shithub: duke3d

ref: 3cdb969ceda035309253a017f5448f3ae0eb463b
dir: /Engine/src/fixedPoint_math.c/

// converted from asm to c by Jonof

#include <stdio.h>
#include <string.h>
#include "platform.h"
#include "fixedPoint_math.h"

void clearbuf(void *d, int32_t c, int32_t a)
{
    // tanguyf: this completely violates strict-aliasing.
	//int32_t *p = (int32_t*)d;
	//while ((c--) > 0) *(p++) = a;

	union
    {
	    struct { uint8_t a,b,c,d; };
	    int32_t value;
    } src;

	src.value = a;

	uint8_t* dst = (uint8_t*) d;

	for (int32_t i = 0; i < c; ++i)
    {
	    dst[i*4 + 0] = src.a;
        dst[i*4 + 1] = src.b;
        dst[i*4 + 2] = src.c;
        dst[i*4 + 3] = src.d;
    }
}

void clearbufbyte(void *D, int32_t c, int32_t a)
{ // Cringe City
	uint8_t  *p = (uint8_t *)D;
	int32_t m[4] = { 0xffl,0xff00l,0xff0000l,0xff000000l };
	int32_t n[4] = { 0,8,16,24 };
	int32_t z=0;
	while ((c--) > 0) {
		*(p++) = (uint8_t )((a & m[z])>>n[z]);
		z=(z+1)&3;
	}
}

void copybuf(void *s, void *d, int32_t c)
{
    // tanguyf: this completely violates strict-aliasing.
	//int32_t *p = (int32_t*)s, *q = (int32_t*)d;
	//while ((c--) > 0) *(q++) = *(p++);
	memcpy(d, s, c * sizeof(int32_t));
}

void copybufbyte(void *S, void *D, int32_t c)
{
	uint8_t  *p = (uint8_t *)S, *q = (uint8_t *)D;
	while((c--) > 0) *(q++) = *(p++);
}

void copybufreverse(void *S, void *D, int32_t c)
{
	uint8_t  *p = (uint8_t *)S, *q = (uint8_t *)D;
	while((c--) > 0) *(q++) = *(p--);
}

void qinterpolatedown16(int32_t* bufptr, int32_t num, int32_t val, int32_t add)
{ // gee, I wonder who could have provided this...
    int32_t i, *lptr = bufptr;
    for(i=0;i<num;i++) { lptr[i] = (val>>16); val += add; }
}

void qinterpolatedown16short(int32_t* bufptr, int32_t num, int32_t val, int32_t add)
{ // ...maybe the same person who provided this too?
    int32_t i; short *sptr = (short *)bufptr;
    for(i=0;i<num;i++) { sptr[i] = (short)(val>>16); val += add; }
}