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Miloslav Číž 2019-10-12 16:29:13 +02:00
parent 10399c778a
commit 733992056a
1 changed files with 24 additions and 14 deletions
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38
raycastlib.h
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@ -26,7 +26,7 @@
author: Miloslav "drummyfish" Ciz
license: CC0 1.0
version: 0.89
version: 0.90
*/
#include <stdint.h>
@ -156,6 +156,8 @@
#define RCL_max(a,b) ((a) > (b) ? (a) : (b))
#define RCL_nonZero(v) (v + (v == 0)) ///< To prevent zero divisions.
#define RCL_zeroClamp(x) (x * (x >= 0))
#define RCL_likely(cond) __builtin_expect(!!(cond),1)
#define RCL_unlikely(cond) __builtin_expect(!!(cond),0)
#define RCL_logV2D(v)\
printf("[%d,%d]\n",v.x,v.y);
@ -550,8 +552,8 @@ static inline RCL_Unit RCL_absVal(RCL_Unit value)
static inline RCL_Unit RCL_wrap(RCL_Unit value, RCL_Unit mod)
{
RCL_profileCall(RCL_wrap);
return value >= 0 ? (value % mod) : (mod + (value % mod) - 1);
RCL_Unit cmp = value < 0;
return cmp * mod + (value % mod) - cmp;
}
/// Performs division, rounding down, NOT towards zero.
@ -696,8 +698,8 @@ RCL_Unit RCL_dist(RCL_Vector2D p1, RCL_Vector2D p2)
RCL_Unit a, b, result;
dx = dx < 0 ? -1 * dx : dx;
dy = dy < 0 ? -1 * dy : dy;
dx = ((dx < 0) * 2 - 1) * dx;
dy = ((dy < 0) * 2 - 1) * dy;
if (dx < dy)
{
@ -807,11 +809,17 @@ void RCL_castRayMultiHit(RCL_Ray ray, RCL_ArrayFunction arrayFunc,
// DDA loop
#define RECIP_SCALE 65536
RCL_Unit rayDirXRecip = RECIP_SCALE / RCL_nonZero(ray.direction.x);
RCL_Unit rayDirYRecip = RECIP_SCALE / RCL_nonZero(ray.direction.y);
// ^ we precompute reciprocals to avoid divisions in the loop
for (uint16_t i = 0; i < constraints.maxSteps; ++i)
{
RCL_Unit currentType = arrayFunc(currentSquare.x,currentSquare.y);
if (currentType != squareType)
if (RCL_unlikely(currentType != squareType))
{
// collision
@ -834,8 +842,9 @@ void RCL_castRayMultiHit(RCL_Ray ray, RCL_ArrayFunction arrayFunc,
}
RCL_Unit diff = h.position.x - ray.start.x;
h.position.y = ray.start.y + ((ray.direction.y * diff) /
RCL_nonZero(ray.direction.x));
h.position.y = // avoid division by multiplying with reciprocal
ray.start.y + ((ray.direction.y * diff) * rayDirXRecip) / RECIP_SCALE;
#if RCL_RECTILINEAR
/* Here we compute the fish eye corrected distance (perpendicular to
@ -846,8 +855,8 @@ void RCL_castRayMultiHit(RCL_Ray ray, RCL_ArrayFunction arrayFunc,
divided by leg B (length along the same axis). */
h.distance =
((h.position.x - ray.start.x) * RCL_UNITS_PER_SQUARE) /
RCL_nonZero(ray.direction.x);
((h.position.x - ray.start.x) * RCL_UNITS_PER_SQUARE * rayDirXRecip)
/ RECIP_SCALE;
#endif
}
else
@ -862,13 +871,14 @@ void RCL_castRayMultiHit(RCL_Ray ray, RCL_ArrayFunction arrayFunc,
}
RCL_Unit diff = h.position.y - ray.start.y;
h.position.x = ray.start.x + ((ray.direction.x * diff) /
RCL_nonZero(ray.direction.y));
h.position.x =
ray.start.x + ((ray.direction.x * diff) * rayDirYRecip) / RECIP_SCALE;
#if RCL_RECTILINEAR
h.distance =
((h.position.y - ray.start.y) * RCL_UNITS_PER_SQUARE) /
RCL_nonZero(ray.direction.y);
((h.position.y - ray.start.y) * RCL_UNITS_PER_SQUARE * rayDirYRecip)
/ RECIP_SCALE;
#endif
}