X-Git-Url: https://git.cworth.org/git?p=acre;a=blobdiff_plain;f=acre.c;h=e3604dcff6a8de23ed264edc96bbeeaf374ee0fa;hp=92ee39beea6aa92e8e623d3c7ab0d9c36e4db63c;hb=803fba5eca929a4e0cb541223182eae86a96f9bb;hpb=c04dc4e942a60d51a540c32e5b0e574be609e49a

diff --git a/acre.c b/acre.c
index 92ee39b..e3604dc 100644
--- a/acre.c
+++ b/acre.c
@@ -26,6 +26,7 @@
 
 #include <string.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <math.h>
 
 #include <lcms.h>
@@ -48,10 +49,17 @@ struct _acre_data {
 
 typedef struct _acre_axis {
     char *label;
+
+    /* Range of data */
     double data_min;
     double data_max;
+
+    /* Range of data to be viewed. */
     double view_min;
     double view_max;
+
+    /* Has the view range been set? */
+    bool view_range_set;
 } acre_axis_t;
 
 typedef struct _acre_color {
@@ -84,6 +92,16 @@ struct _acre {
     PangoRectangle chart;
 };
 
+static void
+_find_x_range_given_y_range (acre_t *acre,
+			     double *x_min, double *x_max,
+			     double y_min, double y_max);
+
+static void
+_find_y_range_given_x_range (acre_t *acre,
+			     double *y_min, double *y_max,
+			     double x_min, double x_max);
+
 /* Create a new, empty plot. */
 acre_t *
 acre_create (void)
@@ -99,12 +117,14 @@ acre_create (void)
     acre->x_axis.data_max = 0.0;
     acre->x_axis.view_min = 0.0;
     acre->x_axis.view_max = 0.0;
+    acre->x_axis.view_range_set = false;
 
     acre->y_axis.label = NULL;
     acre->y_axis.data_min = 0.0;
     acre->y_axis.data_max = 0.0;
     acre->y_axis.view_min = 0.0;
     acre->y_axis.view_max = 0.0;
+    acre->y_axis.view_range_set = false;
 
     acre->data = NULL;
     acre->data_size = 0;
@@ -170,6 +190,110 @@ acre_set_y_axis_label (acre_t *acre, const char *label)
     acre->y_axis.label = strdup (label);
 }
 
+void
+acre_get_x_axis_data_range (acre_t *acre, double *x_min, double *x_max)
+{
+    if (x_min)
+	*x_min = acre->x_axis.data_min;
+
+    if (x_max)
+	*x_max = acre->x_axis.data_max;
+}
+
+void
+acre_get_x_axis_range (acre_t *acre, double *x_min, double *x_max)
+{
+    /* If an X range has been set, return that. */
+    if (acre->x_axis.view_range_set) {
+	if (x_min)
+	    *x_min = acre->x_axis.view_min;
+
+	if (x_max)
+	    *x_max = acre->x_axis.view_max;
+
+	return;
+    }
+
+    /* Otherwise, if a Y range has been set, use that to compute X. */
+    if (acre->y_axis.view_range_set) {
+	_find_x_range_given_y_range (acre, x_min, x_max,
+				     acre->y_axis.view_min,
+				     acre->y_axis.view_max);
+
+	return;
+    }
+
+    /* Neither view range set. Return full, data-based X range. */
+    acre_get_x_axis_data_range (acre, x_min, x_max);
+}
+
+void
+acre_set_x_axis_range (acre_t *acre, double x_min, double x_max)
+{
+    acre->x_axis.view_min = x_min;
+    acre->x_axis.view_max = x_max;
+
+    acre->x_axis.view_range_set = true;
+}
+
+void
+acre_set_x_axis_range_auto (acre_t *acre)
+{
+    acre->x_axis.view_range_set = false;
+}
+
+void
+acre_get_y_axis_data_range (acre_t *acre, double *y_min, double *y_max)
+{
+    if (y_min)
+	*y_min = acre->y_axis.data_min;
+
+    if (y_max)
+	*y_max = acre->y_axis.data_max;
+}
+
+void
+acre_get_y_axis_range (acre_t *acre, double *y_min, double *y_max)
+{
+    /* If a Y range has been set, return that. */
+    if (acre->y_axis.view_range_set) {
+	if (y_min)
+	    *y_min = acre->y_axis.view_min;
+
+	if (y_max)
+	    *y_max = acre->y_axis.view_max;
+
+	return;
+    }
+
+    /* Otherwise, if an X range has been set, use that to compute Y. */
+    if (acre->x_axis.view_range_set) {
+	_find_y_range_given_x_range (acre, y_min, y_max,
+				     acre->x_axis.view_min,
+				     acre->x_axis.view_max);
+
+	return;
+    }
+
+    /* Neither view range set. Return full data-based Y range. */
+    acre_get_y_axis_data_range (acre, y_min, y_max);
+}
+
+void
+acre_set_y_axis_range (acre_t *acre, double y_min, double y_max)
+{
+    acre->y_axis.view_min = y_min;
+    acre->y_axis.view_max = y_max;
+
+    acre->y_axis.view_range_set = true;
+}
+
+void
+acre_set_y_axis_range_auto (acre_t *acre)
+{
+    acre->y_axis.view_range_set = false;
+}
+
 /* Add a dataset to the plot. The plot assumes ownership of the
  * dataset so it is not necessary to call acre_data_destroy on it. */
 void
@@ -467,18 +591,113 @@ _set_transform_to_data_space (acre_t *acre)
     cairo_translate (cr, -acre->x_axis.view_min, -acre->y_axis.view_min);
 }
 
