X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=acre.c;h=290bb1274cbb08d08a4aef9780a3d2e67a8ecf93;hb=afcbeb2a796dca2bc889014dbb589b4f7bceb3ea;hp=b844d755153911710ebad19570b710a06d37a2db;hpb=473e49a97c96edf99c4adaca72b017b632eae7fb;p=acre

diff --git a/acre.c b/acre.c
index b844d75..290bb12 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>
@@ -38,6 +39,9 @@ typedef struct _acre_data_point_2d {
 struct _acre_data {
     char *name;
 
+    acre_data_point_2d_t min;
+    acre_data_point_2d_t max;
+
     acre_data_point_2d_t *points;
     unsigned int points_size;
     unsigned int num_points;
@@ -45,8 +49,17 @@ struct _acre_data {
 
 typedef struct _acre_axis {
     char *label;
-    double min;
-    double max;
+
+    /* 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 {
@@ -79,6 +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)
@@ -90,12 +113,18 @@ acre_create (void)
     acre->title = NULL;
 
     acre->x_axis.label = NULL;
-    acre->x_axis.min = 0.0;
-    acre->x_axis.max = 0.0;
+    acre->x_axis.data_min = 0.0;
+    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.min = 0.0;
-    acre->y_axis.max = 0.0;
+    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;
@@ -161,6 +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
@@ -176,6 +309,25 @@ acre_add_data (acre_t *acre, acre_data_t *data)
     }
 
     acre->data[acre->num_data] = data;
+
+    if (acre->num_data == 0) {
+	acre->x_axis.data_min = data->min.x;
+	acre->y_axis.data_min = data->min.y;
+
+	acre->x_axis.data_max = data->max.x;
+	acre->y_axis.data_max = data->max.y;
+    } else {
+	if (data->min.x < acre->x_axis.data_min)
+	    acre->x_axis.data_min = data->min.x;
+	if (data->min.y < acre->y_axis.data_min)
+	    acre->y_axis.data_min = data->min.y;
+
+	if (data->max.x > acre->x_axis.data_max)
+	    acre->x_axis.data_max = data->max.x;
+	if (data->max.y > acre->y_axis.data_max)
+	    acre->y_axis.data_max = data->max.y;
+    }
+
     acre->num_data++;
 }
 
@@ -285,9 +437,9 @@ _draw_title_and_labels (acre_t *acre)
     y_axis_layout = _create_layout (acre, acre->y_axis.label);
 
     min_y = _create_layout_printf (acre, "%g",
-				   round (acre->y_axis.min));
+				   round (acre->y_axis.view_min));
     max_y = _create_layout_printf (acre, "%g",
-				   round (acre->y_axis.max));
+				   round (acre->y_axis.view_max));
 
     pango_layout_get_pixel_size (min_y, &min_y_width, NULL);
     pango_layout_get_pixel_size (max_y, &max_y_width, NULL);
@@ -434,37 +586,116 @@ _set_transform_to_data_space (acre_t *acre)
 		     acre->chart.x,
 		     acre->chart.y + acre->chart.height);
     cairo_scale (cr,
-		 acre->chart.width / (acre->x_axis.max - acre->x_axis.min),
-		 - acre->chart.height /(acre->y_axis.max - acre->y_axis.min));
-    cairo_translate (cr, -acre->x_axis.min, -acre->y_axis.min);
+		 acre->chart.width / (acre->x_axis.view_max - acre->x_axis.view_min),
+		 - acre->chart.height /(acre->y_axis.view_max - acre->y_axis.view_min));
+    cairo_translate (cr, -acre->x_axis.view_min, -acre->y_axis.view_min);
 }
 
 static void
-_compute_axis_ranges (acre_t *acre)
+_find_x_range_given_y_range (acre_t *acre,
+			     double *x_min, double *x_max,
+			     double y_min, double y_max)
 {
-    unsigned int d, i;
     acre_data_t *data;
-    double x_adjust, y_adjust;
-    cairo_t *cr = acre->cr;
+    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;
 
-    acre->x_axis.min = acre->data[0]->points[0].x;
-    acre->x_axis.max = acre->data[0]->points[0].x;
-    acre->y_axis.min = acre->data[0]->points[0].y;
-    acre->y_axis.min = acre->data[0]->points[0].y;
+    first = true;
 
-    /* First, simply find the extrema of the data. */
     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 < acre->x_axis.min)
-		acre->x_axis.min = data->points[i].x;
-	    if (data->points[i].x > acre->x_axis.max)
-		acre->x_axis.max = data->points[i].x;
-
-	    if (data->points[i].y < acre->y_axis.min)
-		acre->y_axis.min = data->points[i].y;
-	    if (data->points[i].y > acre->y_axis.max)
-		acre->y_axis.max = data->points[i].y;
+	    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;
+
+    /* 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;
+    } 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);
 	}
     }
 
@@ -480,20 +711,20 @@ _compute_axis_ranges (acre_t *acre)
 	y = ACRE_TICK_MAJOR_SIZE + 2.0;
 	cairo_device_to_user_distance (cr, &x, &y);
 
