1 files changed, 148 insertions, 0 deletions

diff --git a/apps/plugins/pacbox/wsg3.c b/apps/plugins/pacbox/wsg3.c
new file mode 100644
index 0000000000..3c861312b9
--- /dev/null
+++ b/apps/plugins/pacbox/wsg3.c
@@ -0,0 +1,148 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Pacbox - a Pacman Emulator for Rockbox
+ *
+ * Based on PIE - Pacman Instructional Emulator
+ *
+ * Namco custom waveform sound generator 3 (Pacman hardware)
+ *
+ * Copyright (c) 2003,2004 Alessandro Scotti
+ * http://www.ascotti.org/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+#include "wsg3.h"
+
+struct wsg3 wsg3;
+
+static bool wsg3_get_voice(struct wsg3_voice *voice, int index)
+{
+    int base = 5*index;
+    const unsigned char *regs = wsg3.sound_regs;
+    unsigned x;
+    
+    x = regs[0x15 + base] & 0x0F;
+
+    if (x == 0)
+        return false;
+
+    voice->volume = x;
+
+    x =            (regs[0x14 + base] & 0x0F);
+    x = (x << 4) | (regs[0x13 + base] & 0x0F);
+    x = (x << 4) | (regs[0x12 + base] & 0x0F);
+    x = (x << 4) | (regs[0x11 + base] & 0x0F);
+    x = (x << 4);
+
+    if (index == 0)
+    {
+        /* The first voice has an extra 4-bit of data */
+        x |= regs[0x10 + base] & 0x0F; 
+    }
+
+    if (x == 0)
+        return false;
+
+    voice->frequency = x;
+
+    voice->waveform = regs[0x05 + base] & 0x07;
+
+    return true;
+}
+
+void wsg3_play_sound(int * buf, int len)
+{
+    struct wsg3_voice voice;
+
+    if (wsg3_get_voice(&voice, 0))
+    {
+        unsigned offset = wsg3.wave_offset[0];
+        unsigned step = voice.frequency * wsg3.resample_step;
+        int * wave_data = wsg3.sound_wave_data + 32 * voice.waveform;
+        int volume = voice.volume;
+        int i;
+
+        for (i = 0; i < len; i++)
+        {
+            /* Should be shifted right by 15, but we must also get rid
+             * of the 10 bits used for decimals */
+            buf[i] += wave_data[(offset >> 25) & 0x1F] * volume;
+            offset += step;
+        }
+
+        wsg3.wave_offset[0] = offset;
+    }
+
+    if (wsg3_get_voice(&voice, 1))
+    {
+        unsigned offset = wsg3.wave_offset[1];
+        unsigned step = voice.frequency * wsg3.resample_step;
+        int * wave_data = wsg3.sound_wave_data + 32 * voice.waveform;
+        int volume = voice.volume;
+        int i;
+
+        for (i = 0; i < len; i++)
+        {
+            /* Should be shifted right by 15, but we must also get rid
+             * of the 10 bits used for decimals */
+            buf[i] += wave_data[(offset >> 25) & 0x1F] * volume;
+            offset += step;
+        }
+
+        wsg3.wave_offset[1] = offset;
+    }
+
+    if (wsg3_get_voice(&voice, 2))
+    {
+        unsigned offset = wsg3.wave_offset[2];
+        unsigned step = voice.frequency * wsg3.resample_step;
+        int * wave_data = wsg3.sound_wave_data + 32 * voice.waveform;
+        int volume = voice.volume;
+        int i;
+
+        for (i = 0; i < len; i++)
+        {
+            /* Should be shifted right by 15, but we must also get rid
+             * of the 10 bits used for decimals */
+            buf[i] += wave_data[(offset >> 25) & 0x1F] * volume;
+            offset += step;
+        }
+
+        wsg3.wave_offset[2] = offset;
+    }
+}
+
+void wsg3_set_sampling_rate(unsigned sampling_rate)
+{
+    wsg3.sampling_rate = sampling_rate;
+    wsg3.resample_step = (wsg3.master_clock << 10) / sampling_rate;
+}
+
+void wsg3_set_sound_prom( const unsigned char * prom )
+{
+    int i;
+
+    for (i = 0; i < 32*8; i++)
+        wsg3.sound_wave_data[i] = (int)*prom++ - 8;
+}
+
+void wsg3_init(unsigned master_clock)
+{
+    memset(&wsg3, 0, sizeof (struct wsg3));
+    wsg3.master_clock = master_clock;
+}