Add orx-image-fit

orx-image-fit/README.md

@@ -2,11 +2,12 @@
 
 Fits images in frames with two options, contain and cover. Similar to CSS object-fit (https://www.w3schools.com/css/css3_object-fit.asp)
 
-## usage
+`orx-image-fit` provides an extension function`imageFit` for `Drawer`.
+
+## Usage
 
 `imageFit(img: ColorBuffer, x: Double, y: Double, w: Double, h: Double, fitMethod, horizontalPosition:Double, verticalPosition:Double)`
 
-
 fitMethod
  - `contain`
  - `cover`
@@ -18,3 +19,20 @@ horizontal values
  vertical values
  - top ... bottom
  - `-1.0` ... `1.0`
+ 
+## Example 
+ 
+A quick example that fits an image to the window rectangle with a 10 pixel margin. By default
+`imageFit` uses the cover mode, which fills the target rectangle with an image.
+  
+```kotlin
+fun main() = application {
+    program {
+        val image = loadImage("data/images/pm5544.png")
+        extend {
+            drawer.imageFit(10.0, 10.0, width - 20.0, height - 20.0)
+        }
+    }
+}
+``` 
+ 

orx-image-fit/src/main/kotlin/ImageFit.kt

@@ -11,7 +11,16 @@ enum class FitMethod {
     Contain
 }
 
-fun Drawer.imageFit(img: ColorBuffer, x: Double = 0.0, y: Double = 0.0, w: Double, h: Double, fitMethod:FitMethod = FitMethod.Cover, horizontalPosition:Double = 0.0, verticalPosition:Double = 0.0) {
+fun Drawer.imageFit(
+        img: ColorBuffer,
+        x: Double = 0.0,
+        y: Double = 0.0,
+        width: Double = img.width.toDouble(),
+        height: Double = img.height.toDouble(),
+        fitMethod: FitMethod = FitMethod.Cover,
+        horizontalPosition: Double = 0.0,
+        verticalPosition: Double = 0.0
+) {
     val sourceWidth = img.width.toDouble()
     val sourceHeight = img.height.toDouble()
 
@@ -26,23 +35,23 @@ fun Drawer.imageFit(img: ColorBuffer, x: Double = 0.0, y: Double = 0.0, w: Doubl
 
     when (fitMethod) {
         FitMethod.Contain -> {
-            targetWidth = w
+            targetWidth = width
-            targetHeight = h
+            targetHeight = height
 
-            if (w <= targetWidth) {
+            if (width <= targetWidth) {
-                targetWidth = w
+                targetWidth = width
-                targetHeight = (sourceHeight / sourceWidth) * w
+                targetHeight = (sourceHeight / sourceWidth) * width
             }
 
-            if (h <= targetHeight) {
+            if (height <= targetHeight) {
-                targetHeight = h
+                targetHeight = height
-                targetWidth = (sourceWidth / sourceHeight) * h
+                targetWidth = (sourceWidth / sourceHeight) * height
             }
 
             val left = x
-            val right = x + w - targetWidth
+            val right = x + width - targetWidth
             val top = y
-            val bottom = y + h - targetHeight
+            val bottom = y + height - targetHeight
 
             targetX = map(-1.0, 1.0, left, right, horizontalPosition)
             targetY = map(-1.0, 1.0, top, bottom, verticalPosition)
@@ -57,12 +66,12 @@ fun Drawer.imageFit(img: ColorBuffer, x: Double = 0.0, y: Double = 0.0, w: Doubl
 
             if (sourceWidth <= targetWidth) {
                 targetWidth = sourceWidth
-                targetHeight = (h / w) * sourceWidth
+                targetHeight = (height / width) * sourceWidth
             }
 
             if (sourceHeight <= targetHeight) {
                 targetHeight = sourceHeight
-                targetWidth = (w / h) * sourceHeight
+                targetWidth = (width / height) * sourceHeight
             }
 
             val left = 0.0
@@ -74,7 +83,7 @@ fun Drawer.imageFit(img: ColorBuffer, x: Double = 0.0, y: Double = 0.0, w: Doubl
             targetY = map(-1.0, 1.0, top, bottom, verticalPosition)
 
             source = Rectangle(targetX, targetY, targetWidth, targetHeight)
-            target = Rectangle(x, y, w, h)
+            target = Rectangle(x, y, width, height)
         }
     }