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dy = -(ray - 4);
} else if (ray >= 5 && ray < 7) {
dx = ray - 6;
dy = -1;
} else {
dx = 1;
dy = ray > 4 ? ray - 8 : ray;
};
if (SOLID(S(fast_f2nat(sx),
fast_f2nat(
sy)))) // 90% of time spend in this
// function is on this line
{
};
};
} else {
rdist[i] = 2;
};
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dy = -(ray - 4);
} else if (ray >= 5 && ray < 7) {
dx = ray - 6;
dy = -1;
} else {
dx = 1;
dy = ray > 4 ? ray - 8 : ray;
}
float sx = vx;
float sy = vy;
for (;;) {
sx += dx;
sy += dy;
// 90% of time spend in this function is on this
// line
if (SOLID(S(fast_f2nat(sx), fast_f2nat(sy)))) {
rdist[i] = (float)(fabs(sx - vx) +
fabs(sy - vy));
break;
}
}
} else
rdist[i] = 2;
}
}
// test occlusion for a cube... one of the most computationally expensive
// functions in the engine as its done for every cube and entity, but its effect
// is more than worth it!
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4;
l = ma(-(cx + csize - vx), -(cy - vy)) +
4;
} // D
} else {
h = ca(cy + csize - vy, -(cx + csize - vx)) + 2;
l = ca(cy - vy, -(cx - vx)) + 2;
}; // F
} else // BG
{
if (cy <= vy) {
if (cy + csize < vy) {
h = ma(-(cy + csize - vy), cx - vx) + 6;
l = ma(-(cy + csize - vy),
cx + csize - vx) +
6;
} // B
else
return 0;
} else {
h = ma(cy - vy, -(cx + csize - vx)) + 2;
l = ma(cy - vy, -(cx - vx)) + 2;
}; // G
};
} else // CEH
{
if (cy <= vy) // CE
{
if (cy + csize < vy) {
h = ca(-(cy - vy), cx - vx) + 6;
l = ca(-(cy + csize - vy), cx + csize - vx) + 6;
} // C
else {
h = ma(cx - vx, cy - vy);
l = ma(cx - vx, cy + csize - vy);
}; // E
} else {
h = ca(cx + csize - vx, cy - vy);
l = ca(cx - vx, cy + csize - vy);
}; // H
};
int si = fast_f2nat(h * (NUMRAYS / 8)) +
NUMRAYS; // get indexes into occlusion map from angles
int ei = fast_f2nat(l * (NUMRAYS / 8)) + NUMRAYS + 1;
if (ei <= si)
ei += NUMRAYS;
for (int i = si; i <= ei; i++) {
if (dist < rdist[i & (NUMRAYS - 1)])
return 0; // if any value in this segment of the
// occlusion map is further away then cube is
// not occluded
};
return 1; // cube is entirely occluded
}
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4;
l = ma(-(cx + csize - vx), -(cy - vy)) +
4;
} // D
} else {
h = ca(cy + csize - vy, -(cx + csize - vx)) + 2;
l = ca(cy - vy, -(cx - vx)) + 2;
} // F
} else { // BG
if (cy <= vy) {
if (cy + csize < vy) {
h = ma(-(cy + csize - vy), cx - vx) + 6;
l = ma(-(cy + csize - vy),
cx + csize - vx) +
6;
} // B
else
return 0;
} else {
h = ma(cy - vy, -(cx + csize - vx)) + 2;
l = ma(cy - vy, -(cx - vx)) + 2;
} // G
}
} else // CEH
{
if (cy <= vy) // CE
{
if (cy + csize < vy) {
h = ca(-(cy - vy), cx - vx) + 6;
l = ca(-(cy + csize - vy), cx + csize - vx) + 6;
} // C
else {
h = ma(cx - vx, cy - vy);
l = ma(cx - vx, cy + csize - vy);
} // E
} else {
h = ca(cx + csize - vx, cy - vy);
l = ca(cx - vx, cy + csize - vy);
} // H
}
int si = fast_f2nat(h * (NUMRAYS / 8)) +
NUMRAYS; // get indexes into occlusion map from angles
int ei = fast_f2nat(l * (NUMRAYS / 8)) + NUMRAYS + 1;
if (ei <= si)
ei += NUMRAYS;
for (int i = si; i <= ei; i++) {
if (dist < rdist[i & (NUMRAYS - 1)])
// if any value in this segment of the occlusion map is
// further away then cube is not occluded
return 0;
}
return 1; // cube is entirely occluded
}
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