rsvg246.c

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/*
 * Copyright 2022 Vincent Sanders <vince@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/**
 * \file
 * implementation of content handler for image/svg using librsvg 2.46 API.
 *
 * SVG files are rendered to a NetSurf bitmap by creating a Cairo rendering
 * surface (content_rsvg_data.cs) over the bitmap's data, creating a Cairo
 * drawing context using that surface, and then passing that drawing context
 * to librsvg which then uses Cairo calls to plot the graphic to the bitmap.
 * We store this in content->bitmap, and then use the usual bitmap plotter
 * function to render it for redraw requests.
 */
 
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <string.h>
#include <sys/types.h>
 
#include <librsvg/rsvg.h>
 
#include <nsutils/endian.h>
 
#include "utils/log.h"
#include "utils/utils.h"
#include "utils/messages.h"
#include "netsurf/plotters.h"
#include "netsurf/bitmap.h"
#include "netsurf/content.h"
#include "content/llcache.h"
#include "content/content_protected.h"
#include "content/content_factory.h"
#include "desktop/gui_internal.h"
#include "desktop/bitmap.h"
 
#include "image/image_cache.h"
 
#include "image/rsvg.h"
 
 
typedef struct rsvg_content {
        struct content base;
 
        RsvgHandle *rsvgh;      /**< Context handle for RSVG renderer */
} rsvg_content;
 
 
static nserror
rsvg_create(const content_handler *handler,
            lwc_string *imime_type,
            const struct http_parameter *params,
            llcache_handle *llcache,
            const char *fallback_charset,
            bool quirks,
            struct content **c)
{
        rsvg_content *svg;
        nserror error;
 
        svg = calloc(1, sizeof(rsvg_content));
        if (svg == NULL)
                return NSERROR_NOMEM;
 
        error = content__init(&svg->base, handler, imime_type, params,
                              llcache, fallback_charset, quirks);
        if (error != NSERROR_OK) {
                free(svg);
                return error;
        }
 
        *c = (struct content *)svg;
 
        return NSERROR_OK;
}
 
 
/**
 * create a bitmap from jpeg content for the image cache.
 */
static struct bitmap *
rsvg_cache_convert(struct content *c)
{
        rsvg_content *svgc = (rsvg_content *)c;
        struct bitmap *bitmap;
        cairo_surface_t *cs;
        cairo_t *cr;
        RsvgRectangle viewport;
        gboolean renderres;
 
        if ((bitmap = guit->bitmap->create(c->width, c->height, BITMAP_NONE)) == NULL) {
                NSLOG(netsurf, INFO, "Failed to create bitmap for rsvg render.");
                return NULL;
        }
 
        if ((cs = cairo_image_surface_create_for_data(
                     (unsigned char *)guit->bitmap->get_buffer(bitmap),
                     CAIRO_FORMAT_ARGB32,
                     c->width, c->height,
                     guit->bitmap->get_rowstride(bitmap))) == NULL) {
                NSLOG(netsurf, INFO, "Failed to create Cairo image surface for rsvg render.");
                guit->bitmap->destroy(bitmap);
                return NULL;
        }
        if ((cr = cairo_create(cs)) == NULL) {
                NSLOG(netsurf, INFO,
                      "Failed to create Cairo drawing context for rsvg render.");
                cairo_surface_destroy(cs);
                guit->bitmap->destroy(bitmap);
                return NULL;
        }
 
        viewport.x = 0;
        viewport.y = 0;
        viewport.width = c->width;
        viewport.height = c->height;
        renderres = rsvg_handle_render_document(svgc->rsvgh, cr, &viewport, NULL);
        NSLOG(netsurf, DEBUG, "rsvg render:%d, width:%d, height %d", renderres, c->width, c->height);
 
        bitmap_format_to_client(bitmap, &(bitmap_fmt_t) {
                        .layout = BITMAP_LAYOUT_ARGB8888,
                });
        guit->bitmap->modified(bitmap);
 
        cairo_destroy(cr);
        cairo_surface_destroy(cs);
 
