imagelib: Implement setImageColor

imagelib/src/main/kotlin/pikt/error/ImageValueType.kt

@@ -7,4 +7,5 @@ object ImageValueType {
 
     const val IMAGE = "image"
     const val WRITABLE_IMAGE = "writable image"
+    const val COLOR = "color"
 }

imagelib/src/main/kotlin/pikt/imagelib/AwtImage.kt

@@ -7,7 +7,7 @@ import java.io.File
 import java.io.IOException
 import javax.imageio.ImageIO
 
-private typealias AWTColor = java.awt.Color
+private typealias AwtColor = java.awt.Color
 
 /**
  * [Image] implementation based on AWT [BufferedImage] for the JVM.
@@ -22,25 +22,35 @@ class AwtImage(private val image: BufferedImage) : WritableImage {
     override val height: Int
         get() = image.height
 
-    override fun getColor(x: Int, y: Int): Color {
+    private fun checkCoordinates(x: Int, y: Int, reference: Any) {
         if (x < 0 || x >= image.width) {
             throw PiktIndexOutOfBoundsException(
                 index = x,
                 size = image.width,
-                reference = object {}
+                reference
             )
         }
 
         if (y < 0 || y >= image.height) {
             throw PiktIndexOutOfBoundsException(
                 index = y,
                 size = image.height,
-                reference = object {}
+                reference
             )
         }
+    }
+
+    override fun getColor(x: Int, y: Int): Color {
+        this.checkCoordinates(x, y, reference = object {})
 
         val rgb = image.getRGB(x, y)
-        return AWTColor(rgb).toPiktColor()
+        return AwtColor(rgb).toPiktColor()
+    }
+
+    override fun setColor(x: Int, y: Int, color: Color) {
+        this.checkCoordinates(x, y, reference = object {})
+
+        image.setRGB(x, y, color.toAwtColor().rgb)
     }
 
     override fun save(file: File) {
@@ -53,7 +63,8 @@ class AwtImage(private val image: BufferedImage) : WritableImage {
 
     override fun toString() = "AwtImage (width=$width, height=$height)"
 
-    private fun AWTColor.toPiktColor() = Color(red, green, blue)
+    private fun AwtColor.toPiktColor() = Color(red, green, blue)
+    private fun Color.toAwtColor() = AwtColor(red, green, blue)
 
     companion object : ImageFactory<AwtImage> {
 

imagelib/src/main/kotlin/pikt/imagelib/ImageFunctions.kt

@@ -1,5 +1,6 @@
 package pikt.imagelib
 
+import pikt.error.ImageValueType.COLOR
 import pikt.error.ImageValueType.IMAGE
 import pikt.error.ImageValueType.WRITABLE_IMAGE
 import pikt.error.PiktIOException
@@ -12,6 +13,42 @@ import java.io.File
 // Top-level functions to access image methods from Pikt.
 // The only supported implementation is currently the AWT one for the JVM.
 
+/**
+ * @throws PiktWrongArgumentTypeException if [image] is not an [Image], or is not a [WritableImage] and [requireWritable] is `true`.
+ */
+private fun checkImageType(image: Any, requireWritable: Boolean = false, reference: Any) {
+    if (image !is Image || (requireWritable && image !is WritableImage)) {
+        throw PiktWrongArgumentTypeException(
+            parameterName = "image",
+            argumentValue = image,
+            expectedType = if (requireWritable) WRITABLE_IMAGE else IMAGE,
+            reference
+        )
+    }
+}
+
+/**
+ * @throws PiktWrongArgumentTypeException if [x] and/or [y] are not numbers.
+ */
+private fun checkCoordinatesType(x: Any, y: Any, reference: Any) {
+    if (x !is Int) {
+        throw PiktWrongArgumentTypeException(
+            parameterName = "x",
+            argumentValue = x,
+            expectedType = NUMBER,
+            reference
+        )
+    }
+    if (y !is Int) {
+        throw PiktWrongArgumentTypeException(
+            parameterName = "y",
+            argumentValue = y,
+            expectedType = NUMBER,
+            reference
+        )
+    }
+}
+
 /**
  * Instantiates a new writable [Image].
  * @param width image width as [Int]
@@ -53,48 +90,24 @@ fun newImage(pathOrFile: Any): WritableImage = AwtImage.fromFile(newFile(pathOrF
  * @throws PiktIOException if the image could not be saved
  */
 fun saveImage(image: Any, pathOrFile: Any) {
-    if (image !is WritableImage) {
-        throw PiktWrongArgumentTypeException(
-            parameterName = "image",
-            argumentValue = image,
-            expectedType = WRITABLE_IMAGE,
-            reference = object {}
-        )
-    }
-
-    image.save(newFile(pathOrFile))
+    checkImageType(image, requireWritable = true, reference = object {})
+    (image as WritableImage).save(newFile(pathOrFile))
 }
 