-	acre->x_axis.min -= x;
-	acre->y_axis.min += y;
+	acre->x_axis.view_min -= x;
+	acre->y_axis.view_min += y;
     }
     cairo_restore (cr);
 
     /* Then, increase the axis ranges just enough so that the step
      * sizes for the ticks will be integers.
      */
-    _expand_range_for_width (&acre->x_axis.min,
-			     &acre->x_axis.max,
+    _expand_range_for_width (&acre->x_axis.view_min,
+			     &acre->x_axis.view_max,
 			     acre->chart.width);
 
-    _expand_range_for_width (&acre->y_axis.min,
-			     &acre->y_axis.max,
+    _expand_range_for_width (&acre->y_axis.view_min,
+			     &acre->y_axis.view_max,
 			     acre->chart.height);
 
     /* Finally, we also translate the axis ranges slightly so that the
@@ -510,11 +741,11 @@ _compute_axis_ranges (acre_t *acre)
 	y_adjust = (round (y_adjust + 0.5) - 0.5) - y_adjust;
 	cairo_device_to_user_distance (cr, &x_adjust, &y_adjust);
 
-	acre->x_axis.min -= x_adjust;
-	acre->x_axis.max -= x_adjust;
+	acre->x_axis.view_min -= x_adjust;
+	acre->x_axis.view_max -= x_adjust;
 
-	acre->y_axis.min -= y_adjust;
-	acre->y_axis.max -= y_adjust;
+	acre->y_axis.view_min -= y_adjust;
+	acre->y_axis.view_max -= y_adjust;
     }
     cairo_restore (cr);
 }
@@ -620,6 +851,11 @@ _draw_data (acre_t *acre)
 
     cairo_save (cr);
 
+    cairo_rectangle (cr,
+		     acre->chart.x, acre->chart.y,
+		     acre->chart.width, acre->chart.height);
+    cairo_clip (cr);
+
     cairo_set_source_rgb (cr, 0, 0, 0);
 
     _set_transform_to_data_space (acre);
@@ -631,7 +867,9 @@ _draw_data (acre_t *acre)
 			      acre->colors[color].green,
 			      acre->colors[color].blue);
 	data = acre->data[d];
+
 	cairo_new_path (cr);
+
 	for (i = 0; i < data->num_points; i++) {
 	    cairo_line_to (cr,
 			   data->points[i].x,
@@ -681,9 +919,9 @@ _draw_ticks (acre_t *acre,
 	cairo_save (cr);
 	{
 	    if (ticks == ACRE_TICKS_X)
-		cairo_move_to (cr, t, acre->y_axis.min);
+		cairo_move_to (cr, t, acre->y_axis.view_min);
 	    else
-		cairo_move_to (cr, acre->x_axis.min, t);
+		cairo_move_to (cr, acre->x_axis.view_min, t);
 
 	    cairo_identity_matrix (cr);
 
@@ -711,9 +949,9 @@ _draw_ticks (acre_t *acre,
 	    layout = _create_layout_printf (acre, "%g", t);
 
 	    if (ticks == ACRE_TICKS_X)
-		cairo_move_to (cr, t, acre->y_axis.min);
+		cairo_move_to (cr, t, acre->y_axis.view_min);
 	    else
-		cairo_move_to (cr, acre->x_axis.min, t);
+		cairo_move_to (cr, acre->x_axis.view_min, t);
 
 	    cairo_identity_matrix (cr);
 	    pango_layout_get_pixel_size (layout, &width, &height);
@@ -801,8 +1039,8 @@ _draw_frame_and_ticks (acre_t *acre)
     cairo_set_source_rgb (cr, 0, 0, 0); /* black */
 
     /* ticks */
-    _draw_ticks (acre, acre->x_axis.min, acre->x_axis.max, ACRE_TICKS_X);
-    _draw_ticks (acre, acre->y_axis.min, acre->y_axis.max, ACRE_TICKS_Y);
+    _draw_ticks (acre, acre->x_axis.view_min, acre->x_axis.view_max, ACRE_TICKS_X);
+    _draw_ticks (acre, acre->y_axis.view_min, acre->y_axis.view_max, ACRE_TICKS_Y);
 
     /* frame */
     cairo_rectangle (cr,
@@ -906,5 +1144,24 @@ acre_data_add_point_2d (acre_data_t *data, double x, double y)
 
     data->points[data->num_points].x = x;
     data->points[data->num_points].y = y;
+
+    if (data->num_points == 0) {
+	data->min.x = x;
+	data->min.y = y;
+
+	data->max.x = x;
+	data->max.y = y;
+    } else {
+	if (x < data->min.x)
+	    data->min.x = x;
+	if (y < data->min.y)
+	    data->min.y = y;
+
+	if (x > data->max.x)
+	    data->max.x = x;
+	if (y > data->max.y)
+	    data->max.y = y;
+    }
+
     data->num_points++;
 }