Support 16-bit color in LXBlend by adding the blend(PolyBuffer...) me…

…thod.

src/heronarts/lx/blend/LXBlend.java

@@ -23,6 +23,9 @@
 import heronarts.lx.LX;
 import heronarts.lx.LXBuffer;
 import heronarts.lx.LXModulatorComponent;
+import heronarts.lx.PolyBuffer;
+import heronarts.lx.color.LXColor;
+import heronarts.lx.color.LXColor16;
 
 /**
  * An LXBlend is a loop-based implementation of a compositing algorithm.
@@ -80,34 +83,57 @@ public String getName() {
     return this.name;
   }
 
-  /**
-   * Gets the name of this blend.
-   *
-   */
+  /** Gets the name of this blend. */
   @Override
   public String getLabel() {
     return getName();
   }
 
-  /**
-   * Name of the blend
-   */
+  /** Name of the blend */
   @Override
   public String toString() {
     return getName();
   }
 
+  @Deprecated
   public void blend(int[] dst, int[] src, double alpha, LXBuffer buffer) {
     blend(dst, src, alpha, buffer.getArray());
   }
 
   /**
-   * Blends the src buffer onto the destination buffer at the specified alpha amount.
+   * Old-style subclasses override this method to implement the blend.
+   * New-style subclasses should override the PolyBuffer-based blend()
+   * method below, instead.
    *
-   * @param dst Destination buffer (lower layer)
-   * @param src Source buffer (top layer)
-   * @param alpha Alpha blend, from 0-1
-   * @param output Output buffer, which may be the same as src or dst
+   * @param base Base source (when amount = 0, the result equals the base)
+   * @param overlay Overlay source (to be blended on top of the base)
+   * @param alpha Amount of blending (from 0 to 1)
+   * @param dest Destination array, which may be the same as overlay or base
    */
-  public abstract void blend(int[] dst, int[] src, double alpha, int[] output);
+  @Deprecated
+  public /* abstract */ void blend(int[] base, int[] overlay, double alpha, int[] dest) { }
+
+  /**
+   * Takes the base buffer, blends the overlay buffer onto it by a
+   * specified amount, and writes the result into the destination buffer.
+   *
+   * @param base Base source (when amount = 0, the result equals the base)
+   * @param overlay Overlay source (to be blended on top of the base)
+   * @param alpha Amount of blending (from 0 to 1)
+   * @param dest Destination buffer, which may be the same as overlay or base
+   * @param preferredSpace A hint as to which color space to operate in for
+   *     the greatest efficiency (performing the blend in a different color
+   *     space will still work, but will necessitate color space conversion)
+   */
+  public void blend(PolyBuffer base, PolyBuffer overlay, double alpha, PolyBuffer dest, PolyBuffer.Space preferredSpace) {
+    // For compatibility, this invokes the method that previous subclasses were
+    // supposed to implement, and then marks the destination as modified.
+    blend(base.getArray(), overlay.getArray(), alpha, dest.getArray());
+    dest.markModified();
+
+    // New subclasses should override and replace this method with one that
+    // reads color arrays from base.getArray(space) and overlay.getArray(space),
+    // writes the result into dest.getArray(space), and finally marks the
+    // destination buffer modified with a call to dest.markModified(space).
+  }
 }