+static void
+_find_x_range_given_y_range (acre_t *acre,
+			     double *x_min, double *x_max,
+			     double y_min, double y_max)
+{
+    acre_data_t *data;
+    unsigned d, i;
+    bool first;
+
+    first = true;
+
+    for (d = 0; d < acre->num_data; d++) {
+	data = acre->data[d];
+	for (i = 0; i < data->num_points; i++) {
+	    if (data->points[i].y >= y_min &&
+		data->points[i].y <= y_max)
+	    {
+		if (first) {
+		    *x_min = data->points[i].x;
+		    *x_max = data->points[i].x;
+		    first = false;
+		} else {
+		    if (data->points[i].x < *x_min)
+			*x_min = data->points[i].x;
+		    if (data->points[i].x > *x_max)
+			*x_max = data->points[i].x;
+		}
+	    }
+	}
+    }
+
+    /* If nothing is visible, punt to full X data range. */
+    if (first) {
+	*x_min = acre->x_axis.data_min;
+	*x_max = acre->x_axis.data_max;
+    }
+}
+
+static void
+_find_y_range_given_x_range (acre_t *acre,
+			     double *y_min, double *y_max,
+			     double x_min, double x_max)
+{
+    acre_data_t *data;
+    unsigned d, i;
+    bool first;
+
+    first = true;
+
+    for (d = 0; d < acre->num_data; d++) {
+	data = acre->data[d];
+	for (i = 0; i < data->num_points; i++) {
+	    if (data->points[i].x >= x_min &&
+		data->points[i].x <= x_max)
+	    {
+		if (first) {
+		    *y_min = data->points[i].y;
+		    *y_max = data->points[i].y;
+		    first = false;
+		} else {
+		    if (data->points[i].y < *y_min)
+			*y_min = data->points[i].y;
+		    if (data->points[i].y > *y_max)
+			*y_max = data->points[i].y;
+		}
+	    }
+	}
+    }
+
+    /* If nothing is visible, punt to full Y data range. */
+    if (first) {
+	*y_min = acre->y_axis.data_min;
+	*y_max = acre->y_axis.data_max;
+    }
+}
+
 static void
 _compute_axis_ranges (acre_t *acre)
 {
     double x_adjust, y_adjust;
     cairo_t *cr = acre->cr;
 
-    /* First, simply set view ranges to data ranges. */
-    acre->x_axis.view_min = acre->x_axis.data_min;
-    acre->x_axis.view_max = acre->x_axis.data_max;
+    /* If neither view range is set, set both to data ranges. */
+    if (! acre->x_axis.view_range_set && ! acre->y_axis.view_range_set)
+    {
+	acre->x_axis.view_min = acre->x_axis.data_min;
+	acre->x_axis.view_max = acre->x_axis.data_max;
 
-    acre->y_axis.view_min = acre->y_axis.data_min;
-    acre->y_axis.view_max = acre->y_axis.data_max;
+	acre->y_axis.view_min = acre->y_axis.data_min;
+	acre->y_axis.view_max = acre->y_axis.data_max;
+    } else {
+	/* Otherwise, auto-fit unset range based on data. */
+	if (acre->x_axis.view_range_set && ! acre->y_axis.view_range_set) {
+	    _find_y_range_given_x_range (acre,
+					 &acre->y_axis.view_min,
+					 &acre->y_axis.view_max,
+					 acre->x_axis.view_min,
+					 acre->x_axis.view_max);
+	}
+	else if (acre->y_axis.view_range_set && ! acre->x_axis.view_range_set) {
+	    _find_x_range_given_y_range (acre,
+					 &acre->x_axis.view_min,
+					 &acre->x_axis.view_max,
+					 acre->y_axis.view_min,
+					 acre->y_axis.view_max);
+	}
+    }
 
     /* Next, we want to ensure that the data never collides with the
      * ticks. So we expand each axis on its minimum side as needed. */
@@ -629,6 +848,7 @@ _draw_data (acre_t *acre)
     cairo_t *cr = acre->cr;
     unsigned int d, i;
     acre_data_t *data;
+    bool pen_up;
 
     cairo_save (cr);
 
@@ -643,11 +863,29 @@ _draw_data (acre_t *acre)
 			      acre->colors[color].green,
 			      acre->colors[color].blue);
 	data = acre->data[d];
+
+	pen_up = true;
 	cairo_new_path (cr);
+
 	for (i = 0; i < data->num_points; i++) {
-	    cairo_line_to (cr,
-			   data->points[i].x,
-			   data->points[i].y);
+	    if (data->points[i].x >= acre->x_axis.view_min &&
+		data->points[i].x <= acre->x_axis.view_max &&
+		data->points[i].y >= acre->y_axis.view_min &&
+		data->points[i].y <= acre->y_axis.view_max)
+	    {
+		if (pen_up)
+		    cairo_move_to (cr,
+				   data->points[i].x,
+				   data->points[i].y);
+		else
+		    cairo_line_to (cr,
+				   data->points[i].x,
+				   data->points[i].y);
+
+		pen_up = false;
+	    } else {
+		pen_up = true;
+	    }
 	}
 	cairo_save (cr);
 	{