trunk/src/osm-gps-map-osd-classic.c

/* -*- Mode: C; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4 -*- */
/* vim:set et sw=4 ts=4 cino=t0,(0: */
/*
 * Copyright (C) Till Harbaum 2009 <till@harbaum.org>
 *
 * osm-gps-map 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 3 of the License, or
 * (at your option) any later version.
 *
 * osm-gps-map 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/>.
 */

#include "config.h" 
#include <stdlib.h>  // abs
#include <math.h>    // M_PI

/* parameters that can be overwritten from the config file: */
/* OSM_GPS_MAP_OSD_DIAMETER */

#ifndef USE_CAIRO
#error "OSD control display lacks a non-cairo implementation!"
#endif

#include <cairo.h>

#include "osm-gps-map.h"
#include "osm-gps-map-osd-classic.h"

//the osd controls
typedef struct {
    GdkPixmap *backup;
    gint backup_x, backup_y;
    cairo_surface_t *overlay;
} osd_priv_t;

/* position and extent of bounding box */
#define OSD_X      (10)
#define OSD_Y      (10)

#define OSD_COLOR            0.5, 0.5, 1
#define OSD_COLOR_DISABLED   0.8, 0.8, 0.8

/* parameters of the direction shape */
#ifndef OSM_GPS_MAP_OSD_DIAMETER
#define D_RAD  (30)         // diameter of dpad
#else
#define D_RAD  (OSM_GPS_MAP_OSD_DIAMETER)
#endif
#define D_TIP  (4*D_RAD/5)  // distance of arrow tip from dpad center
#define D_LEN  (D_RAD/4)    // length of arrow
#define D_WID  (D_LEN)      // width of arrow

/* parameters of the "zoom" pad */
#define Z_STEP   (D_RAD/4)  // distance between dpad and zoom
#define Z_RAD    (D_RAD/2)  // radius of "caps" of zoom bar

/* shadow also depends on control size */
#define OSD_SHADOW (D_RAD/6)

/* total width and height of controls incl. shadow */
#define OSD_W    (2*D_RAD + OSD_SHADOW)
#define OSD_H    (2*D_RAD + Z_STEP + 2*Z_RAD + OSD_SHADOW)

#define OSD_LBL_SHADOW (OSD_SHADOW/2)

#define Z_TOP    (2 * D_RAD + Z_STEP)
#define Z_MID    (Z_TOP + Z_RAD)
#define Z_BOT    (Z_MID + Z_RAD)
#define Z_LEFT   (Z_RAD)
#define Z_RIGHT  (2 * D_RAD - Z_RAD)


/* create the cairo shape used for the zoom buttons */
static void 
osm_gps_map_osd_zoom_shape(cairo_t *cr, gint x, gint y) 
{
    cairo_move_to (cr, x+Z_LEFT,    y+Z_TOP);
    cairo_line_to (cr, x+Z_RIGHT,   y+Z_TOP);
    cairo_arc     (cr, x+Z_RIGHT,   y+Z_MID, Z_RAD, -M_PI/2,  M_PI/2);
    cairo_line_to (cr, x+Z_LEFT,    y+Z_BOT);
    cairo_arc     (cr, x+Z_LEFT,    y+Z_MID, Z_RAD,  M_PI/2, -M_PI/2);
}

/* create the cairo shape used for the dpad */
static void 
osm_gps_map_osd_dpad_shape(cairo_t *cr, gint x, gint y) 
{
    cairo_arc (cr, x+D_RAD, y+D_RAD, D_RAD, 0, 2 * M_PI);
}

static gboolean
osm_gps_map_in_circle(gint x, gint y, gint cx, gint cy, gint rad) 
{
    return( pow(cx - x, 2) + pow(cy - y, 2) < rad * rad);
}

/* check whether x/y is within the dpad */
static osd_button_t
osm_gps_map_osd_check_dpad(gint x, gint y) 
{
    /* within entire dpad circle */
    if( osm_gps_map_in_circle(x, y, OSD_X + D_RAD, OSD_Y + D_RAD, D_RAD)) 
    {
        /* convert into position relative to dpads centre */
        x -= (OSD_X + D_RAD);
        y -= (OSD_Y + D_RAD);

