KiCad PCB EDA Suite
stroke_font.cpp
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1 /*
2  * This program source code file is part of KICAD, a free EDA CAD application.
3  *
4  * Copyright (C) 2012 Torsten Hueter, torstenhtr <at> gmx.de
5  * Copyright (C) 2013 CERN
6  * @author Maciej Suminski <maciej.suminski@cern.ch>
7  * Copyright (C) 2016 Kicad Developers, see change_log.txt for contributors.
8  *
9  * Stroke font class
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * as published by the Free Software Foundation; either version 2
14  * of the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, you may find one here:
23  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
24  * or you may search the http://www.gnu.org website for the version 2 license,
25  * or you may write to the Free Software Foundation, Inc.,
26  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
27  */
28 
29 #include <gal/stroke_font.h>
31 #include <text_utils.h>
32 #include <wx/string.h>
33 
34 
35 using namespace KIGFX;
36 
37 const double STROKE_FONT::INTERLINE_PITCH_RATIO = 1.5;
38 const double STROKE_FONT::OVERBAR_POSITION_FACTOR = 1.22;
39 const double STROKE_FONT::BOLD_FACTOR = 1.3;
40 const double STROKE_FONT::STROKE_FONT_SCALE = 1.0 / 21.0;
41 const double STROKE_FONT::ITALIC_TILT = 1.0 / 8;
42 
44  m_gal( aGal )
45 {
46 }
47 
48 
49 bool STROKE_FONT::LoadNewStrokeFont( const char* const aNewStrokeFont[], int aNewStrokeFontSize )
50 {
51  m_glyphs.clear();
52  m_glyphBoundingBoxes.clear();
53  m_glyphs.resize( aNewStrokeFontSize );
54  m_glyphBoundingBoxes.resize( aNewStrokeFontSize );
55 
56  for( int j = 0; j < aNewStrokeFontSize; j++ )
57  {
58  GLYPH& glyph = m_glyphs[j];
59  double glyphStartX = 0.0;
60  double glyphEndX = 0.0;
61  VECTOR2D glyphBoundingX;
62 
63  std::deque<VECTOR2D>* pointList = nullptr;
64 
65  int i = 0;
66 
67  while( aNewStrokeFont[j][i] )
68  {
69  VECTOR2D point( 0.0, 0.0 );
70  char coordinate[2] = { 0, };
71 
72  for( int k = 0; k < 2; k++ )
73  {
74  coordinate[k] = aNewStrokeFont[j][i + k];
75  }
76 
77  if( i < 2 )
78  {
79  // The first two values contain the width of the char
80  glyphStartX = ( coordinate[0] - 'R' ) * STROKE_FONT_SCALE;
81  glyphEndX = ( coordinate[1] - 'R' ) * STROKE_FONT_SCALE;
82  glyphBoundingX = VECTOR2D( 0, glyphEndX - glyphStartX );
83  }
84  else if( ( coordinate[0] == ' ' ) && ( coordinate[1] == 'R' ) )
85  {
86  // Raise pen
87  pointList = nullptr;
88  }
89  else
90  {
91  // In stroke font, coordinates values are coded as <value> + 'R',
92  // <value> is an ASCII char.
93  // therefore every coordinate description of the Hershey format has an offset,
94  // it has to be subtracted
95  // Note:
96  // * the stroke coordinates are stored in reduced form (-1.0 to +1.0),
97  // and the actual size is stroke coordinate * glyph size
98  // * a few shapes have a height slightly bigger than 1.0 ( like '{' '[' )
99  point.x = (double) ( coordinate[0] - 'R' ) * STROKE_FONT_SCALE - glyphStartX;
100  #define FONT_OFFSET -10
101  // FONT_OFFSET is here for historical reasons, due to the way the stroke font
102  // was built. It allows shapes coordinates like W M ... to be >= 0
103  // Only shapes like j y have coordinates < 0
104  point.y = (double) ( coordinate[1] - 'R' + FONT_OFFSET ) * STROKE_FONT_SCALE;
105 
106  if( !pointList )
107  {
108  glyph.emplace_back( std::deque<VECTOR2D>() );
109  pointList = &glyph.back();
110  }
111 
112  pointList->push_back( point );
113  }
114 
115  i += 2;
116  }
117 
118  // Compute the bounding box of the glyph
119  m_glyphBoundingBoxes[j] = computeBoundingBox( glyph, glyphBoundingX );
120  }
121 
122  return true;
123 }
124 
125 
126 // Static function:
127 double STROKE_FONT::GetInterline( double aGlyphHeight, double aGlyphThickness )
128 {
129  return ( aGlyphHeight * INTERLINE_PITCH_RATIO ) + aGlyphThickness;
130 }
131 
132 
134 {
136 }
137 
138 
139 BOX2D STROKE_FONT::computeBoundingBox( const GLYPH& aGLYPH, const VECTOR2D& aGLYPHBoundingX ) const
140 {
142 
143  std::deque<VECTOR2D> boundingPoints;
144 
145  boundingPoints.emplace_back( VECTOR2D( aGLYPHBoundingX.x, 0 ) );
