#define _ISOC99_SOURCE /* for round() */
#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE /* for asprintf() */
#include "acre.h"
#include "xmalloc.h"
/* Data for drawing. */
cairo_t *cr;
+ PangoFontDescription *font;
/* Total size including labels. */
int width;
#define ACRE_PAD (ACRE_FONT_SIZE)
#define ACRE_TICK_SIZE 6
+static PangoLayout *
+_create_layout (acre_t *acre, const char *text)
+{
+ PangoLayout *layout;
+
+ layout = pango_cairo_create_layout (acre->cr);
+ pango_layout_set_font_description (layout, acre->font);
+ pango_layout_set_text (layout, text, -1);
+ pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);
+
+ return layout;
+}
+
+static void
+_destroy_layout (PangoLayout *layout)
+{
+ g_object_unref (layout);
+}
+
+static void
+_show_layout (cairo_t *cr, PangoLayout *layout)
+{
+ pango_cairo_show_layout (cr, layout);
+
+ _destroy_layout (layout);
+}
+
static void
_draw_title_and_labels (acre_t *acre)
{
cairo_t *cr = acre->cr;
- PangoFontDescription *acre_font, *title_font;
+ PangoFontDescription *title_font;
PangoLayout *title_layout, *x_axis_layout, *y_axis_layout;
int title_width, title_height;
int x_axis_width, x_axis_height;
cairo_save (cr);
- acre_font = pango_font_description_new ();
- pango_font_description_set_family (acre_font, ACRE_FONT_FAMILY);
- pango_font_description_set_absolute_size (acre_font,
+ acre->font = pango_font_description_new ();
+ pango_font_description_set_family (acre->font, ACRE_FONT_FAMILY);
+ pango_font_description_set_absolute_size (acre->font,
ACRE_FONT_SIZE * PANGO_SCALE);
title_font = pango_font_description_new ();
pango_font_description_set_absolute_size (title_font,
ACRE_TITLE_FONT_SIZE * PANGO_SCALE);
- title_layout = pango_cairo_create_layout (cr);
+ title_layout = _create_layout (acre, acre->title);
pango_layout_set_font_description (title_layout, title_font);
- pango_layout_set_text (title_layout, acre->title, -1);
- pango_layout_set_alignment (title_layout, PANGO_ALIGN_CENTER);
-
- x_axis_layout = pango_cairo_create_layout (cr);
- pango_layout_set_font_description (x_axis_layout, acre_font);
- pango_layout_set_text (x_axis_layout, acre->x_axis.label, -1);
- pango_layout_set_alignment (x_axis_layout, PANGO_ALIGN_CENTER);
- y_axis_layout = pango_cairo_create_layout (cr);
- pango_layout_set_font_description (y_axis_layout, acre_font);
- pango_layout_set_text (y_axis_layout, acre->y_axis.label, -1);
- pango_layout_set_alignment (y_axis_layout, PANGO_ALIGN_CENTER);
+ x_axis_layout = _create_layout (acre, acre->x_axis.label);
+ y_axis_layout = _create_layout (acre, acre->y_axis.label);
/* Iterate with the layout of the title and axis labels until they
* are stable, (this requires iteration since we don't know what
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_move_to (cr, acre->chart.x, ACRE_PAD);
- pango_cairo_show_layout (cr, title_layout);
+ _show_layout (cr, title_layout);
cairo_save (cr);
{
cairo_translate (cr, ACRE_PAD, acre->chart.y + acre->chart.height);
cairo_rotate (cr, - M_PI / 2.0);
cairo_move_to (cr, 0, 0);
- pango_cairo_show_layout (cr, y_axis_layout);
+ _show_layout (cr, y_axis_layout);
}
cairo_restore (cr);
cairo_move_to (cr, acre->chart.x,
acre->chart.y + acre->chart.height +
ACRE_FONT_SIZE + ACRE_PAD);
- pango_cairo_show_layout (cr, x_axis_layout);
+ _show_layout (cr, x_axis_layout);
cairo_restore (cr);
}
* amount for the major ticks (see _step_for_range). To get
* nice-looking pixel-snapped ticks we want to expand the range
* slightly. */
-static double
-_expand_range (double data_range, int pixel_size)
+static void
+_expand_range_for_width (double *axis_min, double *axis_max, int pixel_size)
{
- double step, pixel_step;
+ double range, new_range, step, pixel_step;
+
+ range = *axis_max - *axis_min;
- step = _step_for_range (data_range);
- pixel_step = step * pixel_size / data_range;
+ step = _step_for_range (range);
+ pixel_step = step * pixel_size / range;
/* We expand the range by the ratio of the pixel step to the floor
* of the pixel_step.
