From 04554f634be015878771d02ebad5454278e18573 Mon Sep 17 00:00:00 2001
From: Emilia Allison <EAllison@highresbio.com>
Date: Fri, 15 Nov 2024 15:28:01 -0600
Subject: [PATCH] fix: Optimize region transfer map

---
 plate-tool-lib/src/transfer_region.rs | 58 ++++++++++++++++-----------
 1 file changed, 35 insertions(+), 23 deletions(-)

diff --git a/plate-tool-lib/src/transfer_region.rs b/plate-tool-lib/src/transfer_region.rs
index a2227a2..a452c8a 100644
--- a/plate-tool-lib/src/transfer_region.rs
+++ b/plate-tool-lib/src/transfer_region.rs
@@ -202,22 +202,30 @@ impl TransferRegion {
                         );
                         let count = (
                             // How many times can we replicate?
-                            (1..)
-                                .position(|n| {
-                                    n * number_used_src_wells.0 * il_dest.0.unsigned_abs()
-                                        - il_dest.0.unsigned_abs()
-                                        + 1
-                                        > d_dims.0
-                                })
-                                .unwrap() as u8,
-                            (1..)
-                                .position(|n| {
-                                    n * number_used_src_wells.1 * il_dest.1.unsigned_abs()
-                                        - il_dest.1.unsigned_abs()
-                                        + 1
-                                        > d_dims.1
-                                })
-                                .unwrap() as u8,
+                            if il_dest.0.unsigned_abs() == 0 {
+                                1
+                            } else {
+                                (1..)
+                                    .position(|n| {
+                                        (n * number_used_src_wells.0 * il_dest.0.unsigned_abs())
+                                            .saturating_sub(il_dest.0.unsigned_abs())
+                                            + 1
+                                            > d_dims.0
+                                    })
+                                    .unwrap() as u8
+                            },
+                            if il_dest.1.unsigned_abs() == 0 {
+                                1
+                            } else {
+                                (1..)
+                                    .position(|n| {
+                                        (n * number_used_src_wells.1 * il_dest.1.unsigned_abs())
+                                            .saturating_sub(il_dest.1.unsigned_abs())
+                                            + 1
+                                            > d_dims.1
+                                    })
+                                    .unwrap() as u8
+                            },
                         );
                         let i = i
                             .saturating_sub(s_ul.row)
@@ -225,30 +233,34 @@ impl TransferRegion {
                         let j = j
                             .saturating_sub(s_ul.col)
                             .saturating_div(il_source.1.unsigned_abs());
+                        let checked_il_dest = (u8::max(il_dest.0.unsigned_abs(), 1u8),
+                                                u8::max(il_dest.1.unsigned_abs(), 1u8));
+                        let row_modulus = number_used_src_wells.0 * checked_il_dest.0;
+                        let column_modulus = number_used_src_wells.1 * checked_il_dest.1;
 
                         Some(
                             possible_destination_wells
                                 .into_iter()
-                                .filter(|Well { row: x , ..}| {
+                                .filter(|Well { row: x, .. }| {
                                     x.checked_sub(d_ul.row).unwrap()
-                                        % (number_used_src_wells.0 * il_dest.0.unsigned_abs()) // Counter along x
+                                        % row_modulus // Counter along x
                                     == (il_dest.0.unsigned_abs() *i)
-                                        % (number_used_src_wells.0 * il_dest.0.unsigned_abs())
+                                        % row_modulus
                                 })
                                 .filter(|Well { col: y, .. }| {
                                     y.checked_sub(d_ul.col).unwrap()
-                                        % (number_used_src_wells.1 * il_dest.1.unsigned_abs()) // Counter along u
+                                        % column_modulus // Counter along u
                                     == (il_dest.1.unsigned_abs() *j)
-                                        % (number_used_src_wells.1 * il_dest.1.unsigned_abs())
+                                        % column_modulus
                                 })
                                 .filter(|Well { row: x, col: y }| {
                                     // How many times have we replicated? < How many are we allowed
                                     // to replicate?
                                     x.checked_sub(d_ul.row).unwrap().div_euclid(
-                                        number_used_src_wells.0 * il_dest.0.unsigned_abs(),
+                                        row_modulus
                                     ) < count.0
                                         && y.checked_sub(d_ul.col).unwrap().div_euclid(
-                                            number_used_src_wells.1 * il_dest.1.unsigned_abs(),
+                                            column_modulus
                                         ) < count.1
                                 })
                                 .collect(),