1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2004, 2009, 2010, 2011 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 #include "output/cairo-chart.h"
22 #include <cairo/cairo.h>
23 #include <pango/pango.h>
24 #include <pango/pangocairo.h>
33 #include "libpspp/assertion.h"
34 #include "math/chart-geometry.h"
35 #include "output/cairo.h"
36 #include "output/chart-item.h"
39 #include "gl/xalloc.h"
40 #include "gl/xvasprintf.h"
43 #define _(msgid) gettext (msgid)
46 xrchart_geometry_init (cairo_t *cr, struct xrchart_geometry *geom,
47 double width, double length)
49 /* Set default chartetry. */
50 geom->axis[SCALE_ORDINATE].data_max = 0.900 * length;
51 geom->axis[SCALE_ABSCISSA].data_max = 0.800 * width;
52 geom->axis[SCALE_ORDINATE].data_min = 0.120 * length;
53 geom->axis[SCALE_ABSCISSA].data_min = 0.150 * width;
54 geom->abscissa_top = 0.070 * length;
55 geom->ordinate_right = 0.120 * width;
56 geom->title_bottom = 0.920 * length;
57 geom->legend_left = 0.810 * width;
58 geom->legend_right = width;
59 geom->font_size = 15.0;
60 geom->in_path = false;
64 geom->fill_colour.red = 255;
65 geom->fill_colour.green = 0;
66 geom->fill_colour.blue = 0;
68 cairo_set_line_width (cr, 1.0);
70 cairo_rectangle (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min,
71 geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min,
72 geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min);
77 xrchart_geometry_free (cairo_t *cr UNUSED, struct xrchart_geometry *geom)
81 for (i = 0 ; i < geom->n_datasets; ++i)
82 free (geom->dataset[i]);
86 #if ! PANGO_VERSION_CHECK (1, 22, 0)
87 int pango_layout_get_baseline (PangoLayout *layout);
89 /* Shamelessly copied from the pango source */
91 pango_layout_get_baseline (PangoLayout *layout)
95 /* XXX this is so inefficient */
96 PangoLayoutIter *iter = pango_layout_get_iter (layout);
97 baseline = pango_layout_iter_get_baseline (iter);
98 pango_layout_iter_free (iter);
106 const struct xrchart_colour data_colour[XRCHART_N_COLOURS] =
108 { 165, 42, 42 }, /* brown */
109 { 255, 0, 0 }, /* red */
110 { 255, 165, 0 }, /* orange */
111 { 255, 255, 0 }, /* yellow */
112 { 0, 255, 0 }, /* green */
113 { 0, 0, 255 }, /* blue */
114 { 238, 130, 238 }, /* violet */
115 { 190, 190, 190 }, /* grey */
116 { 255, 192, 203 }, /* pink */
120 xrchart_draw_marker (cairo_t *cr, double x, double y,
121 enum xrmarker_type marker, double size)
124 cairo_translate (cr, x, y);
125 cairo_scale (cr, size / 2.0, size / 2.0);
126 cairo_set_line_width (cr, cairo_get_line_width (cr) / (size / 2.0));
129 case XRMARKER_CIRCLE:
130 cairo_arc (cr, 0, 0, 1.0, 0, 2 * M_PI);
134 case XRMARKER_ASTERISK:
135 cairo_move_to (cr, 0, -1.0); /* | */
136 cairo_line_to (cr, 0, 1.0);
137 cairo_move_to (cr, -M_SQRT1_2, -M_SQRT1_2); /* / */
138 cairo_line_to (cr, M_SQRT1_2, M_SQRT1_2);
139 cairo_move_to (cr, -M_SQRT1_2, M_SQRT1_2); /* \ */
140 cairo_line_to (cr, M_SQRT1_2, -M_SQRT1_2);
144 case XRMARKER_SQUARE:
145 cairo_rectangle (cr, -1.0, -1.0, 2.0, 2.0);
153 xrchart_label (cairo_t *cr, int horz_justify, int vert_justify,
154 double font_size, const char *string)
156 PangoFontDescription *desc;
160 desc = pango_font_description_from_string ("sans serif");
166 pango_font_description_set_absolute_size (desc, font_size * PANGO_SCALE);
169 cairo_get_current_point (cr, &x, &y);
170 cairo_translate (cr, x, y);
171 cairo_move_to (cr, 0, 0);
172 cairo_scale (cr, 1.0, -1.0);
174 layout = pango_cairo_create_layout (cr);
175 pango_layout_set_font_description (layout, desc);
176 pango_layout_set_text (layout, string, -1);