146  boundingPoints.emplace_back( VECTOR2D( aGLYPHBoundingX.y, 0 ) );
147 
148  for( GLYPH::const_iterator pointListIt = aGLYPH.begin(); pointListIt != aGLYPH.end(); ++pointListIt )
149  {
150  for( std::deque<VECTOR2D>::const_iterator pointIt = pointListIt->begin();
151  pointIt != pointListIt->end(); ++pointIt )
152  {
153  boundingPoints.emplace_back( VECTOR2D( aGLYPHBoundingX.x, pointIt->y ) );
154  }
155  }
156 
157  boundingBox.Compute( boundingPoints );
158 
159  return boundingBox;
160 }
161 
162 
163 void STROKE_FONT::Draw( const UTF8& aText, const VECTOR2D& aPosition, double aRotationAngle )
164 {
165  if( aText.empty() )
166  return;
167 
168  // Context needs to be saved before any transformations
169  m_gal->Save();
170 
171  m_gal->Translate( aPosition );
172  m_gal->Rotate( -aRotationAngle );
173 
174  // Single line height
175  int lineHeight = getInterline( );
176  int lineCount = linesCount( aText );
177  const VECTOR2D& glyphSize = m_gal->GetGlyphSize();
178 
179  // align the 1st line of text
180  switch( m_gal->GetVerticalJustify() )
181  {
183  m_gal->Translate( VECTOR2D( 0, glyphSize.y ) );
184  break;
185 
187  m_gal->Translate( VECTOR2D( 0, glyphSize.y / 2.0 ) );
188  break;
189 
191  break;
192 
193  default:
194  break;
195  }
196 
197  if( lineCount > 1 )
198  {
199  switch( m_gal->GetVerticalJustify() )
200  {
202  break;
203 
205  m_gal->Translate( VECTOR2D(0, -( lineCount - 1 ) * lineHeight / 2) );
206  break;
207 
209  m_gal->Translate( VECTOR2D(0, -( lineCount - 1 ) * lineHeight ) );
210  break;
211  }
212  }
213 
214  m_gal->SetIsStroke( true );
215  //m_gal->SetIsFill( false );
216 
217  if( m_gal->IsFontBold() )
219 
220  // Split multiline strings into separate ones and draw them line by line
221  size_t begin = 0;
222  size_t newlinePos = aText.find( '\n' );
223 
224  while( newlinePos != aText.npos )
225  {
226  size_t length = newlinePos - begin;
227 
228  drawSingleLineText( aText.substr( begin, length ) );
229  m_gal->Translate( VECTOR2D( 0.0, lineHeight ) );
230 
231  begin = newlinePos + 1;
232  newlinePos = aText.find( '\n', begin );
233  }
234 
235  // Draw the last (or the only one) line
236  if( !aText.empty() )
237  drawSingleLineText( aText.substr( begin ) );
238 
239  m_gal->Restore();
240 }
241 
242 
244 {
245  double xOffset;
246  VECTOR2D glyphSize( m_gal->GetGlyphSize() );
247  double overbar_italic_comp = computeOverbarVerticalPosition() * ITALIC_TILT;
248 
249  if( m_gal->IsTextMirrored() )
250  overbar_italic_comp = -overbar_italic_comp;
251 
252  // Compute the text size
253  VECTOR2D textSize = computeTextLineSize( aText );
254  double half_thickness = m_gal->GetLineWidth()/2;
255 
256  // Context needs to be saved before any transformations
257  m_gal->Save();
258 
259  // First adjust: the text X position is corrected by half_thickness
260  // because when the text with thickness is draw, its full size is textSize,
261  // but the position of lines is half_thickness to textSize - half_thickness
262  // so we must translate the coordinates by half_thickness on the X axis
263  // to place the text inside the 0 to textSize X area.
264  m_gal->Translate( VECTOR2D( half_thickness, 0 ) );
265 
266  // Adjust the text position to the given horizontal justification
267  switch( m_gal->GetHorizontalJustify() )
268  {
270  m_gal->Translate( VECTOR2D( -textSize.x / 2.0, 0 ) );
271  break;
272 
274  if( !m_gal->IsTextMirrored() )
275  m_gal->Translate( VECTOR2D( -textSize.x, 0 ) );
276  break;
277 
279  if( m_gal->IsTextMirrored() )
280  m_gal->Translate( VECTOR2D( -textSize.x, 0 ) );
281  break;
282 
283  default:
284  break;
285  }
286 
287  if( m_gal->IsTextMirrored() )
288  {
289  // In case of mirrored text invert the X scale of points and their X direction
290  // (m_glyphSize.x) and start drawing from the position where text normally should end
291  // (textSize.x)
292  xOffset = textSize.x - m_gal->GetLineWidth();
293  glyphSize.x = -glyphSize.x;
294  }
295  else
296  {
297  xOffset = 0.0;
298  }
299 
300  // The overbar is indented inward at the beginning of an italicized section, but
301  // must not be indented on subsequent letters to ensure that the bar segments
302  // overlap.
