path: root/src/extension/internal/cairo-renderer-pdf-out.cpp

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * A quick hack to use the Cairo renderer to write out a file.  This
 * then makes 'save as...' PDF.
 *
 * Authors:
 *   Ted Gould <ted@gould.cx>
 *   Ulf Erikson <ulferikson@users.sf.net>
 *   Johan Engelen <goejendaagh@zonnet.nl>
 *   Jon A. Cruz <jon@joncruz.org>
 *   Abhishek Sharma
 *
 * Copyright (C) 2004-2010 Authors
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include <cairo.h>
#ifdef CAIRO_HAS_PDF_SURFACE

#include "cairo-renderer-pdf-out.h"
#include "cairo-render-context.h"
#include "cairo-renderer.h"
#include "latex-text-renderer.h"
#include "path-chemistry.h"
#include <print.h>
#include "extension/system.h"
#include "extension/print.h"
#include "extension/db.h"
#include "extension/output.h"

#include "display/drawing.h"
#include "display/curve.h"

#include "object/sp-item.h"
#include "object/sp-root.h"
#include "object/sp-page.h"

#include <2geom/affine.h>
#include "page-manager.h"
#include "document.h"

#include "util/units.h"

namespace Inkscape {
namespace Extension {
namespace Internal {

bool CairoRendererPdfOutput::check(Inkscape::Extension::Extension * /*module*/)
{
    bool result = true;

    if (nullptr == Inkscape::Extension::db.get("org.inkscape.output.pdf.cairorenderer")) {
        result = false;
    }

    return result;
}

// TODO: Make this function more generic so that it can do both PostScript and PDF; expose in the headers
static bool
pdf_render_document_to_file(SPDocument *doc, gchar const *filename, unsigned int level, PDFOptions flags,
                            int resolution)
{
    if (flags.text_to_path) {
        assert(!flags.text_to_latex);
        // Cairo's text-to-path method has numerical precision and font matching
        // issues (https://gitlab.com/inkscape/inkscape/-/issues/1979).
        // We get better results by using Inkscape's Object-to-Path method.
        Inkscape::convert_text_to_curves(doc);
    }

    doc->ensureUpToDate();

    SPRoot *root = doc->getRoot();
    if (!root) {
        return false;
    }
    
    /* Create new drawing */
    Inkscape::Drawing drawing;
    unsigned dkey = SPItem::display_key_new(1);
    drawing.setRoot(root->invoke_show(drawing, dkey, SP_ITEM_SHOW_DISPLAY));
    drawing.setExact();

    /* Create renderer and context */
    CairoRenderer *renderer = new CairoRenderer();
    CairoRenderContext *ctx = renderer->createContext();
    ctx->setPDFLevel(level);
    ctx->setTextToPath(flags.text_to_path);
    ctx->setOmitText(flags.text_to_latex);
    ctx->setFilterToBitmap(flags.rasterize_filters);
    ctx->setBitmapResolution(resolution);

    bool ret = ctx->setPdfTarget (filename);
    if(ret) {
        /* Render document */
        ret = renderer->setupDocument(ctx, doc, root);
        if (ret) {
            /* Render multiple pages */
            ret = renderer->renderPages(ctx, doc, flags.stretch_to_fit);
            ctx->finish();
        }
    }

    root->invoke_hide(dkey);

    renderer->destroyContext(ctx);
    delete renderer;

    return ret;
}

/**
    \brief  This function calls the output module with the filename
    \param  mod   unused
    \param  doc   Document to be saved
    \param  filename   Filename to save to (probably will end in .pdf)

    The most interesting thing that this function does is just attach
    an '>' on the front of the filename.  This is the syntax used to
    tell the printing system to save to file.
*/
void
CairoRendererPdfOutput::save(Inkscape::Extension::Output *mod, SPDocument *doc, gchar const *filename)
{
    Inkscape::Extension::Extension * ext;
    unsigned int ret;

    ext = Inkscape::Extension::db.get("org.inkscape.output.pdf.cairorenderer");
    if (ext == nullptr)
        return;

    int level = 0;
    try {
        const gchar *new_level = mod->get_param_optiongroup("PDFversion");
        if((new_level != nullptr) && (g_ascii_strcasecmp("PDF-1.5", new_level) == 0)) {
            level = 1;
        }
    }
    catch(...) {
        g_warning("Parameter <PDFversion> might not exist");
    }

