Jungfraujoch/image_analysis/bragg_integration/BraggPassA.h

// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

// Pass A of BraggIntegrationEngineCPU, as the data it hands on: what the walk over one reflection's box
// counts, and the clip sums of its background ring. Integers only, so the counts do not depend on the
// order the pixels are visited in: the Metal engine walks the boxes on the GPU and gets the CPU's
// counts exactly. Compiled by the host and by the Metal compiler, so the two agree on the layout -
// which is also why there are no default member initialisers (Metal does not take a struct with them
// as a buffer type); zero one with {}.

#ifndef __METAL_VERSION__
#include <cstdint>
#endif

struct BraggBoxSums {
    int64_t I_sum, I_sum_x, I_sum_y;   // readable signal-disk pixels, and their first moments
    int64_t x_sum, y_sum;              // the positions behind I_sum, to take the background out of the centroid
    int64_t bkg_sum;                   // ring pixels kept for the background
    int64_t n_inner, n_inner_valid;    // signal-disk pixels kept, and how many of them were readable
    int32_t n_disk, n_own;             // signal-disk pixels, and how many of them are this reflection's
    int32_t n_bkg;                     // ring pixels behind bkg_sum
    int32_t n_ring, n_clean;           // readable ring pixels, and those no predicted neighbour covers
    int32_t overloaded;                // a signal-disk pixel was saturated, or unreadable on this frame only
    int32_t n_saturated;               // signal-disk pixels at the saturation limit
    int32_t unused;
};

// The ring pixels at or below a reflection's clip threshold (BraggIntegrationEngineCPU::ClipThreshold).
struct BraggClipSums {
    int64_t sum;
    int32_t n;
    int32_t unused;
};

// What the Metal kernels are told about the frame, beside the stencil (BraggStencilParams).
struct BraggPassAFrame {
    int32_t width, height;
    float r1_sq, r2_sq, r3_sq;
    float claim, inv_claim;      // how far a reflection claims pixels in the owner map
    int32_t use_owner;           // an overlap treatment is on, so the owner map is built and read
    int32_t exclude;             // ... and a pixel a neighbour owns leaves the signal disk
    int32_t n_rad;               // radial background bins; 0 when the curve is not accumulated
    int32_t n_curve;             // bins of the handed-over curve the clip follows (RadialClipOffset); 0: none
    uint32_t static_mask_words;  // length of the run's packed pixel mask
    uint32_t n;                  // reflections
};

// Compiled on both sides, so a layout the host and the Metal compiler disagree on fails to compile.
static_assert(sizeof(BraggBoxSums) == 96, "BraggBoxSums layout shared with the Metal kernels");
static_assert(sizeof(BraggClipSums) == 16, "BraggClipSums layout shared with the Metal kernels");
static_assert(sizeof(BraggPassAFrame) == 52, "BraggPassAFrame layout shared with the Metal kernels");