rockbox/apps/plugins/sdl/progs/quake/snd_mix_generic.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

69 lines
1.8 KiB
C

/* 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);
}
}