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This commit is contained in:
Miloslav Číž 2019-08-17 13:15:57 +02:00
parent 57c2bb34e4
commit e52fb3e665
1 changed files with 20 additions and 3 deletions
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raycastlib.h
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@ -225,8 +225,12 @@ typedef struct
typedef struct typedef struct
{ {
RCL_Unit distance; /**< Distance (perpend.) to the hit position, or -1 RCL_Unit distance; /**< Distance to the hit position, or -1 if no
if no collision happened. */ collision happened. If RCL_EQUILINEAR != 0, then
the distance is perpendicular to the projection
plane (fish eye correction), otherwise it is
the straight distance to the ray start
position. */
uint8_t direction; ///< Direction of hit. uint8_t direction; ///< Direction of hit.
RCL_Unit textureCoord; /**< Normalized (0 to RCL_UNITS_PER_SQUARE - 1) RCL_Unit textureCoord; /**< Normalized (0 to RCL_UNITS_PER_SQUARE - 1)
texture coordinate (horizontal). */ texture coordinate (horizontal). */
@ -314,7 +318,9 @@ RCL_PixelInfo RCL_mapToScreen(RCL_Vector2D worldPosition, RCL_Unit height,
/** /**
Casts a single ray and returns a list of collisions. Casts a single ray and returns a list of collisions.
@param ray ray to be cast @param ray ray to be cast, if RCL_EQUILINEAR != 0 then the computed hit
distance is divided by the ray direction vector length (to correct
the fish eye effect)
@param arrayFunc function that will be used to determine collisions (hits) @param arrayFunc function that will be used to determine collisions (hits)
with the ray (squares for which this function returns different values with the ray (squares for which this function returns different values
are considered to have a collision between them), this will typically are considered to have a collision between them), this will typically
@ -834,6 +840,13 @@ void RCL_castRayMultiHit(RCL_Ray ray, RCL_ArrayFunction arrayFunc,
RCL_nonZero(ray.direction.x)); RCL_nonZero(ray.direction.x));
#if RCL_EQUILINEAR #if RCL_EQUILINEAR
/* Here we compute the fish eye corrected distance (perpendicular to
the projection plane) as the Euclidean distance divided by the length
of the ray direction vector. This can be computed without actually
computing Euclidean distances as a hypothenuse A (distance) divided
by hypothenuse B (length) is equal to leg A (distance along one axis)
divided by leg B (length along the same axis). */
h.distance = h.distance =
((h.position.x - ray.start.x) * RCL_UNITS_PER_SQUARE) / ((h.position.x - ray.start.x) * RCL_UNITS_PER_SQUARE) /
RCL_nonZero(ray.direction.x); RCL_nonZero(ray.direction.x);
@ -968,6 +981,10 @@ void RCL_castRaysMultiHit(RCL_Camera cam, RCL_ArrayFunction arrayFunc,
for (int16_t i = 0; i < cam.resolution.x; ++i) for (int16_t i = 0; i < cam.resolution.x; ++i)
{ {
/* Here by linearly interpolating the direction vector its length changes,
which in result achieves correcting the fish eye effect (computing
perpendicular distance). */
r.direction.x = dir1.x + currentDX / cam.resolution.x; r.direction.x = dir1.x + currentDX / cam.resolution.x;
r.direction.y = dir1.y + currentDY / cam.resolution.x; r.direction.y = dir1.y + currentDY / cam.resolution.x;