font handling fixes
[imager-graph.git] / lib / Imager / Graph / Pie.pm
CommitLineData
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1package Imager::Graph::Pie;
2
3=head1 NAME
4
5 Imager::Graph::Pie - a tool for drawing pie charts on Imager images
6
7=head1 SYNOPSIS
8
9 use Imager::Graph::Pie;
10
11 my $chart = Imager::Graph::Pie->new;
12 # see Imager::Graph for options
81453d28 13 my $img = $chart->draw(
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14 data => [ $first_amount, $second_amount ],
15 size => 350);
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16
17=head1 DESCRIPTION
18
19Imager::Graph::Pie is intender to make it simple to use L<Imager> to
20create good looking pie graphs.
21
22Most of the basic layout and color selection is handed off to
23L<Imager::Graph>.
24
25=over
26
27=cut
28
29use strict;
30use vars qw(@ISA);
31use Imager::Graph;
32@ISA = qw(Imager::Graph);
33use Imager::Graph::Util;
34use POSIX qw(floor);
35
36use constant PI => 3.1415926535;
37
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38=item $graph->draw(...)
39
40Draws a pie graph onto a new image and returns the image.
41
81453d28 42You must at least supply a C<data> parameter and should probably supply a C<labels> parameter. If you supply a C<labels> parameter, you must supply a C<font> parameter.
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43
44The C<data> parameter should be a reference to an array containing the
45data the pie graph should present.
46
47The C<labels> parameter is a reference to an array of labels,
48corresponding to the values in C<data>.
49
50=back
51
52=head1 FEATURES
53
54As described in L<Imager::Graph> you can enable extra features for
55your graph. The features you can use with pie graphs are:
56
57=over
58
59=item legend
60
61adds a legend to your graph. Requires the labels parameter
62
63=item labels
64
65labels each segment of the graph. If the label doesn't fit inside the
66segment it is presented as a callout.
67
68=item labelspc
69
70adds the percentage of the pie to each label.
71
72=item labelspconly
73
74the segments are labels with their percentages only.
75
76=item allcallouts
77
78all labels are presented as callouts
79
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80=item outline
81
82the pie segments are outlined.
83
84=item dropshadow
85
86the pie is given a drop shadow.
87
88=back
89
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90=head1 PIE CHART STYLES
91
92The following style values are specific to pie charts:
93
94Controlling callouts, the C<callout> option:
95
96=over
97
98=item *
99
100color - the color of the callout line and the callout text.
101
102=item *
103
104font, size - font and size of the callout text
105
106=item *
107
108outside - the distance the radial callout line goes outside the pie
109
110=item *
111
112leadlen - the length of the horizontal callout line from the end of
113the radial line.
114
115=item *
116
117gap - the distance between the end of the horizontal callout line and
118the label.
119
120=item *
121
122inside - the length of the radial callout line within the pie.
123
124=back
125
126The outline, line option controls the color of the pie segment
127outlines, if enabled with the C<outline> feature.
128
129Under C<pie>:
130
131=over
132
133=item *
134
135maxsegment - any segment below this fraction of the total of the
136segments will be put into the "others" segment. Default: 0.01
137
138=back
139
140The top level C<otherlabel> setting controls the label for the
141"others" segment, default "(others)".
