diff options
Diffstat (limited to 'vcl/unx/generic/gdi/cairotextrender.cxx')
| -rw-r--r-- | vcl/unx/generic/gdi/cairotextrender.cxx | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/vcl/unx/generic/gdi/cairotextrender.cxx b/vcl/unx/generic/gdi/cairotextrender.cxx new file mode 100644 index 0000000000..7e7ce9ca70 --- /dev/null +++ b/vcl/unx/generic/gdi/cairotextrender.cxx @@ -0,0 +1,526 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <sal/config.h> + +#include <comphelper/scopeguard.hxx> +#include <unx/cairotextrender.hxx> +#include <unx/fc_fontoptions.hxx> +#include <unx/freetype_glyphcache.hxx> +#include <unx/gendata.hxx> +#include <headless/CairoCommon.hxx> +#include <vcl/svapp.hxx> +#include <sallayout.hxx> +#include <salinst.hxx> + +#include <cairo.h> +#include <cairo-ft.h> +#if defined(CAIRO_HAS_SVG_SURFACE) +#include <cairo-svg.h> +#elif defined(CAIRO_HAS_PDF_SURFACE) +#include <cairo-pdf.h> +#endif + +#include <deque> + +namespace { + +typedef struct FT_FaceRec_* FT_Face; + +class CairoFontsCache +{ +public: + struct CacheId + { + FT_Face maFace; + const FontConfigFontOptions *mpOptions; + bool mbEmbolden; + bool mbVerticalMetrics; + bool operator ==(const CacheId& rOther) const + { + return maFace == rOther.maFace && + mpOptions == rOther.mpOptions && + mbEmbolden == rOther.mbEmbolden && + mbVerticalMetrics == rOther.mbVerticalMetrics; + } + }; + +private: + typedef std::deque< std::pair<cairo_font_face_t*, CacheId> > LRUFonts; + static LRUFonts maLRUFonts; +public: + CairoFontsCache() = delete; + + static void CacheFont(cairo_font_face_t* pFont, const CacheId &rId); + static cairo_font_face_t* FindCachedFont(const CacheId &rId); +}; + +CairoFontsCache::LRUFonts CairoFontsCache::maLRUFonts; + +void CairoFontsCache::CacheFont(cairo_font_face_t* pFont, const CairoFontsCache::CacheId &rId) +{ + maLRUFonts.push_front( std::pair<cairo_font_face_t*, CairoFontsCache::CacheId>(pFont, rId) ); + if (maLRUFonts.size() > 8) + { + cairo_font_face_destroy(maLRUFonts.back().first); + maLRUFonts.pop_back(); + } +} + +cairo_font_face_t* CairoFontsCache::FindCachedFont(const CairoFontsCache::CacheId &rId) +{ + auto aI = std::find_if(maLRUFonts.begin(), maLRUFonts.end(), + [&rId](const LRUFonts::value_type& rFont) { return rFont.second == rId; }); + if (aI != maLRUFonts.end()) + return aI->first; + return nullptr; +} + +} + +namespace +{ + bool hasRotation(int nRotation) + { + return nRotation != 0; + } + + double toRadian(Degree10 nDegree10th) + { + return toRadians(3600_deg10 - nDegree10th); + } + + cairo_t* syncCairoContext(cairo_t* cr) + { + //rhbz#1283420 tdf#117413 bodge to force a read from the underlying surface which has + //the side effect of making the mysterious xrender related problem go away + cairo_surface_t *target = cairo_get_target(cr); + if (cairo_surface_get_type(target) == CAIRO_SURFACE_TYPE_XLIB) + { + cairo_surface_t *throw_away = cairo_surface_create_similar(target, cairo_surface_get_content(target), 1, 1); + cairo_t *force_read_cr = cairo_create(throw_away); + cairo_set_source_surface(force_read_cr, target, 0, 0); + cairo_paint(force_read_cr); + cairo_destroy(force_read_cr); + cairo_surface_destroy(throw_away); + } + return cr; + } +} + +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) +extern "C" +{ + __attribute__((weak)) void __lsan_disable(); + __attribute__((weak)) void __lsan_enable(); +} +#endif + +namespace { + struct