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;
}

static bool
pdf_render_document_to_file(SPDocument *doc, gchar const *filename, unsigned int level,
                            bool texttopath, bool omittext, bool filtertobitmap, int resolution,
                            const gchar * const exportId, bool exportDrawing, bool exportCanvas, double bleedmargin_px)
{
    if (texttopath) {
        assert(!omittext);
        // 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();
    SPItem *base = nullptr;

    bool pageBoundingBox = TRUE;
    if (exportId && strcmp(exportId, "")) {
        // we want to export the given item only
        base = SP_ITEM(doc->getObjectById(exportId));
        if (!base) {
            throw Inkscape::Extension::Output::export_id_not_found(exportId);
        }
        root->cropToObject(base); // TODO: This is inconsistent in CLI (should only happen for --export-id-only)
        pageBoundingBox = exportCanvas;
    }
    else {
        // we want to export the entire document from root
        base = root;
        pageBoundingBox = !exportDrawing;
    }

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

    /* Create renderer and context */
    CairoRenderer *renderer = new CairoRenderer();
    CairoRenderContext *ctx = renderer->createContext();
    ctx->setPDFLevel(level);
    ctx->setTextToPath(texttopath);
    ctx->setOmitText(omittext);
    ctx->setFilterToBitmap(filtertobitmap);
    ctx->setBitmapResolution(resolution);

    bool ret = ctx->setPdfTarget (filename);
    if(ret) {
        /* Render document */
        ret = renderer->setupDocument(ctx, doc, pageBoundingBox, bleedmargin_px, base);

        auto pages = doc->getPageManager().getPages();
        if (pages.size() == 0) {
            // Output the page bounding box as already set up in the initial setupDocument.
            renderer->renderItem(ctx, root);
            ret = ctx->finish();
        } else {
            auto scale = doc->getDocumentScale();

            // Set root transformation, which copies a bit of what happens above the
            // reason for this manual process is because we need to slide in the page
            // offset transformations so need fine-control over placing the children.
            ctx->transform(scale);
            ctx->transform(root->transform);

            int index = 1;
            for (auto &page : pages) {
                ctx->pushState();

                auto pt = Inkscape::Util::Quantity::convert(1, "px", "pt");
                auto rect = page->getRect();
                // Conclude previous page and set new page width and height.
                auto big_rect = rect * scale;
                ctx->nextPage(big_rect.width() * pt, big_rect.height() * pt, page->label());

                // Set up page transformation which pushes objects back into the 0,0 location
                ctx->transform(Geom::Translate(rect.corner(0)).inverse());

                for (auto &child : page->getOverlappingItems(false)) {
                    ctx->pushState();

                    // This process does not return layers, so those affines are added manually.
                    for (auto anc : child->ancestorList(true)) {
                        if (auto layer = dynamic_cast<SPItem *>(anc)) {
                            if (layer != child && layer != root) {
                                ctx->transform(layer->transform);
                            }
                        }
                    }

                    // Render the page into the context in the new location.
                    renderer->renderItem(ctx, child, nullptr, page);
                    ctx->popState();
                }
                ret = ctx->finishPage();
                index += 1;

                ctx->popState();
            }
            ret = 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");
    }

    bool new_textToPath  = FALSE;
    try {
        new_textToPath = (strcmp(mod->get_param_optiongroup("textToPath"), "paths") == 0);
    }
    catch(...) {
        g_warning("Parameter <textToPath> might not exist");
    }

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

    bool new_blurToBitmap  = FALSE;
    try {
        new_blurToBitmap  = 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");
    }

    const gchar *new_exportId = nullptr;
    try {
        new_exportId = mod->get_param_string("exportId");
    }
    catch(...) {
        g_warning("Parameter <exportId> might not exist");
    }

    bool new_exportCanvas  = true;
    try {
        new_exportCanvas = (strcmp(ext->get_param_optiongroup("area"), "page") == 0);
    } catch(...) {
        g_warning("Parameter <area> might not exist");
    }
    bool new_exportDrawing  = !new_exportCanvas;

    double new_bleedmargin_px = 0.;
    try {
        new_bleedmargin_px = Inkscape::Util::Quantity::convert(mod->get_param_float("bleed"), "mm", "px");
    }
    catch(...) {
        g_warning("Parameter <bleed> 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,
                                          new_textToPath, new_textToLaTeX, new_blurToBitmap, new_bitmapResolution,
                                          new_exportId, new_exportDrawing, new_exportCanvas, new_bleedmargin_px);
        g_free(final_name);

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

    // Create LaTeX file (if requested)
    if (new_textToLaTeX) {
        ret = latex_render_document_text_to_file(doc, filename, new_exportId, new_exportDrawing, new_exportCanvas, new_bleedmargin_px, 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"
            "<param name=\"area\" gui-text=\"" N_("Output page size:") "\" type=\"optiongroup\" appearance=\"radio\" >\n"
                "<option value=\"page\">" N_("Use document's page size") "</option>"
                "<option value=\"drawing\">" N_("Use exported object's size") "</option>"
            "</param>"
            "<param name=\"bleed\" gui-text=\"" N_("Bleed/margin (mm):") "\" type=\"float\" min=\"-10000\" max=\"10000\">0</param>\n"
            "<param name=\"exportId\" gui-text=\"" N_("Limit export to the object with ID:") "\" type=\"string\"></param>\n"
            "<output is_exported='true'>\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 */