path: root/xps/xpspage.c

/* Copyright (C) 2001-2023 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/


/* XPS interpreter - page parsing */

#include "ghostxps.h"

int
xps_parse_canvas(xps_context_t *ctx, char *base_uri, xps_resource_t *dict, xps_item_t *root)
{
    xps_resource_t *new_dict = NULL;
    xps_item_t *node;
    char *opacity_mask_uri;
    int code;

    char *transform_att;
    char *clip_att;
    char *opacity_att;
    char *opacity_mask_att;

    xps_item_t *transform_tag = NULL;
    xps_item_t *clip_tag = NULL;
    xps_item_t *opacity_mask_tag = NULL;

    gs_matrix transform;

    transform_att = xps_att(root, "RenderTransform");
    clip_att = xps_att(root, "Clip");
    opacity_att = xps_att(root, "Opacity");
    opacity_mask_att = xps_att(root, "OpacityMask");

    for (node = xps_down(root); node; node = xps_next(node))
    {
        if (!strcmp(xps_tag(node), "Canvas.Resources") && xps_down(node))
        {
            code = xps_parse_resource_dictionary(ctx, &new_dict, base_uri, xps_down(node));
            if (code)
                return gs_rethrow(code, "cannot load Canvas.Resources");
            if (new_dict && new_dict != dict)
            {
                new_dict->parent = dict;
                dict = new_dict;
            }
        }

        if (!strcmp(xps_tag(node), "Canvas.RenderTransform"))
            transform_tag = xps_down(node);
        if (!strcmp(xps_tag(node), "Canvas.Clip"))
            clip_tag = xps_down(node);
        if (!strcmp(xps_tag(node), "Canvas.OpacityMask"))
            opacity_mask_tag = xps_down(node);
    }

    opacity_mask_uri = base_uri;
    xps_resolve_resource_reference(ctx, dict, &transform_att, &transform_tag, NULL);
    xps_resolve_resource_reference(ctx, dict, &clip_att, &clip_tag, NULL);
    xps_resolve_resource_reference(ctx, dict, &opacity_mask_att, &opacity_mask_tag, &opacity_mask_uri);

    gs_gsave(ctx->pgs);

    gs_make_identity(&transform);
    if (transform_att)
        xps_parse_render_transform(ctx, transform_att, &transform);
    if (transform_tag)
        xps_parse_matrix_transform(ctx, transform_tag, &transform);
    gs_concat(ctx->pgs, &transform);

    if (clip_att || clip_tag)
    {
        if (clip_att)
            xps_parse_abbreviated_geometry(ctx, clip_att);
        if (clip_tag)
            xps_parse_path_geometry(ctx, dict, clip_tag, 0);
        xps_clip(ctx);
    }

    code = xps_begin_opacity(ctx, opacity_mask_uri, dict, opacity_att, opacity_mask_tag, false, false);
    if (code)
    {
        gs_grestore(ctx->pgs);
        return gs_rethrow(code, "cannot create transparency group");
    }

    for (node = xps_down(root); node; node = xps_next(node))
    {
        code = xps_parse_element(ctx, base_uri, dict, node);
        if (code)
        {
            xps_end_opacity(ctx, opacity_mask_uri, dict, opacity_att, opacity_mask_tag);
            gs_grestore(ctx->pgs);
            return gs_rethrow(code, "cannot parse child of Canvas");
        }
    }

    xps_end_opacity(ctx, opacity_mask_uri, dict, opacity_att, opacity_mask_tag);

    gs_grestore(ctx->pgs);

    if (new_dict)
        xps_free_resource_dictionary(ctx, new_dict);

    return 0;
}

int
xps_parse_fixed_page(xps_context_t *ctx, xps_part_t *part)
{
    xps_item_t *root, *node;
    xps_resource_t *dict;
    char *width_att;
    char *height_att;
    char base_uri[1024];
    char *s;
    int code, code1, code2;
    int page_spot_colors = 0;

    if_debug1m('|', ctx->memory, "doc: parsing page %s\n", part->name);

    gs_strlcpy(base_uri, part->name, sizeof base_uri);
    s = strrchr(base_uri, '/');
    if (s)
        s[1] = 0;

    root = xps_parse_xml(ctx, part->data, part->size);
    if (!root)
        return gs_rethrow(-1, "cannot parse xml");

    if (!strcmp(xps_tag(root), "AlternateContent"))
    {
        xps_item_t *node = xps_lookup_alternate_content(root);
        if (!node)
        {
            xps_free_item(ctx, root);
            return gs_throw(-1, "expected FixedPage alternate content element");
        }
        xps_detach_and_free_remainder(ctx, root, node);
        root = node;
    }

    if (strcmp(xps_tag(root), "FixedPage"))
    {
        xps_free_item(ctx, root);
        return gs_throw(-1, "expected FixedPage element");
    }

    width_att = xps_att(root, "Width");
    height_att = xps_att(root, "Height");

    if (!width_att)
    {
        xps_free_item(ctx, root);
        return gs_throw(-1, "FixedPage missing required attribute: Width");
    }
    if (!height_att)
    {
        xps_free_item(ctx, root);
        return gs_throw(-1, "FixedPage missing required attribute: Height");
    }

    dict = NULL;

