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, 113 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/quake/snd_sdl.c b/apps/plugins/sdl/progs/quake/snd_sdl.c
new file mode 100644
index 0000000000..644d4e1acf
--- /dev/null
+++ b/apps/plugins/sdl/progs/quake/snd_sdl.c
@@ -0,0 +1,113 @@
+
+#include <stdio.h>
+#include "SDL_audio.h"
+#include "SDL_byteorder.h"
+#include "quakedef.h"
+
+static dma_t the_shm;
+static int snd_inited;
+
+extern int desired_speed;
+extern int desired_bits;
+
+// SDL hereby demands `len' samples in stream, *NOW*!
+static void paint_audio(void *unused, Uint8 *stream, int len)
+{
+        if ( shm ) {
+                shm->buffer = stream;
+                shm->samplepos += len/(shm->samplebits/8)/2;
+                // Check for samplepos overflow?
+                S_PaintChannels (shm->samplepos);
+        }
+}
+
+qboolean SNDDMA_Init(void)
+{
+        SDL_AudioSpec desired, obtained;
+
+        snd_inited = 0;
+
+        /* Set up the desired format */
+        desired.freq = desired_speed;
+        switch (desired_bits) {
+                case 8:
+                        desired.format = AUDIO_U8;
+                        break;
+                case 16:
+                        if ( SDL_BYTEORDER == SDL_BIG_ENDIAN )
+                                desired.format = AUDIO_S16MSB;
+                        else
+                                desired.format = AUDIO_S16LSB;
+                        break;
+                default:
+                        Con_Printf("Unknown number of audio bits: %d\n",
+                                                                desired_bits);
+                        return 0;
+        }
+        desired.channels = 2;
+        desired.samples = 1024;
+        desired.callback = paint_audio;
+
+        /* Open the audio device */
+        if ( SDL_OpenAudio(&desired, &obtained) < 0 ) {
+                Con_Printf("Couldn't open SDL audio: %s\n", SDL_GetError());
+                return 0;
+        }
+
+        /* Make sure we can support the audio format */
+        switch (obtained.format) {
+                case AUDIO_U8:
+                        /* Supported */
+                        break;
+                case AUDIO_S16LSB:
+                case AUDIO_S16MSB:
+                        if ( ((obtained.format == AUDIO_S16LSB) &&
+                             (SDL_BYTEORDER == SDL_LIL_ENDIAN)) ||
+                             ((obtained.format == AUDIO_S16MSB) &&
+                             (SDL_BYTEORDER == SDL_BIG_ENDIAN)) ) {
+                                /* Supported */
+                                break;
+                        }
+                        /* Unsupported, fall through */;
+                default:
+                        /* Not supported -- force SDL to do our bidding */
+                        SDL_CloseAudio();
+                        if ( SDL_OpenAudio(&desired, NULL) < 0 ) {
+                                Con_Printf("Couldn't open SDL audio: %s\n",
+                                                        SDL_GetError());
+                                return 0;
+                        }
+                        memcpy(&obtained, &desired, sizeof(desired));
+                        break;
+        }
+        SDL_PauseAudio(0);
+
+        /* Fill the audio DMA information block */
+        shm = &the_shm;
+        shm->splitbuffer = 0;
+        shm->samplebits = (obtained.format & 0xFF);
+        shm->speed = obtained.freq;
+        shm->channels = obtained.channels;
+        shm->samples = obtained.samples*shm->channels;
+        shm->samplepos = 0;
+        shm->submission_chunk = 1;
+        shm->buffer = NULL;
+
+        snd_inited = 1;
+        return 1;
+}
+
+int SNDDMA_GetDMAPos(void)
+{
+        return shm->samplepos;
+}
+
+void SNDDMA_Shutdown(void)
+{
+        if (snd_inited)
+        {
+                SDL_CloseAudio();
+                snd_inited = 0;
+        }
+}
+