]> git.tdb.fi Git - ext/subsurface.git/blobdiff - profile.c
Define all colors in one place
[ext/subsurface.git] / profile.c
index d2ebf4a097b94bb6964c2a453bb74b12949aec6c..7f8ad638584cff9f3b8440572b82ee534cec9adc 100644 (file)
--- a/profile.c
+++ b/profile.c
@@ -44,15 +44,66 @@ struct plot_info {
 #define INTERPOLATED_PR 1
 #define SENSOR_PRESSURE(_entry) (_entry)->pressure[SENSOR_PR]
 #define INTERPOLATED_PRESSURE(_entry) (_entry)->pressure[INTERPOLATED_PR]
+#define GET_PRESSURE(_entry) (SENSOR_PRESSURE(_entry) ? : INTERPOLATED_PRESSURE(_entry))
+
+typedef enum { TEXT_BACKGROUND, TRIANGULAR_BG, TRIANGULAR_FG, EVENTS, SAMPLE_DEEP, SAMPLE_SHALLOW,
+       SMOOTHED, MINUTE, TIME_MARKER, TIME_TEXT, DEPTH_MARKER, MEAN_DEPTH, DEPTH_TOP,
+       DEPTH_BOTTOM, DEPTH_FILL_PRINTER, DEPTH_STROKE_PRINTER, TEMP_TEXT, TEMP_PLOT, SAC_DEFAULT,
+       BOUNDING_BOX, PRESSURE_TEXT, VELO_STABLE, VELO_SLOW, VELO_MODERATE, VELO_FAST, VELO_CRAZY,
+       SAC_1, SAC_2, SAC_3, SAC_4, SAC_5, SAC_6, SAC_7, SAC_8, SAC_9, BACKGROUND } color_t;
 
 /* convert velocity to colors */
 typedef struct { double r, g, b; } rgb_t;
-static const rgb_t rgb[] = {
-       [STABLE]   = {0.0, 0.4, 0.0},
-       [SLOW]     = {0.4, 0.8, 0.0},
-       [MODERATE] = {0.8, 0.8, 0.0},
-       [FAST]     = {0.8, 0.5, 0.0},
-       [CRAZY]    = {1.0, 0.0, 0.0},
+static const color_t velocity_color[] = {
+       [STABLE]   = VELO_STABLE,
+       [SLOW]     = VELO_SLOW,
+       [MODERATE] = VELO_MODERATE,
+       [FAST]     = VELO_FAST,
+       [CRAZY]    = VELO_CRAZY,
+};
+
+static const rgb_t profile_color[] = {
+       [TEXT_BACKGROUND] = {0.95, 0.95, 0.95},
+       [TRIANGULAR_BG]   = {1.0, 1.0, 0.1},
+       [TRIANGULAR_FG]   = {0.0, 0.0, 0.0},
+       [EVENTS]          = {1.0, 0.2, 0.2},
+       [SAMPLE_DEEP]     = {0.8, 0.2, 0.2},
+       [SAMPLE_SHALLOW]  = {0.8, 0.2, 0.2},
+       [SMOOTHED]        = {1.0, 0.2, 0.2},
+       [MINUTE]          = {0.7, 0.2, 0.7},
+       [TIME_MARKER]     = {1.0, 1.0, 1.0},
+       [TIME_TEXT]       = {0.1, 0.5, 0.1},
+       [DEPTH_MARKER]    = {1.0, 1.0, 1.0},
+       [MEAN_DEPTH]      = {1.0, 0.2, 0.2},
+       [DEPTH_TOP]       = {0.2, 0.2, 0.8},
+       [DEPTH_BOTTOM]    = {0.9, 0.9, 0.9},
+       [DEPTH_FILL_PRINTER] = {1.0, 1.0, 1.0},
+       [DEPTH_STROKE_PRINTER] = {1.0, 1.0, 1.0},
+       [TEMP_TEXT]       = {0.2, 0.2, 0.7},
+       [TEMP_PLOT]       = {0.2, 0.2, 0.9},
+       [SAC_DEFAULT]     = {1.0, 1.0, 1.0},
+       [BOUNDING_BOX]    = {1.0, 1.0, 1.0},
+       [PRESSURE_TEXT]   = {0.2, 0.4, 0.2},
+       [VELO_STABLE]     = {0.0, 0.4, 0.0},
+       [VELO_SLOW]       = {0.4, 0.8, 0.0},
+       [VELO_MODERATE]   = {0.8, 0.8, 0.0},
+       [VELO_FAST]       = {0.8, 0.5, 0.0},
+       [VELO_CRAZY]      = {1.0, 0.0, 0.0},
+       [SAC_1]           = {0.0, 0.4, 0.2},
+       [SAC_2]           = {0.2, 0.6, 0.2},
+       [SAC_3]           = {0.4, 0.8, 0.2},
+       [SAC_4]           = {0.6, 0.8, 0.2},
+       [SAC_5]           = {0.8, 0.8, 0.2},
+       [SAC_6]           = {0.8, 0.6, 0.2},
+       [SAC_7]           = {0.8, 0.4, 0.2},
+       [SAC_8]           = {0.9, 0.3, 0.2},
+       [SAC_9]           = {1.0, 0.2, 0.2},
+       [BACKGROUND]      = {0.95, 0.95, 0.9},
+};
+
+#define SAC_COLORS 9
+static const color_t sac_color[SAC_COLORS] = {
+       SAC_1, SAC_2, SAC_3, SAC_4, SAC_5, SAC_6, SAC_7, SAC_8, SAC_9
 };
 
