~aio-launchpad/seq24/seq24

Committer: Sebastien Alaiwan
Date: 2012-01-05 07:08:37 UTC
Revision ID: ace17@free.fr-20120105070837-25h5y6tls37tp696

Use integer division to compute delta_tick. This way, the division does not loose precision (because the remainder is re-injected into the next division) and the sum of all delta_tick (i.e clock_tick) does not drift (relative to the system clock.).

files modified:
src/perform.cpp

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src/perform.cpp

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/* tick and tick fraction */

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double current_tick = 0.0;

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double total_tick = 0.0;

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double clock_tick = 0.0;

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long clock_tick = 0;

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long delta_tick_frac = 0;

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long stats_total_tick = 0;

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int bpm = m_master_bus.get_bpm();

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/* get delta ticks, delta_ticks_f is in 1000th of a tick */

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double delta_tick = (double) (bpm * ppqn * (delta_us/60000000.0f));

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long long delta_tick_num = bpm * ppqn * delta_us + delta_tick_frac;

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long long delta_tick_denom = 60000000;

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long delta_tick = (long)(delta_tick_num / delta_tick_denom);

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delta_tick_frac = (long)(delta_tick_num % delta_tick_denom);

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if (m_usemidiclock) {

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delta_tick = m_midiclocktick;

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* as soon as jack gets a good lock on playback */

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if (init_clock) {

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m_master_bus.init_clock( (long)clock_tick );

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m_master_bus.init_clock( clock_tick );

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init_clock = false;

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}

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//printf( "play[%d]\n", current_tick );

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/* midi clock */

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m_master_bus.clock( (long) clock_tick );

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m_master_bus.clock( clock_tick );

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if ( global_stats ){

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