Merge branch 'sacplot' of git://git.hohndel.org/subsurface

* 'sacplot' of git://git.hohndel.org/subsurface:
  Make pressure plot shading by sac rate consistent
  Improve tank pressure sac coloring
  Be more consistent in our handling of rgb value tables
  Remove redundant linear sample tank pressure data

2 files changed, 100 insertions, 46 deletions

diff --git a/dive.c b/dive.c
index cd797d276..31be3291d 100644
--- a/dive.c
+++ b/dive.c
@@ -236,7 +236,7 @@ static int same_rounded_pressure(pressure_t a, pressure_t b)
 
 struct dive *fixup_dive(struct dive *dive)
 {
-	int i;
+	int i,j;
 	double depthtime = 0;
 	int lasttime = 0;
 	int lastindex = -1;
@@ -244,6 +244,7 @@ struct dive *fixup_dive(struct dive *dive)
 	int maxdepth = 0, mintemp = 0;
 	int lastdepth = 0;
 	int lasttemp = 0, lastpressure = 0;
+	int pressure_delta[MAX_CYLINDERS] = {INT_MAX, };
 
 	for (i = 0; i < dive->samples; i++) {
 		struct sample *sample = dive->sample + i;
@@ -253,10 +254,25 @@ struct dive *fixup_dive(struct dive *dive)
 		int pressure = sample->cylinderpressure.mbar;
 		int index = sample->cylinderindex;
 
-		/* Remove duplicate redundant pressure information */
-		if (pressure == lastpressure && index == lastindex)
-			sample->cylinderpressure.mbar = 0;
-
+		if (index == lastindex) {
+			/* Remove duplicate redundant pressure information */
+			if (pressure == lastpressure)
+				sample->cylinderpressure.mbar = 0;
+			/* check for simply linear data in the samples
+			   +INT_MAX means uninitialized, -INT_MAX means not linear */
+			if (pressure_delta[index] != -INT_MAX && lastpressure) {
+				if (pressure_delta[index] == INT_MAX) {
+					pressure_delta[index] = abs(pressure - lastpressure);
+				} else {
+					int cur_delta = abs(pressure - lastpressure);
+					if (cur_delta && abs(cur_delta - pressure_delta[index]) > 150) {
+						/* ok the samples aren't just a linearisation
+						 * between start and end */
+						pressure_delta[index] = -INT_MAX;
+					}
+				}
+			}
+		}
 		lastindex = index;
 		lastpressure = pressure;
 
@@ -290,6 +306,33 @@ struct dive *fixup_dive(struct dive *dive)
 		lastdepth = depth;
 		lasttime = time;
 	}
+	/* if all the samples for a cylinder have pressure data that
+	 * is basically equidistant throw out the sample cylinder pressure
+	 * information but make sure we still have a valid start and end
+	 * pressure
+	 * this happens when DivingLog decides to linearalize the
+	 * pressure between beginning and end and for strange reasons
+	 * decides to put that in the sample data as if it came from
+	 * the dive computer; we don't want that (we'll visualize with
+	 * constant SAC rate instead)
+	 * WARNING WARNING - I have only seen this in single tank dives
+	 * --- maybe I should try to create a multi tank dive and see what
+	 * --- divinglog does there - but the code right now is only tested
+	 * --- for the single tank case */
+	for (j = 0; j < MAX_CYLINDERS; j++) {
+		if (abs(pressure_delta[j]) != INT_MAX) {
+			cylinder_t *cyl = dive->cylinder + j;
+			for (i = 0; i < dive->samples; i++)
+				if (dive->sample[i].cylinderindex == j)
+					dive->sample[i].cylinderpressure.mbar = 0;
+			if (! cyl->start.mbar)
+				cyl->start.mbar = cyl->sample_start.mbar;
+			if (! cyl->end.mbar)
+				cyl->end.mbar = cyl->sample_end.mbar;
+			cyl->sample_start.mbar = 0;
+			cyl->sample_end.mbar = 0;
+		}
+	}
 	if (end < 0)
 		return dive;
 
diff --git a/profile.c b/profile.c
index 1b1546c0f..9fab8b2e8 100644
--- a/profile.c
+++ b/profile.c
@@ -48,7 +48,7 @@ struct plot_info {
 
