dvi-document.c

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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
/*
 * Copyright (C) 2005, Nickolay V. Shmyrev <nshmyrev@yandex.ru>
 *
 * This program 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; either version 2, or (at your option)
 * any later version.
 *
 * This program 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "config.h"

#include "dvi-document.h"
#include "texmfcnf.h"
#include "ev-document-misc.h"
#include "ev-file-exporter.h"
#include "ev-file-helpers.h"

#include "mdvi.h"
#include "fonts.h"
#include "color.h"
#include "cairo-device.h"

#include <glib/gi18n-lib.h>
#include <ctype.h>
#ifdef G_OS_WIN32
# define WIFEXITED(x) ((x) != 3)
# define WEXITSTATUS(x) (x)
#else
# include <sys/wait.h>
#endif
#include <stdlib.h>

static GMutex dvi_context_mutex;

enum {
    PROP_0,
    PROP_TITLE
};

struct _DviDocumentClass
{
    EvDocumentClass parent_class;
};

struct _DviDocument
{
    EvDocument parent_instance;

    DviContext *context;
    DviPageSpec *spec;
    DviParams *params;
    
    /* To let document scale we should remember width and height */
    double base_width;
    double base_height;
    
    gchar *uri;

    /* PDF exporter */
    gchar        *exporter_filename;
    GString      *exporter_opts;
};

typedef struct _DviDocumentClass DviDocumentClass;

static void dvi_document_file_exporter_iface_init (EvFileExporterInterface       *iface);
static void dvi_document_do_color_special         (DviContext                    *dvi,
                           const char                    *prefix,
                           const char                    *arg);

EV_BACKEND_REGISTER_WITH_CODE (DviDocument, dvi_document,
     {
      EV_BACKEND_IMPLEMENT_INTERFACE (EV_TYPE_FILE_EXPORTER, dvi_document_file_exporter_iface_init);
     });

static gboolean
dvi_document_load (EvDocument  *document,
           const char  *uri,
           GError     **error)
{
    gchar *filename;
    DviDocument *dvi_document = DVI_DOCUMENT(document);
    
    filename = g_filename_from_uri (uri, NULL, error);
    if (!filename)
            return FALSE;
    
    g_mutex_lock (&dvi_context_mutex);
    if (dvi_document->context)
        mdvi_destroy_context (dvi_document->context);

    dvi_document->context = mdvi_init_context(dvi_document->params, dvi_document->spec, filename);
    g_mutex_unlock (&dvi_context_mutex);
    g_free (filename);
    
    if (!dvi_document->context) {
            g_set_error_literal (error,
                                     EV_DOCUMENT_ERROR,
                                     EV_DOCUMENT_ERROR_INVALID,
                                     _("DVI document has incorrect format"));
            return FALSE;
    }
    
    mdvi_cairo_device_init (&dvi_document->context->device);
    
    
    dvi_document->base_width = dvi_document->context->dvi_page_w * dvi_document->context->params.conv 
        + 2 * unit2pix(dvi_document->params->dpi, MDVI_HMARGIN) / dvi_document->params->hshrink;
    
    dvi_document->base_height = dvi_document->context->dvi_page_h * dvi_document->context->params.vconv 
            + 2 * unit2pix(dvi_document->params->vdpi, MDVI_VMARGIN) / dvi_document->params->vshrink;
    
    g_free (dvi_document->uri);
    dvi_document->uri = g_strdup (uri);
    
    return TRUE;
}


static gboolean
dvi_document_save (EvDocument  *document,
              const char  *uri,
              GError     **error)
{
    DviDocument *dvi_document = DVI_DOCUMENT (document);

    return ev_xfer_uri_simple (dvi_document->uri, uri, error);
}

static int
dvi_document_get_n_pages (EvDocument *document)
{
    DviDocument *dvi_document = DVI_DOCUMENT (document);
    
    return dvi_document->context->npages;
}

static void
dvi_document_get_page_size (EvDocument *document,
                EvPage     *page,
                double     *width,
                double     *height)
{
    DviDocument *dvi_document = DVI_DOCUMENT (document);    

