MMD Animation format

MMD Animation Section
    Pointer Table (4 bytes offset from the section start)
    <Animation>
        uint16_t -> frameCount + hasScale (MSB 1 -> hasScale)
        <for each Node, except Root>
            Scale (3x fixed point 16-bit | optional, only when hasScale is set)
            Location (3x int16_t)
            Rotation (3x fixed point 16-bit)
        <instructions>
            read in words, with 4-bit opcode
                opcode 0x0 - keyframe | <4-bit opcode> <12-bit time code>
                    frame data | quasi opcode 8
                        1-bit always set
                        3-bit enabled scale axis
                        3-bit enabled rotation axis
                        3-bit enabled translation axis
                        6-bit affected node
                        16-bit scale value
                        <for each enabled axis>
                            16-bit momentum value, gets divided by scale
                opcode 0x1 - loop start | <4-bit opcode> <4-bit empty> <8-bit loopCount>
                    sets loop count
                    sets loop start
                opcode 0x2 - loop end | <4-bit opcode> <12-bit time code> <16-bit frameValue>
                    reduces loop count by 1, except for endless loops
                    if loop count == 0
                        jumps after the loop
                    else
                        jumps to loop start, sets frame counter to frameValue
                opcode 0x3 - change texture | <4-bit opcode> <12-bit time code>
                    uint8_t srcY
                    uint8_t srcX
                    uint8_t height
                    uint8_t width
                    uint8_t destY
                    uint8_t destX
                opcode 0x4 - play sound | <4-bit opcode> <12-bit time code> <8-bit soundId> <8-bit vabId>
                    plays a sound