177 if (horz_justify != 'l')
182 pango_layout_get_size (layout, &width_pango, NULL);
183 width = (double) width_pango / PANGO_SCALE;
184 if (horz_justify == 'r')
185 cairo_rel_move_to (cr, -width, 0);
187 cairo_rel_move_to (cr, -width / 2.0, 0);
189 if (vert_justify == 'x')
191 int baseline_pango = pango_layout_get_baseline (layout);
192 double baseline = (double) baseline_pango / PANGO_SCALE;
193 cairo_rel_move_to (cr, 0, -baseline);
195 else if (vert_justify != 't')
200 pango_layout_get_size (layout, NULL, &height_pango);
201 height = (double) height_pango / PANGO_SCALE;
202 if (vert_justify == 'b')
203 cairo_rel_move_to (cr, 0, -height);
204 else if (vert_justify == 'c')
205 cairo_rel_move_to (cr, 0, -height / 2.0);
207 pango_cairo_show_layout (cr, layout);
208 g_object_unref (layout);
214 pango_font_description_free (desc);
217 /* Draw a tick mark at position
218 If label is non zero, then print it at the tick mark
221 draw_tick (cairo_t *cr, const struct xrchart_geometry *geom,
222 enum tick_orientation orientation,
224 const char *label, ...)
226 const int tickSize = 10;
229 cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min);
231 if (orientation == SCALE_ABSCISSA)
233 cairo_rel_move_to (cr, position, 0);
234 cairo_rel_line_to (cr, 0, -tickSize);
236 else if (orientation == SCALE_ORDINATE)
238 cairo_rel_move_to (cr, 0, position);
239 cairo_rel_line_to (cr, -tickSize, 0);
243 cairo_get_current_point (cr, &x, &y);
252 cairo_move_to (cr, x, y);
254 va_start (ap, label);
255 s = xvasprintf (label, ap);
256 if (orientation == SCALE_ABSCISSA)
257 xrchart_label (cr, 'c', 't', geom->font_size, s);
258 else if (orientation == SCALE_ORDINATE)
260 if (fabs (position) < DBL_EPSILON)
261 cairo_rel_move_to (cr, 0, 10);
262 xrchart_label (cr, 'r', 'c', geom->font_size, s);
270 /* Write the title on a chart*/
272 xrchart_write_title (cairo_t *cr, const struct xrchart_geometry *geom,
273 const char *title, ...)
279 cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->title_bottom);
282 s = xvasprintf (title, ap);
283 xrchart_label (cr, 'l', 'x', geom->font_size * 1.5, s);
291 /* Set the scale for the ordinate */
293 xrchart_write_scale (cairo_t *cr, struct xrchart_geometry *geom,
294 double smin, double smax, int ticks, enum tick_orientation orient)
298 const double tick_interval =
299 chart_rounded_tick ((smax - smin) / (double) ticks);
301 geom->axis[orient].max = ceil (smax / tick_interval) * tick_interval;
302 geom->axis[orient].min = floor (smin / tick_interval) * tick_interval;
304 geom->axis[orient].scale = (fabs (geom->axis[orient].data_max - geom->axis[orient].data_min)
305 / fabs (geom->axis[orient].max - geom->axis[orient].min));
307 for (s = 0 ; s < (geom->axis[orient].max - geom->axis[orient].min) / tick_interval; ++s)
309 double pos = s * tick_interval + geom->axis[orient].min;
310 if (fabs (pos) < DBL_EPSILON)
312 draw_tick (cr, geom, orient,
313 s * tick_interval * geom->axis[orient].scale, "%g", pos);
318 xrchart_write_yscale (cairo_t *cr, struct xrchart_geometry *geom,
319 double smin, double smax, int ticks)
321 xrchart_write_scale (cr, geom, smin, smax, ticks, SCALE_ORDINATE);
324 /* Set the scale for the abscissa */
326 xrchart_write_xscale (cairo_t *cr, struct xrchart_geometry *geom,
327 double smin, double smax, int ticks)
329 xrchart_write_scale (cr, geom, smin, smax, ticks, SCALE_ABSCISSA);
333 /* Write the abscissa label */
335 xrchart_write_xlabel (cairo_t *cr, const struct xrchart_geometry *geom,
338 cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->abscissa_top);
