2 Commits

Include renames

Author	SHA1	Message	Date
leonarski_fandClaude Opus 5	8f1b0b2281	spot_finding: accumulate spot centroids in integers ... The photon-weighted position sums were floats, so the centroid's last bit depended on the build rather than on the data: gcc contracts the multiply-add in AddPixel into an FMA under -march=x86-64-v3 and cannot at the baseline, and MSVC does not contract at all under /fp:precise. The GPU extractor had to match with __fmaf_rn, and the parity test still needed a two-ulp slack for hosts that do not fuse. Column, line and the per-pixel count are all integral, so the sums are exact in int64 and both implementations reach the same bits with nothing to match. The parity test now demands exact equality unconditionally and gets it, including on a baseline build. ConvertToImageCoordinates keeps the sums integral too: the raw -> image map is a signed axis swap plus an integer translation, so it is applied to the sums instead of to the centroid. Drops the SpotToSave constructor, which had no callers and could not have been converted without quantising the stored centroid. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-02 19:03:35 +02:00
leonarski_fandClaude Opus 5	4bdb229fb8	spot_finding: find connected components on the GPU ... The spot finder flagged strong pixels on the device and then labelled them on the host, so every frame sent the packed bitmask back - 2.26 MB on a large detector - and the host walked all of it to recover a few hundred pixels. Do the labelling on the device instead: compact the bitmask into a flat-index-sorted list, find each pixel's backward neighbours by binary search, union them lock-free with path halving, then label, accumulate and filter in one kernel. Only the spot list comes back, and only one stream synchronisation per frame. The gain in the ordinary case is modest - about a quarter off per-image spot finding - because the host algorithm is genuinely fast on a normal frame. What justifies it is the frame that is not ordinary. The host labels a sorted sparse list through a window spanning two detector lines, so its cost is quadratic in how many strong pixels share a line. A lit band of detector rows - a hot module, a panel edge - costs 33 ms at two rows and 377 ms at fifteen, all of it under the pixel cap that was supposed to bound this, and none of it maskable when the cause is a diffraction ring rather than a defect: a ring runs tangent to a row at its top and bottom, which is exactly the shape that hurts. The device version is flat at 0.05 to 0.64 ms across every geometry tried, so an online run no longer stalls a quarter of a second on an ice ring. Rejecting an over-cap frame is now free too, since the count is known before any pixel is written. Also label once and filter three times. The per-image minimum-pixel search runs the extraction at three settings, but that setting only decides which components are kept - it does not change the components - so the search itself need not be repeated. This helps the host path as much as the device one. The resolution mask moves to the device as a bit mask, uploaded when the limits change rather than per frame, since the compaction needs it there. Parity is asserted permanently rather than argued: five cases covering realistic frames, occupancy from a hundred pixels to past the cap, the pathological geometries including rings, the resolution mask, and a hundred-repeat determinism check - requiring the same partition, the same spot order, and identical counts. The centroid is a float sum and therefore order-dependent, so the device walks each component from its root in ascending order and fuses its multiply-add the way the host's does; note that whether the host fuses at all depends on the architecture flags, so exact centroid equality is asserted where the compiler fuses and a two-ulp bound otherwise. Making those accumulators integer would remove that dependence entirely and is worth doing separately. Regression set: all 37 crystals identical to the last printed digit. Unit suite passes with the new cases. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-02 13:34:43 +02:00