src/vikcoordlayer.c

/*
 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
 *
 * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
 *
 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include <glib/gi18n.h>

#include "viking.h"
#include "vikcoordlayer_pixmap.h"

static void coord_layer_marshall( VikCoordLayer *vcl, guint8 **data, gint *len );
static VikCoordLayer *coord_layer_unmarshall( guint8 *data, gint len, VikViewport *vvp );
static gboolean coord_layer_set_param ( VikCoordLayer *vcl, guint16 id, VikLayerParamData data, VikViewport *vp );
static VikLayerParamData coord_layer_get_param ( VikCoordLayer *vcl, guint16 id );
static void coord_layer_update_gc ( VikCoordLayer *vcl, VikViewport *vp, const gchar *color );
static void coord_layer_post_read ( VikLayer *vl, VikViewport *vp, gboolean from_file );

static VikLayerParamScale param_scales[] = {
  { 0.05, 60.0, 0.25, 10 },
  { 1, 10, 1, 0 },
};

static VikLayerParam coord_layer_params[] = {
  { "color", VIK_LAYER_PARAM_STRING, VIK_LAYER_GROUP_NONE, N_("Color:"), VIK_LAYER_WIDGET_ENTRY },
  { "min_inc", VIK_LAYER_PARAM_DOUBLE, VIK_LAYER_GROUP_NONE, N_("Minutes Width:"), VIK_LAYER_WIDGET_SPINBUTTON, param_scales + 0 },
  { "line_thickness", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, N_("Line Thickness:"), VIK_LAYER_WIDGET_SPINBUTTON, param_scales + 1 },
};


enum { PARAM_COLOR = 0, PARAM_MIN_INC, PARAM_LINE_THICKNESS, NUM_PARAMS };

VikLayerInterface vik_coord_layer_interface = {
  "Coord",
  &coordlayer_pixbuf,

  NULL,
  0,

  coord_layer_params,
  NUM_PARAMS,
  NULL,
  0,

  VIK_MENU_ITEM_ALL,

  (VikLayerFuncCreate)                  vik_coord_layer_create,
  (VikLayerFuncRealize)                 NULL,
                                        coord_layer_post_read,
  (VikLayerFuncFree)                    vik_coord_layer_free,

  (VikLayerFuncProperties)              NULL,
  (VikLayerFuncDraw)                    vik_coord_layer_draw,
  (VikLayerFuncChangeCoordMode)         NULL,

  (VikLayerFuncSetMenuItemsSelection)   NULL,
  (VikLayerFuncGetMenuItemsSelection)   NULL,

  (VikLayerFuncAddMenuItems)            NULL,
  (VikLayerFuncSublayerAddMenuItems)    NULL,

  (VikLayerFuncSublayerRenameRequest)   NULL,
  (VikLayerFuncSublayerToggleVisible)   NULL,

  (VikLayerFuncMarshall)		coord_layer_marshall,
  (VikLayerFuncUnmarshall)		coord_layer_unmarshall,

  (VikLayerFuncSetParam)                coord_layer_set_param,
  (VikLayerFuncGetParam)                coord_layer_get_param,

  (VikLayerFuncReadFileData)            NULL,
  (VikLayerFuncWriteFileData)           NULL,

  (VikLayerFuncDeleteItem)              NULL,
  (VikLayerFuncCopyItem)                NULL,
  (VikLayerFuncPasteItem)               NULL,
  (VikLayerFuncFreeCopiedItem)          NULL,
  (VikLayerFuncDragDropRequest)		NULL,
};

struct _VikCoordLayer {
  VikLayer vl;
  GdkGC *gc;
  gdouble deg_inc;
  guint8 line_thickness;
  gchar *color;
};