142
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143=head1 EXAMPLES
144
145Assuming:
146
147 # from the Netcraft September 2001 web survey
148 # http://www.netcraft.com/survey/
149 my @data = qw(17874757 8146372 1321544 811406 );
150 my @labels = qw(Apache Microsoft iPlanet Zeus );
151
152 my $pie = Imager::Graph::Pie->new;
153
154First a simple graph, normal size, no labels:
155
156 my $img = $pie->draw(data=>\@data)
157 or die $pie->error;
158
159label the segments:
160
161 # error handling omitted for brevity from now on
162 $img = $pie->draw(data=>\@data, labels=>\@labels, features=>'labels');
163
164just percentages in the segments:
165
166 $img = $pie->draw(data=>\@data, features=>'labelspconly');
167
168add a legend as well:
169
170 $img = $pie->draw(data=>\@data, labels=>\@labels,
171 features=>[ 'labelspconly', 'legend' ]);
172
173and a title, but move the legend down, and add a dropshadow:
174
175 $img = $pie->draw(data=>\@data, labels=>\@labels,
176 title=>'Netcraft Web Survey',
177 legend=>{ valign=>'bottom' },
178 features=>[ qw/labelspconly legend dropshadow/ ]);
179
180something a bit prettier:
181
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182 $img = $pie->draw(data=>\@data, labels=>\@labels,
183 style=>'fount_lin', features=>'legend');
184
185suitable for monochrome output:
186
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187 $img = $pie->draw(data=>\@data, labels=>\@labels,
188 style=>'mono', features=>'legend');
189
190=cut
191
192# this function is too long
193sub draw {
194 my ($self, %opts) = @_;
195
196 $opts{data}
197 or return $self->_error("No data parameter supplied");
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198 my @data = @{$opts{data}}
199 or return $self->_error("No values in the data parameter");
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200 my @labels;
201 @labels = @{$opts{labels}} if $opts{labels};
202
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203 my $total = 0;
204 {
205 my $index = 0;
206 for my $item (@data) {
207 $item < 0
208 and return $self->_error("Data index $index is less than zero");
209
210 $total += $item;
211
212 ++$index;
213 }
214 }
215 $total == 0
216 and return $self->_error("Sum of all data values is zero");
217
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218 $self->_style_setup(\%opts);
219
220 my $style = $self->{_style};
221
222 my $img = $self->_make_img()
223 or return;
224
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225 my @chart_box = ( 0, 0, $img->getwidth-1, $img->getheight-1 );
226 if ($style->{title}{text}) {
227 $self->_draw_title($img, \@chart_box)
228 or return;
229 }
230
231 # consolidate any segments that are too small to display
232 $self->_consolidate_segments(\@data, \@labels, $total);
233
234 if ($style->{features}{legend} && $opts{labels}) {
235 $self->_draw_legend($img, \@labels, \@chart_box)
236 or return;
237 }
238
239 # the following code is fairly ugly
240 # it attempts to work out a good layout for the components of the chart
241 my @info;
242 my $index = 0;
243 my $pos = 0;
244 my @ebox = (0, 0, 0, 0);
245 defined(my $callout_outside = $self->_get_number('callout.outside'))
246 or return;
247 defined(my $callout_leadlen = $self->_get_number('callout.leadlen'))
248 or return;
249 defined(my $callout_gap = $self->_get_number('callout.gap'))
250 or return;
251 defined(my $label_vpad = $self->_get_number('label.vpad'))
252 or return;
253 defined(my $label_hpad = $self->_get_number('label.hpad'))
254 or return;
255 my $guessradius =
256 int($self->_small_extent(\@chart_box) * $style->{pie}{guessfactor} * 0.5);
257 for my $data (@data) {
258 my $item = { data=>$data, index=>$index };
259 my $size = 2 * PI * $data / $total;
260 $item->{begin} = $pos;
261 $pos += $size;
262 $item->{end} = $pos;
263 if ($opts{labels}) {
264 $item->{text} = $labels[$index];
265 }
266 if ($style->{features}{labelspconly}) {
267 $item->{text} =
268 $style->{label}{pconlyformat}->($data/$total * 100);
269 }
270 if ($item->{text}) {
271 if ($style->{features}{labelspc}) {
272 $item->{text} =
273 $style->{label}{pcformat}->($item->{text}, $data/$total * 100);
274 $item->{label} = 1;
275 }
276 elsif ($style->{features}{labelspconly}) {
