Quake!

This ports id Software's Quake to run on the SDL plugin runtime. The
source code originated from id under the GPLv2 license. I used
https://github.com/ahefner/sdlquake as the base of my port.

Performance is, unsurprisingly, not on par with what you're probably
used to on PC. I average about 10FPS on ipod6g, but it's still
playable.

Sound works well enough, but in-game music is not supported. I've
written ARM assembly routines for the inner sound loop. Make sure you
turn the "brightness" all the way down, or colors will look funky.

To run, extract Quake's data files to /.rockbox/quake. Have fun!

Change-Id: I4285036e967d7f0722802d43cf2096c808ca5799

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);
+        }
+}