 #define plot_info_size(nr) (sizeof(struct plot_info) + (nr)*sizeof(struct plot_data))
@@ -72,8 +123,12 @@ 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)
+static void set_source_rgba(struct graphics_context *gc, color_t c, double a)
 {
+       const rgb_t *rgb = &profile_color[c];
+       double r = rgb->r;
+       double g = rgb->g;
+       double b = rgb->b;
        /*
         * For printers, we still honor 'a', but ignore colors
         * for now. Black is white and white is black
@@ -88,9 +143,20 @@ static void set_source_rgba(struct graphics_context *gc, double r, double g, dou
        cairo_set_source_rgba(gc->cr, r, g, b, a);
 }
 
-void set_source_rgb(struct graphics_context *gc, double r, double g, double b)
+static void set_source_rgb(struct graphics_context *gc, color_t c)
+{
+       set_source_rgba(gc, c, 1);
+}
+
+void init_profile_background(struct graphics_context *gc)
 {
-       set_source_rgba(gc, r, g, b, 1);
+       set_source_rgb(gc, BACKGROUND);
+}
+
+void pattern_add_color_stop_rgba(cairo_pattern_t *pat, double o, color_t c, double a)
+{
+       const rgb_t *rgb = &profile_color[c];
+       cairo_pattern_add_color_stop_rgba (pat, o, rgb->r, rgb->g, rgb->b, a);
 }
 
 #define ROUND_UP(x,y) ((((x)+(y)-1)/(y))*(y))
@@ -137,7 +203,7 @@ static int get_maxdepth(struct plot_info *pi)
 
 typedef struct {
        int size;
-       double r,g,b;
+       color_t color;
        double hpos, vpos;
 } text_render_options_t;
 
@@ -173,13 +239,13 @@ static void plot_text(struct graphics_context *gc, const text_render_options_t *
        cairo_rel_move_to(cr, dx, dy);
 
        cairo_text_path(cr, buffer);
-       set_source_rgb(gc, 0, 0, 0);
+       set_source_rgba(gc, TEXT_BACKGROUND, 0.95);
        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);
+       set_source_rgb(gc, tro->color);
        cairo_show_text(cr, buffer);
 }
 
