From 4d4c174a1bee3c36ad5b43fdcef9da884b462d23 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Mon, 28 Oct 2019 21:43:26 -0500
Subject: [PATCH] Allow voxel plots to be colored by material

---
 src/plot.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/plot.cpp b/src/plot.cpp
index 98a3645c7..ba63da16b 100644
--- a/src/plot.cpp
+++ b/src/plot.cpp
@@ -908,11 +908,13 @@ void create_voxel(Plot pl)
     // generate ids using plotbase
     IdData ids = pltbase.get_map<IdData>();
 
-    // select only cell ID data and flip the y-axis
-    xt::xtensor<int32_t, 2> data1 = xt::flip(xt::view(ids.data_, xt::all(), xt::all(), 0), 0);
+    // select only cell/material ID data and flip the y-axis
+    int idx = pl.color_by_ == PlotColorBy::cells ? 0 : 1;
+    xt::xtensor<int32_t, 2> data_slice = xt::view(ids.data_, xt::all(), xt::all(), idx);
+    xt::xtensor<int32_t, 2> data_flipped = xt::flip(data_slice, 0);
 
     // Write to HDF5 dataset
-    voxel_write_slice(z, dspace, dset, memspace, &(data1(0,0)));
+    voxel_write_slice(z, dspace, dset, memspace, data_flipped.data());
   }
 
   voxel_finalize(dspace, dset, memspace);