Implemented import functionality for Aseprite animations

src/de/gurkenlabs/litiengine/graphics/animation/AsepriteHandler.java

@@ -1,21 +1,181 @@
 package de.gurkenlabs.litiengine.graphics.animation;
 
+import java.io.File;
+import java.io.FileReader;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.awt.Dimension;
 import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.util.Set;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.List;
+import javax.imageio.ImageIO;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.annotations.SerializedName;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+import com.google.gson.JsonObject;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.List;
-
+import de.gurkenlabs.litiengine.graphics.Spritesheet;
 import de.gurkenlabs.litiengine.graphics.animation.Animation;
 import de.gurkenlabs.litiengine.graphics.animation.KeyFrame;
-import de.gurkenlabs.litiengine.graphics.Spritesheet;
 
+/**
+ * Offers an interface to import Aseprite JSON export format.
+ * Note: requires animation key frames to have same dimensions to support internal animation format.
+ * */
 public class AsepriteHandler {
 
+  /** 
+   * Thrown to indicate error when importing Aseprite JSON format.
+   * */
+  public static class ImportAnimationException extends Error {
+    public ImportAnimationException(String message) {
+      super(message);
+    }
+  }
+
+  /** 
+   * Imports an Aseprite animation (.json + sprite sheet).
+   * Note: searches for sprite sheet path through .json metadata, specifically 'image' element. This should be an absolute path in system.
+   *
+   * @param jsonPath path (including filename) to Aseprite JSON.
+   * 
+   * @return Animation object represented by each key frame in Aseprite sprite sheet.
+   * */
+  public static Animation importAnimation(String jsonPath) throws IOException, FileNotFoundException, AsepriteHandler.ImportAnimationException {
+
+    JsonElement rootElement = null;
+    try { rootElement = getRootJsonElement(jsonPath); }
+    catch(FileNotFoundException e) {
+      throw new FileNotFoundException("FileNotFoundException: Could not find .json file " + jsonPath);
+    }
+
+    String spriteSheetPath = getSpriteSheetPath(rootElement);
+    File spriteSheetFile = new File(spriteSheetPath);
+    if(!spriteSheetFile.exists()) {
+      throw new FileNotFoundException("FileNotFoundException: Could not find sprite sheet file. " +
+                                      "Expected location is 'image' in .json metadata, which evaluates to: " + spriteSheetPath);
+    }
+
+    Dimension keyFrameDimensions = getKeyFrameDimensions(rootElement);
+    if(areKeyFramesSameDimensions(rootElement, keyFrameDimensions)) {
+
+      BufferedImage image = null;
+      try { image = ImageIO.read(spriteSheetFile); }
+      catch(IOException e) {
+        throw new IOException("IOException: Could not write sprite sheet data to BufferedImage object.");
+      }
+
+      Spritesheet spriteSheet = new Spritesheet(image,
+                                                spriteSheetPath,
+                                                (int)keyFrameDimensions.getWidth(),
+                                                (int)keyFrameDimensions.getHeight());
+
+      return new Animation(spriteSheet, false, getKeyFrameDurations(rootElement));
+    }
+
+    throw new AsepriteHandler.ImportAnimationException("AsepriteHandler.ImportAnimationException: animation key frames require same dimensions.");
+  }
+
+  /**
+   * @param jsonPath path (including filename) to Aseprite .json file.
+   *
+   * @return root element of JSON data.
+   * */
+  private static JsonElement getRootJsonElement(String jsonPath) throws FileNotFoundException {
+
+    File jsonFile = new File(jsonPath);
+
+    try { 
+      JsonElement rootElement = JsonParser.parseReader(new FileReader(jsonFile)); 
+      return rootElement;
+    }
+    catch(FileNotFoundException e) { throw e; }
+  }
+
+  /**
+   * @param rootElement root element of JSON data.
+   *
+   * @return path (including filename) to animation sprite sheet.
+   * */
+  private static String getSpriteSheetPath(JsonElement rootElement) {
+
+    JsonElement metaData = rootElement.getAsJsonObject().get("meta");
+    String spriteSheetPath = metaData.getAsJsonObject().get("image").getAsString();
+
+    return spriteSheetPath;
+  }
+
+  /**
+   * @param rootElement root element of JSON data.
+   *
+   * @return dimensions of first key frame.
+   * */
+  private static Dimension getKeyFrameDimensions(JsonElement rootElement) {
+
+    JsonElement frames = rootElement.getAsJsonObject().get("frames");
+
+    JsonObject firstFrameObject = frames.getAsJsonObject().entrySet().iterator().next().getValue().getAsJsonObject();
+    JsonObject frameDimensions = firstFrameObject.get("sourceSize").getAsJsonObject();
+
+    int frameWidth = frameDimensions.get("w").getAsInt();
+    int frameHeight = frameDimensions.get("h").getAsInt();
+
+    return new Dimension(frameWidth, frameHeight);
+  }
+
+  /**
+   * @param rootElement root element of JSON data.
+   * @param expected expected dimensions of each key frame.
+   *
+   * @return true if key frames have same duration.
+   * */
+  private static boolean areKeyFramesSameDimensions(JsonElement rootElement, Dimension expected) {
+
+    JsonElement frames = rootElement.getAsJsonObject().get("frames");
+
+    for(Map.Entry<String, JsonElement> entry : frames.getAsJsonObject().entrySet()) {
+      JsonObject frameObject = entry.getValue().getAsJsonObject();
+      JsonObject frameDimensions = frameObject.get("sourceSize").getAsJsonObject();
+
+      int frameWidth = frameDimensions.get("w").getAsInt();
+      int frameHeight = frameDimensions.get("h").getAsInt();
+
+      if(frameWidth != expected.getWidth() || frameHeight != expected.getHeight())
+        return false;
+    }
+
+    return true;
+  }
+
+  /**
+   * @param rootElement root element of JSON data.
+   *
+   * @return integer array representing duration of each key frame.
+   * */
+  public static int[] getKeyFrameDurations(JsonElement rootElement) {
+
+    JsonElement frames = rootElement.getAsJsonObject().get("frames");
+
+    Set<Map.Entry<String, JsonElement>> keyFrameSet = frames.getAsJsonObject().entrySet();
+
+    int[] keyFrameDurations = new int[keyFrameSet.size()];
+
+    int frameIndex = 0;
+    for(Map.Entry<String, JsonElement> entry : keyFrameSet) {
+      JsonObject frameObject = entry.getValue().getAsJsonObject();
+      int frameDuration = frameObject.get("duration").getAsInt();
+      keyFrameDurations[frameIndex++] = frameDuration;
+    }
+
+    return keyFrameDurations;
+  }
+
     /**
      * Error that is thrown by the export class
      */
@@ -207,6 +367,4 @@ public Layer(String name, int opacity, String blendMode){
         }
 
