+int selected_dive = 0;
+
+/* Plot info with smoothing and one-, two- and three-minute minimums and maximums */
+struct plot_info {
+ int nr;
+ int maxtime;
+ int meandepth, maxdepth;
+ int minpressure, maxpressure;
+ int mintemp, maxtemp;
+ struct plot_data {
+ int sec;
+ int pressure, temperature;
+ /* Depth info */
+ int val;
+ int smoothed;
+ struct plot_data *min[3];
+ struct plot_data *max[3];
+ int avg[3];
+ } entry[];
+};
+#define plot_info_size(nr) (sizeof(struct plot_info) + (nr)*sizeof(struct plot_data))
+
+/* Scale to 0,0 -> maxx,maxy */
+#define SCALEX(gc,x) (((x)-gc->leftx)/(gc->rightx-gc->leftx)*gc->maxx)
+#define SCALEY(gc,y) (((y)-gc->topy)/(gc->bottomy-gc->topy)*gc->maxy)
+#define SCALE(gc,x,y) SCALEX(gc,x),SCALEY(gc,y)
+
+static void move_to(struct graphics_context *gc, double x, double y)
+{
+ cairo_move_to(gc->cr, SCALE(gc, x, y));
+}
+
+static void line_to(struct graphics_context *gc, double x, double y)
+{
+ cairo_line_to(gc->cr, SCALE(gc, x, y));
+}
+
+static void set_source_rgba(struct graphics_context *gc, double r, double g, double b, double a)
+{
+ if (gc->printer) {
+ /* Black is white and white is black */
+ double sum = r+g+b;
+ if (sum > 2)
+ r = g = b = 0;
+ else if (sum < 1)
+ r = g = b = 1;
+ }
+ cairo_set_source_rgba(gc->cr, r, g, b, a);
+}
+
+static void set_source_rgb(struct graphics_context *gc, double r, double g, double b)
+{
+ set_source_rgba(gc, r, g, b, 1);
+}
+
+#define ROUND_UP(x,y) ((((x)+(y)-1)/(y))*(y))
+
+/*
+ * When showing dive profiles, we scale things to the
+ * current dive. However, we don't scale past less than
+ * 30 minutes or 90 ft, just so that small dives show
+ * up as such.
+ */
+static int get_maxtime(struct plot_info *pi)
+{
+ int seconds = pi->maxtime;
+ /* min 30 minutes, rounded up to 5 minutes, with at least 2.5 minutes to spare */
+ return MAX(30*60, ROUND_UP(seconds+150, 60*5));
+}
+
+static int get_maxdepth(struct plot_info *pi)
+{
+ unsigned mm = pi->maxdepth;
+ /* Minimum 30m, rounded up to 10m, with at least 3m to spare */
+ return MAX(30000, ROUND_UP(mm+3000, 10000));
+}
+
+typedef struct {
+ int size;
+ double r,g,b;
+ double hpos, vpos;
+} text_render_options_t;
+
+#define RIGHT (-1.0)
+#define CENTER (-0.5)
+#define LEFT (0.0)
+
+#define TOP (1)
+#define MIDDLE (0)
+#define BOTTOM (-1)
+
+static void plot_text(struct graphics_context *gc, const text_render_options_t *tro,
+ double x, double y, const char *fmt, ...)
+{
+ cairo_t *cr = gc->cr;
+ cairo_font_extents_t fe;
+ cairo_text_extents_t extents;
+ double dx, dy;
+ char buffer[80];
+ va_list args;
+
+ va_start(args, fmt);
+ vsnprintf(buffer, sizeof(buffer), fmt, args);
+ va_end(args);
+
+ cairo_set_font_size(cr, tro->size);
+ cairo_font_extents(cr, &fe);
+ cairo_text_extents(cr, buffer, &extents);
+ dx = tro->hpos * extents.width + extents.x_bearing;
+ dy = tro->vpos * extents.height + fe.descent;
+
+ move_to(gc, x, y);
+ cairo_rel_move_to(cr, dx, dy);
+
+ cairo_text_path(cr, buffer);
+ set_source_rgb(gc, 0, 0, 0);
+ cairo_stroke(cr);
+
+ move_to(gc, x, y);
+ cairo_rel_move_to(cr, dx, dy);
+
+ set_source_rgb(gc, tro->r, tro->g, tro->b);
+ cairo_show_text(cr, buffer);
+}
+
+static void render_depth_sample(struct graphics_context *gc, struct plot_data *entry, const text_render_options_t *tro)
+{
+ int sec = entry->sec;
+ depth_t depth = { entry->val };
+ const char *fmt;
+ double d;
+
+ switch (output_units.length) {
+ case METERS:
+ d = depth.mm / 1000.0;
+ fmt = "%.1f";
+ break;
+ case FEET:
+ d = to_feet(depth);
