/*

 * 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

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 */

#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 */