        /* check for dpad center goes here! */
        if( osm_gps_map_in_circle(x, y, 0, 0, D_RAD/3)) 
            return OSD_GPS;

        if( y < 0 && abs(x) < abs(y))
            return OSD_UP;

        if( y > 0 && abs(x) < abs(y))
            return OSD_DOWN;

        if( x < 0 && abs(y) < abs(x))
            return OSD_LEFT;

        if( x > 0 && abs(y) < abs(x))
            return OSD_RIGHT;

        return OSD_BG;
    }
    return OSD_NONE;
}

/* check whether x/y is within the zoom pads */
static osd_button_t
osm_gps_map_osd_check_zoom(gint x, gint y) {
    if( x > OSD_X && x < (OSD_X + OSD_W) && y > Z_TOP && y < (OSD_Y+Z_BOT)) {

        /* within circle around (-) label */
        if( osm_gps_map_in_circle(x, y, OSD_X + Z_LEFT, OSD_Y + Z_MID, Z_RAD)) 
            return OSD_OUT;

        /* between center of (-) button and center of entire zoom control area */
        if(x > OSD_LEFT && x < OSD_X + D_RAD) 
            return OSD_OUT;

        /* within circle around (+) label */
        if( osm_gps_map_in_circle(x, y, OSD_X + Z_RIGHT, OSD_Y + Z_MID, Z_RAD)) 
            return OSD_IN;

        /* between center of (+) button and center of entire zoom control area */
        if(x < OSD_RIGHT && x > OSD_X + D_RAD) 
            return OSD_IN;
    }
 
    return OSD_NONE;
}

static osd_button_t
osm_gps_map_osd_check(gint x, gint y) {
    osd_button_t but = OSD_NONE;

    /* first do a rough test for the OSD area. */
    /* this is just to avoid an unnecessary detailed test */
    if(x > OSD_X && x < OSD_X + OSD_W && 
       y > OSD_Y && y < OSD_Y + OSD_H) {
        but = osm_gps_map_osd_check_dpad(x, y);

        if(but == OSD_NONE) 
            but = osm_gps_map_osd_check_zoom(x, y);
    }

    return but;
}

static void 
osm_gps_map_osd_shape_shadow(cairo_t *cr) {
    cairo_set_source_rgba (cr, 0, 0, 0, 0.2);
    cairo_fill (cr);
    cairo_stroke (cr);
}

static void 
osm_gps_map_osd_shape(cairo_t *cr) {
    cairo_set_source_rgb (cr, 1, 1, 1);
    cairo_fill_preserve (cr);
    cairo_set_source_rgb (cr, OSD_COLOR);
    cairo_set_line_width (cr, 1);
    cairo_stroke (cr);
}

static void
osm_gps_map_osd_dpad_labels(cairo_t *cr, gint x, gint y) {
    /* move reference to dpad center */
    x += D_RAD;
    y += D_RAD;

    const static gint offset[][3][2] = {
        /* left arrow/triangle */
        { { -D_TIP+D_LEN, -D_WID }, { -D_LEN, D_WID }, { +D_LEN, D_WID } },
        /* right arrow/triangle */
        { { +D_TIP-D_LEN, -D_WID }, { +D_LEN, D_WID }, { -D_LEN, D_WID } },
        /* top arrow/triangle */
        { { -D_WID, -D_TIP+D_LEN }, { D_WID, -D_LEN }, { D_WID, +D_LEN } },
        /* bottom arrow/triangle */
        { { -D_WID, +D_TIP-D_LEN }, { D_WID, +D_LEN }, { D_WID, -D_LEN } }
    };

    int i;
    for(i=0;i<4;i++) {
        cairo_move_to (cr, x + offset[i][0][0], y + offset[i][0][1]);
        cairo_rel_line_to (cr, offset[i][1][0], offset[i][1][1]);
        cairo_rel_line_to (cr, offset[i][2][0], offset[i][2][1]);
    }
}

/* draw the sattelite dish icon in the center of the dpad */
#define GPS_V0  (D_RAD/8)
#define GPS_V1  (D_RAD/10)
#define GPS_V2  (D_RAD/5)

