Mercurial > repos > blastem
annotate cdd_fader.c @ 2081:cfd53c94fffb
Initial stab at RF5C164 emulation
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Thu, 03 Feb 2022 23:15:42 -0800 |
| parents | bafb757e1cd2 |
| children | 4fbe1e7c4a73 |
| rev | line source |
|---|---|
| 2080 | 1 #include "cdd_fader.h" |
| 2 #include <stdio.h> | |
| 3 | |
| 4 void cdd_fader_init(cdd_fader *fader) | |
| 5 { | |
|
2081
cfd53c94fffb
Initial stab at RF5C164 emulation
Michael Pavone <pavone@retrodev.com>
parents:
2080
diff
changeset
|
6 fader->audio = render_audio_source("CDDA", 16934400, 384, 2); |
| 2080 | 7 fader->cur_attenuation = 0x4000; |
| 8 fader->dst_attenuation = 0x4000; | |
| 9 fader->attenuation_step = 0; | |
| 10 } | |
| 11 void cdd_fader_attenuation_write(cdd_fader *fader, uint16_t attenuation) | |
| 12 { | |
| 13 fader->dst_attenuation = attenuation & 0xFFF0; | |
| 14 fader->flags = attenuation & 0xE; | |
| 15 if (fader->dst_attenuation > fader->cur_attenuation) { | |
| 16 fader->attenuation_step = (fader->dst_attenuation - fader->cur_attenuation) >> 4; | |
| 17 } else if (fader->dst_attenuation < fader->cur_attenuation) { | |
| 18 fader->attenuation_step = (fader->cur_attenuation - fader->dst_attenuation) >> 4; | |
| 19 } else { | |
| 20 fader->attenuation_step = 0; | |
| 21 } | |
| 22 } | |
| 23 | |
| 24 void cdd_fader_data(cdd_fader *fader, uint8_t byte) | |
| 25 { | |
| 26 fader->bytes[fader->byte_counter++] = byte; | |
| 27 if (fader->byte_counter == sizeof(fader->bytes)) { | |
| 28 fader->byte_counter = 0; | |
| 29 int32_t left = (fader->bytes[1] << 8) | fader->bytes[0]; | |
| 30 int32_t right = (fader->bytes[3] << 8) | fader->bytes[2]; | |
| 31 if (left & 0x8000) { | |
| 32 left |= 0xFFFF0000; | |
| 33 } | |
| 34 if (right & 0x8000) { | |
| 35 right |= 0xFFFF0000; | |
| 36 } | |
| 37 if (!fader->cur_attenuation) { | |
| 38 left = right = 0; | |
| 39 } else if (fader->cur_attenuation >= 4) { | |
| 40 left *= fader->cur_attenuation & 0x7FF0; | |
| 41 right *= fader->cur_attenuation & 0x7FF0; | |
| 42 left >>= 14; | |
| 43 right >>= 14; | |
| 44 } else { | |
| 45 //TODO: FIXME | |
| 46 left = right = 0; | |
| 47 } | |
| 48 render_put_stereo_sample(fader->audio, left, right); | |
| 49 if (fader->attenuation_step) { | |
| 50 if (fader->dst_attenuation > fader->cur_attenuation) { | |
| 51 fader->cur_attenuation += fader->attenuation_step; | |
| 52 if (fader->cur_attenuation >= fader->dst_attenuation) { | |
| 53 fader->cur_attenuation = fader->dst_attenuation; | |
| 54 fader->attenuation_step = 0; | |
| 55 } | |
| 56 } else { | |
| 57 fader->cur_attenuation -= fader->attenuation_step; | |
| 58 if (fader->cur_attenuation <= fader->dst_attenuation) { | |
| 59 fader->cur_attenuation = fader->dst_attenuation; | |
| 60 fader->attenuation_step = 0; | |
| 61 } | |
| 62 } | |
| 63 } | |
| 64 } | |
| 65 } |