        return bitmap;
}
 
static void rsvg__get_demensions(const rsvg_content *svgc,
                int *width, int *height)
{
#if LIBRSVG_MAJOR_VERSION >= 2 && LIBRSVG_MINOR_VERSION >= 52
        gdouble rwidth;
        gdouble rheight;
        gboolean gotsize;
 
        gotsize = rsvg_handle_get_intrinsic_size_in_pixels(svgc->rsvgh,
                                                           &rwidth,
                                                           &rheight);
        if (gotsize == TRUE) {
                *width = rwidth;
                *height = rheight;
        } else {
                RsvgRectangle ink_rect;
                RsvgRectangle logical_rect;
                rsvg_handle_get_geometry_for_element(svgc->rsvgh,
                                                     NULL,
                                                     &ink_rect,
                                                     &logical_rect,
                                                     NULL);
                *width = ink_rect.width;
                *height = ink_rect.height;
        }
#else
        RsvgDimensionData rsvgsize;
 
        rsvg_handle_get_dimensions(svgc->rsvgh, &rsvgsize);
        *width = rsvgsize.width;
        *height = rsvgsize.height;
#endif
        NSLOG(netsurf, DEBUG, "rsvg width:%d height:%d.", *width, *height);
}
 
static bool rsvg_convert(struct content *c)
{
        rsvg_content *svgc = (rsvg_content *)c;
        const uint8_t *data; /* content data */
        size_t size; /* content data size */
        GInputStream * istream;
        GError *gerror = NULL;
 
        /* check image header is valid and get width/height */
 
        data = content__get_source_data(c, &size);
 
        istream = g_memory_input_stream_new_from_data(data, size, NULL);
        svgc->rsvgh = rsvg_handle_new_from_stream_sync(istream,
                                                       NULL,
                                                       RSVG_HANDLE_FLAGS_NONE,
                                                       NULL,
                                                       &gerror);
        g_object_unref(istream);
        if (svgc->rsvgh == NULL) {
                NSLOG(netsurf, INFO, "Failed to create rsvg handle for content.");
                return false;
        }
 
        rsvg__get_demensions(svgc, &c->width, &c->height);
 
        c->size = c->width * c->height * 4;
 
        image_cache_add(c, NULL, rsvg_cache_convert);
 
        content_set_ready(c);
        content_set_done(c);
        content_set_status(c, ""); /* Done: update status bar */
 
        return true;
}
 
 
static nserror rsvg_clone(const struct content *old, struct content **newc)
{
        rsvg_content *svg;
        nserror error;
 
        svg = calloc(1, sizeof(rsvg_content));
        if (svg == NULL)
                return NSERROR_NOMEM;
 
        error = content__clone(old, &svg->base);
        if (error != NSERROR_OK) {
                content_destroy(&svg->base);
                return error;
        }
 
        /* re-convert if the content is ready */
        if ((old->status == CONTENT_STATUS_READY) ||
            (old->status == CONTENT_STATUS_DONE)) {
                if (rsvg_convert(&svg->base) == false) {
                        content_destroy(&svg->base);
                        return NSERROR_CLONE_FAILED;
                }
        }
 
        *newc = (struct content *)svg;
 
        return NSERROR_OK;
}
 
 
static void rsvg_destroy(struct content *c)
{
        rsvg_content *d = (rsvg_content *) c;
 
        if (d->rsvgh != NULL) {
                g_object_unref(d->rsvgh);
                d->rsvgh = NULL;
        }
 
        return image_cache_destroy(c);
}
 
static const content_handler rsvg_content_handler = {
        .create = rsvg_create,
        .data_complete = rsvg_convert,
        .destroy = rsvg_destroy,
        .redraw = image_cache_redraw,
        .clone = rsvg_clone,
        .get_internal = image_cache_get_internal,
        .type = image_cache_content_type,
        .is_opaque = image_cache_is_opaque,
        .no_share = false,
};
 
static const char *rsvg_types[] = {
        "image/svg",
        "image/svg+xml"
};
 
CONTENT_FACTORY_REGISTER_TYPES(nsrsvg, rsvg_types, rsvg_content_handler);