+ fmt = "%.0f";
+ break;
+ }
+ plot_text(gc, tro, sec, depth.mm, fmt, d);
+}
+
+static void plot_text_samples(struct graphics_context *gc, struct plot_info *pi)
+{
+ static const text_render_options_t deep = {14, 1.0, 0.2, 0.2, CENTER, TOP};
+ static const text_render_options_t shallow = {14, 1.0, 0.2, 0.2, CENTER, BOTTOM};
+ int i;
+
+ for (i = 0; i < pi->nr; i++) {
+ struct plot_data *entry = pi->entry + i;
+
+ if (entry->val < 2000)
+ continue;
+
+ if (entry == entry->max[2])
+ render_depth_sample(gc, entry, &deep);
+
+ if (entry == entry->min[2])
+ render_depth_sample(gc, entry, &shallow);
+ }
+}
+
+static void plot_depth_text(struct graphics_context *gc, struct plot_info *pi)
+{
+ int maxtime, maxdepth;
+
+ /* Get plot scaling limits */
+ maxtime = get_maxtime(pi);
+ maxdepth = get_maxdepth(pi);
+
+ gc->leftx = 0; gc->rightx = maxtime;
+ gc->topy = 0; gc->bottomy = maxdepth;
+
+ plot_text_samples(gc, pi);
+}
+
+static void plot_smoothed_profile(struct graphics_context *gc, struct plot_info *pi)
+{
+ int i;
+ struct plot_data *entry = pi->entry;
+
+ cairo_set_source_rgba(gc->cr, 1, 0.2, 0.2, 0.20);
+ move_to(gc, entry->sec, entry->smoothed);
+ for (i = 1; i < pi->nr; i++) {
+ entry++;
+ line_to(gc, entry->sec, entry->smoothed);
+ }
+ cairo_stroke(gc->cr);
+}
+
+static void plot_minmax_profile_minute(struct graphics_context *gc, struct plot_info *pi,
+ int index, double a)
+{
+ int i;
+ struct plot_data *entry = pi->entry;
+
+ cairo_set_source_rgba(gc->cr, 1, 0.2, 1, a);
+ move_to(gc, entry->sec, entry->min[index]->val);
+ for (i = 1; i < pi->nr; i++) {
+ entry++;
+ line_to(gc, entry->sec, entry->min[index]->val);
+ }
+ for (i = 1; i < pi->nr; i++) {
+ line_to(gc, entry->sec, entry->max[index]->val);
+ entry--;
+ }
+ cairo_close_path(gc->cr);
+ cairo_fill(gc->cr);
+}
+
+static void plot_minmax_profile(struct graphics_context *gc, struct plot_info *pi)
+{
+ if (gc->printer)
+ return;
+ plot_minmax_profile_minute(gc, pi, 2, 0.1);
+ plot_minmax_profile_minute(gc, pi, 1, 0.1);
+ plot_minmax_profile_minute(gc, pi, 0, 0.1);
+}
+
+static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi)
+{
+ int i;
+ cairo_t *cr = gc->cr;
+ int begins, sec, depth;
+ struct plot_data *entry;
+ int maxtime, maxdepth, marker;
+
+ /* Get plot scaling limits */
+ maxtime = get_maxtime(pi);
+ maxdepth = get_maxdepth(pi);
+
+ /* Time markers: every 5 min */
+ gc->leftx = 0; gc->rightx = maxtime;
+ gc->topy = 0; gc->bottomy = 1.0;
+ for (i = 5*60; i < maxtime; i += 5*60) {
+ move_to(gc, i, 0);
+ line_to(gc, i, 1);
+ }
+
+ /* Depth markers: every 30 ft or 10 m*/
+ gc->leftx = 0; gc->rightx = 1.0;
+ gc->topy = 0; gc->bottomy = maxdepth;
+ switch (output_units.length) {
+ case METERS: marker = 10000; break;
+ case FEET: marker = 9144; break; /* 30 ft */
+ }
+
+ set_source_rgba(gc, 1, 1, 1, 0.5);
+ for (i = marker; i < maxdepth; i += marker) {
+ move_to(gc, 0, i);
+ line_to(gc, 1, i);
+ }
+ cairo_stroke(cr);
+
+ /* Show mean depth */
+ set_source_rgba(gc, 1, 0.2, 0.2, 0.40);
+ move_to(gc, 0, pi->meandepth);
+ line_to(gc, 1, pi->meandepth);
+ cairo_stroke(cr);
+
+ gc->leftx = 0; gc->rightx = maxtime;
+
+ plot_smoothed_profile(gc, pi);
+ plot_minmax_profile(gc, pi);
+
+ entry = pi->entry;
+ set_source_rgba(gc, 1, 0.2, 0.2, 0.80);
+ begins = entry->sec;
+ move_to(gc, entry->sec, entry->val);
+ for (i = 1; i < pi->nr; i++) {
+ entry++;
+ sec = entry->sec;
+ if (sec <= maxtime) {
+ depth = entry->val;
+ line_to(gc, sec, depth);
+ }
+ }
+ gc->topy = 0; gc->bottomy = 1.0;
+ line_to(gc, MIN(sec,maxtime), 0);
