///
/// @file updatetraj.cl
///
/// Various functions to compute trajectories and record data along them
///
/// @author CPS
/// @bug No known bugs
///
///
/// @defgroup trajectoryfns Trajectory stepping and recording functions
/// Functions to carry out Runge-Kutta integration steps along streamlines & record them
///
#ifdef KERNEL_INTEGRATE_FIELDS
///
/// Update variables tracking trajectory length and integration step counter.
/// Write length and count data to global arrays.
///
/// Compiled if KERNEL_INTEGRATE_TRAJECTORY is defined.
///
/// @param[in] dl: step distance
/// @param[in,out] l_trajectory: total streamline distance so far
/// @param[in] vec: current (x,y) coordinate vector at tip of streamline trajectory
/// @param[in] prev_vec: previous (x,y) coordinate vector on streamline trajectory
/// @param[in,out] n_steps: number of integration steps so far in streamline trajectory
/// @param[in,out] idx: array index of pixel at current (x,y) position
/// @param[in] mask_array: grid pixel mask (padded),
/// with @p true = masked, @p false = good
/// @param[in,out] slc_array: grid recording accumulated count of streamline integration
/// steps across each pixel (padded)
/// @param[in,out] slt_array: grid recording accumulated count of streamline segment
/// lengths crossing each pixel (padded)
///
/// @returns void
///
/// @ingroup trajectoryfns
///
static inline void update_trajectory_write_sl_data(
float dl, float *l_trajectory, float2 vec, float2 prev_vec,
uint *n_steps, uint *idx,
__global const bool *mask_array,
__global uint *slt_array, __global uint *slc_array) {
// Step to next point along streamline, adding to trajectory length
// and n_steps counter.
// Compress step delta vector into fixed-point integer form & record in traj.
// Write to slt, slc arrays to record passage of this streamline.
*l_trajectory += dl;
*n_steps += 1u;
// Current pixel position in data array
*idx = get_array_idx(vec);
check_atomic_write_sl_data(*idx, mask_array[*idx],
&slt_array[*idx], &slc_array[*idx], *l_trajectory);
}
#endif
#ifdef KERNEL_INTEGRATE_TRAJECTORY
///
/// Update variables tracking trajectory length and integration step counter.
/// Record (to global array) a compressed version of the current trajectory step vector.
///
/// Compiled if KERNEL_INTEGRATE_TRAJECTORY is defined.
///
/// @param[in] dl: step distance
/// @param[in,out] l_trajectory: total streamline distance so far
/// @param[in] vec: current (x,y) coordinate vector at tip of streamline trajectory
/// @param[in] prev_vec: previous (x,y) coordinate vector on streamline trajectory
/// @param[in,out] n_steps: number of integration steps so far in streamline trajectory
/// @param[in,out] trajectory_vec: streamline trajectory record
/// (2d array of compressed (x,y) vectors)
///
/// @returns void
///
/// @ingroup trajectoryfns
///
static inline void update_record_trajectory(
float dl, float *l_trajectory, float2 vec, float2 prev_vec,
uint *n_steps, __global char2 *trajectory_vec) {
// Step to next point along streamline, adding to trajectory length
// and n_steps counter.
// Compress step delta vector into fixed-point integer form.
*l_trajectory += dl;
trajectory_vec[*n_steps] = compress(vec-prev_vec);
*n_steps += 1u;
}
#endif
#ifdef KERNEL_CONNECT_CHANNELS
///
/// Update variables tracking trajectory length and integration step counter.
/// Record (to private array) a compressed version of the current trajectory step vector.
///
/// Compiled if KERNEL_INTEGRATE_TRAJECTORY is defined.
///
/// @param[in] dl: step distance
/// @param[in,out] l_trajectory: total streamline distance so far
/// @param[in] vec: current (x,y) coordinate vector at tip of streamline trajectory
/// @param[in] prev_vec: previous (x,y) coordinate vector on streamline trajectory
/// @param[in,out] n_steps: number of integration steps so far in streamline trajectory
/// @param[in,out] trajectory_vec: streamline trajectory record
/// (2d array of compressed (x,y) vectors)
///
/// @returns void
///
/// @ingroup trajectoryfns
///
static inline void update_record_private_trajectory(
float dl, float *l_trajectory, float2 vec, float2 prev_vec,
uint *n_steps, __private char2 *trajectory_vec) {
// Step to next point along streamline, adding to trajectory length
// and n_steps counter.
// Compress step delta vector into fixed-point integer form.
*l_trajectory += dl;
trajectory_vec[*n_steps] = compress(vec-prev_vec);
*n_steps += 1u;
}
#endif
#ifdef KERNEL_HILLSLOPE_LENGTHS
///
/// Update variables tracking trajectory length and integration step counter.
///
/// Compiled if KERNEL_INTEGRATE_TRAJECTORY is defined.
///
/// @param[in] dl: step distance
/// @param[in,out] l_trajectory: total streamline distance so far
/// @param[in,out] n_steps: number of integration steps so far in streamline trajectory
///
/// @returns void
///
/// @ingroup trajectoryfns
///
static inline void update_trajectory(
float dl, float *l_trajectory, uint *n_steps) {
// Step to next point along streamline, adding to trajectory length
// and n_steps counter.
// Compress step delta vector into fixed-point integer form.
*l_trajectory += dl;
*n_steps += 1u;
}
#endif
#ifdef KERNEL_INTEGRATE_TRAJECTORY
///
/// Record the (final) trajectory length and count of integration steps
/// to global arrays @p traj_length_array and @p traj_nsteps_array respectively.
/// This action takes place at the end of streamline tracing in each integration
/// kernel instance.
///
/// Compiled if KERNEL_INTEGRATE_TRAJECTORY is defined.
///
/// @param[in] global_id: ID of the kernel instance
/// @param[in] n_steps: number of integration steps so far in streamline trajectory
/// @param[in] l_trajectory: total streamline distance so far
/// @param[out] traj_nsteps_array: list of number of steps along each trajectory;
/// one per @p seed_point_array vector
/// @param[out] traj_length_array: list of lengths of each trajectory;
/// one per @p seed_point_array vector
///
/// @returns void
///
/// @ingroup trajectoryfns
///
static inline void finalize_trajectory(const uint global_id, uint n_steps,
float l_trajectory,
__global ushort *traj_nsteps_array,
__global float *traj_length_array) {
// Record the total stream length in pixels and point count for rtn to CPU
traj_nsteps_array[global_id] = n_steps;
traj_length_array[global_id] = l_trajectory;
}
#endif
