rockbox/apps/plugins/sdl/progs/quake/snd_mix.c
Franklin Wei 5d05b9d3e9 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
2019-07-19 22:37:40 -04:00

132 lines
3.8 KiB
C

/*
Copyright (C) 1996-1997 Id Software, Inc.
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 program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// snd_mix.c -- portable code to mix sounds for snd_dma.c
#include "quakedef.h"
#define DWORD unsigned long
// why not write straight to SHM buffer?!?
//portable_samplepair_t paintbuffer[PAINTBUFFER_SIZE];
int16_t *paintbuffer; // stereo interleaved samples
/*
===============================================================================
CHANNEL MIXING
===============================================================================
*/
// in snd_mix_*
void SND_PaintChannelFrom8 (int true_lvol, int true_rvol, signed char *sfx, int count);
void SND_PaintChannelFrom16 (int true_lvol, int true_rvol, signed short *sfx, int count);
void S_PaintChannels(int endtime)
{
int i;
int end;
channel_t *ch;
sfxcache_t *sc;
int ltime, count;
paintbuffer = shm->buffer;
//while (paintedtime < endtime)
//{
// if paintbuffer is smaller than DMA buffer
end = endtime;
//if (endtime - paintedtime > PAINTBUFFER_SIZE)
//end = paintedtime + PAINTBUFFER_SIZE;
// clear the paint buffer
memset(paintbuffer, 0, (end - paintedtime) * sizeof(int16_t));
// 0-255
int volume_fp = volume.value * 255;
// paint in the channels.
ch = channels;
for (i=0; i<total_channels ; i++, ch++)
{
if (!ch->sfx)
continue;
if (!ch->leftvol && !ch->rightvol)
continue;
sc = S_LoadSound (ch->sfx); // sound fx cache
if (!sc)
continue;
ltime = paintedtime;
while (ltime < end)
{ // paint up to end of sound channel, or end of buffer, whichever is greatest
if (ch->end < end)
count = ch->end - ltime;
else
count = end - ltime;
//if(count == 1)
// rb->splashf(HZ, "Potential problem");
if (count > 0)
{
int true_lvol, true_rvol;
true_lvol = (volume_fp * ch->leftvol) / 256;
true_rvol = (volume_fp * ch->rightvol) / 256;
if (sc->width == 1)
{
signed char *sfx = (char*)sc->data + ch->pos;
SND_PaintChannelFrom8(true_lvol, true_rvol, sfx, count);
}
else
{
signed short *sfx = (short*)sc->data + ch->pos;
SND_PaintChannelFrom16(true_lvol, true_rvol, sfx, count);
}
ch->pos += count;
ltime += count;
}
// if at end of loop, restart
if (ltime >= ch->end)
{
if (sc->loopstart >= 0)
{
ch->pos = sc->loopstart;
ch->end = ltime + sc->length - ch->pos;
}
else
{ // channel just stopped
ch->sfx = NULL;
break;
}
}
}
}
// transfer out according to DMA format
//S_TransferPaintBuffer(end);
paintedtime = end;
}