Docs: clarify which axis is used when mirroring

lovell · May 11, 2023 · e873978 · e873978
1 parent 5255964
commit e873978
Show file tree

Hide file tree

Showing 4 changed files with 11 additions and 7 deletions.
diff --git a/docs/api-operation.md b/docs/api-operation.md
@@ -57,7 +57,8 @@ const resizeThenRotate = await sharp(input)
 
 
 ## flip
-Flip the image about the vertical Y axis. This always occurs before rotation, if any.
+Mirror the image vertically (up-down) about the x-axis.
+This always occurs before rotation, if any.
 The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
 
 
@@ -73,7 +74,8 @@ const output = await sharp(input).flip().toBuffer();
 
 
 ## flop
-Flop the image about the horizontal X axis. This always occurs before rotation, if any.
+Mirror the image horizontally (left-right) about the y-axis.
+This always occurs before rotation, if any.
 The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
 
 

diff --git a/docs/search-index.json b/docs/search-index.json
diff --git a/lib/operation.js b/lib/operation.js
@@ -80,7 +80,8 @@ function rotate (angle, options) {
 }
 
 /**
- * Flip the image about the vertical Y axis. This always occurs before rotation, if any.
+ * Mirror the image vertically (up-down) about the x-axis.
+ * This always occurs before rotation, if any.
  * The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
  *
  * @example
@@ -95,7 +96,8 @@ function flip (flip) {
 }
 
 /**
- * Flop the image about the horizontal X axis. This always occurs before rotation, if any.
+ * Mirror the image horizontally (left-right) about the y-axis.
+ * This always occurs before rotation, if any.
  * The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
  *
  * @example

diff --git a/src/pipeline.cc b/src/pipeline.cc
@@ -380,11 +380,11 @@ class PipelineWorker : public Napi::AsyncWorker {
       if (autoRotation != VIPS_ANGLE_D0) {
         image = image.rot(autoRotation);
       }
-      // Flip (mirror about Y axis)
+      // Mirror vertically (up-down) about the x-axis
       if (baton->flip || autoFlip) {
         image = image.flip(VIPS_DIRECTION_VERTICAL);
       }
-      // Flop (mirror about X axis)
+      // Mirror horizontally (left-right) about the y-axis
       if (baton->flop || autoFlop) {
         image = image.flip(VIPS_DIRECTION_HORIZONTAL);
       }