    /* Setup new page */
    {
        gs_memory_t *mem = ctx->memory;
        gs_gstate *pgs = ctx->pgs;
        gx_device *dev = gs_currentdevice(pgs);
        gs_param_float_array fa;
        float fv[2];
        gs_c_param_list list;

        gs_c_param_list_write(&list, mem);

        fv[0] = atoi(width_att) / 96.0 * 72.0;
        fv[1] = atoi(height_att) / 96.0 * 72.0;
        fa.persistent = false;
        fa.data = fv;
        fa.size = 2;

        /* Pre-parse looking for transparency */
        ctx->has_transparency = false;
        for (node = xps_down(root); node; node = xps_next(node))
        {
            if (!strcmp(xps_tag(node), "FixedPage.Resources") && xps_down(node))
                if (xps_resource_dictionary_has_transparency(ctx, base_uri, xps_down(node)))
                {
                    ctx->has_transparency = true;
                    break;
                }
            if (xps_element_has_transparency(ctx, base_uri, node))
            {
                ctx->has_transparency = true;
                break;
            }
        }

        /* At some point we may want to add the pre-parse for named colors and n-channel
           colors here. The XPS spec makes it optional to put the colorant names in the
           ICC profile. So we would need some sort of fall back and we would need to know
           if a name color that we encounter is one that we already encountered, which would get
           very messy in terms of comparing ICC profiles. Especially for example, if
           the same spot color was used individually AND in an n-channel color profile.
           Since XPS usage is rare, and the demand for support of real spot color separation
           non-existent, we will set the PageSpotColors to 0 at this point. */

        code  = param_write_int((gs_param_list *)&list, "PageSpotColors", &(page_spot_colors));
        code1 = param_write_bool((gs_param_list *)&list, "PageUsesTransparency", &(ctx->has_transparency));
        code2 = param_write_float_array((gs_param_list *)&list, ".MediaSize", &fa);
        if ( code >= 0 || code1 >= 0 || code2 >= 0)
        {
            gs_c_param_list_read(&list);
            code = gs_putdeviceparams(dev, (gs_param_list *)&list);
            if (code < 0) {
                gs_c_param_list_release(&list);
                xps_free_item(ctx, root);
                return gs_rethrow(code, "cannot set device parameters");
            }
        }
        gs_c_param_list_release(&list);

        /* nb this is for the demo it is wrong and should be removed */
        gs_initgraphics(pgs);

        /* 96 dpi default - and put the origin at the top of the page */

        gs_initmatrix(pgs);

        code = gs_scale(pgs, 72.0/96.0, -72.0/96.0);
        if (code < 0) {
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot set page transform");
        }

        code = gs_translate(pgs, 0.0, -atoi(height_att));
        if (code < 0) {
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot set page transform");
        }

        code = gs_erasepage(pgs);
        if (code < 0) {
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot clear page");
        }
    }

    /* save the state with the original device before we push */
    gs_gsave(ctx->pgs);

    if (ctx->use_transparency && ctx->has_transparency)
    {
        code = gs_push_pdf14trans_device(ctx->pgs, false, false, 0, 0);
        if (code < 0)
        {
            gs_grestore(ctx->pgs);
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot install transparency device");
        }
    }

    /* Draw contents */

    for (node = xps_down(root); node; node = xps_next(node))
    {
        if (!strcmp(xps_tag(node), "FixedPage.Resources") && xps_down(node))
        {
            code = xps_parse_resource_dictionary(ctx, &dict, base_uri, xps_down(node));
            if (code)
            {
                gs_pop_pdf14trans_device(ctx->pgs, false);
                gs_grestore(ctx->pgs);
                if (dict)
                    xps_free_resource_dictionary(ctx, dict);
                xps_free_item(ctx, root);
                return gs_rethrow(code, "cannot load FixedPage.Resources");
            }
        }
        code = xps_parse_element(ctx, base_uri, dict, node);
        if (code)
        {
            gs_pop_pdf14trans_device(ctx->pgs, false);
            gs_grestore(ctx->pgs);
            if (dict)
                xps_free_resource_dictionary(ctx, dict);
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot parse child of FixedPage");
        }
    }

    if (ctx->use_transparency && ctx->has_transparency)
    {
        code = gs_pop_pdf14trans_device(ctx->pgs, false);
        if (code < 0)
        {
            gs_grestore(ctx->pgs);
            if (dict)
                xps_free_resource_dictionary(ctx, dict);
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot uninstall transparency device");
        }
    }

    /* Flush page */
    {
        code = xps_show_page(ctx, 1, true); /* copies, flush */
        if (code < 0)
        {
            gs_grestore(ctx->pgs);
            if (dict)
                xps_free_resource_dictionary(ctx, dict);
            xps_free_item(ctx, root);
            return gs_rethrow(code, "cannot flush page");
        }
    }

    /* restore the original device, discarding the pdf14 compositor */
    gs_grestore(ctx->pgs);

    if (dict)
    {
        xps_free_resource_dictionary(ctx, dict);
    }

    xps_free_item(ctx, root);

    return 0;
}