/* draw a satellite receiver dish */
static void
osm_gps_map_osd_dpad_gps(cairo_t *cr, gint x, gint y) {
    /* move reference to dpad center */
    x += D_RAD;
    y += D_RAD + GPS_V0;

    cairo_move_to (cr, x-GPS_V0, y+GPS_V0);
    cairo_rel_line_to (cr, +GPS_V0, -GPS_V0);
    cairo_rel_line_to (cr, +GPS_V0, +GPS_V0);
    cairo_close_path (cr);

    cairo_move_to (cr, x+GPS_V1-GPS_V2, y-2*GPS_V2);
    cairo_curve_to (cr, x-GPS_V2, y, x+GPS_V1, y+GPS_V1, x+GPS_V1+GPS_V2, y);
    cairo_close_path (cr);

    x += GPS_V1;
    cairo_move_to (cr, x, y-GPS_V2);
    cairo_rel_line_to (cr, +GPS_V1, -GPS_V1);
}

#define Z_LEN  (2*Z_RAD/3)

static void
osm_gps_map_osd_zoom_labels(cairo_t *cr, gint x, gint y) {
    cairo_move_to (cr, x + Z_LEFT  - Z_LEN, y + Z_MID);
    cairo_line_to (cr, x + Z_LEFT  + Z_LEN, y + Z_MID);

    cairo_move_to (cr, x + Z_RIGHT,         y + Z_MID - Z_LEN);
    cairo_line_to (cr, x + Z_RIGHT,         y + Z_MID + Z_LEN);
    cairo_move_to (cr, x + Z_RIGHT - Z_LEN, y + Z_MID);
    cairo_line_to (cr, x + Z_RIGHT + Z_LEN, y + Z_MID);
}

static void
osm_gps_map_osd_labels(cairo_t *cr, gint width, gboolean enabled) {
    if(enabled)  cairo_set_source_rgb (cr, OSD_COLOR);
    else         cairo_set_source_rgb (cr, OSD_COLOR_DISABLED);
    cairo_set_line_width (cr, width);
    cairo_stroke (cr);
}

static void 
osm_gps_map_osd_labels_shadow(cairo_t *cr, gint width, gboolean enabled) {
    cairo_set_source_rgba (cr, 0, 0, 0, enabled?0.3:0.15);
    cairo_set_line_width (cr, width);
    cairo_stroke (cr);
}

static void
osm_gps_map_osd_render(osm_gps_map_osd_t *osd) {
    osd_priv_t *priv = (osd_priv_t*)osd->priv; 

    /* first fill with transparency */
    cairo_t *cr = cairo_create(priv->overlay);
    cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
    cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 0.0);
    cairo_paint(cr);

    cairo_set_operator(cr, CAIRO_OPERATOR_OVER);

    /* --------- draw zoom and dpad shape shadow ----------- */
    gint x = 0, y = 0;

    osm_gps_map_osd_zoom_shape(cr, x + OSD_SHADOW, y + OSD_SHADOW);
    osm_gps_map_osd_shape_shadow(cr);
    osm_gps_map_osd_dpad_shape(cr, x + OSD_SHADOW, y + OSD_SHADOW);
    osm_gps_map_osd_shape_shadow(cr);

    /* --------- draw zoom and dpad shape ----------- */

    osm_gps_map_osd_zoom_shape(cr, x, y);
    osm_gps_map_osd_shape(cr);
    osm_gps_map_osd_dpad_shape(cr, x, y);
    osm_gps_map_osd_shape(cr);

    /* --------- draw zoom and dpad labels --------- */

    osm_gps_map_osd_zoom_labels(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW);
    osm_gps_map_osd_dpad_labels(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW);
    osm_gps_map_osd_labels_shadow(cr, Z_RAD/3, TRUE);
    osm_gps_map_osd_dpad_gps(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW); 
    osm_gps_map_osd_labels_shadow(cr, Z_RAD/6, osd->cb != NULL);

    osm_gps_map_osd_zoom_labels(cr, x, y);
    osm_gps_map_osd_dpad_labels(cr, x, y);
    osm_gps_map_osd_labels(cr, Z_RAD/3, TRUE);
    osm_gps_map_osd_dpad_gps(cr, x, y);
    osm_gps_map_osd_labels(cr, Z_RAD/6, osd->cb != NULL);
    
    cairo_destroy(cr);
}

static void
osm_gps_map_osd_draw(osm_gps_map_osd_t *osd, gint xoffset, gint yoffset)
{
    osd_priv_t *priv = (osd_priv_t*)osd->priv; 