GType vik_coord_layer_get_type ()
{
  static GType vcl_type = 0;

  if (!vcl_type)
  {
    static const GTypeInfo vcl_info =
    {
      sizeof (VikCoordLayerClass),
      NULL, /* base_init */
      NULL, /* base_finalize */
      NULL, /* class init */
      NULL, /* class_finalize */
      NULL, /* class_data */
      sizeof (VikCoordLayer),
      0,
      NULL /* instance init */
    };
    vcl_type = g_type_register_static ( VIK_LAYER_TYPE, "VikCoordLayer", &vcl_info, 0 );
  }

  return vcl_type;
}

static void coord_layer_marshall( VikCoordLayer *vcl, guint8 **data, gint *len )
{
  vik_layer_marshall_params ( VIK_LAYER(vcl), data, len );
}

static VikCoordLayer *coord_layer_unmarshall( guint8 *data, gint len, VikViewport *vvp )
{
  VikCoordLayer *rv = vik_coord_layer_new ( vvp );
  vik_layer_unmarshall_params ( VIK_LAYER(rv), data, len, vvp );
  return rv;
}

gboolean coord_layer_set_param ( VikCoordLayer *vcl, guint16 id, VikLayerParamData data, VikViewport *vp )
{
  switch ( id )
  {
    case PARAM_COLOR: if ( vcl->color ) g_free ( vcl->color ); vcl->color = g_strdup ( data.s ); break;
    case PARAM_MIN_INC: vcl->deg_inc = data.d / 60.0; break;
    case PARAM_LINE_THICKNESS: if ( data.u >= 1 && data.u <= 15 ) vcl->line_thickness = data.u; break;
  }
  return TRUE;
}

static VikLayerParamData coord_layer_get_param ( VikCoordLayer *vcl, guint16 id )
{
  VikLayerParamData rv;
  switch ( id )
  {
    case PARAM_COLOR: rv.s = vcl->color ? vcl->color : ""; break;
    case PARAM_MIN_INC: rv.d = vcl->deg_inc * 60.0; break;
    case PARAM_LINE_THICKNESS: rv.i = vcl->line_thickness; break;
  }
  return rv;
}

static void coord_layer_post_read ( VikLayer *vl, VikViewport *vp, gboolean from_file )
{
  VikCoordLayer *vcl = VIK_COORD_LAYER(vl);
  if ( vcl->gc )
    g_object_unref ( G_OBJECT(vcl->gc) );

  vcl->gc = vik_viewport_new_gc ( vp, vcl->color, vcl->line_thickness );
}

VikCoordLayer *vik_coord_layer_new ( )
{
  VikCoordLayer *vcl = VIK_COORD_LAYER ( g_object_new ( VIK_COORD_LAYER_TYPE, NULL ) );
  vik_layer_init ( VIK_LAYER(vcl), VIK_LAYER_COORD );

  vcl->gc = NULL;
  vcl->deg_inc = 1.0/60.0;
  vcl->line_thickness = 3;
  vcl->color = NULL;
  return vcl;
}

void vik_coord_layer_draw ( VikCoordLayer *vcl, gpointer data )
{
  VikViewport *vp = (VikViewport *) data;

  if ( !vcl->gc ) {
    return;
  }

  if ( vik_viewport_get_coord_mode(vp) != VIK_COORD_UTM )
  {
    VikCoord left, right, left2, right2;
    gdouble l, r, i, j;
    gint x1, y1, x2, y2, smod = 1, mmod = 1;
    gboolean mins = FALSE, secs = FALSE;
    GdkGC *dgc = vik_viewport_new_gc(vp, vcl->color, vcl->line_thickness);
    GdkGC *mgc = vik_viewport_new_gc(vp, vcl->color, MAX(vcl->line_thickness/2, 1));
    GdkGC *sgc = vik_viewport_new_gc(vp, vcl->color, MAX(vcl->line_thickness/5, 1));

    vik_viewport_screen_to_coord ( vp, 0, 0, &left );
    vik_viewport_screen_to_coord ( vp, vik_viewport_get_width(vp), 0, &right );
    vik_viewport_screen_to_coord ( vp, 0, vik_viewport_get_height(vp), &left2 );
    vik_viewport_screen_to_coord ( vp, vik_viewport_get_width(vp), vik_viewport_get_height(vp), &right2 );