277 $item->{text} =
278 $style->{label}{pconlyformat}->($data/$total * 100);
279 $item->{label} = 1;
280 }
281 elsif ($style->{features}{labels}) {
282 $item->{label} = 1;
283 }
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284 $item->{callout} = 1 if $style->{features}{allcallouts};
285 if (!$item->{callout}) {
286 my @lbox = $self->_text_bbox($item->{text}, 'label')
287 or return;
288 $item->{lbox} = \@lbox;
289 if ($item->{label}) {
290 unless ($self->_fit_text(0, 0, 'label', $item->{text}, $guessradius,
291 $item->{begin}, $item->{end})) {
292 $item->{callout} = 1;
293 }
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294 }
295 }
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296 if ($item->{callout}) {
297 $item->{label} = 0;
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298 my @cbox = $self->_text_bbox($item->{text}, 'callout')
299 or return;
300 $item->{cbox} = \@cbox;
301 $item->{cangle} = ($item->{begin} + $item->{end}) / 2;
302 my $dist = cos($item->{cangle}) * ($guessradius+
35574351 303 $callout_outside);
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304 my $co_size = $callout_leadlen + $callout_gap + $item->{cbox}[2];
305 if ($dist < 0) {
306 $dist -= $co_size - $guessradius;
307 $dist < $ebox[0] and $ebox[0] = $dist;
308 }
309 else {
310 $dist += $co_size - $guessradius;
311 $dist > $ebox[2] and $ebox[2] = $dist;
312 }
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313 }
314 }
315 push(@info, $item);
316 ++$index;
317 }
318
319 my $radius =
320 int($self->_small_extent(\@chart_box) * $style->{pie}{size} * 0.5);
321 my $max_width = $chart_box[2] - $chart_box[0] + $ebox[0] - $ebox[2];
322 if ($radius > $max_width / 2) {
3c9a5609 323 $radius = int($max_width / 2);
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324 }
325 $chart_box[0] -= $ebox[0];
326 $chart_box[2] -= $ebox[2];
327 my $cx = int(($chart_box[0] + $chart_box[2]) / 2);
328 my $cy = int(($chart_box[1] + $chart_box[3]) / 2);
329 if ($style->{features}{dropshadow}) {
330 my @shadow_fill = $self->_get_fill('dropshadow.fill')
331 or return;
332 my $offx = $self->_get_number('dropshadow.offx')
333 or return;
334 my $offy = $self->_get_number('dropshadow.offy');
335 for my $item (@info) {
bfcf9414 336 $img->arc(x=>$cx+$offx, 'y'=>$cy+$offy, r=>$radius+1, aa => 1,
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337 d1=>180/PI * $item->{begin}, d2=>180/PI * $item->{end},
338 @shadow_fill);
339 }
340 $self->_filter_region($img,
341 $cx+$offx-$radius-10, $cy+$offy-$radius-10,
342 $cx+$offx+$radius+10, $cy+$offy+$radius+10,
343 'dropshadow.filter')
344 if $style->{dropshadow}{filter};
345 }
bfcf9414 346
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347 my @fill_box = ( $cx-$radius, $cy-$radius, $cx+$radius, $cy+$radius );
348 for my $item (@info) {
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349 $item->{begin} < $item->{end}
350 or next;
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351 my @fill = $self->_data_fill($item->{index}, \@fill_box)
352 or return;
bfcf9414 353 $img->arc(x=>$cx, 'y'=>$cy, r=>$radius, aa => 1,
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354 d1=>180/PI * $item->{begin}, d2=>180/PI * $item->{end},
355 @fill);
356 }
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357 if ($style->{features}{outline}) {
358 my $outcolor = $self->_get_color('outline.line');
359 for my $item (@info) {
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360 my $px = int($cx + $radius * cos($item->{begin}));
361 my $py = int($cy + $radius * sin($item->{begin}));
26c93f46 362 $item->{begin} < $item->{end}
d7fd5863 363 or next;
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364 $img->line(x1=>$cx, y1=>$cy, x2=>$px, y2=>$py, color=>$outcolor);
365 for (my $i = $item->{begin}; $i < $item->{end}; $i += PI/180) {
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366 my $stroke_end = $i + PI/180;
367 $stroke_end = $item->{end} if $stroke_end > $item->{end};
368 my $nx = int($cx + $radius * cos($stroke_end));
369 my $ny = int($cy + $radius * sin($stroke_end));
370 $img->line(x1=>$px, y1=>$py, x2=>$nx, y2=>$ny, color=>$outcolor,
371 antialias=>1);
372 ($px, $py) = ($nx, $ny);
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373 }