339 xrchart_label (cr, 'l', 't', geom->font_size, label);
342 /* Write the ordinate label */
344 xrchart_write_ylabel (cairo_t *cr, const struct xrchart_geometry *geom,
348 cairo_translate (cr, -geom->axis[SCALE_ORDINATE].data_min, -geom->ordinate_right);
349 cairo_move_to (cr, 0, 0);
350 cairo_rotate (cr, M_PI / 2.0);
351 xrchart_label (cr, 'l', 'x', geom->font_size, label);
357 xrchart_write_legend (cairo_t *cr, const struct xrchart_geometry *geom)
360 const int vstep = geom->font_size * 2;
363 const int swatch = 20;
364 const int legend_top = geom->axis[SCALE_ORDINATE].data_max;
365 const int legend_bottom = legend_top -
366 (vstep * geom->n_datasets + 2 * ypad );
370 cairo_rectangle (cr, geom->legend_left, legend_top,
371 geom->legend_right - xpad - geom->legend_left,
372 legend_bottom - legend_top);
375 for (i = 0 ; i < geom->n_datasets ; ++i )
377 const int ypos = legend_top - vstep * (i + 1);
378 const int xpos = geom->legend_left + xpad;
379 const struct xrchart_colour *colour;
381 cairo_move_to (cr, xpos, ypos);
384 colour = &data_colour [ i % XRCHART_N_COLOURS];
385 cairo_set_source_rgb (cr,
387 colour->green / 255.0,
388 colour->blue / 255.0);
389 cairo_rectangle (cr, xpos, ypos, swatch, swatch);
390 cairo_fill_preserve (cr);
394 cairo_move_to (cr, xpos + swatch * 1.5, ypos);
395 xrchart_label (cr, 'l', 'x', geom->font_size, geom->dataset[i]);
401 /* Start a new vector called NAME */
403 xrchart_vector_start (cairo_t *cr, struct xrchart_geometry *geom, const char *name)
405 const struct xrchart_colour *colour;
409 colour = &data_colour[geom->n_datasets % XRCHART_N_COLOURS];
410 cairo_set_source_rgb (cr,
412 colour->green / 255.0,
413 colour->blue / 255.0);
416 geom->dataset = xrealloc (geom->dataset,
417 geom->n_datasets * sizeof (*geom->dataset));
419 geom->dataset[geom->n_datasets - 1] = strdup (name);
422 /* Plot a data point */
424 xrchart_datum (cairo_t *cr, const struct xrchart_geometry *geom,
425 int dataset UNUSED, double x, double y)
427 double x_pos = (x - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
428 double y_pos = (y - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
430 xrchart_draw_marker (cr, x_pos, y_pos, XRMARKER_SQUARE, 15);
434 xrchart_vector_end (cairo_t *cr, struct xrchart_geometry *geom)
438 geom->in_path = false;
441 /* Plot a data point */
443 xrchart_vector (cairo_t *cr, struct xrchart_geometry *geom, double x, double y)
446 (x - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min ;
449 (y - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min ;
452 cairo_line_to (cr, x_pos, y_pos);
455 cairo_move_to (cr, x_pos, y_pos);
456 geom->in_path = true;
462 /* Draw a line with slope SLOPE and intercept INTERCEPT.
463 between the points limit1 and limit2.
464 If lim_dim is XRCHART_DIM_Y then the limit{1,2} are on the
465 y axis otherwise the x axis
468 xrchart_line(cairo_t *cr, const struct xrchart_geometry *geom,
469 double slope, double intercept,
470 double limit1, double limit2, enum xrchart_dim lim_dim)
475 if ( lim_dim == XRCHART_DIM_Y )
477 x1 = ( limit1 - intercept ) / slope;
478 x2 = ( limit2 - intercept ) / slope;
486 y1 = slope * x1 + intercept;
487 y2 = slope * x2 + intercept;
490 y1 = (y1 - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
491 y2 = (y2 - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
492 x1 = (x1 - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
493 x2 = (x2 - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
495 cairo_move_to (cr, x1, y1);
496 cairo_line_to (cr, x2, y2);