    /* backup previous contents */
    if(!priv->backup)
        priv->backup = gdk_pixmap_new(osd->pixmap, OSD_W+2, OSD_H+2, -1);

    gint x = OSD_X + xoffset;
    gint y = OSD_Y + yoffset;

    /* create backup of background */
    gdk_draw_drawable(priv->backup, 
        osd->widget->style->fg_gc[GTK_WIDGET_STATE(osd->widget)],
                      osd->pixmap, x-1, y-1, 0, 0, OSD_W+2, OSD_H+2);

    priv->backup_x = x-1;
    priv->backup_y = y-1;

    /* OSD itself uses some off-screen rendering, so check if the */
    /* offscreen buffer is present and create it if not */
    if(!priv->overlay) {
        /* create overlay ... */
        priv->overlay = 
            cairo_image_surface_create(CAIRO_FORMAT_ARGB32, OSD_W, OSD_H);
        /* ... and render it */
        osm_gps_map_osd_render(osd);
    }

    // now draw this onto the original context 
    cairo_t *cr = gdk_cairo_create(osd->pixmap);
    cairo_set_source_surface(cr, priv->overlay, x, y);
    cairo_paint(cr);
    cairo_destroy(cr);
}

static void
osm_gps_map_osd_restore (osm_gps_map_osd_t *osd) 
{
    osd_priv_t *priv = (osd_priv_t*)osd->priv; 

    /* restore backup of previous contents */
    if(priv->backup) {
        /* create backup of background */
        gdk_draw_drawable(osd->pixmap,
                          osd->widget->style->fg_gc[GTK_WIDGET_STATE(osd->widget)],
                          priv->backup, 0, 0, 
                          priv->backup_x, priv->backup_y, OSD_W+2, OSD_H+2);
    }
}

static void
osm_gps_map_osd_free(osm_gps_map_osd_t *osd) 
{
    osd_priv_t *priv = (osd_priv_t *)(osd->priv);

    if (priv->backup)
        g_object_unref(priv->backup);

    if (priv->overlay)
         cairo_surface_destroy(priv->overlay);

    g_free(priv);
}

static osm_gps_map_osd_t osd_classic = {
    .restore    = osm_gps_map_osd_restore,
    .draw       = osm_gps_map_osd_draw,
    .check      = osm_gps_map_osd_check,
    .render     = osm_gps_map_osd_render,
    .free       = osm_gps_map_osd_free,

    .cb         = NULL,
    .data       = NULL,

    .priv       = NULL
};

/* this is the only function that's externally visible */
void
osm_gps_map_osd_classic_init(OsmGpsMap *map) 
{
    osd_priv_t *priv = osd_classic.priv = g_new0(osd_priv_t, 1);

    osd_classic.priv = priv;

    osm_gps_map_register_osd(map, &osd_classic);
}


void osm_gps_map_osd_enable_gps (OsmGpsMap *map, OsmGpsMapOsdCallback cb, gpointer data) {
    osm_gps_map_osd_t *osd = osm_gps_map_osd_get(map);

    g_return_if_fail (osd);

    osd->cb = cb;
    osd->data = data;

    /* this may have changed the state of the gps button */
    /* we thus re-render the overlay */
    osd->render(osd);