+ line_to(gc, begins, 0);
+ cairo_close_path(cr);
+ set_source_rgba(gc, 1, 0.2, 0.2, 0.20);
+ cairo_fill_preserve(cr);
+ set_source_rgba(gc, 1, 0.2, 0.2, 0.80);
+ cairo_stroke(cr);
+}
+
+static int setup_temperature_limits(struct graphics_context *gc, struct plot_info *pi)
+{
+ int maxtime, mintemp, maxtemp, delta;
+
+ /* Get plot scaling limits */
+ maxtime = get_maxtime(pi);
+ mintemp = pi->mintemp;
+ maxtemp = pi->maxtemp;
+
+ gc->leftx = 0; gc->rightx = maxtime;
+ /* Show temperatures in roughly the lower third, but make sure the scale
+ is at least somewhat reasonable */
+ delta = maxtemp - mintemp;
+ if (delta > 3000) { /* more than 3K in fluctuation */
+ gc->topy = maxtemp + delta*2;
+ gc->bottomy = mintemp - delta/2;
+ } else {
+ gc->topy = maxtemp + 1500 + delta*2;
+ gc->bottomy = mintemp - delta/2;
+ }
+
+ return maxtemp > mintemp;
+}
+
+static void plot_single_temp_text(struct graphics_context *gc, int sec, int mkelvin)
+{
+ int deg;
+ const char *unit;
+ static const text_render_options_t tro = {12, 0.2, 0.2, 1.0, LEFT, TOP};
+ temperature_t temperature = { mkelvin };
+
+ if (output_units.temperature == FAHRENHEIT) {
+ deg = to_F(temperature);
+ unit = "F";
+ } else {
+ deg = to_C(temperature);
+ unit = "C";
+ }
+ plot_text(gc, &tro, sec, temperature.mkelvin, "%d %s", deg, unit);
+}
+
+static void plot_temperature_text(struct graphics_context *gc, struct plot_info *pi)
+{
+ int i;
+ int last = 0, sec = 0;
+ int last_temperature = 0, last_printed_temp = 0;
+
+ if (!setup_temperature_limits(gc, pi))
+ return;
+
+ for (i = 0; i < pi->nr; i++) {
+ struct plot_data *entry = pi->entry+i;
+ int mkelvin = entry->temperature;
+
+ if (!mkelvin)
+ continue;
+ last_temperature = mkelvin;
+ sec = entry->sec;
+ if (sec < last + 300)
+ continue;
+ last = sec;
+ plot_single_temp_text(gc,sec,mkelvin);
+ last_printed_temp = mkelvin;
+ }
+ /* it would be nice to print the end temperature, if it's different */
+ if (abs(last_temperature - last_printed_temp) > 500)
+ plot_single_temp_text(gc, sec, last_temperature);
+}
+
+static void plot_temperature_profile(struct graphics_context *gc, struct plot_info *pi)
+{
+ int i;
+ cairo_t *cr = gc->cr;
+ int last = 0;
+
+ if (!setup_temperature_limits(gc, pi))
+ return;
+
+ set_source_rgba(gc, 0.2, 0.2, 1.0, 0.8);
+ for (i = 0; i < pi->nr; i++) {
+ struct plot_data *entry = pi->entry + i;
+ int mkelvin = entry->temperature;
+ int sec = entry->sec;
+ if (!mkelvin) {
+ if (!last)
+ continue;
+ mkelvin = last;
+ }
+ if (last)
+ line_to(gc, sec, mkelvin);
+ else
+ move_to(gc, sec, mkelvin);
+ last = mkelvin;
+ }
+ cairo_stroke(cr);
+}
+
+/* gets both the actual start and end pressure as well as the scaling factors */
+static int get_cylinder_pressure_range(struct graphics_context *gc, struct plot_info *pi)
+{
+ gc->leftx = 0;
+ gc->rightx = get_maxtime(pi);
+
+ gc->topy = 0; gc->bottomy = pi->maxpressure * 1.5;
+ return pi->maxpressure != 0;
+}
+
+static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info *pi)
+{
+ int i;
+
+ if (!get_cylinder_pressure_range(gc, pi))
+ return;
+
+ cairo_set_source_rgba(gc->cr, 0.2, 1.0, 0.2, 0.80);
+
+ move_to(gc, 0, pi->maxpressure);
+ for (i = 1; i < pi->nr; i++) {
+ int mbar;
+ struct plot_data *entry = pi->entry + i;
+
+ mbar = entry->pressure;
+ if (!mbar)
+ continue;
+ line_to(gc, entry->sec, mbar);
+ }
+ line_to(gc, pi->maxtime, pi->minpressure);
+ cairo_stroke(gc->cr);
+}
+
+/*
+ * Return air usage (in liters).
+ */
+static double calculate_airuse(struct dive *dive)