コード例 #1
0
ファイル: BBox.cpp プロジェクト: Mak13/Fast-BVH
bool BBox::intersect(const Ray& ray, float *tnear, float *tfar) const {

	// you may already have those values hanging around somewhere
	const __m128
		plus_inf	= loadps(ps_cst_plus_inf),
		minus_inf	= loadps(ps_cst_minus_inf);

	// use whatever's apropriate to load.
	const __m128
		box_min	= loadps(&min),
		box_max	= loadps(&max),
		pos	= loadps(&ray.o),
		inv_dir	= loadps(&ray.inv_d);

	// use a div if inverted directions aren't available
	const __m128 l1 = mulps(subps(box_min, pos), inv_dir);
	const __m128 l2 = mulps(subps(box_max, pos), inv_dir);

	// the order we use for those min/max is vital to filter out
	// NaNs that happens when an inv_dir is +/- inf and
	// (box_min - pos) is 0. inf * 0 = NaN
	const __m128 filtered_l1a = minps(l1, plus_inf);
	const __m128 filtered_l2a = minps(l2, plus_inf);

	const __m128 filtered_l1b = maxps(l1, minus_inf);
	const __m128 filtered_l2b = maxps(l2, minus_inf);

	// now that we're back on our feet, test those slabs.
	__m128 lmax = maxps(filtered_l1a, filtered_l2a);
	__m128 lmin = minps(filtered_l1b, filtered_l2b);

	// unfold back. try to hide the latency of the shufps & co.
	const __m128 lmax0 = rotatelps(lmax);
	const __m128 lmin0 = rotatelps(lmin);
	lmax = minss(lmax, lmax0);
	lmin = maxss(lmin, lmin0);

	const __m128 lmax1 = muxhps(lmax,lmax);
	const __m128 lmin1 = muxhps(lmin,lmin);
	lmax = minss(lmax, lmax1);
	lmin = maxss(lmin, lmin1);

	const bool ret = _mm_comige_ss(lmax, _mm_setzero_ps()) & _mm_comige_ss(lmax,lmin);

	storess(lmin, tnear);
	storess(lmax, tfar);

	return  ret;
}
コード例 #2
0
inline bool ray_box_intersect(const box_t & b, const ray_t & ray, rayseg_t & rs) {
    /* you may already have those values hanging around somewhere */
    const __m128
        plus_inf = loadps(ps_cst_plus_inf), minus_inf = loadps(ps_cst_minus_inf);

    /* use whatever's apropriate to load. */
    const __m128
        box_min = loadps(&b.min), box_max = loadps(&b.max), pos =
        loadps(&ray.pos), inv_dir = loadps(&ray.inv_dir);

    /* use a div if inverted directions aren't available */
    const __m128 l1 = mulps(subps(box_min, pos), inv_dir);
    const __m128 l2 = mulps(subps(box_max, pos), inv_dir);

    /* the order we use for those min/max is vital to filter out */
    /* NaNs that happens when an inv_dir is +/- inf and */
    /* (box_min - pos) is 0. inf * 0 = NaN */
    const __m128 filtered_l1a = minps(l1, plus_inf);
    const __m128 filtered_l2a = minps(l2, plus_inf);
    const __m128 filtered_l1b = maxps(l1, minus_inf);
    const __m128 filtered_l2b = maxps(l2, minus_inf);

    /* now that we're back on our feet, test those slabs. */
    __m128 lmax = maxps(filtered_l1a, filtered_l2a);
    __m128 lmin = minps(filtered_l1b, filtered_l2b);

    /* unfold back. try to hide the latency of the shufps & co. */
    const __m128 lmax0 = rotatelps(lmax);
    const __m128 lmin0 = rotatelps(lmin);
    lmax = minss(lmax, lmax0);
    lmin = maxss(lmin, lmin0);
    const __m128 lmax1 = muxhps(lmax, lmax);
    const __m128 lmin1 = muxhps(lmin, lmin);
    lmax = minss(lmax, lmax1);
    lmin = maxss(lmin, lmin1);
    const bool ret =
        _mm_comige_ss(lmax, _mm_setzero_ps()) & _mm_comige_ss(lmax, lmin);
    storess(lmin, &rs.t_near);
    storess(lmax, &rs.t_far);
    return ret;
}