sound, add panning for ym2612 dac

diff --git a/pico/sound/sound.c b/pico/sound/sound.c
index 650f7ac..74f9967 100644 (file)
--- a/pico/sound/sound.c
+++ b/pico/sound/sound.c
@@ -16,6 +16,8 @@
 #include "resampler.h"\r
 #include "mix.h"\r
 \r
+#define YM2612_CH6PAN   0x1b6   // panning register for channel 6 (used for DAC)\r
+\r
 void (*PsndMix_32_to_16)(s16 *dest, s32 *src, int count) = mix_32_to_16_stereo;\r
 \r
 // master int buffer to mix to\r
@@ -282,9 +284,12 @@ PICO_INTERNAL void PsndDoDAC(int cyc_to)
   // 1 sample delay for correct IIR filtering over audio frame boundaries\r
   if (PicoIn.opt & POPT_EN_STEREO) {\r
     s16 *d = PicoIn.sndOut + pos*2;\r
-    // left channel only, mixed ro right channel in mixing phase\r
-    *d++ += Pico.snd.dac_val2, *d++ += Pico.snd.dac_val2;\r
-    while (--len) *d++ += Pico.snd.dac_val, *d++ += Pico.snd.dac_val;\r
+    int pan = ym2612.REGS[YM2612_CH6PAN];\r
+    int l = pan & 0x80 ? Pico.snd.dac_val : 0;\r
+    int r = pan & 0x40 ? Pico.snd.dac_val : 0;\r
+    *d++ += pan & 0x80 ? Pico.snd.dac_val2 : 0;\r
+    *d++ += pan & 0x40 ? Pico.snd.dac_val2 : 0;\r
+    while (--len) *d++ += l, *d++ += r;\r
   } else {\r
     s16 *d = PicoIn.sndOut + pos;\r
     *d++ += Pico.snd.dac_val2;\r
@@ -516,13 +521,21 @@ static int PsndRender(int offset, int length)
 \r
   // Fill up DAC output in case of missing samples (Q rounding errors)\r
   if (length-daclen > 0 && PicoIn.sndOut) {\r
-    s16 *dacbuf = PicoIn.sndOut + (daclen << stereo);\r
     Pico.snd.dac_pos += (length-daclen) << 20;\r
-    *dacbuf++ += Pico.snd.dac_val2;\r
-    if (stereo) *dacbuf++ += Pico.snd.dac_val2;\r
-    for (daclen++; length-daclen > 0; daclen++) {\r
-      *dacbuf++ += Pico.snd.dac_val;\r
-      if (stereo) *dacbuf++ += Pico.snd.dac_val;\r
+    if (PicoIn.opt & POPT_EN_STEREO) {\r
+      s16 *d = PicoIn.sndOut + daclen*2;\r
+      int pan = ym2612.REGS[YM2612_CH6PAN];\r
+      int l = pan & 0x80 ? Pico.snd.dac_val : 0;\r
+      int r = pan & 0x40 ? Pico.snd.dac_val : 0;\r
+      *d++ += pan & 0x80 ? Pico.snd.dac_val2 : 0;\r
+      *d++ += pan & 0x40 ? Pico.snd.dac_val2 : 0;\r
+      if (l|r) for (daclen++; length-daclen > 0; daclen++)\r
+          *d++ += l, *d++ += r;\r
+    } else {\r
+      s16 *d = PicoIn.sndOut + daclen;\r
+      *d++ += Pico.snd.dac_val2;\r
+      if (Pico.snd.dac_val) for (daclen++; length-daclen > 0; daclen++)\r
+        *d++ += Pico.snd.dac_val;\r
     }\r
     Pico.snd.dac_val2 = Pico.snd.dac_val;\r
   }\r