     } 
-}
-
-
+}

tests/de/gurkenlabs/litiengine/graphics/animation/AsepriteHandlerTests.java

@@ -1,32 +1,92 @@
 package de.gurkenlabs.litiengine.graphics.animation;
 
+import java.io.IOException;
 import java.io.FileNotFoundException;
 import java.awt.image.BufferedImage;
 
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
-
 import de.gurkenlabs.litiengine.graphics.Spritesheet;
 import de.gurkenlabs.litiengine.graphics.animation.Animation;
+import de.gurkenlabs.litiengine.graphics.animation.AsepriteHandler.ImportAnimationException;
+import de.gurkenlabs.litiengine.resources.ImageFormat;
 
 public class AsepriteHandlerTests {
 
+  /**
+   * Tests that Aseprite animation import works as expected when given valid input.
+   */
+  @Test
+  public void importAsepriteAnimationTest() {
+    try {
+      Animation animation = AsepriteHandler.importAnimation("tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0001.json");
+      assertEquals("Sprite-0001-sheet", animation.getName());
+      assertEquals(300, animation.getTotalDuration());
+      for(int keyFrameDuration : animation.getKeyFrameDurations())
+        assertEquals(100, keyFrameDuration);
+
+      Spritesheet spriteSheet = animation.getSpritesheet();
+      assertEquals(32, spriteSheet.getSpriteHeight());
+      assertEquals(32, spriteSheet.getSpriteWidth());
+      assertEquals(3, spriteSheet.getTotalNumberOfSprites());
+      assertEquals(1, spriteSheet.getRows());
+      assertEquals(3, spriteSheet.getColumns());
+      assertEquals(ImageFormat.PNG, spriteSheet.getImageFormat());
+
+      BufferedImage image = spriteSheet.getImage();
+      assertEquals(96, image.getWidth());
+      assertEquals(32, image.getHeight());
+    }
+    catch(FileNotFoundException e) {
+      fail(e.getMessage());
+    }
+    catch(IOException e) {
+      fail(e.getMessage());
+    }
+    catch(AsepriteHandler.ImportAnimationException e) {
+      fail(e.getMessage());
+    }
+  }
+
+  /**
+   * Test that if AsepriteHandler.ImportAnimationException will be throwed if different frame dimensions are provided.
+   */
+  @Test
+  public void ImportAnimationExceptionTest() {
+
+      Throwable exception = assertThrows(ImportAnimationException.class, () -> AsepriteHandler.importAnimation("tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0002.json"));
+      assertEquals("AsepriteHandler.ImportAnimationException: animation key frames require same dimensions.", exception.getMessage());   
+  }
+
+  /**
+   * Tests thrown FileNotFoundException when importing an Aseprite animation.
+   *
+   * 1.first, we test if FileNotFoundException would be throwed if .json file cannot be found.
+   * 2.then we test if FileNotFoundException would be throwed if spritesheet file cannot be found.
+   */
+  @Test
+  public void FileNotFoundExceptionTest(){
+    Throwable exception_withoutJsonFile = assertThrows(FileNotFoundException.class, () -> AsepriteHandler.importAnimation("tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0003.json"));
+    assertEquals("FileNotFoundException: Could not find .json file tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0003.json", exception_withoutJsonFile.getMessage());
+    Throwable exception_withoutSpriteSheet = assertThrows(FileNotFoundException.class, () -> AsepriteHandler.importAnimation("tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0004.json"));
+    assertEquals("FileNotFoundException: Could not find sprite sheet file. Expected location is 'image' in .json metadata, which evaluates to: tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0002-sheet.png", exception_withoutSpriteSheet.getMessage());
+  }
 
   /**
    * Test that just create a json and prints in to standard output. 
    */
   @Test
   public void exportAnimationTest() {
-    String spritesheetPath = "C:/Users/Nikla/Documents/Programmering/SoftwareFundamentals/Assignment-3-EC/litiengine/tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animation/Sprite-0001-sheet.png";
+    String spritesheetPath = "tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0001-sheet.png";
     BufferedImage image = new BufferedImage(96, 32, BufferedImage.TYPE_4BYTE_ABGR);
     Spritesheet spritesheet = new Spritesheet(image, spritesheetPath, 32, 32);
     Animation animation = new Animation(spritesheet, false, false, 2,2,2);
 
     AsepriteHandler aseprite = new AsepriteHandler();
     String result = aseprite.exportAnimation(animation);
     System.out.println(result);
-
   }
-}
+}

tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0001.json

@@ -0,0 +1,40 @@
+{ "frames": {
+   "Sprite-0001 0.png": {
+    "frame": { "x": 0, "y": 0, "w": 32, "h": 32 },
+    "rotated": false,
+    "trimmed": false,
+    "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+    "sourceSize": { "w": 32, "h": 32 },
+    "duration": 100
+   },
+   "Sprite-0001 1.png": {
+    "frame": { "x": 32, "y": 0, "w": 32, "h": 32 },
+    "rotated": false,
+    "trimmed": false,
+    "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+    "sourceSize": { "w": 32, "h": 32 },
+    "duration": 100
+   },
+   "Sprite-0001 2.png": {
+    "frame": { "x": 64, "y": 0, "w": 32, "h": 32 },
+    "rotated": false,
+    "trimmed": false,
+    "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+    "sourceSize": { "w": 32, "h": 32 },
+    "duration": 100
+   }
+ },
+ "meta": {
+  "app": "http://www.aseprite.org/",
+  "version": "1.1.9-dev",
+  "image": "tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0001-sheet.png",
+  "format": "RGBA8888",
+  "size": { "w": 96, "h": 32 },
+  "scale": "1",
+  "frameTags": [
+  ],
+  "layers": [
+   { "name": "Layer 1", "opacity": 255, "blendMode": "normal" }
+  ]
+ }
+}

tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0002.json

@@ -0,0 +1,41 @@
+{ "frames": {
+    "Sprite-0002 0.png": {
+     "frame": { "x": 0, "y": 0, "w": 32, "h": 32 },
+     "rotated": false,
+     "trimmed": false,
+     "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+     "sourceSize": { "w": 32, "h": 32 },
+     "duration": 100
+    },
+    "Sprite-0002 1.png": {
+     "frame": { "x": 32, "y": 0, "w": 32, "h": 32 },
+     "rotated": false,
+     "trimmed": false,
+     "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+     "sourceSize": { "w": 64, "h": 64 },
+     "duration": 100
+    },
+    "Sprite-0002 2.png": {
+     "frame": { "x": 64, "y": 0, "w": 32, "h": 32 },
+     "rotated": false,
+     "trimmed": false,
+     "spriteSourceSize": { "x": 0, "y": 0, "w": 32, "h": 32 },
+     "sourceSize": { "w": 32, "h": 32 },
+     "duration": 100
+    }
+  },
+  "meta": {
+   "app": "http://www.aseprite.org/",
+   "version": "1.1.9-dev",
+   "image": "tests/de/gurkenlabs/litiengine/graphics/animation/aseprite_test_animations/Sprite-0001-sheet.png",
+   "format": "RGBA8888",
+   "size": { "w": 96, "h": 32 },
+   "scale": "1",
+   "frameTags": [
+   ],
+   "layers": [
+    { "name": "Layer 1", "opacity": 255, "blendMode": "normal" }
+   ]
+  }
+ }
+