 /* convert velocity to colors */
 typedef struct { double r, g, b; } rgb_t;
-static const rgb_t rgb[] = {
+static const rgb_t velocity_color[] = {
 	[STABLE]   = {0.0, 0.4, 0.0},
 	[SLOW]     = {0.4, 0.8, 0.0},
 	[MODERATE] = {0.8, 0.8, 0.0},
@@ -89,6 +89,11 @@ static void set_source_rgba(struct graphics_context *gc, double r, double g, dou
 	cairo_set_source_rgba(gc->cr, r, g, b, a);
 }
 
+static void set_source_rgb_struct(struct graphics_context *gc, const rgb_t *rgb)
+{
+	set_source_rgba(gc, rgb->r, rgb->g, rgb->b, 1);
+}
+
 void set_source_rgb(struct graphics_context *gc, double r, double g, double b)
 {
 	set_source_rgba(gc, r, g, b, 1);
@@ -476,9 +481,8 @@ 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_struct(gc, &velocity_color[entry->velocity]);
 		move_to(gc, entry[-1].sec, entry[-1].depth);
 		line_to(gc, sec, depth);
 		cairo_stroke(cr);
@@ -595,29 +599,35 @@ static int get_cylinder_pressure_range(struct graphics_context *gc, struct plot_
 	return pi->maxpressure != 0;
 }
 
+#define SAC_COLORS 9
+static const rgb_t sac_color[SAC_COLORS] = {
+	{ 0.0, 0.4, 0.2},
+	{ 0.2, 0.6, 0.2},
+	{ 0.4, 0.8, 0.2},
+	{ 0.6, 0.8, 0.2},
+	{ 0.8, 0.8, 0.2},
+	{ 0.8, 0.6, 0.2},
+	{ 0.8, 0.4, 0.2},
+	{ 0.9, 0.3, 0.2},
+	{ 1.0, 0.2, 0.2},
+};
+
 /* set the color for the pressure plot according to temporary sac rate
- * as compared to avg_sac */
+ * 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 delta = sac - avg_sac;
-	if (delta < -6000)
-		set_source_rgb(gc, 0.0, 0.4, 0.2);
-	else if (delta < -4000)
-		set_source_rgb(gc, 0.2, 0.6, 0.2);
-	else if (delta < -2000)
-		set_source_rgb(gc, 0.4, 0.8, 0.2);
-	else if (delta < 0)
-		set_source_rgb(gc, 0.6, 0.8, 0.2);
-	else if (delta < 2000)
-		set_source_rgb(gc, 0.8, 0.8, 0.2);
-	else if (delta < 4000)
-		set_source_rgb(gc, 0.8, 0.6, 0.2);
-	else if (delta < 6000)
-		set_source_rgb(gc, 0.8, 0.4, 0.2);
-	else if (delta < 8000)
-		set_source_rgb(gc, 0.9, 0.3, 0.2);
-	else
-		set_source_rgb(gc, 1.0, 0.2, 0.2);
+	int sac_index = 0;
+	int delta = sac - avg_sac + 7000;
+
+	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_struct(gc, &sac_color[sac_index]);
 }
 
 /* calculate the current SAC in ml/min and convert to int */
@@ -660,19 +670,19 @@ static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info
 			last = i;
 			last_entry = entry;
 			if (first_plot) {
-				/* don't start with a sac of 0 */
-				int fe = i + 1;
-				struct plot_data *future_entry = pi->entry + fe;
-				while (fe < pi->nr && future_entry->sec - entry->sec < SAC_WINDOW) {
-					fe++;
-					future_entry = pi->entry + fe;
-				}
-				sac = GET_LOCAL_SAC(entry, future_entry, dive);
+				/* don't start with a sac of 0, so just calculate the first one */
+				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;
 			}
-		} else if (entry->sec - last_entry->sec >= SAC_WINDOW) {
-			sac = GET_LOCAL_SAC(last_entry, entry, dive);
-			last++;
-			last_entry = pi->entry + last;
 		}
 		set_sac_color(gc, sac, dive->sac);
 		if (lift_pen) {
@@ -988,10 +998,11 @@ static void fill_missing_tank_pressures(struct dive *dive, struct plot_info *pi,
 					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] = INTERPOLATED_PRESSURE(entry);
@@ -1207,7 +1218,7 @@ 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);
 	}
 
@@ -1301,13 +1312,13 @@ 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, dive);
-
 	/* 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);