374 }
375 }
376
377 my $callout_inside = $radius - $self->_get_number('callout.inside');
378 $callout_outside += $radius;
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379 my %callout_text;
380 my %label_text;
35574351 381 for my $label (@info) {
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382 if ($label->{label} && !$label->{callout}) {
383 # at this point we know we need the label font, to calculate
384 # whether the label will fit if anything else
385 unless (%label_text) {
386 %label_text = $self->_text_style('label')
387 or return;
388 }
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389 my @loc = $self->_fit_text($cx, $cy, 'label', $label->{text}, $radius,
390 $label->{begin}, $label->{end});
391 if (@loc) {
392 my $tcx = ($loc[0]+$loc[2])/2;
393 my $tcy = ($loc[1]+$loc[3])/2;
394 #$img->box(xmin=>$loc[0], ymin=>$loc[1], xmax=>$loc[2], ymax=>$loc[3],
395 # color=>Imager::Color->new(0,0,0));
396 $img->string(%label_text, x=>$tcx-$label->{lbox}[2]/2,
397 'y'=>$tcy+$label->{lbox}[3]/2+$label->{lbox}[1],
398 text=>$label->{text});
399 }
400 else {
401 $label->{callout} = 1;
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402 my @cbox = $self->_text_bbox($label->{text}, 'callout')
403 or return;
5d622bb8 404 $label->{cbox} = \@cbox;
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405 $label->{cangle} = ($label->{begin} + $label->{end}) / 2;
406 }
407 }
408 if ($label->{callout}) {
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409 unless (%callout_text) {
410 %callout_text = $self->_text_style('callout')
411 or return;
412 }
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413 my $ix = floor(0.5 + $cx + $callout_inside * cos($label->{cangle}));
414 my $iy = floor(0.5 + $cy + $callout_inside * sin($label->{cangle}));
415 my $ox = floor(0.5 + $cx + $callout_outside * cos($label->{cangle}));
416 my $oy = floor(0.5 + $cy + $callout_outside * sin($label->{cangle}));
417 my $lx = ($ox < $cx) ? $ox - $callout_leadlen : $ox + $callout_leadlen;
418 $img->line(x1=>$ix, y1=>$iy, x2=>$ox, y2=>$oy, antialias=>1,
d7fd5863 419 color=>$self->_get_color('callout.color'));
35574351 420 $img->line(x1=>$ox, y1=>$oy, x2=>$lx, y2=>$oy, antialias=>1,
d7fd5863 421 color=>$self->_get_color('callout.color'));
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422 #my $tx = $lx + $callout_gap;
423 my $ty = $oy + $label->{cbox}[3]/2+$label->{cbox}[1];
424 if ($lx < $cx) {
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425 $img->string(%callout_text, x=>$lx-$callout_gap-$label->{cbox}[2],
426 'y'=>$ty, text=>$label->{text});
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427 }
428 else {
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429 $img->string(%callout_text, x=>$lx+$callout_gap, 'y'=>$ty,
430 text=>$label->{text});
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431 }
432 }
433 }
434
435 $img;
436}
437
438=head1 INTERNAL FUNCTIONS
439
440These are used in the implementation of Imager::Graph, and are
441documented for debuggers and developers.
442
443=over
444
445=item _consolidate_segments($data, $labels, $total)
446
447Consolidate segments that are too small into an 'others' segment.
448
449=cut
450
451sub _consolidate_segments {
452 my ($self, $data, $labels, $total) = @_;
453
454 my @others;
455 my $index;
456 for my $item (@$data) {
457 if ($item / $total < $self->{_style}{pie}{maxsegment}) {
458 push(@others, $index);
459 }
460 ++$index;
461 }
462 if (@others) {
463 my $others = 0;
464 for my $index (reverse @others) {
465 $others += $data->[$index];
466 splice(@$labels, $index, 1);
467 splice(@$data, $index, 1);
468 }
469 push(@$labels, $self->{_style}{otherlabel}) if @$labels;
470 push(@$data, $others);
471 }
472}
473
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474# used for debugging
475sub _test_line {
476 my ($x, $y, @l) = @_;
477
478 my $res = $l[0]*$x + $l[1] * $y + $l[2];
479 print "test ", (abs($res) < 0.000001) ? "success\n" : "failure $res\n";
480}
481
482=item _fit_text($cx, $cy, $name, $text, $radius, $begin, $end)
483
484Attempts to fit text into a pie segment with its center at ($cx, $cy)
485with the given radius, covering the angles $begin through $end.
