// license:BSD-3-Clause // copyright-holders:Miodrag Milanovic /*************************************************************************** audio/special.cpp Functions to emulate sound hardware of Specialist MX ( based on code of DAI interface ) ****************************************************************************/ #include "emu.h" #include "special.h" // device type definition DEFINE_DEVICE_TYPE(SPECIMX_SND, specimx_sound_device, "specimx_sound", "Specialist MX Custom Sound") //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // specimx_sound_device - constructor //------------------------------------------------- specimx_sound_device::specimx_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, SPECIMX_SND, tag, owner, clock) , device_sound_interface(mconfig, *this) , m_mixer_channel(nullptr) , m_specimx_input{ 0, 0, 0 } { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void specimx_sound_device::device_start() { m_specimx_input[0] = m_specimx_input[1] = m_specimx_input[2] = 0; m_mixer_channel = stream_alloc(0, 1, machine().sample_rate()); } //------------------------------------------------- // sound_stream_update - handle a stream update //------------------------------------------------- void specimx_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) { int16_t channel_0_signal; int16_t channel_1_signal; int16_t channel_2_signal; stream_sample_t *sample_left = outputs[0]; channel_0_signal = m_specimx_input[0] ? 3000 : -3000; channel_1_signal = m_specimx_input[1] ? 3000 : -3000; channel_2_signal = m_specimx_input[2] ? 3000 : -3000; while (samples--) { *sample_left = 0; /* music channel 0 */ *sample_left += channel_0_signal; /* music channel 1 */ *sample_left += channel_1_signal; /* music channel 2 */ *sample_left += channel_2_signal; sample_left++; } } //------------------------------------------------- // PIT callbacks //------------------------------------------------- WRITE_LINE_MEMBER(specimx_sound_device::set_input_ch0) { m_mixer_channel->update(); m_specimx_input[0] = state; } WRITE_LINE_MEMBER(specimx_sound_device::set_input_ch1) { m_mixer_channel->update(); m_specimx_input[1] = state; } WRITE_LINE_MEMBER(specimx_sound_device::set_input_ch2) { m_mixer_channel->update(); m_specimx_input[2] = state; }