was 4 bytes long. Nah ah! Incorrect!

    ByteArrays for IndexBuffer3D purposes should be written with writeShort(), since it utilizes 16-bit numbers instead of 32-bit. Therefore, it only uses 2 bytes per indexes.

    CORRECT:

    _buffer.uploadFromByteArray(_dataBytes, 0, 0, _dataBytes.length >> 1);

    Hope that clarifies it up for other Stage3D users! :)