#define CLINE(gc, c1, c2) { \
	  vik_viewport_coord_to_screen(vp, (c1), &x1, &y1);  \
	  vik_viewport_coord_to_screen(vp, (c2), &x2, &y2);  \
	  vik_viewport_draw_line (vp, (gc), x1, y1, x2, y2); \
	}

    l = left.east_west;
    r = right.east_west;
    if (60*fabs(l-r) < 4) {
      secs = TRUE;
      smod = MIN(6, (int)ceil(3600*fabs(l-r)/30.0));
    }
    if (fabs(l-r) < 4) {
      mins = TRUE;
      mmod = MIN(6, (int)ceil(60*fabs(l-r)/30.0));
    }
    for (i=floor(l*60); i<ceil(r*60); i+=1.0) {
      if (secs) {
	for (j=i*60+1; j<(i+1)*60; j+=1.0) {
	  left.east_west = j/3600.0;
	  left2.east_west = j/3600.0;
	  if ((int)j % smod == 0) CLINE(sgc, &left, &left2);
	}
      }
      if (mins) {
	left.east_west = i/60.0;
	left2.east_west = i/60.0;
	if ((int)i % mmod == 0) CLINE(mgc, &left, &left2);
      }
      if ((int)i % 60 == 0) {
	left.east_west = i/60.0;
	left2.east_west = i/60.0;
	CLINE(dgc, &left, &left2);
      }
    }

    vik_viewport_screen_to_coord ( vp, 0, 0, &left );
    l = left2.north_south;
    r = left.north_south;
    for (i=floor(l*60); i<ceil(r*60); i+=1.0) {
      if (secs) {
	for (j=i*60+1; j<(i+1)*60; j+=1.0) {
	  left.north_south = j/3600.0;
	  right.north_south = j/3600.0;
	  if ((int)j % smod == 0) CLINE(sgc, &left, &right);
	}
      }
      if (mins) {
	left.north_south = i/60.0;
	right.north_south = i/60.0;
	if ((int)i % mmod == 0) CLINE(mgc, &left, &right);
      }
      if ((int)i % 60 == 0) {
	left.north_south = i/60.0;
	right.north_south = i/60.0;
	CLINE(dgc, &left, &right);
      }
    }
#undef CLINE
    g_object_unref(dgc);
    g_object_unref(sgc);
    g_object_unref(mgc);
    return;
  }

  if ( vik_viewport_get_coord_mode(vp) == VIK_COORD_UTM )
  {
    const struct UTM *center = (const struct UTM *)vik_viewport_get_center ( vp );
    gdouble xmpp = vik_viewport_get_xmpp ( vp ), ympp = vik_viewport_get_ympp ( vp );
    guint16 width = vik_viewport_get_width ( vp ), height = vik_viewport_get_height ( vp );
    struct LatLon ll, ll2, min, max;
    double lon;
    int x1, x2;
    struct UTM utm;

    utm = *center;
    utm.northing = center->northing - ( ympp * height / 2 );

    a_coords_utm_to_latlon ( &utm, &ll );

    utm.northing = center->northing + ( ympp * height / 2 );

    a_coords_utm_to_latlon ( &utm, &ll2 );

    {
      /* find corner coords in lat/lon.
        start at whichever is less: top or bottom left lon. goto whichever more: top or bottom right lon
      */
      struct LatLon topleft, topright, bottomleft, bottomright;
      struct UTM temp_utm;
      temp_utm = *center;
      temp_utm.easting -= (width/2)*xmpp;
      temp_utm.northing += (height/2)*ympp;
      a_coords_utm_to_latlon ( &temp_utm, &topleft );
      temp_utm.easting += (width*xmpp);
      a_coords_utm_to_latlon ( &temp_utm, &topright );
      temp_utm.northing -= (height*ympp);
      a_coords_utm_to_latlon ( &temp_utm, &bottomright );
      temp_utm.easting -= (width*xmpp);
      a_coords_utm_to_latlon ( &temp_utm, &bottomleft );
      min.lon = (topleft.lon < bottomleft.lon) ? topleft.lon : bottomleft.lon;
      max.lon = (topright.lon > bottomright.lon) ? topright.lon : bottomright.lon;
      min.lat = (bottomleft.lat < bottomright.lat) ? bottomleft.lat : bottomright.lat;
      max.lat = (topleft.lat > topright.lat) ? topleft.lat : topright.lat;
    }

