diff --git a/Components/AY38910/AY38910.cpp b/Components/AY38910/AY38910.cpp index c5544b21a..9d9dbdaa7 100644 --- a/Components/AY38910/AY38910.cpp +++ b/Components/AY38910/AY38910.cpp @@ -71,11 +71,13 @@ AY38910::AY38910(Personality personality, Concurrency::DeferringAsyncTaskQueue & } void AY38910::set_sample_volume_range(std::int16_t range) { - // set up volume lookup table + // Set up volume lookup table; the function below is based on a combination of the graph + // from the YM's datasheet, showing a clear power curve, and fitting that to observed + // values reported elsewhere. const float max_volume = float(range) / 3.0f; // As there are three channels. constexpr float root_two = 1.414213562373095f; for(int v = 0; v < 32; v++) { - volumes_[v] = int(max_volume / powf(root_two, float(v ^ 0x1f) / 2.0f)); + volumes_[v] = int(max_volume / powf(root_two, float(v ^ 0x1f) / 3.18f)); } volumes_[0] = 0; // Tie level 0 to silence. evaluate_output_volume(); @@ -185,7 +187,7 @@ void AY38910::evaluate_output_volume() { #undef channel_volume // Mix additively. - output_volume_ = static_cast( + output_volume_ = int16_t( volumes_[volumes[0]] * channel_levels[0] + volumes_[volumes[1]] * channel_levels[1] + volumes_[volumes[2]] * channel_levels[2] @@ -220,7 +222,7 @@ void AY38910::set_register_value(uint8_t value) { int channel = selected_register >> 1; if(selected_register & 1) - tone_periods_[channel] = (tone_periods_[channel] & 0xff) | static_cast((value&0xf) << 8); + tone_periods_[channel] = (tone_periods_[channel] & 0xff) | uint16_t((value&0xf) << 8); else tone_periods_[channel] = (tone_periods_[channel] & ~0xff) | value; } @@ -235,7 +237,7 @@ void AY38910::set_register_value(uint8_t value) { break; case 12: - envelope_period_ = (envelope_period_ & 0xff) | static_cast(value << 8); + envelope_period_ = (envelope_period_ & 0xff) | int(value << 8); break; case 13: @@ -331,15 +333,15 @@ uint8_t AY38910::get_data_output() { } void AY38910::set_control_lines(ControlLines control_lines) { - switch(static_cast(control_lines)) { + switch(int(control_lines)) { default: control_state_ = Inactive; break; - case static_cast(BDIR | BC2 | BC1): + case int(BDIR | BC2 | BC1): case BDIR: case BC1: control_state_ = LatchAddress; break; - case static_cast(BC2 | BC1): control_state_ = Read; break; - case static_cast(BDIR | BC2): control_state_ = Write; break; + case int(BC2 | BC1): control_state_ = Read; break; + case int(BDIR | BC2): control_state_ = Write; break; } update_bus();