@@ -248,14 +314,14 @@ static void plot_one_event(struct graphics_context *gc, struct plot_info *pi, st
        /* draw a little tirangular marker and attach tooltip */
        x = SCALEX(gc, event->time.seconds);
        y = SCALEY(gc, depth);
-       set_source_rgba(gc, 1.0, 1.0, 0.1, 0.8);
+       set_source_rgba(gc, TRIANGULAR_BG, 0.8);
        cairo_move_to(gc->cr, x-15, y+6);
        cairo_line_to(gc->cr, x-3  , y+6);
        cairo_line_to(gc->cr, x-9, y-6);
        cairo_line_to(gc->cr, x-15, y+6);
        cairo_stroke_preserve(gc->cr);
        cairo_fill(gc->cr);
-       set_source_rgba(gc, 0.0, 0.0, 0.0, 0.8);
+       set_source_rgba(gc, TRIANGULAR_FG, 0.8);
        cairo_move_to(gc->cr, x-9, y-3);
        cairo_line_to(gc->cr, x-9, y+1);
        cairo_move_to(gc->cr, x-9, y+4);
@@ -266,7 +332,7 @@ static void plot_one_event(struct graphics_context *gc, struct plot_info *pi, st
 
 static void plot_events(struct graphics_context *gc, struct plot_info *pi, struct dive *dive)
 {
-       static const text_render_options_t tro = {14, 1.0, 0.2, 0.2, CENTER, TOP};
+       static const text_render_options_t tro = {14, EVENTS, CENTER, TOP};
        struct event *event = dive->events;
 
        if (gc->printer)
@@ -290,8 +356,8 @@ static void render_depth_sample(struct graphics_context *gc, struct plot_data *e
 
 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};
+       static const text_render_options_t deep = {14, SAMPLE_DEEP, CENTER, TOP};
+       static const text_render_options_t shallow = {14, SAMPLE_SHALLOW, CENTER, BOTTOM};
        int i;
        int last = -1;
 
@@ -335,7 +401,7 @@ static void plot_smoothed_profile(struct graphics_context *gc, struct plot_info
        int i;
        struct plot_data *entry = pi->entry;
 
-       set_source_rgba(gc, 1, 0.2, 0.2, 0.20);
+       set_source_rgba(gc, SMOOTHED, 0.20);
        move_to(gc, entry->sec, entry->smoothed);
        for (i = 1; i < pi->nr; i++) {
                entry++;
@@ -350,7 +416,7 @@ static void plot_minmax_profile_minute(struct graphics_context *gc, struct plot_
        int i;
        struct plot_data *entry = pi->entry;
 
-       set_source_rgba(gc, 1, 0.2, 1, a);
+       set_source_rgba(gc, MINUTE, a);
        move_to(gc, entry->sec, entry->min[index]->depth);
        for (i = 1; i < pi->nr; i++) {
                entry++;
@@ -401,7 +467,9 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
 
        gc->leftx = 0; gc->rightx = maxtime;
        gc->topy = 0; gc->bottomy = 1.0;
-       set_source_rgba(gc, 1, 1, 1, 0.5);
+       set_source_rgba(gc, TIME_MARKER, 0.5);
+       cairo_set_line_width(gc->cr, 1);
+
        for (i = incr; i < maxtime; i += incr) {
                move_to(gc, i, 0);
                line_to(gc, i, 1);
@@ -409,7 +477,7 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
        cairo_stroke(cr);
 
        /* now the text on every second time marker */
-       text_render_options_t tro = {10, 0.2, 1.0, 0.2, CENTER, TOP};
+       text_render_options_t tro = {10, TIME_TEXT, CENTER, TOP};
        for (i = incr; i < maxtime; i += 2 * incr)
                plot_text(gc, &tro, i, 1, "%d", i/60);
 
@@ -421,7 +489,7 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
        case FEET: marker = 9144; break;        /* 30 ft */
        }
 