486
487Returns a list defining the bounding box of the text if it does fit.
488
489=cut
490
491sub _fit_text {
492 my ($self, $cx, $cy, $name, $text, $radius, $begin, $end) = @_;
493
494 #print "fit: $cx, $cy '$text' $radius $begin $end\n";
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495 my @tbox = $self->_text_bbox($text, $name)
496 or return;
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497 my $tcx = floor(0.5+$cx + cos(($begin+$end)/2) * $radius *3/5);
498 my $tcy = floor(0.5+$cy + sin(($begin+$end)/2) * $radius *3/5);
499 my $topy = $tcy - $tbox[3]/2;
500 my $boty = $topy + $tbox[3];
501 my @lines;
502 for my $y ($topy, $boty) {
503 my %entry = ( 'y'=>$y );
504 $entry{line} = [ line_from_points($tcx, $y, $tcx+1, $y) ];
505 $entry{left} = -$radius;
506 $entry{right} = $radius;
507 for my $angle ($begin, $end) {
508 my $ex = $cx + cos($angle)*$radius;
509 my $ey = $cy + sin($angle)*$radius;
510 my @line = line_from_points($cx, $cy, $ex, $ey);
511 #_test_line($cx, $cy, @line);
512 #_test_line($ex, $ey, @line);
513 my $goodsign = $line[0] * $tcx + $line[1] * $tcy + $line[2];
514 for my $pos (@entry{qw/left right/}) {
515 my $sign = $line[0] * ($pos+$tcx) + $line[1] * $y + $line[2];
516 if ($goodsign * $sign < 0) {
517 if (my @p = intersect_lines(@line, @{$entry{line}})) {
518 # die "$goodsign $sign ($pos, $tcx) no intersect (@line) (@{$entry{line}})" ; # this would be wierd
519 #_test_line(@p, @line);
520 #_test_line(@p, @{$entry{line}});
521 $pos = $p[0]-$tcx;
522 }
523 else {
524 return;
525 }
526
527 }
528
529 # circle
530 my $dist2 = ($pos+$tcx-$cx) * ($pos+$tcx-$cx)
531 + ($y - $cy) * ($y - $cy);
532 if ($dist2 > $radius * $radius) {
533 my @points =
534 intersect_line_and_circle(@{$entry{line}}, $cx, $cy, $radius);
535 while (@points) {
536 my @p = splice(@points, 0, 2);
537 if ($p[0] < $cx && $tcx+$pos < $p[0]) {
538 $pos = $p[0]-$tcx;
539 }
540 elsif ($p[0] > $cx && $tcx+$pos > $p[0]) {
541 $pos = $p[0]-$tcx;
542 }
543 }
544 }
545 }
546 }
547 push(@lines, \%entry);
548 }
549 my $left = $lines[0]{left} > $lines[1]{left} ? $lines[0]{left} : $lines[1]{left};
550 my $right = $lines[0]{right} < $lines[1]{right} ? $lines[0]{right} : $lines[1]{right};
551 return if $right - $left < $tbox[2];
552
553 return ($tcx+$left, $topy, $tcx+$right, $boty);
554}
555
556sub _composite {
557 ( 'pie', $_[0]->SUPER::_composite() );
558}
559
560sub _style_defs {
561 my ($self) = @_;
562
563 my %work = %{$self->SUPER::_style_defs()};
564 $work{otherlabel} = "(others)";
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565 $work{pie} =
566 {
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567 guessfactor=>0.6,
568 size=>0.8,
320f5a49 569 maxsegment=> 0.01,
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570 };
571
572 \%work;
573}
574
5751;
576__END__
577
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578=back
579
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580=head1 AUTHOR
581
582Tony Cook <tony@develop-help.com>
583
584=head1 SEE ALSO
585
586Imager::Graph(3), Imager(3), perl(1)
587
588=cut