    PDFOptions flags;
    flags.text_to_path = false;
    try {
        flags.text_to_path = (strcmp(mod->get_param_optiongroup("textToPath"), "paths") == 0);
    }
    catch(...) {
        g_warning("Parameter <textToPath> might not exist");
    }

    flags.text_to_latex = false;
    try {
        flags.text_to_latex = (strcmp(mod->get_param_optiongroup("textToPath"), "LaTeX") == 0);
    }
    catch(...) {
        g_warning("Parameter <textToLaTeX> might not exist");
    }

    flags.rasterize_filters = false;
    try {
        flags.rasterize_filters = mod->get_param_bool("blurToBitmap");
    }
    catch(...) {
        g_warning("Parameter <blurToBitmap> might not exist");
    }

    int new_bitmapResolution  = 72;
    try {
        new_bitmapResolution = mod->get_param_int("resolution");
    }
    catch(...) {
        g_warning("Parameter <resolution> might not exist");
    }

    flags.stretch_to_fit = false;
    try {
        flags.stretch_to_fit = (strcmp(ext->get_param_optiongroup("stretch"), "relative") == 0);
    } catch(...) {
        g_warning("Parameter <stretch> might not exist");
    }

    // Create PDF file
    {
        gchar * final_name;
        final_name = g_strdup_printf("> %s", filename);
        ret = pdf_render_document_to_file(doc, final_name, level, flags, new_bitmapResolution);
        g_free(final_name);

        if (!ret)
            throw Inkscape::Extension::Output::save_failed();
    }

    // Create LaTeX file (if requested)
    if (flags.text_to_latex) {
        ret = latex_render_document_text_to_file(doc, filename, true);

        if (!ret)
            throw Inkscape::Extension::Output::save_failed();
    }
}

#include "clear-n_.h"

/**
    \brief   A function allocate a copy of this function.

    This is the definition of Cairo PDF out.  This function just
    calls the extension system with the memory allocated XML that
    describes the data.
*/
void
CairoRendererPdfOutput::init ()
{
    // clang-format off
    Inkscape::Extension::build_from_mem(
        "<inkscape-extension xmlns=\"" INKSCAPE_EXTENSION_URI "\">\n"
            "<name>Portable Document Format</name>\n"
            "<id>org.inkscape.output.pdf.cairorenderer</id>\n"
            "<param name=\"PDFversion\" gui-text=\"" N_("Restrict to PDF version:") "\" type=\"optiongroup\" appearance=\"combo\" >\n"
                "<option value='PDF-1.5'>" N_("PDF 1.5") "</option>\n"
                "<option value='PDF-1.4'>" N_("PDF 1.4") "</option>\n"
            "</param>\n"
            "<param name=\"textToPath\" gui-text=\"" N_("Text output options:") "\" type=\"optiongroup\" appearance=\"radio\">\n"
                "<option value=\"embed\">" N_("Embed fonts") "</option>\n"
                "<option value=\"paths\">" N_("Convert text to paths") "</option>\n"
                "<option value=\"LaTeX\">" N_("Omit text in PDF and create LaTeX file") "</option>\n"
            "</param>\n"
            "<param name=\"blurToBitmap\" gui-text=\"" N_("Rasterize filter effects") "\" type=\"bool\">true</param>\n"
            "<param name=\"resolution\" gui-text=\"" N_("Resolution for rasterization (dpi):") "\" type=\"int\" min=\"1\" max=\"10000\">96</param>\n"
            "<spacer size=\"10\" />"
            "<param name=\"stretch\" gui-text=\"" N_("Rounding compensation:") "\" gui-description=\""
                N_("Exporting to PDF rounds the document size to the next whole number in pt units. Compensation may stretch the drawing slightly (up to 0.35mm for width and/or height). When not compensating, object sizes will be preserved strictly, but this can sometimes cause white gaps along the page margins.")
                "\" type=\"optiongroup\" appearance=\"radio\" >\n"
                "<option value=\"relative\">" N_("Compensate for rounding (recommended)") "</option>"
                "<option value=\"absolute\">" N_("Do not compensate") "</option>"
            "</param><separator/>"
            "<hbox indent=\"1\"><image>info-outline</image><spacer/><vbox><spacer/>"
                "<label>" N_("When exporting from the Export dialog, you can choose objects to export. 'Save a copy' / 'Save as' will export all pages.") "</label>"
                "<spacer size=\"5\" />"
                "<label>" N_("The page bleed can be set with the Page tool.") "</label>"
            "</vbox></hbox>"
            "<output is_exported='true' priority='5'>\n"
                "<extension>.pdf</extension>\n"
                "<mimetype>application/pdf</mimetype>\n"
                "<filetypename>Portable Document Format (*.pdf)</filetypename>\n"
                "<filetypetooltip>PDF File</filetypetooltip>\n"
            "</output>\n"
        "</inkscape-extension>", new CairoRendererPdfOutput());
    // clang-format on

    return;
}

} } }  /* namespace Inkscape, Extension, Internal */

#endif /* HAVE_CAIRO_PDF */