    lon = ((double) ((long) ((min.lon)/ vcl->deg_inc))) * vcl->deg_inc;
    ll.lon = ll2.lon = lon;

    for (; ll.lon <= max.lon; ll.lon+=vcl->deg_inc, ll2.lon+=vcl->deg_inc )
    {
      a_coords_latlon_to_utm ( &ll, &utm );
      x1 = ( (utm.easting - center->easting) / xmpp ) + (width / 2);
      a_coords_latlon_to_utm ( &ll2, &utm );
      x2 = ( (utm.easting - center->easting) / xmpp ) + (width / 2);
      vik_viewport_draw_line (vp, vcl->gc, x1, height, x2, 0);
    }

    utm = *center;
    utm.easting = center->easting - ( xmpp * width / 2 );

    a_coords_utm_to_latlon ( &utm, &ll );

    utm.easting = center->easting + ( xmpp * width / 2 );

    a_coords_utm_to_latlon ( &utm, &ll2 );

    /* really lat, just reusing a variable */
    lon = ((double) ((long) ((min.lat)/ vcl->deg_inc))) * vcl->deg_inc;
    ll.lat = ll2.lat = lon;

    for (; ll.lat <= max.lat ; ll.lat+=vcl->deg_inc, ll2.lat+=vcl->deg_inc )
    {
      a_coords_latlon_to_utm ( &ll, &utm );
      x1 = (height / 2) - ( (utm.northing - center->northing) / ympp );
      a_coords_latlon_to_utm ( &ll2, &utm );
      x2 = (height / 2) - ( (utm.northing - center->northing) / ympp );
      vik_viewport_draw_line (vp, vcl->gc, width, x2, 0, x1);
    }
  }
}

void vik_coord_layer_free ( VikCoordLayer *vcl )
{
  if ( vcl->gc != NULL )
    g_object_unref ( G_OBJECT(vcl->gc) );

  if ( vcl->color != NULL )
    g_free ( vcl->color );
}

static void coord_layer_update_gc ( VikCoordLayer *vcl, VikViewport *vp, const gchar *color )
{
  if ( vcl->color )
    g_free ( vcl->color );

  vcl->color = g_strdup ( color );

  if ( vcl->gc )
    g_object_unref ( G_OBJECT(vcl->gc) );

  vcl->gc = vik_viewport_new_gc ( vp, vcl->color, vcl->line_thickness );
}

VikCoordLayer *vik_coord_layer_create ( VikViewport *vp )
{
  VikCoordLayer *vcl = vik_coord_layer_new ();
  coord_layer_update_gc ( vcl, vp, "red" );
  return vcl;
}
Commit	Line	Data
	1	/*
	2	* viking -- GPS Data and Topo Analyzer, Explorer, and Manager
	3	*
	4	* Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21	#ifdef HAVE_CONFIG_H
	22	#include "config.h"
	23	#endif
	24	#include <math.h>
	25	#include <glib/gi18n.h>
	26
	27	#include "viking.h"
	28	#include "vikcoordlayer_pixmap.h"
	29
	30	static void coord_layer_marshall( VikCoordLayer vcl, guint8 data, gint len );
	31	static VikCoordLayer coord_layer_unmarshall( guint8 data, gint len, VikViewport *vvp );
	32	static gboolean coord_layer_set_param ( VikCoordLayer vcl, guint16 id, VikLayerParamData data, VikViewport vp );
	33	static VikLayerParamData coord_layer_get_param ( VikCoordLayer *vcl, guint16 id );
	34	static void coord_layer_update_gc ( VikCoordLayer vcl, VikViewport vp, const gchar *color );
	35	static void coord_layer_post_read ( VikLayer vl, VikViewport vp, gboolean from_file );
	36
	37	static VikLayerParamScale param_scales[] = {
	38	{ 0.05, 60.0, 0.25, 10 },
	39	{ 1, 10, 1, 0 },
	40	};
	41
	42	static VikLayerParam coord_layer_params[] = {
	43	{ "color", VIK_LAYER_PARAM_STRING, VIK_LAYER_GROUP_NONE, N_("Color:"), VIK_LAYER_WIDGET_ENTRY },
	44	{ "min_inc", VIK_LAYER_PARAM_DOUBLE, VIK_LAYER_GROUP_NONE, N_("Minutes Width:"), VIK_LAYER_WIDGET_SPINBUTTON, param_scales + 0 },
	45	{ "line_thickness", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, N_("Line Thickness:"), VIK_LAYER_WIDGET_SPINBUTTON, param_scales + 1 },
	46	};
	47
	48
	49	enum { PARAM_COLOR = 0, PARAM_MIN_INC, PARAM_LINE_THICKNESS, NUM_PARAMS };
	50
	51	VikLayerInterface vik_coord_layer_interface = {
	52	"Coord",
	53	&coordlayer_pixbuf,
	54
	55	NULL,
	56	0,
	57
	58	coord_layer_params,
	59	NUM_PARAMS,
	60	NULL,
	61	0,
	62
	63	VIK_MENU_ITEM_ALL,
	64
	65	(VikLayerFuncCreate) vik_coord_layer_create,
	66	(VikLayerFuncRealize) NULL,
	67	coord_layer_post_read,
	68	(VikLayerFuncFree) vik_coord_layer_free,
	69
	70	(VikLayerFuncProperties) NULL,
	71	(VikLayerFuncDraw) vik_coord_layer_draw,
	72	(VikLayerFuncChangeCoordMode) NULL,
	73
	74	(VikLayerFuncSetMenuItemsSelection) NULL,
	75	(VikLayerFuncGetMenuItemsSelection) NULL,
	76
	77	(VikLayerFuncAddMenuItems) NULL,
	78	(VikLayerFuncSublayerAddMenuItems) NULL,
	79
	80	(VikLayerFuncSublayerRenameRequest) NULL,
	81	(VikLayerFuncSublayerToggleVisible) NULL,
	82
	83	(VikLayerFuncMarshall) coord_layer_marshall,
	84	(VikLayerFuncUnmarshall) coord_layer_unmarshall,
	85
	86	(VikLayerFuncSetParam) coord_layer_set_param,
	87	(VikLayerFuncGetParam) coord_layer_get_param,
	88
	89	(VikLayerFuncReadFileData) NULL,
	90	(VikLayerFuncWriteFileData) NULL,
	91
	92	(VikLayerFuncDeleteItem) NULL,
	93	(VikLayerFuncCopyItem) NULL,
	94	(VikLayerFuncPasteItem) NULL,
	95	(VikLayerFuncFreeCopiedItem) NULL,
	96	(VikLayerFuncDragDropRequest) NULL,
	97	};
	98
	99	struct _VikCoordLayer {
	100	VikLayer vl;
	101	GdkGC *gc;
	102	gdouble deg_inc;
	103	guint8 line_thickness;
	104	gchar *color;
	105	};
	106
	107	GType vik_coord_layer_get_type ()
	108	{
	109	static GType vcl_type = 0;
	110
	111	if (!vcl_type)
	112	{
	113	static const GTypeInfo vcl_info =
	114	{
	115	sizeof (VikCoordLayerClass),
	116	NULL, /* base_init */
	117	NULL, /* base_finalize */
	118	NULL, /* class init */
	119	NULL, /* class_finalize */
	120	NULL, /* class_data */
	121	sizeof (VikCoordLayer),
	122	0,
	123	NULL /* instance init */
	124	};
	125	vcl_type = g_type_register_static ( VIK_LAYER_TYPE, "VikCoordLayer", &vcl_info, 0 );
	126	}
	127
	128	return vcl_type;
	129	}
	130
	131	static void coord_layer_marshall( VikCoordLayer vcl, guint8 data, gint len )
	132	{
	133	vik_layer_marshall_params ( VIK_LAYER(vcl), data, len );
	134	}
	135
	136	static VikCoordLayer coord_layer_unmarshall( guint8 data, gint len, VikViewport *vvp )
	137	{
	138	VikCoordLayer *rv = vik_coord_layer_new ( vvp );
	139	vik_layer_unmarshall_params ( VIK_LAYER(rv), data, len, vvp );
	140	return rv;
	141	}
	142
	143	gboolean coord_layer_set_param ( VikCoordLayer vcl, guint16 id, VikLayerParamData data, VikViewport vp )
	144	{
	145	switch ( id )
	146	{
	147	case PARAM_COLOR: if ( vcl->color ) g_free ( vcl->color ); vcl->color = g_strdup ( data.s ); break;
	148	case PARAM_MIN_INC: vcl->deg_inc = data.d / 60.0; break;
	149	case PARAM_LINE_THICKNESS: if ( data.u >= 1 && data.u <= 15 ) vcl->line_thickness = data.u; break;
	150	}
	151	return TRUE;
	152	}
	153
	154	static VikLayerParamData coord_layer_get_param ( VikCoordLayer *vcl, guint16 id )
	155	{
	156	VikLayerParamData rv;
	157	switch ( id )
	158	{
	159	case PARAM_COLOR: rv.s = vcl->color ? vcl->color : ""; break;
	160	case PARAM_MIN_INC: rv.d = vcl->deg_inc * 60.0; break;
	161	case PARAM_LINE_THICKNESS: rv.i = vcl->line_thickness; break;
	162	}
	163	return rv;
	164	}
	165
	166	static void coord_layer_post_read ( VikLayer vl, VikViewport vp, gboolean from_file )
	167	{
	168	VikCoordLayer *vcl = VIK_COORD_LAYER(vl);
	169	if ( vcl->gc )
	170	g_object_unref ( G_OBJECT(vcl->gc) );
	171
	172	vcl->gc = vik_viewport_new_gc ( vp, vcl->color, vcl->line_thickness );
	173	}
	174
	175	VikCoordLayer *vik_coord_layer_new ( )
	176	{
	177	VikCoordLayer *vcl = VIK_COORD_LAYER ( g_object_new ( VIK_COORD_LAYER_TYPE, NULL ) );
	178	vik_layer_init ( VIK_LAYER(vcl), VIK_LAYER_COORD );
	179
	180	vcl->gc = NULL;
	181	vcl->deg_inc = 1.0/60.0;
	182	vcl->line_thickness = 3;
	183	vcl->color = NULL;
	184	return vcl;
	185	}
	186
	187	void vik_coord_layer_draw ( VikCoordLayer *vcl, gpointer data )
	188	{
	189	VikViewport vp = (VikViewport ) data;
	190
	191	if ( !vcl->gc ) {
	192	return;
	193	}
	194
	195	if ( vik_viewport_get_coord_mode(vp) != VIK_COORD_UTM )
	196	{
	197	VikCoord left, right, left2, right2;
	198	gdouble l, r, i, j;
	199	gint x1, y1, x2, y2, smod = 1, mmod = 1;
	200	gboolean mins = FALSE, secs = FALSE;
	201	GdkGC *dgc = vik_viewport_new_gc(vp, vcl->color, vcl->line_thickness);
	202	GdkGC *mgc = vik_viewport_new_gc(vp, vcl->color, MAX(vcl->line_thickness/2, 1));
	203	GdkGC *sgc = vik_viewport_new_gc(vp, vcl->color, MAX(vcl->line_thickness/5, 1));
	204
	205	vik_viewport_screen_to_coord ( vp, 0, 0, &left );
	206	vik_viewport_screen_to_coord ( vp, vik_viewport_get_width(vp), 0, &right );
	207	vik_viewport_screen_to_coord ( vp, 0, vik_viewport_get_height(vp), &left2 );
	208	vik_viewport_screen_to_coord ( vp, vik_viewport_get_width(vp), vik_viewport_get_height(vp), &right2 );
	209
	210	#define CLINE(gc, c1, c2) { \
	211	vik_viewport_coord_to_screen(vp, (c1), &x1, &y1); \
	212	vik_viewport_coord_to_screen(vp, (c2), &x2, &y2); \
	213	vik_viewport_draw_line (vp, (gc), x1, y1, x2, y2); \
	214	}
	215
	216	l = left.east_west;
	217	r = right.east_west;
	218	if (60*fabs(l-r) < 4) {
	219	secs = TRUE;
	220	smod = MIN(6, (int)ceil(3600*fabs(l-r)/30.0));
	221	}
	222	if (fabs(l-r) < 4) {
	223	mins = TRUE;
	224	mmod = MIN(6, (int)ceil(60*fabs(l-r)/30.0));
	225	}
	226	for (i=floor(l60); i<ceil(r60); i+=1.0) {
	227	if (secs) {
	228	for (j=i60+1; j<(i+1)60; j+=1.0) {
	229	left.east_west = j/3600.0;
	230	left2.east_west = j/3600.0;
	231	if ((int)j % smod == 0) CLINE(sgc, &left, &left2);
	232	}
	233	}
	234	if (mins) {
	235	left.east_west = i/60.0;
	236	left2.east_west = i/60.0;
	237	if ((int)i % mmod == 0) CLINE(mgc, &left, &left2);
	238	}
	239	if ((int)i % 60 == 0) {
	240	left.east_west = i/60.0;
	241	left2.east_west = i/60.0;
	242	CLINE(dgc, &left, &left2);
	243	}
	244	}
	245
	246	vik_viewport_screen_to_coord ( vp, 0, 0, &left );
	247	l = left2.north_south;
	248	r = left.north_south;
	249	for (i=floor(l60); i<ceil(r60); i+=1.0) {
	250	if (secs) {
	251	for (j=i60+1; j<(i+1)60; j+=1.0) {
	252	left.north_south = j/3600.0;
	253	right.north_south = j/3600.0;
	254	if ((int)j % smod == 0) CLINE(sgc, &left, &right);
	255	}
	256	}
	257	if (mins) {
	258	left.north_south = i/60.0;
	259	right.north_south = i/60.0;
	260	if ((int)i % mmod == 0) CLINE(mgc, &left, &right);
	261	}
	262	if ((int)i % 60 == 0) {
	263	left.north_south = i/60.0;
	264	right.north_south = i/60.0;
	265	CLINE(dgc, &left, &right);
	266	}
	267	}
	268	#undef CLINE
	269	g_object_unref(dgc);
	270	g_object_unref(sgc);
	271	g_object_unref(mgc);
	272	return;
	273	}
	274
	275	if ( vik_viewport_get_coord_mode(vp) == VIK_COORD_UTM )
	276	{
	277	const struct UTM center = (const struct UTM )vik_viewport_get_center ( vp );
	278	gdouble xmpp = vik_viewport_get_xmpp ( vp ), ympp = vik_viewport_get_ympp ( vp );
	279	guint16 width = vik_viewport_get_width ( vp ), height = vik_viewport_get_height ( vp );
	280	struct LatLon ll, ll2, min, max;
	281	double lon;
	282	int x1, x2;
	283	struct UTM utm;
	284
	285	utm = *center;
	286	utm.northing = center->northing - ( ympp * height / 2 );
	287
	288	a_coords_utm_to_latlon ( &utm, &ll );
	289
	290	utm.northing = center->northing + ( ympp * height / 2 );
	291
	292	a_coords_utm_to_latlon ( &utm, &ll2 );
	293
	294	{
	295	/* find corner coords in lat/lon.
	296	start at whichever is less: top or bottom left lon. goto whichever more: top or bottom right lon
	297	*/
	298	struct LatLon topleft, topright, bottomleft, bottomright;
	299	struct UTM temp_utm;
	300	temp_utm = *center;
	301	temp_utm.easting -= (width/2)*xmpp;
	302	temp_utm.northing += (height/2)*ympp;
	303	a_coords_utm_to_latlon ( &temp_utm, &topleft );
	304	temp_utm.easting += (width*xmpp);
	305	a_coords_utm_to_latlon ( &temp_utm, &topright );
	306	temp_utm.northing -= (height*ympp);
	307	a_coords_utm_to_latlon ( &temp_utm, &bottomright );
	308	temp_utm.easting -= (width*xmpp);
	309	a_coords_utm_to_latlon ( &temp_utm, &bottomleft );
	310	min.lon = (topleft.lon < bottomleft.lon) ? topleft.lon : bottomleft.lon;
	311	max.lon = (topright.lon > bottomright.lon) ? topright.lon : bottomright.lon;
	312	min.lat = (bottomleft.lat < bottomright.lat) ? bottomleft.lat : bottomright.lat;
	313	max.lat = (topleft.lat > topright.lat) ? topleft.lat : topright.lat;
	314	}
	315
	316	lon = ((double) ((long) ((min.lon)/ vcl->deg_inc))) * vcl->deg_inc;
	317	ll.lon = ll2.lon = lon;
	318
	319	for (; ll.lon <= max.lon; ll.lon+=vcl->deg_inc, ll2.lon+=vcl->deg_inc )
	320	{
	321	a_coords_latlon_to_utm ( &ll, &utm );
	322	x1 = ( (utm.easting - center->easting) / xmpp ) + (width / 2);
	323	a_coords_latlon_to_utm ( &ll2, &utm );
	324	x2 = ( (utm.easting - center->easting) / xmpp ) + (width / 2);
	325	vik_viewport_draw_line (vp, vcl->gc, x1, height, x2, 0);
	326	}
	327
	328	utm = *center;
	329	utm.easting = center->easting - ( xmpp * width / 2 );
	330
	331	a_coords_utm_to_latlon ( &utm, &ll );
	332
	333	utm.easting = center->easting + ( xmpp * width / 2 );
	334
	335	a_coords_utm_to_latlon ( &utm, &ll2 );
	336
	337	/* really lat, just reusing a variable */
	338	lon = ((double) ((long) ((min.lat)/ vcl->deg_inc))) * vcl->deg_inc;
	339	ll.lat = ll2.lat = lon;
	340
	341	for (; ll.lat <= max.lat ; ll.lat+=vcl->deg_inc, ll2.lat+=vcl->deg_inc )
	342	{
	343	a_coords_latlon_to_utm ( &ll, &utm );
	344	x1 = (height / 2) - ( (utm.northing - center->northing) / ympp );
	345	a_coords_latlon_to_utm ( &ll2, &utm );
	346	x2 = (height / 2) - ( (utm.northing - center->northing) / ympp );
	347	vik_viewport_draw_line (vp, vcl->gc, width, x2, 0, x1);
	348	}
	349	}
	350	}
	351
	352	void vik_coord_layer_free ( VikCoordLayer *vcl )
	353	{
	354	if ( vcl->gc != NULL )
	355	g_object_unref ( G_OBJECT(vcl->gc) );
	356
	357	if ( vcl->color != NULL )
	358	g_free ( vcl->color );
	359	}
	360
	361	static void coord_layer_update_gc ( VikCoordLayer vcl, VikViewport vp, const gchar *color )
	362	{
	363	if ( vcl->color )
	364	g_free ( vcl->color );
	365
	366	vcl->color = g_strdup ( color );
	367
	368	if ( vcl->gc )
	369	g_object_unref ( G_OBJECT(vcl->gc) );
	370
	371	vcl->gc = vik_viewport_new_gc ( vp, vcl->color, vcl->line_thickness );
	372	}
	373
	374	VikCoordLayer vik_coord_layer_create ( VikViewport vp )
	375	{
	376	VikCoordLayer *vcl = vik_coord_layer_new ();
	377	coord_layer_update_gc ( vcl, vp, "red" );
	378	return vcl;
	379	}
	380