-       set_source_rgba(gc, 1, 1, 1, 0.5);
+       set_source_rgba(gc, DEPTH_MARKER, 0.5);
        for (i = marker; i < maxdepth; i += marker) {
                move_to(gc, 0, i);
                line_to(gc, 1, i);
@@ -430,7 +498,7 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
 
        /* Show mean depth */
        if (! gc->printer) {
-               set_source_rgba(gc, 1, 0.2, 0.2, 0.40);
+               set_source_rgba(gc, MEAN_DEPTH, 0.40);
                move_to(gc, 0, pi->meandepth);
                line_to(gc, 1, pi->meandepth);
                cairo_stroke(cr);
@@ -447,11 +515,17 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
                plot_minmax_profile(gc, pi);
        }
 
-       set_source_rgba(gc, 1, 0.2, 0.2, 0.80);
-
        /* Do the depth profile for the neat fill */
        gc->topy = 0; gc->bottomy = maxdepth;
-       set_source_rgba(gc, 1, 0.2, 0.2, 0.20);
+
+       cairo_pattern_t *pat;
+       pat = cairo_pattern_create_linear (0.0, 0.0,  0.0, 256.0);
+       pattern_add_color_stop_rgba (pat, 1, DEPTH_TOP, 0.6);
+       pattern_add_color_stop_rgba (pat, 0, DEPTH_BOTTOM, 0.6);
+
+       cairo_set_source(gc->cr, pat);
+       cairo_pattern_destroy(pat);
+       cairo_set_line_width(gc->cr, 2);
 
        entry = pi->entry;
        move_to(gc, 0, 0);
@@ -459,9 +533,9 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
                line_to(gc, entry->sec, entry->depth);
        cairo_close_path(gc->cr);
        if (gc->printer) {
-               set_source_rgba(gc, 1, 1, 1, 0.2);
+               set_source_rgba(gc, DEPTH_FILL_PRINTER, 0.2);
                cairo_fill_preserve(cr);
-               set_source_rgb(gc, 1, 1, 1);
+               set_source_rgb(gc, DEPTH_STROKE_PRINTER);
                cairo_stroke(cr);
                return;
        }
@@ -475,9 +549,8 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
                /* we want to draw the segments in different colors
                 * representing the vertical velocity, so we need to
                 * chop this into short segments */
-               rgb_t color = rgb[entry->velocity];
                depth = entry->depth;
-               set_source_rgb(gc, color.r, color.g, color.b);
+               set_source_rgb(gc, velocity_color[entry->velocity]);
                move_to(gc, entry[-1].sec, entry[-1].depth);
                line_to(gc, sec, depth);
                cairo_stroke(cr);
@@ -512,7 +585,7 @@ static void plot_single_temp_text(struct graphics_context *gc, int sec, int mkel
 {
        double deg;
        const char *unit;
-       static const text_render_options_t tro = {12, 0.6, 0.6, 1.0, LEFT, TOP};
+       static const text_render_options_t tro = {12, TEMP_TEXT, LEFT, TOP};
 
        deg = get_temp_units(mkelvin, &unit);
 
@@ -565,7 +638,8 @@ static void plot_temperature_profile(struct graphics_context *gc, struct plot_in
        if (!setup_temperature_limits(gc, pi))
                return;
 
-       set_source_rgba(gc, 0.2, 0.2, 1.0, 0.8);
+       cairo_set_line_width(gc->cr, 2);
+       set_source_rgba(gc, TEMP_PLOT, 0.8);
        for (i = 0; i < pi->nr; i++) {
                struct plot_data *entry = pi->entry + i;
                int mkelvin = entry->temperature;
@@ -594,55 +668,101 @@ static int get_cylinder_pressure_range(struct graphics_context *gc, struct plot_
        return pi->maxpressure != 0;
 }
 