        *width = dvi_document->base_width;
        *height = dvi_document->base_height;;
}

static cairo_surface_t *
dvi_document_render (EvDocument      *document,
             EvRenderContext *rc)
{
    cairo_surface_t *surface;
    cairo_surface_t *rotated_surface;
    DviDocument *dvi_document = DVI_DOCUMENT(document);
    gdouble xscale, yscale;
    gint required_width, required_height;
    gint proposed_width, proposed_height;
    gint xmargin = 0, ymargin = 0;

    /* We should protect our context since it's not 
     * thread safe. The work to the future - 
     * let context render page independently
     */
    g_mutex_lock (&dvi_context_mutex);
    
    mdvi_setpage (dvi_document->context, rc->page->index);
    
    ev_render_context_compute_scales (rc, dvi_document->base_width, dvi_document->base_height,
                      &xscale, &yscale);
    mdvi_set_shrink (dvi_document->context, 
             (int)((dvi_document->params->hshrink - 1) / xscale) + 1,
             (int)((dvi_document->params->vshrink - 1) / yscale) + 1);

    ev_render_context_compute_scaled_size (rc, dvi_document->base_width, dvi_document->base_height,
                           &required_width, &required_height);
    proposed_width = dvi_document->context->dvi_page_w * dvi_document->context->params.conv;
    proposed_height = dvi_document->context->dvi_page_h * dvi_document->context->params.vconv;
    
    if (required_width >= proposed_width)
        xmargin = (required_width - proposed_width) / 2;
    if (required_height >= proposed_height)
        ymargin = (required_height - proposed_height) / 2;
        
    mdvi_cairo_device_set_margins (&dvi_document->context->device, xmargin, ymargin);
    mdvi_cairo_device_set_scale (&dvi_document->context->device, xscale, yscale);
    mdvi_cairo_device_render (dvi_document->context);
    surface = mdvi_cairo_device_get_surface (&dvi_document->context->device);

    g_mutex_unlock (&dvi_context_mutex);

    rotated_surface = ev_document_misc_surface_rotate_and_scale (surface,
                                     required_width,
                                     required_height, 
                                     rc->rotation);
    cairo_surface_destroy (surface);
    
    return rotated_surface;
}

static void
dvi_document_finalize (GObject *object)
{   
    DviDocument *dvi_document = DVI_DOCUMENT(object);
    
    g_mutex_lock (&dvi_context_mutex);
    if (dvi_document->context) {
        mdvi_cairo_device_free (&dvi_document->context->device);
        mdvi_destroy_context (dvi_document->context);
    }
    g_mutex_unlock (&dvi_context_mutex);

    if (dvi_document->params)
        g_free (dvi_document->params);

    if (dvi_document->exporter_filename)
        g_free (dvi_document->exporter_filename);
    
    if (dvi_document->exporter_opts)
        g_string_free (dvi_document->exporter_opts, TRUE);

        g_free (dvi_document->uri);
        
    G_OBJECT_CLASS (dvi_document_parent_class)->finalize (object);
}

static gboolean
dvi_document_support_synctex (EvDocument *document)
{
    return TRUE;
}

static void
dvi_document_class_init (DviDocumentClass *klass)
{
    GObjectClass    *gobject_class = G_OBJECT_CLASS (klass);
    EvDocumentClass *ev_document_class = EV_DOCUMENT_CLASS (klass);
    gchar *texmfcnf;

    gobject_class->finalize = dvi_document_finalize;

    texmfcnf = get_texmfcnf();
    mdvi_init_kpathsea ("evince", MDVI_MFMODE, MDVI_FALLBACK_FONT, MDVI_DPI, texmfcnf);
    g_free(texmfcnf);

    mdvi_register_special ("Color", "color", NULL, dvi_document_do_color_special, 1);
    mdvi_register_fonts ();

    ev_document_class->load = dvi_document_load;
    ev_document_class->save = dvi_document_save;
    ev_document_class->get_n_pages = dvi_document_get_n_pages;
    ev_document_class->get_page_size = dvi_document_get_page_size;
    ev_document_class->render = dvi_document_render;
    ev_document_class->support_synctex = dvi_document_support_synctex;
}

