1 /* 2 * Copyright (C) 2011 Igalia S.L. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "config.h" 27 #include "PlatformContextCairo.h" 28 29 #include <cairo.h> 30 31 namespace WebCore { 32 33 PlatformContextCairo::PlatformContextCairo(cairo_t* cr) 34 : m_cr(cr) 35 { 36 } 37 38 void PlatformContextCairo::restore() 39 { 40 const ImageMaskInformation& maskInformation = m_maskImageStack.last(); 41 if (maskInformation.isValid()) { 42 const FloatRect& maskRect = maskInformation.maskRect(); 43 cairo_pop_group_to_source(m_cr.get()); 44 cairo_mask_surface(m_cr.get(), maskInformation.maskSurface(), maskRect.x(), maskRect.y()); 45 } 46 m_maskImageStack.removeLast(); 47 48 cairo_restore(m_cr.get()); 49 } 50 51 void PlatformContextCairo::save() 52 { 53 m_maskImageStack.append(ImageMaskInformation()); 54 55 cairo_save(m_cr.get()); 56 } 57 58 void PlatformContextCairo::pushImageMask(cairo_surface_t* surface, const FloatRect& rect) 59 { 60 // We must call savePlatformState at least once before we can use image masking, 61 // since we actually apply the mask in restorePlatformState. 62 ASSERT(!m_maskImageStack.isEmpty()); 63 m_maskImageStack.last().update(surface, rect); 64 65 // Cairo doesn't support the notion of an image clip, so we push a group here 66 // and then paint it to the surface with an image mask (which is an immediate 67 // operation) during restorePlatformState. 68 69 // We want to allow the clipped elements to composite with the surface as it 70 // is now, but they are isolated in another group. To make this work, we're 71 // going to blit the current surface contents onto the new group once we push it. 72 cairo_surface_t* currentTarget = cairo_get_target(m_cr.get()); 73 cairo_surface_flush(currentTarget); 74 75 // Pushing a new group ensures that only things painted after this point are clipped. 76 cairo_push_group(m_cr.get()); 77 cairo_set_operator(m_cr.get(), CAIRO_OPERATOR_SOURCE); 78 79 cairo_set_source_surface(m_cr.get(), currentTarget, 0, 0); 80 cairo_rectangle(m_cr.get(), rect.x(), rect.y(), rect.width(), rect.height()); 81 cairo_fill(m_cr.get()); 82 } 83 84 85 } // namespace WebCore 86
