diff options
Diffstat (limited to 'src/models.c')
| -rw-r--r-- | src/models.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/models.c b/src/models.c index 652a6c0..f16620c 100644 --- a/src/models.c +++ b/src/models.c @@ -2531,3 +2531,121 @@ int lmodelsGetRayCollisionQuad( lua_State* L ) { return 1; } + +static inline Vector3 Vector3Floor( Vector3 v ) { + return (Vector3){ (float)floor( v.x ), (float)floor( v.y ), (float)floor( v.z ) }; +} + +static inline Vector3 Vector3Ceil( Vector3 v ) { + return (Vector3){ (float)ceil( v.x ), (float)ceil( v.y ), (float)ceil( v.z ) }; +} + +static inline bool isInsideBox( Vector3 position, BoundingBox box ) { + return box.min.x <= position.x && position.x <= box.max.x + && box.min.y <= position.y && position.y <= box.max.y + && box.min.z <= position.z && position.z <= box.max.z; +} + +/* +> cells = RL.GetRayBoxCells( Ray ray, BoundingBox box, Vector3 cellSize ) + +Get cell positions inside box that intersect with the ray. Returns empty table if ray misses the box + +- Success return Vector3{} +*/ +int lmodelsGetRayBoxCells( lua_State* L ) { + Ray ray = uluaGetRay( L, 1 ); + BoundingBox box = uluaGetBoundingBox( L, 2 ); + Vector3 cellSize = uluaGetVector3( L, 3 ); + + /* To avoid possible div by 0 later. */ + ray.direction.x == 0.0f ? EPSILON : ray.direction.x; + ray.direction.y == 0.0f ? EPSILON : ray.direction.y; + ray.direction.z == 0.0f ? EPSILON : ray.direction.z; + + Vector3 boxSize = Vector3Subtract( box.max, box.min ); + Vector3 boxSizeCells = Vector3Ceil( Vector3Divide( boxSize, cellSize ) ); + Vector3 cellPos = { -1, -1, -1 }; + Vector3 localRayPos = { 0, 0, 0 }; + + /* If camera is inside the box. */ + if ( isInsideBox( ray.position, box ) ) { + localRayPos = Vector3Subtract( ray.position, box.min ); + /* Nudge position a bit to try to get if away from {0, 0, 0}. */ + localRayPos = Vector3Add( localRayPos, Vector3Scale( ray.direction, 0.0001f ) ); + cellPos = Vector3Floor( Vector3Divide( localRayPos, cellSize ) ); + } + /* Else check ray to box to see where we start. */ + else { + RayCollision rayCol = GetRayCollisionBox( ray, box ); + + if ( rayCol.hit ) { + localRayPos = Vector3Subtract( rayCol.point, box.min ); + /* Nudge inside the box. */ + localRayPos = Vector3Add( localRayPos, Vector3Scale( Vector3Negate( rayCol.normal ), 0.0001f ) ); + cellPos = Vector3Floor( Vector3Divide( localRayPos, cellSize ) ); + } + } + lua_newtable( L ); + + /* Find cells along the ray. */ + if ( 0 <= cellPos.x ) { + uluaPushVector3( L, cellPos ); + lua_rawseti( L, -2, 1 ); + + Vector3 signs = { + 0.0f <= ray.direction.x ? 1.0f : -1.0f, + 0.0f <= ray.direction.y ? 1.0f : -1.0f, + 0.0f <= ray.direction.z ? 1.0f : -1.0f + }; + /* We transform everything to absolute space to make this simpler. */ + Vector3 absBounds = { + 0.0f < signs.x ? boxSizeCells.x - cellPos.x : cellPos.x + 1.0f, + 0.0f < signs.y ? boxSizeCells.y - cellPos.y : cellPos.y + 1.0f, + 0.0f < signs.z ? boxSizeCells.z - cellPos.z : cellPos.z + 1.0f + }; + Vector3 absDir = { + fabsf( ray.direction.x ), + fabsf( ray.direction.y ), + fabsf( ray.direction.z ) + }; + Vector3 absPos = { + 0.0f < signs.x ? localRayPos.x - cellPos.x * cellSize.x : cellSize.x - ( localRayPos.x - cellPos.x * cellSize.x ), + 0.0f < signs.y ? localRayPos.y - cellPos.y * cellSize.y : cellSize.y - ( localRayPos.y - cellPos.y * cellSize.y ), + 0.0f < signs.z ? localRayPos.z - cellPos.z * cellSize.z : cellSize.z - ( localRayPos.z - cellPos.z * cellSize.z ) + }; + Vector3 absCell = { 0, 0, 0 }; + int cellId = 2; /* We already added first so we will start at 2. */ + + while ( true ) { + /* Distance to adjacent cell. */ + Vector3 cellDis = { + ( cellSize.x - ( absPos.x - absCell.x * cellSize.x ) ) / absDir.x, + ( cellSize.y - ( absPos.y - absCell.y * cellSize.y ) ) / absDir.y, + ( cellSize.z - ( absPos.z - absCell.z * cellSize.z ) ) / absDir.z, + }; + Vector3 move = { + cellDis.x <= cellDis.y && cellDis.x <= cellDis.z ? 1 : 0, + cellDis.y <= cellDis.x && cellDis.y <= cellDis.z ? 1 : 0, + cellDis.z <= cellDis.x && cellDis.z <= cellDis.y ? 1 : 0 + }; + /* Both relative and real cell pos needs to be moved. */ + absCell = Vector3Add( absCell, move ); + cellPos = Vector3Add( cellPos, Vector3Multiply( move, signs ) ); + + if ( absCell.x < absBounds.x && absCell.y < absBounds.y && absCell.z < absBounds.z ) { + absPos = Vector3Add( absPos, Vector3Scale( absDir, fmin( fmin( cellDis.x, cellDis.y ), cellDis.z ) ) ); + + uluaPushVector3( L, (Vector3){ round( cellPos.x ), round( cellPos.y ), round( cellPos.z ) } ); + lua_rawseti( L, -2, cellId ); + + cellId++; + } + else { + break; + } + } + } + + return 1; +} |