handle single values as greyscale when constructing a costume

HISTORY.md

@@ -4,12 +4,16 @@
 
 * **Notable Changes:**
     * hyperized image attribute reporter primitive (monadic)
+    * when constructing a costume from a pixel list handle single values as greyscale
 * **Notable Fixes:**
     * fixed a glitch in the animation library's "sine in-out" easing function 
     * fixed a postMessage glitch in the API, thanks, Bernat!
 * **Translation Updates:**
     * Tamil, thanks, Barthdry!
 
+### 2021-01-26
+* threads: handle single values as greyscale when constructing a costume from a pixel list
+
 ### 2021-01-25
 * threads: hyperized image attribute reporter primitive (monadic)
 * pulled pending PRs

snap.html

@@ -9,7 +9,7 @@
         <script src="src/symbols.js?version=2020-10-07"></script>
         <script src="src/widgets.js?version=2021-01-05"></script>
         <script src="src/blocks.js?version=2020-12-22"></script>
-        <script src="src/threads.js?version=2021-01-25"></script>
+        <script src="src/threads.js?version=2021-01-26"></script>
         <script src="src/objects.js?version=2021-01-05"></script>
         <script src="src/gui.js?version=2021-01-21"></script>
         <script src="src/paint.js?version=2020-05-17"></script>

src/threads.js

@@ -61,7 +61,7 @@ StageMorph, SpriteMorph, StagePrompterMorph, Note, modules, isString, copy, Map,
 isNil, WatcherMorph, List, ListWatcherMorph, alert, console, TableMorph, BLACK,
 TableFrameMorph, ColorSlotMorph, isSnapObject, newCanvas, Symbol, SVG_Costume*/
 
-modules.threads = '2021-January-25';
+modules.threads = '2021-January-26';
 
 var ThreadManager;
 var Process;
@@ -5922,9 +5922,9 @@ Process.prototype.reportNewCostume = function (pixels, width, height, name) {
     src = pixels.itemsArray();
     dta = ctx.createImageData(width, height);
     for (i = 0; i < src.length; i += 1) {
-        px = src[i].itemsArray();
+        px = src[i] instanceof List ? src[i].itemsArray() : [src[i]];
         for (k = 0; k < 3; k += 1) {
-            dta.data[(i * 4) + k] = +px[k];
+            dta.data[(i * 4) + k] = px[k] === undefined ? +px[0] : +px[k];
         }
         dta.data[i * 4 + 3] = (px[3] === undefined ? 255 : +px[3]);
     }