--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLMaskFill.m	Fri Jun 21 12:08:37 2019 +0530
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef HEADLESS
+
+#include "sun_java2d_metal_MTLMaskFill.h"
+
+#include "MTLMaskFill.h"
+#include "MTLRenderQueue.h"
+#include "MTLVertexCache.h"
+
+/**
+ * This implementation first copies the alpha tile into a texture and then
+ * maps that texture to the destination surface.  This approach appears to
+ * offer the best performance despite being a two-step process.
+ *
+ * When the source paint is a Color, we can simply use the GL_MODULATE
+ * function to multiply the current color (already premultiplied with the
+ * extra alpha value from the AlphaComposite) with the alpha value from
+ * the mask texture tile.  In picture form, this process looks like:
+ *
+ *                        A     R    G     B
+ *     primary color      Pa    Pr   Pg    Pb    (modulated with...)
+ *     texture unit 0     Ca    Ca   Ca    Ca
+ *     ---------------------------------------
+ *     resulting color    Ra    Rr   Rg    Rb
+ *
+ * where:
+ *     Px = current color (already premultiplied by extra alpha)
+ *     Cx = coverage value from mask tile
+ *     Rx = resulting color/alpha component
+ *
+ * When the source paint is not a Color, it means that we are rendering with
+ * a complex paint (e.g. GradientPaint, TexturePaint).  In this case, we
+ * rely on the GL_ARB_multitexture extension to effectively multiply the
+ * paint fragments (autogenerated on texture unit 1, see the
+ * MTLPaints_Set{Gradient,Texture,etc}Paint() methods for more details)
+ * with the coverage values from the mask texture tile (provided on texture
+ * unit 0), all of which is multiplied with the current color value (which
+ * contains the extra alpha value).  In picture form:
+ *
+ *                        A     R    G     B
+ *     primary color      Ea    Ea   Ea    Ea    (modulated with...)
+ *     texture unit 0     Ca    Ca   Ca    Ca    (modulated with...)
+ *     texture unit 1     Pa    Pr   Pg    Pb
+ *     ---------------------------------------
+ *     resulting color    Ra    Rr   Rg    Rb
+ *
+ * where:
+ *     Ea = extra alpha
+ *     Cx = coverage value from mask tile
+ *     Px = gradient/texture paint color (generated for each fragment)
+ *     Rx = resulting color/alpha component
+ *
+ * Here are some descriptions of the many variables used in this method:
+ *   x,y     - upper left corner of the tile destination
+ *   w,h     - width/height of the mask tile
+ *   x0      - placekeeper for the original destination x location
+ *   tw,th   - width/height of the actual texture tile in pixels
+ *   sx1,sy1 - upper left corner of the mask tile source region
+ *   sx2,sy2 - lower left corner of the mask tile source region
+ *   sx,sy   - "current" upper left corner of the mask tile region of interest
+ */
+void
+MTLMaskFill_MaskFill(MTLContext *mtlc, BMTLSDOps * dstOps,
+                     jint x, jint y, jint w, jint h,
+                     jint maskoff, jint maskscan, jint masklen,
+                     unsigned char *pMask)
+{
+    //TODO
+    J2dTraceLn(J2D_TRACE_INFO, "MTLMaskFill_MaskFill");
+}
+
+JNIEXPORT void JNICALL
+Java_sun_java2d_metal_MTLMaskFill_maskFill
+    (JNIEnv *env, jobject self,
+     jint x, jint y, jint w, jint h,
+     jint maskoff, jint maskscan, jint masklen,
+     jbyteArray maskArray)
+{
+    MTLContext *mtlc = MTLRenderQueue_GetCurrentContext();
+    unsigned char *mask;
+    //TODO
+    J2dTraceLn(J2D_TRACE_ERROR, "MTLMaskFill_maskFill");
+}
+
+#endif /* !HEADLESS */