Expose angle option in tile feature (lovell#1121)

Author: BiancoA

lib/output.js

@@ -319,6 +319,7 @@ function toFormat (format, options) {
  * @param {Object} [tile]
  * @param {Number} [tile.size=256] tile size in pixels, a value between 1 and 8192.
  * @param {Number} [tile.overlap=0] tile overlap in pixels, a value between 0 and 8192.
+ * @param {Number} [tile.angle=0] tile, angle of rotation, must be a multiple of 90..
  * @param {String} [tile.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
  * @param {String} [tile.layout='dz'] filesystem layout, possible values are `dz`, `zoomify` or `google`.
  * @returns {Sharp}
@@ -361,13 +362,23 @@ function tile (tile) {
         throw new Error('Invalid tile layout ' + tile.layout);
       }
     }
+
+    // Angle of rotation,
+    if (is.defined(tile.angle)) {
+      if (is.integer(tile.angle) && !(tile.angle % 90)) {
+        this.options.tileAngle = tile.angle;
+      } else {
+        throw new Error('Unsupported angle: angle must be a positive/negative multiple of 90 ' + tile.angle);
+      }
+    }
   }
   // Format
   if (is.inArray(this.options.formatOut, ['jpeg', 'png', 'webp'])) {
     this.options.tileFormat = this.options.formatOut;
   } else if (this.options.formatOut !== 'input') {
     throw new Error('Invalid tile format ' + this.options.formatOut);
   }
+
   return this._updateFormatOut('dz');
 }
 

src/pipeline.cc

@@ -917,7 +917,8 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("overlap", baton->tileOverlap)
             ->set("container", baton->tileContainer)
             ->set("layout", baton->tileLayout)
-            ->set("suffix", const_cast<char*>(suffix.data())));
+            ->set("suffix", const_cast<char*>(suffix.data()))
+            ->set("angle", CalculateAngleRotation(baton->tileAngle)));
           baton->formatOut = "dz";
         } else if (baton->formatOut == "v" || (mightMatchInput && isV) ||
           (willMatchInput && inputImageType == ImageType::VIPS)) {
@@ -1263,6 +1264,7 @@ NAN_METHOD(pipeline) {
   baton->tileSize = AttrTo<uint32_t>(options, "tileSize");
   baton->tileOverlap = AttrTo<uint32_t>(options, "tileOverlap");
   std::string tileContainer = AttrAsStr(options, "tileContainer");
+  baton->tileAngle = AttrTo<int32_t>(options, "tileAngle");
   if (tileContainer == "zip") {
     baton->tileContainer = VIPS_FOREIGN_DZ_CONTAINER_ZIP;
   } else {

src/pipeline.h

@@ -132,6 +132,7 @@ struct PipelineBaton {
   VipsForeignDzContainer tileContainer;
   VipsForeignDzLayout tileLayout;
   std::string tileFormat;
+  int tileAngle;
 
   PipelineBaton():
     input(nullptr),
@@ -206,7 +207,8 @@ struct PipelineBaton {
     tileSize(256),
     tileOverlap(0),
     tileContainer(VIPS_FOREIGN_DZ_CONTAINER_FS),
-    tileLayout(VIPS_FOREIGN_DZ_LAYOUT_DZ) {
+    tileLayout(VIPS_FOREIGN_DZ_LAYOUT_DZ),
+    tileAngle(0){
       background[0] = 0.0;
       background[1] = 0.0;
       background[2] = 0.0;

test/unit/tile.js

@@ -146,13 +146,38 @@ describe('Tile', function () {
 
   it('Prevent larger overlap than default size', function () {
     assert.throws(function () {
-      sharp().tile({overlap: 257});
+      sharp().tile({
+        overlap: 257
+      });
     });
   });
 
   it('Prevent larger overlap than provided size', function () {
     assert.throws(function () {
-      sharp().tile({size: 512, overlap: 513});
+      sharp().tile({
+        size: 512,
+        overlap: 513
+      });
+    });
+  });
+
+  it('Valid rotation angle values pass', function () {
+    [90, 270, -90].forEach(function (angle) {
+      assert.doesNotThrow(function () {
+        sharp().tile({
+          angle: angle
+        });
+      });
+    });
+  });
+
+  it('Invalid rotation angle values fail', function () {
+    ['zoinks', 1.1, -1, 27].forEach(function (angle) {
+      assert.throws(function () {
+        sharp().tile({
+          angle: angle
+        });
+      });
     });
   });
 