-static void plot_pressure_helper(struct graphics_context *gc, struct plot_info *pi, int type)
+/* set the color for the pressure plot according to temporary sac rate
+ * as compared to avg_sac; the calculation simply maps the delta between
+ * sac and avg_sac to indexes 0 .. (SAC_COLORS - 1) with everything
+ * more than 6000 ml/min below avg_sac mapped to 0 */
+
+static void set_sac_color(struct graphics_context *gc, int sac, int avg_sac)
+{
+       int sac_index = 0;
+       int delta = sac - avg_sac + 7000;
+
+       if (!gc->printer) {
+               sac_index = delta / 2000;
+               if (sac_index < 0)
+                       sac_index = 0;
+               if (sac_index > SAC_COLORS - 1)
+                       sac_index = SAC_COLORS - 1;
+               set_source_rgb(gc, sac_color[sac_index]);
+       } else {
+               set_source_rgb(gc, SAC_DEFAULT);
+       }
+}
+
+/* calculate the current SAC in ml/min and convert to int */
+#define GET_LOCAL_SAC(_entry1, _entry2, _dive) (int)                           \
+       ((GET_PRESSURE((_entry1)) - GET_PRESSURE((_entry2))) *                  \
+               (_dive)->cylinder[(_entry1)->cylinderindex].type.size.mliter /  \
+               (((_entry2)->sec - (_entry1)->sec) / 60.0) /                    \
+               (1 + ((_entry1)->depth + (_entry2)->depth) / 20000.0) /         \
+               1000.0)
+
+#define SAC_WINDOW 45  /* sliding window in seconds for current SAC calculation */
+
+static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info *pi,
+                               struct dive *dive)
 {
        int i;
+       int last = -1;
        int lift_pen = FALSE;
+       int first_plot = TRUE;
+       int sac = 0;
+       struct plot_data *last_entry = NULL;
+
+       if (!get_cylinder_pressure_range(gc, pi))
+               return;
+
+       cairo_set_line_width(gc->cr, 2);
 
        for (i = 0; i < pi->nr; i++) {
                int mbar;
                struct plot_data *entry = pi->entry + i;
 
-               mbar = entry->pressure[type];
-               if (!entry->same_cylinder)
+               mbar = GET_PRESSURE(entry);
+               if (!entry->same_cylinder) {
                        lift_pen = TRUE;
+                       last_entry = NULL;
+               }
                if (!mbar) {
                        lift_pen = TRUE;
                        continue;
                }
+               if (!last_entry) {
+                       last = i;
+                       last_entry = entry;
+                       sac = GET_LOCAL_SAC(entry, pi->entry + i + 1, dive);
+               } else {
+                       int j;
+                       sac = 0;
+                       for (j = last; j < i; j++)
+                               sac += GET_LOCAL_SAC(pi->entry + j, pi->entry + j + 1, dive);
+                       sac /= (i - last);
+                       if (entry->sec - last_entry->sec >= SAC_WINDOW) {
+                               last++;
+                               last_entry = pi->entry + last;
+                       }
+               }
+               set_sac_color(gc, sac, dive->sac);
                if (lift_pen) {
-                       if (i > 0 && entry->same_cylinder) {
+                       if (!first_plot && entry->same_cylinder) {
                                /* if we have a previous event from the same tank,
-                                * draw at least a short line .
-                                * This uses the implementation detail that the
-                                * type is either 0 or 1 */
+                                * draw at least a short line */
                                int prev_pr;
-                               prev_pr = (entry-1)->pressure[type] ? : (entry-1)->pressure[1 - type];
+                               prev_pr = GET_PRESSURE(entry - 1);
                                move_to(gc, (entry-1)->sec, prev_pr);
                                line_to(gc, entry->sec, mbar);
-                       } else
+                       } else {
+                               first_plot = FALSE;
                                move_to(gc, entry->sec, mbar);
+                       }
                        lift_pen = FALSE;
-               }
-               else
+               } else {
                        line_to(gc, entry->sec, mbar);
+               }
+               cairo_stroke(gc->cr);
+               move_to(gc, entry->sec, mbar);
        }
-       cairo_stroke(gc->cr);
-
-}
-
-static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info *pi)
-{
-       if (!get_cylinder_pressure_range(gc, pi))
-               return;
-
-       /* first plot the pressure readings we have from the dive computer */
-       set_source_rgba(gc, 0.2, 1.0, 0.2, 0.80);
-       plot_pressure_helper(gc, pi, SENSOR_PR);
-
-       /* then, in a different color, the interpolated values */
-       set_source_rgba(gc, 1.0, 1.0, 0.2, 0.80);
-       plot_pressure_helper(gc, pi, INTERPOLATED_PR);
 }
 