*/
- return data_range * pixel_step / floor (pixel_step);
+ new_range = range * pixel_step / floor (pixel_step);
+
+ /* And spread the increase out on either side of the range. */
+ *axis_min -= (new_range - range) / 2.0;
+ *axis_max += (new_range - range) / 2.0;
}
/* Setup a transformation in acre->cr such that data values plotted
{
unsigned int d, i;
acre_data_t *data;
- double x_range, new_x_range, x_adjust;
- double y_range, new_y_range, y_adjust;
+ double x_adjust, y_adjust;
cairo_t *cr = acre->cr;
/* First, simply find the extrema of the data. */
/* Next, increase the axis ranges just enough so that the step
* sizes for the ticks will be integers.
*/
- x_range = acre->x_axis.max - acre->x_axis.min;
- new_x_range = _expand_range (x_range, acre->chart.width);
-
- y_range = acre->y_axis.max - acre->y_axis.min;
- new_y_range = _expand_range (y_range, acre->chart.height);
-
- /* And spread the increase out on either side of the range. */
- acre->x_axis.min -= (new_x_range - x_range) / 2.0;
- acre->x_axis.max += (new_x_range - x_range) / 2.0;
+ _expand_range_for_width (&acre->x_axis.min,
+ &acre->x_axis.max,
+ acre->chart.width);
- acre->y_axis.min -= (new_y_range - y_range) / 2.0;
- acre->y_axis.max += (new_y_range - y_range) / 2.0;
+ _expand_range_for_width (&acre->y_axis.min,
+ &acre->y_axis.max,
+ acre->chart.height);
/* Finally, we also translate the axis ranges slightly so that the
* ticks land on half-integer device-pixel positions.
cairo_move_to (cr, x, acre->y_axis.min);
cairo_save (cr);
{
- cairo_identity_matrix (cr);
- cairo_rel_line_to (cr, 0, 0.5);
- cairo_rel_line_to (cr, 0, -ACRE_TICK_SIZE-0.5);
- cairo_set_line_width (cr, 1.0);
- cairo_stroke (cr);
+ /* tick */
+ cairo_save (cr);
+ {
+ cairo_identity_matrix (cr);
+ cairo_rel_line_to (cr, 0, 0.5);
+ cairo_rel_line_to (cr, 0, -ACRE_TICK_SIZE-0.5);
+ cairo_set_line_width (cr, 1.0);
+ cairo_stroke (cr);
+ }
+ cairo_restore (cr);
+
+ /* label */
+ cairo_save (cr);
+ {
+ PangoLayout *layout;
+ char *label;
+ int width, height;
+ asprintf (&label, "%g", x);
+ layout = _create_layout (acre, label);
+ free (label);
+ cairo_move_to (cr, x, acre->y_axis.min);
+ cairo_identity_matrix (cr);
+ pango_layout_get_pixel_size (layout, &width, &height);
+ cairo_rel_move_to (cr, -width / 2, 2);
+ _show_layout (cr, layout);
+ }
+ cairo_restore (cr);
}
cairo_restore (cr);
x += step;
cairo_move_to (cr, acre->x_axis.min, y);
cairo_save (cr);
{
- cairo_identity_matrix (cr);
- cairo_rel_line_to (cr, -0.5, 0);
- cairo_rel_line_to (cr, ACRE_TICK_SIZE+0.5, 0);
- cairo_set_line_width (cr, 1.0);
- cairo_stroke (cr);
+ /* tick */
+ cairo_save (cr);
+ {
+ cairo_identity_matrix (cr);
+ cairo_rel_line_to (cr, -0.5, 0);
+ cairo_rel_line_to (cr, ACRE_TICK_SIZE+0.5, 0);
+ cairo_set_line_width (cr, 1.0);
+ cairo_stroke (cr);
+ }
+ cairo_restore (cr);
+
+ /* label */
+ cairo_save (cr);
+ {
+ PangoLayout *layout;
+ char *label;
+ int width, height;
+ asprintf (&label, "%g", y);
+ layout = _create_layout (acre, label);
+ free (label);
+ cairo_move_to (cr, acre->x_axis.min, y);
+ cairo_identity_matrix (cr);
+ pango_layout_get_pixel_size (layout, &width, &height);
+ cairo_rel_move_to (cr, -width-2, -height/2);
+ _show_layout (cr, layout);
+ }
+ cairo_restore (cr);
}
cairo_restore (cr);
y += step;
projects / acre / blobdiff