Source/WebCore/platform/graphics/texmap/ClipStack.cpp

   1 /*
   2  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
   3  * Copyright (C) 2012 Adobe Systems Incorporated
   4  * Copyright (C) 2012, 2016 Igalia S.L.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include "config.h"
  23 #include "ClipStack.h"
  24
  25 #include "GraphicsContext3D.h"
  26
  27 namespace WebCore {
  28
  29 void ClipStack::push()
  30 {
  31     clipStack.append(clipState);
  32     clipStateDirty = true;
  33 }
  34
  35 void ClipStack::pop()
  36 {
  37     if (clipStack.isEmpty())
  38         return;
  39     clipState = clipStack.last();
  40     clipStack.removeLast();
  41     clipStateDirty = true;
  42 }
  43
  44 void ClipStack::reset(const IntRect& rect, ClipStack::YAxisMode mode)
  45 {
  46     clipStack.clear();
  47     size = rect.size();
  48     yAxisMode = mode;
  49     clipState = State(rect);
  50     clipStateDirty = true;
  51 }
  52
  53 void ClipStack::intersect(const IntRect& rect)
  54 {
  55     clipState.scissorBox.intersect(rect);
  56     clipStateDirty = true;
  57 }
  58
  59 void ClipStack::setStencilIndex(int stencilIndex)
  60 {
  61     clipState.stencilIndex = stencilIndex;
  62     clipStateDirty = true;
  63 }
  64
  65 void ClipStack::apply(GraphicsContext3D& context)
  66 {
  67     if (clipState.scissorBox.isEmpty())
  68         return;
  69
  70     context.scissor(clipState.scissorBox.x(),
  71         (yAxisMode == YAxisMode::Inverted) ? size.height() - clipState.scissorBox.maxY() : clipState.scissorBox.y(),
  72         clipState.scissorBox.width(), clipState.scissorBox.height());
  73     context.stencilOp(GraphicsContext3D::KEEP, GraphicsContext3D::KEEP, GraphicsContext3D::KEEP);
  74     context.stencilFunc(GraphicsContext3D::EQUAL, clipState.stencilIndex - 1, clipState.stencilIndex - 1);
  75     if (clipState.stencilIndex == 1)
  76         context.disable(GraphicsContext3D::STENCIL_TEST);
  77     else
  78         context.enable(GraphicsContext3D::STENCIL_TEST);
  79 }
  80
  81 void ClipStack::applyIfNeeded(GraphicsContext3D& context)
  82 {
  83     if (!clipStateDirty)
  84         return;
  85
  86     clipStateDirty = false;
  87     apply(context);
  88 }
  89
  90 } // namespace WebCore