feat: Add the support of 'vips_rot' API

README.md

@@ -11,6 +11,8 @@ This project is deployed and used in production at Criteo to serve billions of i
 
 Not all libvips capabilities are implemented. JVips currently exposes:
 - Resize
+- Rotate by a multiple of 90 degrees
+- Autofix rotation based on image EXIF metadata
 - Pad
 - Crop
 - Find trim (get bounding box)
@@ -189,12 +191,13 @@ The following steps explain how to bind a function from `libvips`.
 
 Let's add `hasAlpha()` method:
 
-1. Declare method in [`VipsImage`](src/main/java/com/criteo/vips/VipsImage.java) interface
-2. Declare native method in [`VipsImageImpl`](src/main/java/com/criteo/vips/VipsImageImpl.java)
+1. Declare the method in [`VipsImage`](src/main/java/com/criteo/vips/VipsImage.java) class and
+   [Image](src/main/java/com/criteo/vips/Image.java) interface
+1. Declare the native method in [`VipsImage`](src/main/java/com/criteo/vips/VipsImage.java) class
 ```java
 public native boolean hasAlpha();
 ```
-3. Run build.sh to generate JNI header file:
+1. Run build.sh to generate JNI header file:
 ```c
 /*
  * Class:     com_criteo_vips_VipsImageImpl
@@ -204,7 +207,7 @@ public native boolean hasAlpha();
 JNIEXPORT jboolean JNICALL Java_com_criteo_vips_VipsImageImpl_hasAlpha
   (JNIEnv *, jobject);
 ```
-4. Define and implement function in src/main/c/VipsImage.c
+1. Define and implement function in [VipsImage.c](src/main/c/VipsImage.c)
 ```c
 JNIEXPORT jboolean JNICALL
 Java_com_criteo_vips_VipsImageImpl_hasAlpha(JNIEnv *env, jobject obj)

src/main/c/VipsImage.c

@@ -796,6 +796,21 @@ JNICALL Java_com_criteo_vips_VipsImage_autorot(JNIEnv *env, jobject image_obj)
     g_object_unref(im);
 }
 
+JNIEXPORT void
+JNICALL Java_com_criteo_vips_VipsImage_rotNative(JNIEnv *env, jobject image_obj, jint angle)
+{
+    VipsImage *im = (VipsImage *) (*env)->GetLongField(env, image_obj, handle_fid);
+    VipsImage *out = NULL;
+
+    if (vips_rot(im, &out, angle, NULL))
+    {
+        throwVipsException(env, "Unable to rotate image");
+        return;
+    }
+    (*env)->SetLongField(env, image_obj, handle_fid, (jlong) out);
+    g_object_unref(im);
+}
+
 JNIEXPORT jobject
 JNICALL Java_com_criteo_vips_VipsImage_clone(JNIEnv *env, jobject image_obj)
 {

src/main/java/com/criteo/vips/Image.java

@@ -365,6 +365,13 @@ public interface Image extends AutoCloseable {
      */
     void autorot() throws VipsException;
 
+    /**
+     * Rotates the image by a multiple of 90 degrees
+     *
+     * @throws VipsException if error
+     */
+    void rot(VipsAngle angle) throws VipsException;
+
     /**
      * Remove the orientation tag on the image
      */

src/main/java/com/criteo/vips/VipsImage.java

@@ -328,6 +328,12 @@ public VipsInterpretation getInterpretation() {
 
     public native void autorot() throws VipsException;
 
+    public void rot(VipsAngle angle) throws VipsException {
+        rotNative(angle.getValue());
+    }
+
+    public native void rotNative(int angle) throws VipsException;
+
     public native void removeAutorotAngle();
 
     public native VipsImage clone() throws VipsException;

src/test/java/com/criteo/vips/VipsImageTest.java

@@ -895,6 +895,19 @@ public void TestExif90CWAutorot() throws IOException, VipsException {
         }
     }
 
+    @Test
+    public void TestD90Rot() throws IOException, VipsException {
+        ByteBuffer buffer = VipsTestUtils.getDirectByteBuffer("in_vips.jpg");
+
+        try (VipsImage img = new VipsImage(buffer, buffer.capacity())) {
+            int width = img.getWidth();
+            int height = img.getHeight();
+            img.rot(VipsAngle.D90);
+            assertEquals(width, img.getHeight());
+            assertEquals(height, img.getWidth());
+        }
+    }
+
     @Test
     public void TestCreateVipsImageFromFile() throws IOException, VipsException {
         String filename = VipsTestUtils.getRessourcePath("in_vips.jpg");