 static void plot_pressure_value(struct graphics_context *gc, int mbar, int sec,
@@ -652,12 +772,10 @@ static void plot_pressure_value(struct graphics_context *gc, int mbar, int sec,
        const char *unit;
 
        pressure = get_pressure_units(mbar, &unit);
-       text_render_options_t tro = {10, 0.2, 1.0, 0.2, xalign, yalign};
+       text_render_options_t tro = {10, PRESSURE_TEXT, xalign, yalign};
        plot_text(gc, &tro, sec, mbar, "%d %s", pressure, unit);
 }
 
-#define GET_PRESSURE(_entry) (SENSOR_PRESSURE(_entry) ? : INTERPOLATED_PRESSURE(_entry))
-
 static void plot_cylinder_pressure_text(struct graphics_context *gc, struct plot_info *pi)
 {
        int i;
@@ -698,7 +816,8 @@ static void plot_cylinder_pressure_text(struct graphics_context *gc, struct plot
                }
        }
        cyl = entry->cylinderindex;
-       last_pressure[cyl] = GET_PRESSURE(entry);
+       if (GET_PRESSURE(entry))
+               last_pressure[cyl] = GET_PRESSURE(entry);
        last_time[cyl] = entry->sec;
 
        for (cyl = 0; cyl < MAX_CYLINDERS; cyl++) {
@@ -889,6 +1008,21 @@ static void list_free(pr_track_t *list)
        free(list);
 }
 
+static void dump_pr_track(pr_track_t **track_pr)
+{
+       int cyl;
+       pr_track_t *list;
+
+       for (cyl = 0; cyl < MAX_CYLINDERS; cyl++) {
+               list = track_pr[cyl];
+               while (list) {
+                       printf("cyl%d: start %d end %d t_start %d t_end %d pt %6.3f\n", cyl,
+                               list->start, list->end, list->t_start, list->t_end, list->pressure_time);
+                       list = list->next;
+               }
+       }
+}
+
 static void fill_missing_tank_pressures(struct dive *dive, struct plot_info *pi,
                                        pr_track_t **track_pr)
 {
@@ -899,6 +1033,10 @@ static void fill_missing_tank_pressures(struct dive *dive, struct plot_info *pi,
        struct plot_data *entry;
        int cur_pr[MAX_CYLINDERS];
 