 /**
  * @return width of [image]
  */
 fun imageWidth(image: Any): Int {
-    if (image !is Image) {
-        throw PiktWrongArgumentTypeException(
-            parameterName = "image",
-            argumentValue = image,
-            expectedType = IMAGE,
-            reference = object {}
-        )
-    }
-
-    return image.width
+    checkImageType(image, reference = object {})
+    return (image as Image).width
 }
 
 /**
  * @return height of [image]
  */
 fun imageHeight(image: Any): Int {
-    if (image !is Image) {
-        throw PiktWrongArgumentTypeException(
-            parameterName = "image",
-            argumentValue = image,
-            expectedType = IMAGE,
-            reference = object {}
-        )
-    }
-
-    return image.height
+    checkImageType(image, reference = object {})
+    return (image as Image).height
 }
 
 /**
@@ -104,31 +117,31 @@ fun imageHeight(image: Any): Int {
  * @throws PiktIndexOutOfBoundsException if one of the coordinates is negative or greater than the image size
  */
 fun getImageColor(image: Any, x: Any, y: Any): Color {
-    if (image !is Image) {
-        throw PiktWrongArgumentTypeException(
-            parameterName = "image",
-            argumentValue = image,
-            expectedType = IMAGE,
-            reference = object {}
-        )
-    }
+    checkImageType(image, reference = object {})
+    checkCoordinatesType(x, y, object {})
 
-    if (x !is Int) {
-        throw PiktWrongArgumentTypeException(
-            parameterName = "x",
-            argumentValue = x,
-            expectedType = NUMBER,
-            reference = object {}
-        )
-    }
-    if (y !is Int) {
+    return (image as Image).getColor(x as Int, y as Int)
+}
+
+/**
+ * Changes the color of a pixel of the [image] at the given coordinates.
+ * @param x X coordinate
+ * @param y Y coordinate
+ * @param color color to set
+ * @throws PiktIndexOutOfBoundsException if one of the coordinates is negative or greater than the image size
+ */
+fun setImageColor(image: Any, x: Any, y: Any, color: Any) {
+    checkImageType(image, requireWritable = true, reference = object {})
+    checkCoordinatesType(x, y, reference = object {})
+
+    if (color !is Color) {
         throw PiktWrongArgumentTypeException(
-            parameterName = "y",
-            argumentValue = y,
-            expectedType = NUMBER,
+            parameterName = "color",
+            argumentValue = color,
+            expectedType = COLOR,
             reference = object {}
         )
     }
 
-    return image.getColor(x, y)
+    return (image as WritableImage).setColor(x as Int, y as Int, color)
 }

imagelib/src/main/kotlin/pikt/imagelib/WritableImage.kt

@@ -1,13 +1,23 @@
 package pikt.imagelib
 
 import pikt.error.PiktIOException
+import pikt.error.PiktIndexOutOfBoundsException
 import java.io.File
 
 /**
  * An image that can be modified and saved on file.
  */
 interface WritableImage : Image {
 
+    /**
+     * Changes the color of a pixel.
+     * @param x X coordinate
+     * @param y Y coordinate
+     * @param color color to set at the given coordinates
+     * @throws PiktIndexOutOfBoundsException if one of the coordinates is negative or greater than the image size
+     */
+    fun setColor(x: Int, y: Int, color: Color)
+
     /**
      * Saves this image to file.
      * @param file file to save the image to

imagelib/src/main/resources/colors.properties

@@ -2,4 +2,5 @@ newImage=B41EFF
 saveImage=681EFF
 imageWidth=
 imageHeight=
-getImageColor=
+getImageColor=
+setImageColor=