/* EvFileExporterIface */
static void
dvi_document_file_exporter_begin (EvFileExporter        *exporter,
                  EvFileExporterContext *fc)
{
    DviDocument *dvi_document = DVI_DOCUMENT(exporter);
    
    if (dvi_document->exporter_filename)
        g_free (dvi_document->exporter_filename);   
    dvi_document->exporter_filename = g_strdup (fc->filename);
    
    if (dvi_document->exporter_opts) {
        g_string_free (dvi_document->exporter_opts, TRUE);
    }
    dvi_document->exporter_opts = g_string_new ("-s ");
}

static void
dvi_document_file_exporter_do_page (EvFileExporter  *exporter,
                    EvRenderContext *rc)
{
       DviDocument *dvi_document = DVI_DOCUMENT(exporter);

       g_string_append_printf (dvi_document->exporter_opts, "%d,", (rc->page->index) + 1);
}

static void
dvi_document_file_exporter_end (EvFileExporter *exporter)
{
    gchar *command_line;
    gint exit_stat;
    GError *err = NULL;
    gboolean success;
    
    DviDocument *dvi_document = DVI_DOCUMENT(exporter);
    
    command_line = g_strdup_printf ("dvipdfm %s -o %s \"%s\"", /* dvipdfm -s 1,2,.., -o exporter_filename dvi_filename */
                    dvi_document->exporter_opts->str,
                    dvi_document->exporter_filename,
                    dvi_document->context->filename);
    
    success = g_spawn_command_line_sync (command_line,
                         NULL,
                         NULL,
                         &exit_stat,
                         &err);

    g_free (command_line);

    if (success == FALSE) {
        g_warning ("Error: %s", err->message);
    } else if (!WIFEXITED(exit_stat) || WEXITSTATUS(exit_stat) != EXIT_SUCCESS){
        g_warning ("Error: dvipdfm does not end normally or exit with a failure status.");
    }

    if (err)
        g_error_free (err);
}

static EvFileExporterCapabilities
dvi_document_file_exporter_get_capabilities (EvFileExporter *exporter)
{
    return  EV_FILE_EXPORTER_CAN_PAGE_SET |
        EV_FILE_EXPORTER_CAN_COPIES |
        EV_FILE_EXPORTER_CAN_COLLATE |
        EV_FILE_EXPORTER_CAN_REVERSE |
        EV_FILE_EXPORTER_CAN_GENERATE_PDF;
}

static void
dvi_document_file_exporter_iface_init (EvFileExporterInterface *iface)
{
        iface->begin = dvi_document_file_exporter_begin;
        iface->do_page = dvi_document_file_exporter_do_page;
        iface->end = dvi_document_file_exporter_end;
    iface->get_capabilities = dvi_document_file_exporter_get_capabilities;
}

#define RGB2ULONG(r,g,b) ((0xFF<<24)|(r<<16)|(g<<8)|(b))

static gboolean
hsb2rgb (float h, float s, float v, guchar *red, guchar *green, guchar *blue)
{
        float f, p, q, t, r, g, b;
        int i;

        s /= 100;
        v /= 100;
        h /= 60;
        i = floor (h);
        if (i == 6)
                i = 0;
        else if ((i > 6) || (i < 0))
                return FALSE;
        f = h - i;
        p = v * (1 - s);
        q = v * (1 - (s * f));
        t = v * (1 - (s * (1 - f)));

    if (i == 0) {
        r = v;
        g = t;
        b = p;
    } else if (i == 1) {
        r = q;
        g = v;
        b = p;
    } else if (i == 2) {
        r = p;
        g = v;
        b = t;
    } else if (i == 3) {
        r = p;
        g = q;
        b = v;
    } else if (i == 4) {
        r = t;
        g = p;
        b = v;
    } else if (i == 5) {
        r = v;
        g = p;
        b = q;
    }

