diff options
Diffstat (limited to 'src/m4a_2.c')
| -rw-r--r-- | src/m4a_2.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/m4a_2.c b/src/m4a_2.c index 176910e..ce9ac19 100644 --- a/src/m4a_2.c +++ b/src/m4a_2.c @@ -1,4 +1,5 @@ #include "gba/m4a_internal.h" +#include "global.h" extern char SoundMainRAM_Buffer[0x400]; @@ -832,3 +833,115 @@ void CgbOscOff(u8 chanNum) REG_NR44 = 0x80; } } + +static inline int CgbPan(struct CgbChannel *chan) +{ + u32 rightVolume = chan->rightVolume; + u32 leftVolume = chan->leftVolume; + + if ((rightVolume = (u8)rightVolume) >= (leftVolume = (u8)leftVolume)) + { + if (rightVolume / 2 >= leftVolume) + { + chan->pan = 0x0F; + return 1; + } + } + else + { + if (leftVolume / 2 >= rightVolume) + { + chan->pan = 0xF0; + return 1; + } + } + + return 0; +} +#ifndef NONMATCHING +NAKED +#endif +void CgbModVol(struct CgbChannel *chan) +{ +#ifdef NONMATCHING + struct SoundInfo *soundInfo = SOUND_INFO_PTR; + + if ((soundInfo->mode & 1) || !CgbPan(chan)) + { + chan->pan = 0xFF; + chan->eg = (u32)(chan->rightVolume + chan->leftVolume) >> 4; + } + else + { + // Force chan->rightVolume and chan->leftVolume to be read from memory again, + // even though there is no reason to do so. + // The command line option "-fno-gcse" achieves the same result as this. + asm("" : : : "memory"); + + chan->eg = (u32)(chan->rightVolume + chan->leftVolume) >> 4; + if (chan->eg > 15) + chan->eg = 15; + } + + chan->sg = (chan->eg * chan->su + 15) >> 4; + chan->pan &= chan->panMask; +#else + asm_unified("\tpush {r4,lr}\n" + "\tadds r1, r0, 0\n" + "\tldrb r0, [r1, 0x2]\n" + "\tlsls r2, r0, 24\n" + "\tlsrs r4, r2, 24\n" + "\tldrb r3, [r1, 0x3]\n" + "\tlsls r0, r3, 24\n" + "\tlsrs r3, r0, 24\n" + "\tcmp r4, r3\n" + "\tbcc _080AFA94\n" + "\tlsrs r0, r2, 25\n" + "\tcmp r0, r3\n" + "\tbcc _080AFAA0\n" + "\tmovs r0, 0xF\n" + "\tstrb r0, [r1, 0x1B]\n" + "\tb _080AFAAE\n" + "_080AFA94:\n" + "\tlsrs r0, 25\n" + "\tcmp r0, r4\n" + "\tbcc _080AFAA0\n" + "\tmovs r0, 0xF0\n" + "\tstrb r0, [r1, 0x1B]\n" + "\tb _080AFAAE\n" + "_080AFAA0:\n" + "\tmovs r0, 0xFF\n" + "\tstrb r0, [r1, 0x1B]\n" + "\tldrb r2, [r1, 0x3]\n" + "\tldrb r3, [r1, 0x2]\n" + "\tadds r0, r2, r3\n" + "\tlsrs r0, 4\n" + "\tb _080AFABE\n" + "_080AFAAE:\n" + "\tldrb r2, [r1, 0x3]\n" + "\tldrb r3, [r1, 0x2]\n" + "\tadds r0, r2, r3\n" + "\tlsrs r0, 4\n" + "\tstrb r0, [r1, 0xA]\n" + "\tcmp r0, 0xF\n" + "\tbls _080AFAC0\n" + "\tmovs r0, 0xF\n" + "_080AFABE:\n" + "\tstrb r0, [r1, 0xA]\n" + "_080AFAC0:\n" + "\tldrb r2, [r1, 0x6]\n" + "\tldrb r3, [r1, 0xA]\n" + "\tadds r0, r2, 0\n" + "\tmuls r0, r3\n" + "\tadds r0, 0xF\n" + "\tasrs r0, 4\n" + "\tstrb r0, [r1, 0x19]\n" + "\tldrb r0, [r1, 0x1C]\n" + "\tldrb r2, [r1, 0x1B]\n" + "\tands r0, r2\n" + "\tstrb r0, [r1, 0x1B]\n" + "\tpop {r4}\n" + "\tpop {r0}\n" + "\tbx r0\n"); +#endif +}
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