sound, increase resolution for calculating psg sound

diff --git a/pico/memory.c b/pico/memory.c
index 25e7831..0487546 100644 (file)
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -394,13 +394,11 @@ void NOINLINE ctl_write_z80reset(u32 d)
   }\r
 }\r
 \r
-static int get_scanline(int is_from_z80);\r
-\r
 static void psg_write_68k(u32 d)\r
 {\r
   // look for volume write and update if needed\r
   if ((d & 0x90) == 0x90)\r
-    PsndDoPSG(Pico.m.scanline);\r
+    PsndDoPSG(z80_cycles_from_68k());\r
 \r
   SN76496Write(d);\r
 }\r
@@ -408,8 +406,7 @@ static void psg_write_68k(u32 d)
 static void psg_write_z80(u32 d)\r
 {\r
   if ((d & 0x90) == 0x90) {\r
-    int scanline = get_scanline(1);\r
-    PsndDoPSG(scanline);\r
+    PsndDoPSG(z80_cyclesDone());\r
   }\r
 \r
   SN76496Write(d);\r

diff --git a/pico/pico_int.h b/pico/pico_int.h
index 2038b6d..f4dcef3 100644 (file)
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -914,9 +914,9 @@ PICO_INTERNAL void PsndExit(void);
 PICO_INTERNAL void PsndReset(void);\r
 PICO_INTERNAL void PsndStartFrame(void);\r
 PICO_INTERNAL void PsndDoDAC(int cycle_to);\r
-PICO_INTERNAL void PsndDoPSG(int line_to);\r
-PICO_INTERNAL void PsndDoYM2413(int line_to);\r
-PICO_INTERNAL void PsndDoFM(int line_to);\r
+PICO_INTERNAL void PsndDoPSG(int cyc_to);\r
+PICO_INTERNAL void PsndDoYM2413(int cyc_to);\r
+PICO_INTERNAL void PsndDoFM(int cyc_to);\r
 PICO_INTERNAL void PsndClear(void);\r
 PICO_INTERNAL void PsndGetSamples(int y);\r
 PICO_INTERNAL void PsndGetSamplesMS(int y);\r

diff --git a/pico/sound/sound.c b/pico/sound/sound.c
index 5cb6832..69cd4fb 100644 (file)
--- a/pico/sound/sound.c
+++ b/pico/sound/sound.c
@@ -161,20 +161,24 @@ PICO_INTERNAL void PsndDoDAC(int cyc_to)
   Pico.snd.dac_val = dout;\r
 }\r
 \r
-PICO_INTERNAL void PsndDoPSG(int line_to)\r
+PICO_INTERNAL void PsndDoPSG(int cyc_to)\r
 {\r
   int pos, len;\r
   int stereo = 0;\r
 \r
-  // Q16, number of samples since last call\r
-  len = ((line_to+1) * Pico.snd.smpl_mult) - Pico.snd.psg_pos;\r
-  if (len <= 0)\r
-    return;\r
+  // number of samples to fill in buffer (Q20)\r
+  len = (cyc_to * Pico.snd.clkl_mult) - Pico.snd.psg_pos;\r
 \r
   // update position and calculate buffer offset and length\r
-  pos = (Pico.snd.psg_pos+0x8000) >> 16;\r
+  pos = (Pico.snd.psg_pos+0x80000) >> 20;\r
   Pico.snd.psg_pos += len;\r
-  len = ((Pico.snd.psg_pos+0x8000) >> 16) - pos;\r
+  len = ((Pico.snd.psg_pos+0x80000) >> 20) - pos;\r
+\r
+  // avoid loss of the 1st sample of a new block (Q rounding issues)\r
+  if (pos+len == 0)\r
+    len = 1, Pico.snd.psg_pos += 0x80000;\r
+  if (len <= 0)\r
+    return;\r
 \r
   if (!PicoIn.sndOut || !(PicoIn.opt & POPT_EN_PSG))\r
     return;\r
@@ -187,21 +191,25 @@ PICO_INTERNAL void PsndDoPSG(int line_to)
 }\r
 \r
 #if 0\r
-PICO_INTERNAL void PsndDoYM2413(int line_to)\r
+PICO_INTERNAL void PsndDoYM2413(int cyc_to)\r
 {\r
   int pos, len;\r
   int stereo = 0;\r
   short *buf;\r
 \r
-  // Q16, number of samples since last call\r
-  len = ((line_to+1) * Pico.snd.smpl_mult) - Pico.snd.ym2413_pos;\r
-  if (len <= 0)\r
-    return;\r
+  // number of samples to fill in buffer (Q20)\r
+  len = (cyc_to * Pico.snd.clkl_mult) - Pico.snd.ym2413_pos;\r
 \r
   // update position and calculate buffer offset and length\r
-  pos = (Pico.snd.ym2413_pos+0x8000) >> 16;\r
+  pos = (Pico.snd.ym2413_pos+0x80000) >> 20;\r
   Pico.snd.ym2413_pos += len;\r
-  len = ((Pico.snd.ym2413_pos+0x8000) >> 16) - pos;\r
+  len = ((Pico.snd.ym2413_pos+0x80000) >> 20) - pos;\r
+\r
+  // avoid loss of the 1st sample of a new block (Q rounding issues)\r
+  if (pos+len == 0)\r
+    len = 1, Pico.snd.ym2413_pos += 0x80000;\r
+  if (len <= 0)\r
+    return;\r
 \r
   if (!PicoIn.sndOut || !(PicoIn.opt & POPT_EN_YM2413))\r
     return;\r