    osm_gps_map_redraw(map);
}
1	/* -- Mode: C; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4 -- */
2	/* vim:set et sw=4 ts=4 cino=t0,(0: */
3	/*
4	* Copyright (C) Till Harbaum 2009 <till@harbaum.org>
5	*
6	* osm-gps-map is free software: you can redistribute it and/or modify it
7	* under the terms of the GNU General Public License as published by the
8	* Free Software Foundation, either version 3 of the License, or
9	* (at your option) any later version.
10	*
11	* osm-gps-map is distributed in the hope that it will be useful, but
12	* WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
14	* See the GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License along
17	* with this program. If not, see <http://www.gnu.org/licenses/>.
18	*/
19
20	#include "config.h"
21	#include <stdlib.h> // abs
22	#include <math.h> // M_PI
23
24	/* parameters that can be overwritten from the config file: */
25	/* OSM_GPS_MAP_OSD_DIAMETER */
26
27	#ifndef USE_CAIRO
28	#error "OSD control display lacks a non-cairo implementation!"
29	#endif
30
31	#include <cairo.h>
32
33	#include "osm-gps-map.h"
34	#include "osm-gps-map-osd-classic.h"
35
36	//the osd controls
37	typedef struct {
38	GdkPixmap *backup;
39	gint backup_x, backup_y;
40	cairo_surface_t *overlay;
41	} osd_priv_t;
42
43	/* position and extent of bounding box */
44	#define OSD_X (10)
45	#define OSD_Y (10)
46
47	#define OSD_COLOR 0.5, 0.5, 1
48	#define OSD_COLOR_DISABLED 0.8, 0.8, 0.8
49
50	/* parameters of the direction shape */
51	#ifndef OSM_GPS_MAP_OSD_DIAMETER
52	#define D_RAD (30) // diameter of dpad
53	#else
54	#define D_RAD (OSM_GPS_MAP_OSD_DIAMETER)
55	#endif
56	#define D_TIP (4*D_RAD/5) // distance of arrow tip from dpad center
57	#define D_LEN (D_RAD/4) // length of arrow
58	#define D_WID (D_LEN) // width of arrow
59
60	/* parameters of the "zoom" pad */
61	#define Z_STEP (D_RAD/4) // distance between dpad and zoom
62	#define Z_RAD (D_RAD/2) // radius of "caps" of zoom bar
63
64	/* shadow also depends on control size */
65	#define OSD_SHADOW (D_RAD/6)
66
67	/* total width and height of controls incl. shadow */
68	#define OSD_W (2*D_RAD + OSD_SHADOW)
69	#define OSD_H (2D_RAD + Z_STEP + 2Z_RAD + OSD_SHADOW)
70
71	#define OSD_LBL_SHADOW (OSD_SHADOW/2)
72
73	#define Z_TOP (2 * D_RAD + Z_STEP)
74	#define Z_MID (Z_TOP + Z_RAD)
75	#define Z_BOT (Z_MID + Z_RAD)
76	#define Z_LEFT (Z_RAD)
77	#define Z_RIGHT (2 * D_RAD - Z_RAD)
78
79
80	/* create the cairo shape used for the zoom buttons */
81	static void
82	osm_gps_map_osd_zoom_shape(cairo_t *cr, gint x, gint y)
83	{
84	cairo_move_to (cr, x+Z_LEFT, y+Z_TOP);
85	cairo_line_to (cr, x+Z_RIGHT, y+Z_TOP);
86	cairo_arc (cr, x+Z_RIGHT, y+Z_MID, Z_RAD, -M_PI/2, M_PI/2);
87	cairo_line_to (cr, x+Z_LEFT, y+Z_BOT);
88	cairo_arc (cr, x+Z_LEFT, y+Z_MID, Z_RAD, M_PI/2, -M_PI/2);
89	}
90
91	/* create the cairo shape used for the dpad */
92	static void
93	osm_gps_map_osd_dpad_shape(cairo_t *cr, gint x, gint y)
94	{
95	cairo_arc (cr, x+D_RAD, y+D_RAD, D_RAD, 0, 2 * M_PI);
96	}
97
98	static gboolean
99	osm_gps_map_in_circle(gint x, gint y, gint cx, gint cy, gint rad)
100	{
101	return( pow(cx - x, 2) + pow(cy - y, 2) < rad * rad);
