2362N/A * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 0N/A * This implementation first copies the alpha tile into a texture and then 0N/A * maps that texture to the destination surface. This approach appears to 0N/A * offer the best performance despite being a two-step process. 0N/A * When the source paint is a Color, we can simply use the GL_MODULATE 0N/A * function to multiply the current color (already premultiplied with the 0N/A * extra alpha value from the AlphaComposite) with the alpha value from 0N/A * the mask texture tile. In picture form, this process looks like: 0N/A * primary color Pa Pr Pg Pb (modulated with...) 0N/A * texture unit 0 Ca Ca Ca Ca 0N/A * --------------------------------------- 0N/A * resulting color Ra Rr Rg Rb 0N/A * Px = current color (already premultiplied by extra alpha) 0N/A * Cx = coverage value from mask tile 0N/A * When the source paint is not a Color, it means that we are rendering with 0N/A * a complex paint (e.g. GradientPaint, TexturePaint). In this case, we 0N/A * rely on the GL_ARB_multitexture extension to effectively multiply the 0N/A * paint fragments (autogenerated on texture unit 1, see the 0N/A * OGLPaints_Set{Gradient,Texture,etc}Paint() methods for more details) 0N/A * with the coverage values from the mask texture tile (provided on texture 0N/A * unit 0), all of which is multiplied with the current color value (which 0N/A * contains the extra alpha value). In picture form: 0N/A * primary color Ea Ea Ea Ea (modulated with...) 0N/A * texture unit 0 Ca Ca Ca Ca (modulated with...) 0N/A * texture unit 1 Pa Pr Pg Pb 0N/A * --------------------------------------- 0N/A * resulting color Ra Rr Rg Rb 0N/A * Cx = coverage value from mask tile 0N/A * Here are some descriptions of the many variables used in this method: 0N/A * x,y - upper left corner of the tile destination 0N/A * x0 - placekeeper for the original destination x location 0N/A * sx1,sy1 - upper left corner of the mask tile source region 0N/A * sx2,sy2 - lower left corner of the mask tile source region 0N/A * sx,sy - "current" upper left corner of the mask tile region of interest 0N/A // 6358147: reset current state, and ensure rendering is flushed to dest 0N/A#
endif /* !HEADLESS */