+       if (0) {
+               /* another great debugging tool */
+               dump_pr_track(track_pr);
+       }
        for (cyl = 0; cyl < MAX_CYLINDERS; cyl++) {
                cur_pr[cyl] = track_pr[cyl]->start;
        }
@@ -934,15 +1072,17 @@ static void fill_missing_tank_pressures(struct dive *dive, struct plot_info *pi,
                                if (!nlist) {
                                        /* just continue without calculating
                                         * interpolated values */
+                                       INTERPOLATED_PRESSURE(entry) = cur_pr[entry->cylinderindex];
                                        list = NULL;
                                        continue;
                                }
-                               magic = (nlist->end - cur_pr[entry->cylinderindex]) / pt;                               }
+                               magic = (nlist->end - cur_pr[entry->cylinderindex]) / pt;
+                       }
                        if (pt != 0.0) {
                                double cur_pt = (entry->sec - (entry-1)->sec) *
-                                       (1 + entry->depth / 10000.0);
+                                       (1 + (entry->depth + (entry-1)->depth) / 20000.0);
                                INTERPOLATED_PRESSURE(entry) =
-                                       cur_pr[entry->cylinderindex] + cur_pt * magic;
+                                       cur_pr[entry->cylinderindex] + cur_pt * magic + 0.5;
                                cur_pr[entry->cylinderindex] = INTERPOLATED_PRESSURE(entry);
                        } else
                                INTERPOLATED_PRESSURE(entry) = cur_pr[entry->cylinderindex];
@@ -1079,8 +1219,13 @@ static struct plot_info *create_plot_info(struct dive *dive, int nr_samples, str
                while (ev && ev->time.seconds < sample->time.seconds) {
                        /* insert two fake plot info structures for the end of
                         * the old tank and the start of the new tank */
-                       entry->sec = ev->time.seconds;
-                       (entry+1)->sec = ev->time.seconds + 1;
+                       if (ev->time.seconds == sample->time.seconds - 1) {
+                               entry->sec = ev->time.seconds - 1;
+                               (entry+1)->sec = ev->time.seconds;
+                       } else {
+                               entry->sec = ev->time.seconds;
+                               (entry+1)->sec = ev->time.seconds + 1;
+                       }
                        /* we need a fake depth - let's interpolate */
                        if (i) {
                                entry->depth = sample->depth.mm -
@@ -1156,7 +1301,7 @@ static struct plot_info *create_plot_info(struct dive *dive, int nr_samples, str
                }
                /* finally, do the discrete integration to get the SAC rate equivalent */
                current->pressure_time += (entry->sec - (entry-1)->sec) *
-                                               (1 + entry->depth / 10000.0);
+                       (1 + (entry->depth + (entry-1)->depth) / 20000.0);
                missing_pr |= !SENSOR_PRESSURE(entry);
        }
 
@@ -1233,7 +1378,7 @@ void plot(struct graphics_context *gc, cairo_rectangle_int_t *drawing_area, stru
        pi = create_plot_info(dive, nr, sample);
 
        cairo_translate(gc->cr, drawing_area->x, drawing_area->y);
-       cairo_set_line_width(gc->cr, 2);
+       cairo_set_line_width(gc->cr, 1);
        cairo_set_line_cap(gc->cr, CAIRO_LINE_CAP_ROUND);
        cairo_set_line_join(gc->cr, CAIRO_LINE_JOIN_ROUND);
 
@@ -1250,13 +1395,13 @@ void plot(struct graphics_context *gc, cairo_rectangle_int_t *drawing_area, stru
        /* Temperature profile */
        plot_temperature_profile(gc, pi);
 
-       /* Cylinder pressure plot */
-       plot_cylinder_pressure(gc, pi);
-
        /* Depth profile */
        plot_depth_profile(gc, pi);
        plot_events(gc, pi, dive);
 
+       /* Cylinder pressure plot */
+       plot_cylinder_pressure(gc, pi, dive);
+
        /* Text on top of all graphs.. */
        plot_temperature_text(gc, pi);
        plot_depth_text(gc, pi);
@@ -1266,7 +1411,8 @@ void plot(struct graphics_context *gc, cairo_rectangle_int_t *drawing_area, stru
        gc->leftx = 0; gc->rightx = 1.0;
        gc->topy = 0; gc->bottomy = 1.0;
 
-       set_source_rgb(gc, 1, 1, 1);
+       set_source_rgb(gc, BOUNDING_BOX);
+       cairo_set_line_width(gc->cr, 1);
        move_to(gc, 0, 0);
        line_to(gc, 0, 1);
        line_to(gc, 1, 1);