@@ -192,6 +217,40 @@ describe('Tile', function () {
     });
   });
 
+  it('Deep Zoom layout with custom size+angle', function (done) {
+    const directory = fixtures.path('output.512_90.dzi_files');
+    rimraf(directory, function () {
+      sharp(fixtures.inputJpg)
+        .tile({
+          size: 512,
+          angle: 90
+        })
+        .toFile(fixtures.path('output.512_90.dzi'), function (err, info) {
+          if (err) throw err;
+          assert.strictEqual('dz', info.format);
+          assert.strictEqual(2725, info.width);
+          assert.strictEqual(2225, info.height);
+          assert.strictEqual(3, info.channels);
+          assert.strictEqual('undefined', typeof info.size);
+          assertDeepZoomTiles(directory, 512, 13, done);
+          // Verifies tiles in 10th level are rotated
+          let tile = path.join(directory, '10', '0_1.jpeg');
+          // verify that the width and height correspond to the rotated image
+          // expected are w=512 and h=170 for the 0_1.jpeg.
+          // if a 0 angle is supplied to the .tile function
+          // the expected values are w=170 and h=512 for the 1_0.jpeg
+          sharp(tile).metadata(function (err, metadata) {
+            if (err) {
+              throw err;
+            } else {
+              assert.strictEqual(true, metadata.width === 512);
+              assert.strictEqual(true, metadata.height === 170);
+            }
+          });
+        });
+    });
+  });
+
   it('Zoomify layout', function (done) {
     const directory = fixtures.path('output.zoomify.dzi');
     rimraf(directory, function () {
@@ -244,7 +303,9 @@ describe('Tile', function () {
     const directory = fixtures.path('output.jpg.google.dzi');
     rimraf(directory, function () {
       sharp(fixtures.inputJpg)
-        .jpeg({ quality: 1 })
+        .jpeg({
+          quality: 1
+        })
         .tile({
           layout: 'google'
         })
@@ -279,7 +340,9 @@ describe('Tile', function () {
     const directory = fixtures.path('output.png.google.dzi');
     rimraf(directory, function () {
       sharp(fixtures.inputJpg)
-        .png({ compressionLevel: 1 })
+        .png({
+          compressionLevel: 1
+        })
         .tile({
           layout: 'google'
         })
@@ -314,7 +377,9 @@ describe('Tile', function () {
     const directory = fixtures.path('output.webp.google.dzi');
     rimraf(directory, function () {
       sharp(fixtures.inputJpg)
-        .webp({ quality: 1 })
+        .webp({
+          quality: 1
+        })
         .tile({
           layout: 'google'
         })
@@ -363,8 +428,12 @@ describe('Tile', function () {
             assert.strictEqual(true, stat.isFile());
             assert.strictEqual(true, stat.size > 0);
             fs.createReadStream(container)
-              .pipe(unzip.Extract({path: path.dirname(extractTo)}))
-              .on('error', function (err) { throw err; })
+              .pipe(unzip.Extract({
+                path: path.dirname(extractTo)
+              }))
+              .on('error', function (err) {
+                throw err;
+              })
               .on('close', function () {
                 assertDeepZoomTiles(directory, 256, 13, done);
               });
@@ -395,8 +464,12 @@ describe('Tile', function () {
             assert.strictEqual(true, stat.isFile());
             assert.strictEqual(true, stat.size > 0);
             fs.createReadStream(container)
-              .pipe(unzip.Extract({path: path.dirname(extractTo)}))
-              .on('error', function (err) { throw err; })
+              .pipe(unzip.Extract({
+                path: path.dirname(extractTo)
+              }))
+              .on('error', function (err) {
+                throw err;
+              })
               .on('close', function () {
                 assertDeepZoomTiles(directory, 256, 13, done);
               });