From 803fba5eca929a4e0cb541223182eae86a96f9bb Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Wed, 6 Nov 2013 15:33:54 -0800 Subject: [PATCH] Allow zooming in or out by setting ranges of data to be shown on either axis. The second axis can also be explicitly set to a desired range, or it can be allowed to be automatically set to fit the data. --- acre-test.c | 53 +++++++++-- acre.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++-- acre.h | 46 ++++++++++ 3 files changed, 340 insertions(+), 13 deletions(-) diff --git a/acre-test.c b/acre-test.c index 472ea98..c0cc883 100644 --- a/acre-test.c +++ b/acre-test.c @@ -1,4 +1,5 @@ #include "acre.h" +#include int main (void) @@ -11,11 +12,10 @@ main (void) acre_t *acre; acre_data_t *data0, *data1, *data2; - surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 800, 600); + surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 1600, 1200); cr = cairo_create (surface); acre = acre_create (); - acre_set_title (acre, "Acre Test Plot"); acre_set_x_axis_label (acre, "X axis"); acre_set_y_axis_label (acre, "Y axis"); @@ -28,15 +28,58 @@ main (void) acre_data_set_name (data2, "Data 2"); for (i = 0; i <= 100; i++) { - acre_data_add_point_2d (data0, i, 100 - (i/4.0)*(i/4.0)); - acre_data_add_point_2d (data1, i, 50 - (i/3.5)*(i/3.5)); - acre_data_add_point_2d (data2, i, 0 - (i/3.0)*(i/3.0)); + acre_data_add_point_2d (data0, i, 0 - (i/3.0)*(i/3.0)); + } + + for (i = 0; i < 100; i++) { + double t = 1.0 - (i / 100.0); + acre_data_add_point_2d (data1, i, -1000 * (1.0 - t*t*t)); + } + + for (i = 0; i <= 1000; i++) { + double t, x, y; + t = i/10.0 - 50; + x = t + 50; + if (t == 0.0) + y = -200; + else + y = -1200 + 1000 * sin(t) / t; + acre_data_add_point_2d (data2, x, y); } acre_add_data (acre, data0); acre_add_data (acre, data1); acre_add_data (acre, data2); + /* Draw a full-data-range graph in upper-left. */ + acre_set_title (acre, "All the data"); + + acre_draw (acre, cr, 800, 600); + + /* Zoom in on X and draw at lower-left. */ + cairo_translate (cr, 0, 600); + + acre_set_title (acre, "Zoom X, auto-size Y"); + acre_set_x_axis_range (acre, 40, 60); + + acre_draw (acre, cr, 800, 600); + + /* Zoom in on Y and draw at upper-right. */ + cairo_translate (cr, 800, -600); + + acre_set_title (acre, "Zoom Y, auto-size X"); + acre_set_x_axis_range_auto (acre); + acre_set_y_axis_range (acre, -250, 0); + + acre_draw (acre, cr, 800, 600); + + /* Zoom out on X and Y lower-right. */ + cairo_translate (cr, 0, 600); + + acre_set_title (acre, "Zoom out X and Y"); + acre_set_x_axis_range (acre, -50, 150); + acre_set_y_axis_range (acre, -1500, 500); + acre_draw (acre, cr, 800, 600); acre_destroy (acre); diff --git a/acre.c b/acre.c index 92ee39b..e3604dc 100644 --- a/acre.c +++ b/acre.c @@ -26,6 +26,7 @@ #include #include +#include #include #include @@ -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); { diff --git a/acre.h b/acre.h index 0c602c1..df23199 100644 --- a/acre.h +++ b/acre.h @@ -42,6 +42,52 @@ acre_set_x_axis_label (acre_t *acre, const char *label); void acre_set_y_axis_label (acre_t *acre, const char *label); +/* Get the range of data values in the X dimension. */ +void +acre_get_x_axis_data_range (acre_t *acre, double *x_min, double *x_max); + +/* Get the range of the currently viewable X axis. */ +void +acre_get_x_axis_range (acre_t *acre, double *x_min, double *x_max); + +/* Set the range of the currently viewable X axis. */ +void +acre_set_x_axis_range (acre_t *acre, double x_min, double x_max); + +/* Set the X axis viewable range to be sized automatically. + * + * If both X and Y axes are sized automatically, then the X range will + * be set to the full range of data in the X dimension. + * + * But if the Y axis has been set to a limited viewable range, (with + * acre_set_y_axis_range), then the X axis will be set to the + * corresponding X range of data that lies within that set Y range. */ +void +acre_set_x_axis_range_auto (acre_t *acre); + +/* Get the range of data values in the Y dimnension. */ +void +acre_get_y_axis_data_range (acre_t *acre, double *y_min, double *y_max); + +/* Get the range of the currently viewable Y axis. */ +void +acre_get_y_axis_range (acre_t *acre, double *y_min, double *y_max); + +/* Set the range of the currently viewable Y axis. */ +void +acre_set_y_axis_range (acre_t *acre, double y_min, double y_max); + +/* Set the Y axis viewable range to be sized automatically. + * + * If both X and Y axes are sized automatically, then the Y range will + * be set to the full range of data in the Y dimension. + * + * But if the X axis has been set to a limited viewable range, (with + * acre_set_x_axis_range), then the Y axis will be set to the + * corresponding Y range of data that lies within that set X range. */ +void +acre_set_y_axis_range_auto (acre_t *acre); + /* 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 -- 2.43.0