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This contains the native files for the backport of OpenJFX 8 to run on Java 7.
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/*
 * Copyright (c) 2011, 2013, 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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 */

//
// Add mode is misleadingly named as it is not equivalent to "Additive" mode but
// is instead a linear dodge. The blend equation is defined by
//
// B(Bc', Tc') = min(1.0, Bc' + Tc')
//
// where Bc' and Tc' are the non-premultiplied bottom and top colors, respectively.
// In our case the colors are premultiplied so this condition is equivalent to
// min(Ba x Ta, Ba x Tc + Ta x Bc).
//
// Actually, you can rewrite the equations to maximize their similarity and see
// that you have:
//
// Rc = (1-Ta)Bc + (1-Ba)Tc + BaTa*min(1.0, Bc/Ba + Tc/Ta)
//     = Bc - TaBc + Tc - BaTc + min(BaTa, TaBc + BaTc)
//
// for (BaTa) being smaller (or equal) we get:
//
// Rc = Bc + Tc - TaBc - BaTc + BaTa
//    = Bc + Tc - (BaTc + TaBc - TaBa)
// [Note that (BaTc + TaBc - TaBa) is >= 0]
//
// for (TaBc + BaTc) being smaller (or equal) we get:
//
// Rc = Bc + Tc - TaBc - BaTc + TaBc + BaTc
//    = Bc + Tc + 0
// [Note that (BaTc + TaBc - TaBa) is <= 0]
//
// So, we subtract that last term, unless it is less than zero (we don't want to
// produce an answer that is greater than Tc+Bc ever).  This would let you use
// vector math to compute that term, then a vector min or max to make sure it is
// clipped at 0.  Also, note that the alpha equation is (Ta + Ba - TaBa) and if
// we compute (BaTa + TaBa - TaBa == TaBa) then we end up with the value we need
// to subtract for alpha as well (and it is never less than 0) and so we can
// symmetrically use this equation for all components.
//
// So, this equation works too:
//
//     R = max(BTa + TBa - TaBa, 0.0)
//
// or in code:
//
//     float4 mix = max(bot*top.a + top*bot.a - top.a*bot.a, 0.0);
//     return bot + top - mix;
//
float4 blend_add(float4 bot, float4 top)
{
    // Separate the expression defining "mix" from the return statement to
    // circumvent a JSL parsing limitation.
    float4 mix = max(bot*top.a + top*bot.a - top.a*bot.a, 0.0);
    return bot + top - mix;
}