102	}
103
104	/* check whether x/y is within the dpad */
105	static osd_button_t
106	osm_gps_map_osd_check_dpad(gint x, gint y)
107	{
108	/* within entire dpad circle */
109	if( osm_gps_map_in_circle(x, y, OSD_X + D_RAD, OSD_Y + D_RAD, D_RAD))
110	{
111	/* convert into position relative to dpads centre */
112	x -= (OSD_X + D_RAD);
113	y -= (OSD_Y + D_RAD);
114
115	/* check for dpad center goes here! */
116	if( osm_gps_map_in_circle(x, y, 0, 0, D_RAD/3))
117	return OSD_GPS;
118
119	if( y < 0 && abs(x) < abs(y))
120	return OSD_UP;
121
122	if( y > 0 && abs(x) < abs(y))
123	return OSD_DOWN;
124
125	if( x < 0 && abs(y) < abs(x))
126	return OSD_LEFT;
127
128	if( x > 0 && abs(y) < abs(x))
129	return OSD_RIGHT;
130
131	return OSD_BG;
132	}
133	return OSD_NONE;
134	}
135
136	/* check whether x/y is within the zoom pads */
137	static osd_button_t
138	osm_gps_map_osd_check_zoom(gint x, gint y) {
139	if( x > OSD_X && x < (OSD_X + OSD_W) && y > Z_TOP && y < (OSD_Y+Z_BOT)) {
140
141	/* within circle around (-) label */
142	if( osm_gps_map_in_circle(x, y, OSD_X + Z_LEFT, OSD_Y + Z_MID, Z_RAD))
143	return OSD_OUT;
144
145	/* between center of (-) button and center of entire zoom control area */
146	if(x > OSD_LEFT && x < OSD_X + D_RAD)
147	return OSD_OUT;
148
149	/* within circle around (+) label */
150	if( osm_gps_map_in_circle(x, y, OSD_X + Z_RIGHT, OSD_Y + Z_MID, Z_RAD))
151	return OSD_IN;
152
153	/* between center of (+) button and center of entire zoom control area */
154	if(x < OSD_RIGHT && x > OSD_X + D_RAD)
155	return OSD_IN;
156	}
157
158	return OSD_NONE;
159	}
160
161	static osd_button_t
162	osm_gps_map_osd_check(gint x, gint y) {
163	osd_button_t but = OSD_NONE;
164
165	/* first do a rough test for the OSD area. */
166	/* this is just to avoid an unnecessary detailed test */
167	if(x > OSD_X && x < OSD_X + OSD_W &&
168	y > OSD_Y && y < OSD_Y + OSD_H) {
169	but = osm_gps_map_osd_check_dpad(x, y);
170
171	if(but == OSD_NONE)
172	but = osm_gps_map_osd_check_zoom(x, y);
173	}
174
175	return but;
176	}
177
178	static void
179	osm_gps_map_osd_shape_shadow(cairo_t *cr) {
180	cairo_set_source_rgba (cr, 0, 0, 0, 0.2);
181	cairo_fill (cr);
182	cairo_stroke (cr);
183	}
184
185	static void
186	osm_gps_map_osd_shape(cairo_t *cr) {
187	cairo_set_source_rgb (cr, 1, 1, 1);
188	cairo_fill_preserve (cr);
189	cairo_set_source_rgb (cr, OSD_COLOR);
190	cairo_set_line_width (cr, 1);
191	cairo_stroke (cr);
192	}
193
194	static void
195	osm_gps_map_osd_dpad_labels(cairo_t *cr, gint x, gint y) {
196	/* move reference to dpad center */
197	x += D_RAD;
198	y += D_RAD;
199
200	const static gint offset[][3][2] = {
201	/* left arrow/triangle */
202	{ { -D_TIP+D_LEN, -D_WID }, { -D_LEN, D_WID }, { +D_LEN, D_WID } },
203	/* right arrow/triangle */
204	{ { +D_TIP-D_LEN, -D_WID }, { +D_LEN, D_WID }, { -D_LEN, D_WID } },
205	/* top arrow/triangle */
206	{ { -D_WID, -D_TIP+D_LEN }, { D_WID, -D_LEN }, { D_WID, +D_LEN } },
207	/* bottom arrow/triangle */
208	{ { -D_WID, +D_TIP-D_LEN }, { D_WID, +D_LEN }, { D_WID, -D_LEN } }
209	};
210
211	int i;
212	for(i=0;i<4;i++) {
213	cairo_move_to (cr, x + offset[i][0][0], y + offset[i][0][1]);
