src/hardware/snd_pc98/common/parts.c

#include    "np2glue.h"

//#include      "compiler.h"
#include        "parts.h"


static  SINT32  randseed = 1;


void PARTSCALL rand_setseed(SINT32 seed) {

        randseed = seed;
}

SINT32 PARTSCALL rand_get(void) {

        randseed = (randseed * 0x343fd) + 0x269ec3;
        return(randseed >> 16);
}

UINT8 PARTSCALL AdjustAfterMultiply(UINT8 value) {

        return((UINT8)(((value / 10) << 4) + (value % 10)));
}

UINT8 PARTSCALL AdjustBeforeDivision(UINT8 value) {

        return((UINT8)(((value >> 4) * 10) + (value & 0xf)));
}

UINT PARTSCALL sjis2jis(UINT sjis) {

        UINT    ret;

        ret = sjis & 0xff;
        ret -= (ret >> 7);
        ret += 0x62;
        if (ret < 256) {
                ret = (ret - 0xa2) & 0x1ff;
        }
        ret += 0x1f21;
        ret += (sjis & 0x3f00) << 1;
        return(ret);
}

UINT PARTSCALL jis2sjis(UINT jis) {

        UINT    high;
        UINT    low;

        low = jis & 0x7f;
        high = (jis >> 8) & 0x7f;
        low += ((high & 1) - 1) & 0x5e;
        if (low >= 0x60) {
                low++;
        }
        high += 0x121;
        low += 0x1f;
        high >>= 1;
        high ^= 0x20;
        return((high << 8) | low);
}

void PARTSCALL satuation_s16(SINT16 *dst, const SINT32 *src, UINT size) {

        size >>= 1;
        while(size--) {
                SINT32 data = *src++;
                if (data > 32767) {
                        data = 32767;
                }
                else if (data < -32768) {
                        data = -32768;
                }
                *dst++ = (SINT16)data;
        }
}

void PARTSCALL satuation_s16x(SINT16 *dst, const SINT32 *src, UINT size) {

        size >>= 2;
        while(size--) {
                SINT32 data = src[0];
                if (data > 32767) {
                        data = 32767;
                }
                else if (data < -32768) {
                        data = -32768;
                }
                dst[1] = (SINT16)data;
                data = src[1];
                if (data > 32767) {
                        data = 32767;
                }
                else if (data < -32768) {
                        data = -32768;
                }
                dst[0] = (SINT16)data;
                src += 2;
                dst += 2;
        }
}