        *red   = (guchar)floor(r * 255.0);
        *green = (guchar)floor(g * 255.0);
        *blue  = (guchar)floor(b * 255.0);
    
        return TRUE;
}

static void
parse_color (const gchar *ptr,
         gdouble     *color,
         gint         n_color)
{
    gchar *p = (gchar *)ptr;
    gint   i;

    for (i = 0; i < n_color; i++) {
        while (isspace (*p)) p++;
        color[i] = g_ascii_strtod (p, NULL);
        while (!isspace (*p) && *p != '\0') p++;
        if (*p == '\0')
            break;
    }
}

static void
dvi_document_do_color_special (DviContext *dvi, const char *prefix, const char *arg)
{
        if (strncmp (arg, "pop", 3) == 0) {
                mdvi_pop_color (dvi);
        } else if (strncmp (arg, "push", 4) == 0) {
                /* Find color source: Named, CMYK or RGB */
                const char *tmp = arg + 4;
        
                while (isspace (*tmp)) tmp++;

                if (!strncmp ("rgb", tmp, 3)) {
            gdouble rgb[3];
                        guchar red, green, blue;

            parse_color (tmp + 4, rgb, 3);
            
                        red = 255 * rgb[0];
                        green = 255 * rgb[1];
                        blue = 255 * rgb[2];

                        mdvi_push_color (dvi, RGB2ULONG (red, green, blue), 0xFFFFFFFF);
                } else if (!strncmp ("hsb", tmp, 4)) {
                        gdouble hsb[3];
                        guchar red, green, blue;

            parse_color (tmp + 4, hsb, 3);
            
                        if (hsb2rgb (hsb[0], hsb[1], hsb[2], &red, &green, &blue))
                                mdvi_push_color (dvi, RGB2ULONG (red, green, blue), 0xFFFFFFFF);
                } else if (!strncmp ("cmyk", tmp, 4)) {
            gdouble cmyk[4];
                        double r, g, b;
            guchar red, green, blue;
            
            parse_color (tmp + 5, cmyk, 4);

                        r = 1.0 - cmyk[0] - cmyk[3];
                        if (r < 0.0)
                                r = 0.0;
                        g = 1.0 - cmyk[1] - cmyk[3];
                        if (g < 0.0)
                                g = 0.0;
                        b = 1.0 - cmyk[2] - cmyk[3];
                        if (b < 0.0)
                                b = 0.0;

            red = r * 255 + 0.5;
            green = g * 255 + 0.5;
            blue = b * 255 + 0.5;
            
                        mdvi_push_color (dvi, RGB2ULONG (red, green, blue), 0xFFFFFFFF);
        } else if (!strncmp ("gray ", tmp, 5)) {
            gdouble gray;
            guchar rgb;

            parse_color (tmp + 5, &gray, 1);

            rgb = gray * 255 + 0.5;

            mdvi_push_color (dvi, RGB2ULONG (rgb, rgb, rgb), 0xFFFFFFFF);
                } else {
                        GdkColor color;
            
                        if (gdk_color_parse (tmp, &color)) {
                guchar red, green, blue;

                red = color.red * 255 / 65535.;
                green = color.green * 255 / 65535.;
                blue = color.blue * 255 / 65535.;

                                mdvi_push_color (dvi, RGB2ULONG (red, green, blue), 0xFFFFFFFF);
            }
                }
        }
}

static void
dvi_document_init_params (DviDocument *dvi_document)
{   
    dvi_document->params = g_new0 (DviParams, 1);   

    dvi_document->params->dpi      = MDVI_DPI;
    dvi_document->params->vdpi     = MDVI_VDPI;
    dvi_document->params->mag      = MDVI_MAGNIFICATION;
    dvi_document->params->density  = MDVI_DEFAULT_DENSITY;
    dvi_document->params->gamma    = MDVI_DEFAULT_GAMMA;
    dvi_document->params->flags    = MDVI_PARAM_ANTIALIASED;
    dvi_document->params->hdrift   = 0;
    dvi_document->params->vdrift   = 0;
    dvi_document->params->hshrink  =  MDVI_SHRINK_FROM_DPI(dvi_document->params->dpi);
    dvi_document->params->vshrink  =  MDVI_SHRINK_FROM_DPI(dvi_document->params->vdpi);
    dvi_document->params->orientation = MDVI_ORIENT_TBLR;

    dvi_document->spec = NULL;
    
        dvi_document->params->bg = 0xffffffff;
        dvi_document->params->fg = 0xff000000;
}

static void
dvi_document_init (DviDocument *dvi_document)
{
    dvi_document->context = NULL;
    dvi_document_init_params (dvi_document);

    dvi_document->exporter_filename = NULL;
    dvi_document->exporter_opts = NULL;
}