miditime.c

/*
# _____     ___ ____     ___ ____
#  ____|   |    ____|   |        | |____|
# |     ___|   |____ ___|    ____| |    \    PS2DEV Open Source Project.
#-----------------------------------------------------------------------
# Copyright ps2dev - http://www.ps2dev.org
# Licenced under Academic Free License version 2.0
# Review ps2sdk README & LICENSE files for further details.
*/
 
#include "libsnd2_internal.h"
 
s32 _SsReadDeltaValue(s16 sep_no, s16 seq_no)
{
    libsnd2_sequence_struct_t *score_struct;
    int delta_value;
    s32 result;
    int dv_mul4;
 
    score_struct = &_ss_score[sep_no][seq_no];
    delta_value = *score_struct->m_seq_ptr;
    score_struct->m_seq_ptr += 1;
    if ( !delta_value )
        return 0;
    if ( (delta_value & 0x80) != 0 )
    {
        char next_byte;
 
        delta_value &= ~0x80;
        do
        {
            next_byte = *score_struct->m_seq_ptr;
            score_struct->m_seq_ptr += 1;
            delta_value = (delta_value << 7) + (next_byte & 0x7F);
        } while ( (next_byte & 0x80) != 0 );
    }
    dv_mul4 = 4 * delta_value;
    result = 2 * (dv_mul4 + delta_value);
    score_struct->m_unk88 += result;
    return result;
}