diff options
Diffstat (limited to 'psg.c')
| -rw-r--r-- | psg.c | 42 |
1 files changed, 8 insertions, 34 deletions
@@ -10,19 +10,11 @@ #include <stdlib.h> #include <stdio.h> #include <math.h> -void psg_init(psg_context * context, uint32_t sample_rate, uint32_t master_clock, uint32_t clock_div, uint32_t samples_frame, uint32_t lowpass_cutoff) +void psg_init(psg_context * context, uint32_t master_clock, uint32_t clock_div) { memset(context, 0, sizeof(*context)); - context->audio = render_audio_source(1); - context->audio_buffer = render_audio_source_buffer(context->audio); + context->audio = render_audio_source(master_clock, clock_div, 1); context->clock_inc = clock_div; - context->sample_rate = sample_rate; - context->samples_frame = samples_frame; - double rc = (1.0 / (double)lowpass_cutoff) / (2.0 * M_PI); - double dt = 1.0 / ((double)master_clock / (double)clock_div); - double alpha = dt / (dt + rc); - context->lowpass_alpha = (int32_t)(((double)0x10000) * alpha); - psg_adjust_master_clock(context, master_clock); for (int i = 0; i < 4; i++) { context->volume[i] = 0xF; } @@ -34,12 +26,9 @@ void psg_free(psg_context *context) free(context); } -#define BUFFER_INC_RES 0x40000000UL - void psg_adjust_master_clock(psg_context * context, uint32_t master_clock) { - uint64_t old_inc = context->buffer_inc; - context->buffer_inc = ((BUFFER_INC_RES * (uint64_t)context->sample_rate) / (uint64_t)master_clock) * (uint64_t)context->clock_inc; + render_audio_adjust_clock(context->audio, master_clock, context->clock_inc); } void psg_write(psg_context * context, uint8_t value) @@ -117,34 +106,19 @@ void psg_run(psg_context * context, uint32_t cycles) } } - context->last_sample = context->accum; - context->accum = 0; + int16_t accum = 0; for (int i = 0; i < 3; i++) { if (context->output_state[i]) { - context->accum += volume_table[context->volume[i]]; + accum += volume_table[context->volume[i]]; } } if (context->noise_out) { - context->accum += volume_table[context->volume[3]]; + accum += volume_table[context->volume[3]]; } - int32_t tmp = context->accum * context->lowpass_alpha + context->last_sample * (0x10000 - context->lowpass_alpha); - context->accum = tmp >> 16; + + render_put_mono_sample(context->audio, accum); - context->buffer_fraction += context->buffer_inc; - while (context->buffer_fraction >= BUFFER_INC_RES) { - context->buffer_fraction -= BUFFER_INC_RES; - int32_t tmp = context->last_sample * ((context->buffer_fraction << 16) / context->buffer_inc); - tmp += context->accum * (0x10000 - ((context->buffer_fraction << 16) / context->buffer_inc)); - context->audio_buffer[context->buffer_pos++] = tmp >> 16; - - if (context->buffer_pos == context->samples_frame) { - if (!headless) { - context->audio_buffer = render_audio_ready(context->audio); - context->buffer_pos = 0; - } - } - } context->cycles += context->clock_inc; } } |