214	cairo_rel_line_to (cr, offset[i][1][0], offset[i][1][1]);
215	cairo_rel_line_to (cr, offset[i][2][0], offset[i][2][1]);
216	}
217	}
218
219	/* draw the sattelite dish icon in the center of the dpad */
220	#define GPS_V0 (D_RAD/8)
221	#define GPS_V1 (D_RAD/10)
222	#define GPS_V2 (D_RAD/5)
223
224	/* draw a satellite receiver dish */
225	static void
226	osm_gps_map_osd_dpad_gps(cairo_t *cr, gint x, gint y) {
227	/* move reference to dpad center */
228	x += D_RAD;
229	y += D_RAD + GPS_V0;
230
231	cairo_move_to (cr, x-GPS_V0, y+GPS_V0);
232	cairo_rel_line_to (cr, +GPS_V0, -GPS_V0);
233	cairo_rel_line_to (cr, +GPS_V0, +GPS_V0);
234	cairo_close_path (cr);
235
236	cairo_move_to (cr, x+GPS_V1-GPS_V2, y-2*GPS_V2);
237	cairo_curve_to (cr, x-GPS_V2, y, x+GPS_V1, y+GPS_V1, x+GPS_V1+GPS_V2, y);
238	cairo_close_path (cr);
239
240	x += GPS_V1;
241	cairo_move_to (cr, x, y-GPS_V2);
242	cairo_rel_line_to (cr, +GPS_V1, -GPS_V1);
243	}
244
245	#define Z_LEN (2*Z_RAD/3)
246
247	static void
248	osm_gps_map_osd_zoom_labels(cairo_t *cr, gint x, gint y) {
249	cairo_move_to (cr, x + Z_LEFT - Z_LEN, y + Z_MID);
250	cairo_line_to (cr, x + Z_LEFT + Z_LEN, y + Z_MID);
251
252	cairo_move_to (cr, x + Z_RIGHT, y + Z_MID - Z_LEN);
253	cairo_line_to (cr, x + Z_RIGHT, y + Z_MID + Z_LEN);
254	cairo_move_to (cr, x + Z_RIGHT - Z_LEN, y + Z_MID);
255	cairo_line_to (cr, x + Z_RIGHT + Z_LEN, y + Z_MID);
256	}
257
258	static void
259	osm_gps_map_osd_labels(cairo_t *cr, gint width, gboolean enabled) {
260	if(enabled) cairo_set_source_rgb (cr, OSD_COLOR);
261	else cairo_set_source_rgb (cr, OSD_COLOR_DISABLED);
262	cairo_set_line_width (cr, width);
263	cairo_stroke (cr);
264	}
265
266	static void
267	osm_gps_map_osd_labels_shadow(cairo_t *cr, gint width, gboolean enabled) {
268	cairo_set_source_rgba (cr, 0, 0, 0, enabled?0.3:0.15);
269	cairo_set_line_width (cr, width);
270	cairo_stroke (cr);
271	}
272
273	static void
274	osm_gps_map_osd_render(osm_gps_map_osd_t *osd) {
275	osd_priv_t priv = (osd_priv_t)osd->priv;
276
277	/* first fill with transparency */
278	cairo_t *cr = cairo_create(priv->overlay);
279	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
280	cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 0.0);
281	cairo_paint(cr);
282
283	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
284
285	/* --------- draw zoom and dpad shape shadow ----------- */
286	gint x = 0, y = 0;
287
288	osm_gps_map_osd_zoom_shape(cr, x + OSD_SHADOW, y + OSD_SHADOW);
289	osm_gps_map_osd_shape_shadow(cr);
290	osm_gps_map_osd_dpad_shape(cr, x + OSD_SHADOW, y + OSD_SHADOW);
291	osm_gps_map_osd_shape_shadow(cr);
292
293	/* --------- draw zoom and dpad shape ----------- */
294
295	osm_gps_map_osd_zoom_shape(cr, x, y);
296	osm_gps_map_osd_shape(cr);
297	osm_gps_map_osd_dpad_shape(cr, x, y);
298	osm_gps_map_osd_shape(cr);
299
300	/* --------- draw zoom and dpad labels --------- */
301
302	osm_gps_map_osd_zoom_labels(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW);
303	osm_gps_map_osd_dpad_labels(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW);
304	osm_gps_map_osd_labels_shadow(cr, Z_RAD/3, TRUE);
305	osm_gps_map_osd_dpad_gps(cr, x + OSD_LBL_SHADOW, y + OSD_LBL_SHADOW);