CairoFontOptions + { + // https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/235 + // I don't want to have CAIRO_ROUND_GLYPH_POS_ON set in the cairo + // surfaces font_options, but that's private, so tricky to achieve + cairo_font_options_t* mpRoundGlyphPosOffOptions; + + CairoFontOptions() + { + // https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/235 + // I don't want to have CAIRO_ROUND_GLYPH_POS_ON set in the cairo surfaces + // font_options when trying subpixel rendering, but that's a private + // feature of cairo_font_options_t, so tricky to achieve. Hack this by + // getting the font options of a backend known to set this private feature + // to CAIRO_ROUND_GLYPH_POS_OFF and then set to defaults the public + // features and the result can be merged with new font options to set + // CAIRO_ROUND_GLYPH_POS_OFF in those + mpRoundGlyphPosOffOptions = cairo_font_options_create(); +#if defined(CAIRO_HAS_SVG_SURFACE) + // svg, pdf and ps backends have CAIRO_ROUND_GLYPH_POS_OFF by default + cairo_surface_t* hack = cairo_svg_surface_create(nullptr, 1, 1); +#elif defined(CAIRO_HAS_PDF_SURFACE) + cairo_surface_t* hack = cairo_pdf_surface_create(nullptr, 1, 1); +#endif + cairo_surface_get_font_options(hack, mpRoundGlyphPosOffOptions); + cairo_surface_destroy(hack); + cairo_font_options_set_antialias(mpRoundGlyphPosOffOptions, CAIRO_ANTIALIAS_DEFAULT); + cairo_font_options_set_subpixel_order(mpRoundGlyphPosOffOptions, CAIRO_SUBPIXEL_ORDER_DEFAULT); + cairo_font_options_set_hint_style(mpRoundGlyphPosOffOptions, CAIRO_HINT_STYLE_DEFAULT); + cairo_font_options_set_hint_metrics(mpRoundGlyphPosOffOptions, CAIRO_HINT_METRICS_DEFAULT); + } + ~CairoFontOptions() + { + cairo_font_options_destroy(mpRoundGlyphPosOffOptions); + } + static const cairo_font_options_t *get() + { + static CairoFontOptions opts; + return opts.mpRoundGlyphPosOffOptions; + } + }; +} + +CairoTextRender::CairoTextRender(CairoCommon& rCairoCommon) + : mrCairoCommon(rCairoCommon) +{ +} + +CairoTextRender::~CairoTextRender() +{ +} + +static void ApplyFont(cairo_t* cr, const CairoFontsCache::CacheId& rId, double nWidth, double nHeight, int nGlyphRotation, + const GenericSalLayout& rLayout) +{ + cairo_font_face_t* font_face = CairoFontsCache::FindCachedFont(rId); + if (!font_face) + { + const FontConfigFontOptions *pOptions = rId.mpOptions; + FcPattern *pPattern = pOptions->GetPattern(); + font_face = cairo_ft_font_face_create_for_pattern(pPattern); + CairoFontsCache::CacheFont(font_face, rId); + } + cairo_set_font_face(cr, font_face); + + cairo_set_font_size(cr, nHeight); + + cairo_matrix_t m; + cairo_matrix_init_identity(&m); + + if (rLayout.GetOrientation()) + cairo_matrix_rotate(&m, toRadian(rLayout.GetOrientation())); + + cairo_matrix_scale(&m, nWidth, nHeight); + + if (nGlyphRotation) + cairo_matrix_rotate(&m, toRadian(Degree10(nGlyphRotation * 900))); + + const LogicalFontInstance& rInstance = rLayout.GetFont(); + if (rInstance.NeedsArtificialItalic()) + { + cairo_matrix_t shear; + cairo_matrix_init_identity(&shear); + shear.xy = -shear.xx * ARTIFICIAL_ITALIC_SKEW; + cairo_matrix_multiply(&m, &shear, &m); + } + + cairo_set_font_matrix(cr, &m); +} + +static CairoFontsCache::CacheId makeCacheId(const GenericSalLayout& rLayout) +{ + const FreetypeFontInstance& rInstance = static_cast<FreetypeFontInstance&>(rLayout.GetFont()); + const FreetypeFont& rFont = rInstance.GetFreetypeFont(); + + FT_Face aFace = rFont.GetFtFace(); + CairoFontsCache::CacheId aId; + aId.maFace = aFace; + aId.mpOptions = rFont.GetFontOptions(); + aId.mbEmbolden = rInstance.NeedsArtificialBold(); + aId.mbVerticalMetrics = false; + + return aId; +} + +void CairoTextRender::DrawTextLayout(const GenericSalLayout& rLayout, const SalGraphics& rGraphics) +{ + const LogicalFontInstance& rInstance = rLayout.GetFont(); + + const bool bSubpixelPositioning = rLayout.GetSubpixelPositioning(); + + /* + * It might be ideal to cache surface and cairo context between calls and + * only destroy it when the drawable changes, but to do that we need to at + * least change the SalFrame etc impls to dtor the SalGraphics *before* the + * destruction of the windows they reference + */ + cairo_t *cr = syncCairoContext(getCairoContext()); + if (!cr) + { + SAL_WARN("vcl", "no cairo context for text"); + return; + } + comphelper::ScopeGuard releaseContext([this, cr]() { releaseCairoContext(cr); }); + + std::vector<cairo_glyph_t> cairo_glyphs; + std::vector<int> glyph_extrarotation; + cairo_glyphs.reserve( 256 ); + + double nSnapToSubPixelDiff = 0.0; + double nXScale, nYScale; + dl_cairo_surface_get_device_scale(cairo_get_target(cr), &nXScale, &nYScale); + + basegfx::B2DPoint aPos; + const GlyphItem* pGlyph; + const GlyphItem* pPrevGlyph = nullptr; + int nStart = 0; + while (rLayout.GetNextGlyph(&pGlyph, aPos, nStart)) + { + cairo_glyph_t aGlyph; + aGlyph.index = pGlyph->glyphId(); + aGlyph.x = aPos.getX(); + aGlyph.y = aPos.getY(); + + const bool bVertical = pGlyph->IsVertical(); + glyph_extrarotation.push_back(bVertical ? 1 : 0); + + if (bSubpixelPositioning) + { + // tdf#150507 like skia, even when subpixel rendering pixel, snap y + if (!bVertical) + aGlyph.y = std::floor(aGlyph.y + 0.5); + else + aGlyph.x = std::floor(aGlyph.x + 0.5); + + // tdf#152094 snap to 1/4 of a pixel after a run of whitespace, + // probably a little dubious, but maybe worth a shot for lodpi + double& rGlyphDimension = !bVertical ? aGlyph.x : aGlyph.y; + const int nSubPixels = 4 * (!bVertical ? nXScale : nYScale); + if (pGlyph->IsSpacing()) + nSnapToSubPixelDiff = 0; + else if (pPrevGlyph && pPrevGlyph->IsSpacing()) + { + double nSnapToSubPixel = std::floor(rGlyphDimension * nSubPixels) / nSubPixels; + nSnapToSubPixelDiff = rGlyphDimension - nSnapToSubPixel; + rGlyphDimension = nSnapToSubPixel; + } + else + rGlyphDimension -= nSnapToSubPixelDiff; + + pPrevGlyph = pGlyph; + } + + cairo_glyphs.push_back(aGlyph); + } + + const size_t nGlyphs = cairo_glyphs.size(); + if (!nGlyphs) + return; + + const vcl::font::FontSelectPattern& rFSD = rInstance.GetFontSelectPattern(); + double nHeight = rFSD.mnHeight; + double nWidth = rFSD.mnWidth ? rFSD.mnWidth : nHeight; + if (nWidth == 0 || nHeight == 0) + return; + + if (nHeight > SAL_MAX_UINT16) + { + // as seen with freetype 2.11.0, so cairo surface status is "fail" + // ("error occurred in libfreetype") and no further operations are + // executed, so this error then leads to later leaks + SAL_WARN("vcl", "rendering text would fail with height: " << nHeight); + return; + } + +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) + if (nHeight > 8000) + { + SAL_WARN("vcl", "rendering text would use > 2G Memory: " << nHeight); + return; + } + + if (nWidth > 2000) + { + SAL_WARN("vcl", "rendering text would use > 2G Memory: " << nWidth); + return; + } +#endif + + clipRegion(cr); + + cairo_set_source_rgba(cr, + mnTextColor.GetRed()/255.0, + mnTextColor.GetGreen()/255.0, + mnTextColor.GetBlue()/255.0, + mnTextColor.GetAlpha()/255.0); + + int nRatio = nWidth * 10 / nHeight; + + // tdf#132112 excessive stretch of underbrace and overbrace can trigger freetype into an error, which propagates to cairo + // and once a cairo surface is in an error state, that cannot be cleared and all subsequent drawing fails, so bodge that + // with a high degree of stretch we draw the brace without stretch to a temp surface and stretch that to give a far + // poorer visual result, but one that can be rendered. + if (nGlyphs == 1 && nRatio > 100 && (cairo_glyphs[0].index == 974 || cairo_glyphs[0].index == 975) && + rFSD.maTargetName == "OpenSymbol" && !glyph_extrarotation.back() && !rLayout.GetOrientation()) + { + CairoFontsCache::CacheId aId = makeCacheId(rLayout); + + ApplyFont(cr, aId, nWidth, nHeight, 0, rLayout); + cairo_text_extents_t stretched_extents; + cairo_glyph_extents(cr, cairo_glyphs.data(), nGlyphs, &stretched_extents); + + ApplyFont(cr, aId, nHeight, nHeight, 0, rLayout); + cairo_text_extents_t unstretched_extents; + cairo_glyph_extents(cr, cairo_glyphs.data(), nGlyphs, &unstretched_extents); + + cairo_surface_t *target = cairo_get_target(cr); + cairo_surface_t *temp_surface = cairo_surface_create_similar(target, cairo_surface_get_content(target), + unstretched_extents.width, unstretched_extents.height); + cairo_t *temp_cr = cairo_create(temp_surface); + cairo_glyph_t glyph; + glyph.x = -unstretched_extents.x_bearing; + glyph.y = -unstretched_extents.y_bearing; + glyph.index = cairo_glyphs[0].index; + + ApplyFont(temp_cr, aId, nHeight, nHeight, 0, rLayout); + + cairo_set_source_rgb(temp_cr, + mnTextColor.GetRed()/255.0, + mnTextColor.GetGreen()/255.0, + mnTextColor.GetBlue()/255.0); + + cairo_show_glyphs(temp_cr, &glyph, 1); + cairo_destroy(temp_cr); + + cairo_set_source_surface(cr, temp_surface, cairo_glyphs[0].x, cairo_glyphs[0].y + stretched_extents.y_bearing); + + cairo_pattern_t* sourcepattern = cairo_get_source(cr); + cairo_matrix_t matrix; + cairo_pattern_get_matrix(sourcepattern, &matrix); + cairo_matrix_scale(&matrix, unstretched_extents.width / stretched_extents.width, 1); + cairo_pattern_set_matrix(sourcepattern, &matrix); + + cairo_rectangle(cr, cairo_glyphs[0].x, cairo_glyphs[0].y + stretched_extents.y_bearing, stretched_extents.width, stretched_extents.height); + cairo_fill(cr); + + cairo_surface_destroy(temp_surface); + + return; + } + + if (nRatio >= 5120) + { + // as seen with freetype 2.12.1, so cairo surface status is "fail" + SAL_WARN("vcl", "rendering text would fail with stretch of: " << nRatio / 10.0); + return; + } + +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) + if (__lsan_disable) + __lsan_disable(); +#endif + + const StyleSettings& rStyleSettings = Application::GetSettings().GetStyleSettings(); + const bool bDisableAA = !rStyleSettings.GetUseFontAAFromSystem() && !rGraphics.getAntiAlias(); + static bool bAllowDefaultHinting = getenv("SAL_ALLOW_DEFAULT_HINTING") != nullptr; + + const cairo_font_options_t* pFontOptions = GetSalInstance()->GetCairoFontOptions(); + if (pFontOptions || bDisableAA || bSubpixelPositioning) + { + cairo_hint_style_t eHintStyle = pFontOptions ? cairo_font_options_get_hint_style(pFontOptions) : CAIRO_HINT_STYLE_DEFAULT; + bool bAllowedHintStyle = !bSubpixelPositioning || bAllowDefaultHinting || (eHintStyle == CAIRO_HINT_STYLE_NONE || eHintStyle == CAIRO_HINT_STYLE_SLIGHT); + + if (bDisableAA || !bAllowedHintStyle || bSubpixelPositioning) + { + // Disable font AA in case global AA setting is supposed to affect + // font rendering (not the default) and AA is disabled. + cairo_font_options_t* pOptions = pFontOptions ? cairo_font_options_copy(pFontOptions) : cairo_font_options_create(); + + if (bDisableAA) + cairo_font_options_set_antialias(pOptions, CAIRO_ANTIALIAS_NONE); + if (!bAllowedHintStyle) + cairo_font_options_set_hint_style(pOptions, CAIRO_HINT_STYLE_SLIGHT); + if (bSubpixelPositioning) + { + // Disable private CAIRO_ROUND_GLYPH_POS_ON by merging with + // font options known to have CAIRO_ROUND_GLYPH_POS_OFF + cairo_font_options_merge(pOptions, CairoFontOptions::get()); + + // a) tdf#153699 skip this with cairo 1.17.8 as it has a problem + // See: https://gitlab.freedesktop.org/cairo/cairo/-/issues/643 + // b) tdf#152675 a similar report for cairo: 1.16.0-4ubuntu1, + // assume that everything <= 1.17.8 is unsafe to disable this + if (cairo_version() > CAIRO_VERSION_ENCODE(1, 17, 8)) + cairo_font_options_set_hint_metrics(pOptions, CAIRO_HINT_METRICS_OFF); + } + cairo_set_font_options(cr, pOptions); + cairo_font_options_destroy(pOptions); + } + else if (pFontOptions) + cairo_set_font_options(cr, pFontOptions); + } + + CairoFontsCache::CacheId aId = makeCacheId(rLayout); + + std::vector<int>::const_iterator aEnd = glyph_extrarotation.end(); + std::vector<int>::const_iterator aStart = glyph_extrarotation.begin(); + std::vector<int>::const_iterator aI = aStart; + while (aI != aEnd) + { + int nGlyphRotation = *aI; + + std::vector<int>::const_iterator aNext = nGlyphRotation?(aI+1):std::find_if(aI+1, aEnd, hasRotation); + + size_t nStartIndex = std::distance(aStart, aI); + size_t nLen = std::distance(aI, aNext); + + aId.mbVerticalMetrics = nGlyphRotation != 0.0; + + ApplyFont(cr, aId, nWidth, nHeight, nGlyphRotation, rLayout); + + cairo_show_glyphs(cr, &cairo_glyphs[nStartIndex], nLen); + if (cairo_status(cr) != CAIRO_STATUS_SUCCESS) + { + SAL_WARN("vcl", "rendering text failed with stretch ratio of: " << nRatio << ", " << cairo_status_to_string(cairo_status(cr))); + } + +#if OSL_DEBUG_LEVEL > 2 + //draw origin + cairo_save (cr); + cairo_rectangle (cr, cairo_glyphs[nStartIndex].x, cairo_glyphs[nStartIndex].y, 5, 5); + cairo_set_source_rgba (cr, 1, 0, 0, 0.80); + cairo_fill (cr); + cairo_restore (cr); +#endif + + aI = aNext; + } + +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) + if (__lsan_enable) + __lsan_enable(); +#endif +} + +cairo_t* CairoTextRender::getCairoContext() +{ + // Note that cairo_set_antialias (bAntiAlias property) doesn't affect cairo + // text rendering. That's affected by cairo_font_options_set_antialias instead. + return mrCairoCommon.getCairoContext(/*bXorModeAllowed*/false, /*bAntiAlias*/true); +} + +void CairoTextRender::clipRegion(cairo_t* cr) +{ + mrCairoCommon.clipRegion(cr); +} + +void CairoTextRender::releaseCairoContext(cairo_t* cr) +{ + mrCairoCommon.releaseCairoContext(cr, /*bXorModeAllowed*/false, basegfx::B2DRange()); +} + +void FontConfigFontOptions::cairo_font_options_substitute(FcPattern* pPattern) +{ + const cairo_font_options_t* pFontOptions = GetSalInstance()->GetCairoFontOptions(); + if( !pFontOptions ) + return; + cairo_ft_font_options_substitute(pFontOptions, pPattern); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |