(#10, #32) Added outline support, polygon builder

New Additions:
- Polygon2D now properly supports outlines (BasicStroke only)
- revamped ModelUtil (PsdfUtil → ModelUtil)
    - Added outline, render style, and transform support
    - Refractored code to allow for later support for more file formats

Breaking Changes:
- Removed public access to all `Polygon2D` constructors. `Polygon2D`s must now be created using `Polygon2D#create`, which corresponds to a `Polygon2DBuilder` instance.
- Renamed `PsdfUtil#loadPsdf` → `ModelUtil#loadModel` & `PsdfUtil#writePsdf` → `ModelUtil#writeModel` to better represent what the methods do.

src/main/java/module-info.java

@@ -34,4 +34,5 @@
     exports tech.fastj.systems.control;
     exports tech.fastj.systems.tags;
     exports tech.fastj.graphics.util.gradients;
+    exports tech.fastj.graphics.util.io;
 }

src/main/java/tech/fastj/graphics/game/Polygon2D.java

@@ -29,7 +29,7 @@ public class Polygon2D extends GameObject {
     /** {@link Paint} representing the default fill paint value as the color black. */
     public static final Paint DefaultPaint = Color.black;
     /** {@link Stroke} representing the default outline stroke value as a 1px outline with sharp edges. */
-    public static final Stroke DefaultOutlineStroke = new BasicStroke(1f, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_MITER, 1.0f);
+    public static final BasicStroke DefaultOutlineStroke = new BasicStroke(1f, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_MITER, 1.0f);
     /** {@link Color} representing the default outline color value as the color black. */
     public static final Color DefaultOutlineColor = Color.black;
 
@@ -38,7 +38,7 @@ public class Polygon2D extends GameObject {
     private RenderStyle renderStyle;
     private Paint fillPaint;
     private Color outlineColor;
-    private Stroke outlineStroke;
+    private BasicStroke outlineStroke;
 
     /**
      * {@code Polygon2D} constructor that takes in an array of points.
@@ -134,7 +134,7 @@ public Color getOutlineColor() {
         return outlineColor;
     }
 
-    public Stroke getOutlineStroke() {
+    public BasicStroke getOutlineStroke() {
         return outlineStroke;
     }
 
@@ -158,12 +158,12 @@ public Polygon2D setOutlineColor(Color newOutlineColor) {
         return this;
     }
 
-    public Polygon2D setOutlineStroke(Stroke newStroke) {
+    public Polygon2D setOutlineStroke(BasicStroke newStroke) {
         outlineStroke = newStroke;
         return this;
     }
 
-    public Polygon2D setOutline(Stroke newStroke, Color newOutlineColor) {
+    public Polygon2D setOutline(BasicStroke newStroke, Color newOutlineColor) {
         outlineStroke = newStroke;
         outlineColor = newOutlineColor;
         return this;

src/main/java/tech/fastj/graphics/game/Polygon2DBuilder.java

@@ -4,9 +4,9 @@
 import tech.fastj.graphics.RenderStyle;
 import tech.fastj.graphics.Transform2D;
 
+import java.awt.BasicStroke;
 import java.awt.Color;
 import java.awt.Paint;
-import java.awt.Stroke;
 import java.util.Objects;
 
 public class Polygon2DBuilder {
@@ -16,7 +16,7 @@ public class Polygon2DBuilder {
     private final RenderStyle renderStyle;
 
     private Paint fillPaint = Polygon2D.DefaultPaint;
-    private Stroke outlineStroke = Polygon2D.DefaultOutlineStroke;
+    private BasicStroke outlineStroke = Polygon2D.DefaultOutlineStroke;
     private Color outlineColor = Polygon2D.DefaultOutlineColor;
 
     private Pointf translation = Transform2D.DefaultTranslation.copy();
@@ -34,7 +34,7 @@ public Polygon2DBuilder withFill(Paint fillPaint) {
         return this;
     }
 
-    public Polygon2DBuilder withOutline(Stroke outlineStroke, Color outlineColor) {
+    public Polygon2DBuilder withOutline(BasicStroke outlineStroke, Color outlineColor) {
         this.outlineStroke = Objects.requireNonNull(outlineStroke, "The outline stroke must not be null.");
         this.outlineColor = Objects.requireNonNull(outlineColor, "The outline color must not be null.");
         return this;

src/main/java/tech/fastj/graphics/util/ModelUtil.java

@@ -0,0 +1,87 @@
+package tech.fastj.graphics.util;
+
+import tech.fastj.engine.CrashMessages;
+import tech.fastj.graphics.game.Model2D;
+import tech.fastj.graphics.game.Polygon2D;
+import tech.fastj.graphics.util.io.PsdfUtil;
+import tech.fastj.graphics.util.io.SupportedFileFormats;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.LinkOption;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
+
+public class ModelUtil {
+
+    private static final Map<String, Function<List<String>, Polygon2D[]>> ModelParser = Map.of(
+            SupportedFileFormats.Psdf, PsdfUtil::parse
+    );
+
+    private static final Map<String, BiConsumer<Path, Model2D>> ModelWriter = Map.of(
+            SupportedFileFormats.Psdf, PsdfUtil::write
+    );
+
+    /**
+     * Gets a {@code Polygon2D} array, loaded from a {@code .psdf} file.
+     * <p>
+     * This method allows the user to load an array of {@code Polygon2D}s from a single file, decreasing the amount of
+     * models that have to be programmed in.
+     * <p>
+     * Furthermore, this allows for easy use of the {@code Model2D} class, allowing you to directly use the resulting
+     * array from this method to create a {@code Model2D} object.
+     *
+     * @param fileLocation Location of the file.
+     * @return An array of {@code Polygon2D}s.
+     */
+    public static Polygon2D[] loadModel(Path fileLocation) {
+        if (!Files.exists(fileLocation, LinkOption.NOFOLLOW_LINKS)) {
+            throw new IllegalArgumentException("A file was not found at \"" + fileLocation.toAbsolutePath() + "\".");
+        }
+
+        String fileExtension = getFileExtension(fileLocation);
+        checkFileExtension(fileExtension);
+
+        List<String> lines;
+        try {
+            lines = Files.readAllLines(fileLocation);
+        } catch (IOException exception) {
+            throw new IllegalStateException(
+                    CrashMessages.theGameCrashed("an issue while trying to parse file \"" + fileLocation.toAbsolutePath() + "\"."),
+                    exception
+            );
+        }
+
+        return ModelParser.get(fileExtension).apply(lines);
+    }
+
+    /**
+     * Writes a model file containing the current state of the {@code Polygon2D}s that make up the specified {@code
+     * Model2D}.
+     *
+     * @param destinationPath The destination path of the model file that will be written.
+     * @param model           The {@code Model2D} that will be written to the file.
+     */
+    public static void writeModel(Path destinationPath, Model2D model) {
+        String fileExtension = getFileExtension(destinationPath);
+        checkFileExtension(fileExtension);
+        ModelWriter.get(fileExtension).accept(destinationPath, model);
+    }
+
+    private static String getFileExtension(Path filePath) {
+        return filePath.toString().substring(filePath.toString().lastIndexOf(".") + 1);
+    }
+
+    private static void checkFileExtension(String fileExtension) {
+        if (SupportedFileFormats.valuesStream.noneMatch(fileFormat -> fileFormat.equalsIgnoreCase(fileExtension))) {
+            throw new IllegalArgumentException(
+                    "Unsupported file extension \"" + fileExtension + "\"."
+                            + System.lineSeparator()
+                            + "This engine only supports files of the following extensions: " + SupportedFileFormats.valuesString
+            );
+        }
+    }
+}