306	osm_gps_map_osd_labels_shadow(cr, Z_RAD/6, osd->cb != NULL);
307
308	osm_gps_map_osd_zoom_labels(cr, x, y);
309	osm_gps_map_osd_dpad_labels(cr, x, y);
310	osm_gps_map_osd_labels(cr, Z_RAD/3, TRUE);
311	osm_gps_map_osd_dpad_gps(cr, x, y);
312	osm_gps_map_osd_labels(cr, Z_RAD/6, osd->cb != NULL);
313
314	cairo_destroy(cr);
315	}
316
317	static void
318	osm_gps_map_osd_draw(osm_gps_map_osd_t *osd, gint xoffset, gint yoffset)
319	{
320	osd_priv_t priv = (osd_priv_t)osd->priv;
321
322	/* backup previous contents */
323	if(!priv->backup)
324	priv->backup = gdk_pixmap_new(osd->pixmap, OSD_W+2, OSD_H+2, -1);
325
326	gint x = OSD_X + xoffset;
327	gint y = OSD_Y + yoffset;
328
329	/* create backup of background */
330	gdk_draw_drawable(priv->backup,
331	osd->widget->style->fg_gc[GTK_WIDGET_STATE(osd->widget)],
332	osd->pixmap, x-1, y-1, 0, 0, OSD_W+2, OSD_H+2);
333
334	priv->backup_x = x-1;
335	priv->backup_y = y-1;
336
337	/* OSD itself uses some off-screen rendering, so check if the */
338	/* offscreen buffer is present and create it if not */
339	if(!priv->overlay) {
340	/* create overlay ... */
341	priv->overlay =
342	cairo_image_surface_create(CAIRO_FORMAT_ARGB32, OSD_W, OSD_H);
343	/* ... and render it */
344	osm_gps_map_osd_render(osd);
345	}
346
347	// now draw this onto the original context
348	cairo_t *cr = gdk_cairo_create(osd->pixmap);
349	cairo_set_source_surface(cr, priv->overlay, x, y);
350	cairo_paint(cr);
351	cairo_destroy(cr);
352	}
353
354	static void
355	osm_gps_map_osd_restore (osm_gps_map_osd_t *osd)
356	{
357	osd_priv_t priv = (osd_priv_t)osd->priv;
358
359	/* restore backup of previous contents */
360	if(priv->backup) {
361	/* create backup of background */
362	gdk_draw_drawable(osd->pixmap,
363	osd->widget->style->fg_gc[GTK_WIDGET_STATE(osd->widget)],
364	priv->backup, 0, 0,
365	priv->backup_x, priv->backup_y, OSD_W+2, OSD_H+2);
366	}
367	}
368
369	static void
370	osm_gps_map_osd_free(osm_gps_map_osd_t *osd)
371	{
372	osd_priv_t priv = (osd_priv_t )(osd->priv);
373
374	if (priv->backup)
375	g_object_unref(priv->backup);
376
377	if (priv->overlay)
378	cairo_surface_destroy(priv->overlay);
379
380	g_free(priv);
381	}
382
383	static osm_gps_map_osd_t osd_classic = {
384	.restore = osm_gps_map_osd_restore,
385	.draw = osm_gps_map_osd_draw,
386	.check = osm_gps_map_osd_check,
387	.render = osm_gps_map_osd_render,
388	.free = osm_gps_map_osd_free,
389
390	.cb = NULL,
391	.data = NULL,
392
393	.priv = NULL
394	};
395
396	/* this is the only function that's externally visible */
397	void
398	osm_gps_map_osd_classic_init(OsmGpsMap *map)
399	{
400	osd_priv_t *priv = osd_classic.priv = g_new0(osd_priv_t, 1);
401
402	osd_classic.priv = priv;
403
404	osm_gps_map_register_osd(map, &osd_classic);
405	}
406
407
408	void osm_gps_map_osd_enable_gps (OsmGpsMap *map, OsmGpsMapOsdCallback cb, gpointer data) {
409	osm_gps_map_osd_t *osd = osm_gps_map_osd_get(map);
410
411	g_return_if_fail (osd);
412
413	osd->cb = cb;
414	osd->data = data;
415
416	/* this may have changed the state of the gps button */
417	/* we thus re-render the overlay */
418	osd->render(osd);
419
420	osm_gps_map_redraw(map);
421	}