Add never_flip_attachments to TOML metadata. (#203)

This adds a new `never_flip_attachments` property to TOML metadata, as discussed in #184, and sets it to `true` for the `face_nest` symbol.

assets/symbols/_template.toml

@@ -37,5 +37,11 @@ attach_to = ["tail", "leg", "arm", "horn", "crown"]
 # If true, symbol will rotate clockwise instead of default counter-clockwise
 rotate_clockwise = false
 
+# If true, this indicates that we should never horizontally flip the
+# orientation of a symbol when attaching it.  Otherwise, we will flip
+# the symbol horizontally if it's facing left, and flip it horizontally
+# again if it's facing down.
+never_flip_attachments = false
+
 # If true, symbol may be used as large background shape in some compositions.
 background = false

assets/symbols/face_nest.toml

@@ -5,5 +5,6 @@ never_be_nested = true
 
 invert_nested = true
 
+never_flip_attachments = true
 
 attach_to = []

lib/creature-symbol.tsx

@@ -127,15 +127,19 @@ const AttachedCreatureSymbol: React.FC<AttachedCreatureSymbolProps> = ({
       continue;
     }
 
+    let xFlip = 1;
+
+    if (!parent.meta?.never_flip_attachments) {
       // If we're attaching something oriented towards the left, horizontally flip
       // the attachment image.
-    let xFlip = parentAp.normal.x < 0 ? -1 : 1;
+      xFlip = parentAp.normal.x < 0 ? -1 : 1;
 
       // Er, things look weird if we don't inverse the flip logic for
       // the downward-facing attachments, like legs...
       if (parentAp.normal.y > 0) {
         xFlip *= -1;
       }
+    }
 
     const t = getAttachmentTransforms(parentAp, {
       point: ourAp.point,

lib/svg-symbol-metadata.ts

@@ -30,6 +30,14 @@ type SvgSymbolMetadataBooleans = {
    * This changes the rotation direction to clockwise.
    */
   rotate_clockwise?: boolean;
+
+  /**
+   * If true, this indicates that we should never horizontally flip the
+   * orientation of a symbol when attaching it.  Otherwise, we will flip
+   * the symbol horizontally if it's facing left, and flip it horizontally
+   * again if it's facing down.
+   */
+  never_flip_attachments?: boolean;
 };
 
 const METADATA_BOOLEANS: Set<keyof SvgSymbolMetadataBooleans> = new Set([
@@ -38,6 +46,7 @@ const METADATA_BOOLEANS: Set<keyof SvgSymbolMetadataBooleans> = new Set([
   "never_be_nested",
   "invert_nested",
   "rotate_clockwise",
+  "never_flip_attachments",
 ]);
 
 function isSvgSymbolMetadataBoolean(