1 files changed, 69 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/quake/snd_mix_generic.c b/apps/plugins/sdl/progs/quake/snd_mix_generic.c
new file mode 100644
index 0000000000..2c4b67b77c
--- /dev/null
+++ b/apps/plugins/sdl/progs/quake/snd_mix_generic.c
@@ -0,0 +1,69 @@
+/* This file is included from snd_mix.c */
+
+#include "SDL.h"
+
+// allow standalone compilation
+#ifndef QUAKE_SOUND
+extern short *paintbuffer;
+#define INLINE
+#else
+#define INLINE static inline
+#endif
+
+// C version
+static inline short CLAMPADD(short a, short b)
+{
+    int val = (int)a + (int)b;
+    if (val > 32767)
+    {
+        //rb->splashf(HZ, "saturate");
+        return 32767;
+    }
+    else if (val < -32768)
+    {
+        //rb->splashf(HZ, "saturate");
+        return -32768;
+    }
+    else
+        return val;
+}
+
+// if not ARMv5
+#ifndef __ARM_ARCH__5TEJ__
+void SND_PaintChannelFrom8 (int true_lvol, int true_rvol, signed char *sfx, int count)
+{
+    //return;
+    //LOGF("mix8\n");
+        int     data;
+        int             i;
+
+        // we have 8-bit sound in sfx[], which we want to scale to
+        // 16bit and take the volume into account
+        for (i=0 ; i<count ; i++)
+        {
+            // We could use the QADD16 instruction on ARMv6+
+            // or just 32-bit QADD with pre-shifted arguments
+            data = sfx[i];
+            paintbuffer[2*i+0] = CLAMPADD(paintbuffer[2*i+0], data * true_lvol); // need saturation
+            paintbuffer[2*i+1] = CLAMPADD(paintbuffer[2*i+1], data * true_rvol);
+        }
+}
+#endif
+
+void SND_PaintChannelFrom16 (int true_lvol, int true_rvol, signed short *sfx, int count)
+{
+    //return;
+    //LOGF("mix16\n");
+        int data;
+        int left, right;
+        int     i;
+
+        for (i=0 ; i<count ; i+=2)
+        {
+                data = sfx[i];
+                left = ((int)data * true_lvol) >> 8;
+                right = ((int)data * true_rvol) >> 8;
+                paintbuffer[2*i+0] = CLAMPADD(paintbuffer[2*i+0], left); // need saturation
+                paintbuffer[2*i+1] = CLAMPADD(paintbuffer[2*i+1], right);
+        }
+}