303  bool last_had_overbar = false;
304  auto processedText = ProcessOverbars( aText );
305  const auto& text = processedText.first;
306  const auto& overbars = processedText.second;
307  int i = 0;
308 
309  for( UTF8::uni_iter chIt = text.ubegin(), end = text.uend(); chIt < end; ++chIt )
310  {
311  int dd = *chIt - ' ';
312 
313  if( dd >= (int) m_glyphBoundingBoxes.size() || dd < 0 )
314  dd = '?' - ' ';
315 
316  GLYPH& glyph = m_glyphs[dd];
317  BOX2D& bbox = m_glyphBoundingBoxes[dd];
318 
319  if( overbars[i] )
320  {
321  double overbar_start_x = xOffset;
322  double overbar_start_y = - computeOverbarVerticalPosition();
323  double overbar_end_x = xOffset + glyphSize.x * bbox.GetEnd().x;
324  double overbar_end_y = overbar_start_y;
325 
326  if( !last_had_overbar )
327  {
328  if( m_gal->IsFontItalic() )
329  overbar_start_x += overbar_italic_comp;
330 
331  last_had_overbar = true;
332  }
333 
334  VECTOR2D startOverbar( overbar_start_x, overbar_start_y );
335  VECTOR2D endOverbar( overbar_end_x, overbar_end_y );
336 
337  m_gal->DrawLine( startOverbar, endOverbar );
338  }
339  else
340  {
341  last_had_overbar = false;
342  }
343 
344  for( GLYPH::iterator pointListIt = glyph.begin(); pointListIt != glyph.end();
345  ++pointListIt )
346  {
347  std::deque<VECTOR2D> pointListScaled;
348 
349  for( std::deque<VECTOR2D>::iterator pointIt = pointListIt->begin();
350  pointIt != pointListIt->end(); ++pointIt )
351  {
352  VECTOR2D pointPos( pointIt->x * glyphSize.x + xOffset, pointIt->y * glyphSize.y );
353 
354  if( m_gal->IsFontItalic() )
355  {
356  // FIXME should be done other way - referring to the lowest Y value of point
357  // because now italic fonts are translated a bit
358  if( m_gal->IsTextMirrored() )
359  pointPos.x += pointPos.y * STROKE_FONT::ITALIC_TILT;
360  else
361  pointPos.x -= pointPos.y * STROKE_FONT::ITALIC_TILT;
362  }
363 
364  pointListScaled.push_back( pointPos );
365  }
366 
367  m_gal->DrawPolyline( pointListScaled );
368  }
369 
370  xOffset += glyphSize.x * bbox.GetEnd().x;
371  ++i;
372  }
373 
374  m_gal->Restore();
375 }
376 
377 
378 double STROKE_FONT::ComputeOverbarVerticalPosition( double aGlyphHeight, double aGlyphThickness ) const
379 {
380  // Static method.
381  // Compute the Y position of the overbar. This is the distance between
382  // the text base line and the overbar axis.
383  return aGlyphHeight * OVERBAR_POSITION_FACTOR + aGlyphThickness;
384 }
385 
386 
388 {
389  // Compute the Y position of the overbar. This is the distance between
390  // the text base line and the overbar axis.
392 }
393 
394 
396 {
398 }
399 
400 
402  double aGlyphThickness ) const
403 {
404  VECTOR2D string_bbox;
405  int line_count = 1;
406  double maxX = 0.0, curX = 0.0;
407 
408  for( UTF8::uni_iter it = aText.ubegin(), end = aText.uend(); it < end; ++it )
409  {
410  if( *it == '\n' )
411  {
412  curX = 0.0;
413  maxX = std::max( maxX, curX );
414  ++line_count;
415  continue;
416  }
417 
418  // If it is double tilda, then it is displayed as a single tilda
419  // If it is single tilda, then it is toggling overbar, so we need to skip it
420  if( *it == '~' )
421  {
422  if( ++it >= end )
423  break;
424  }
425 
426  // Index in the bounding boxes table
427  int dd = *it - ' ';
428 
429  if( dd >= (int) m_glyphBoundingBoxes.size() || dd < 0 )
430  dd = '?' - ' ';
431 
432  const BOX2D& box = m_glyphBoundingBoxes[dd];
433  curX += box.GetEnd().x;
434  }
435 
436  string_bbox.x = std::max( maxX, curX );
437  string_bbox.x *= aGlyphSize.x;
438  string_bbox.x += aGlyphThickness;
439  string_bbox.y = line_count * GetInterline( aGlyphSize.y, aGlyphThickness );
440 
441  // For italic correction, take in account italic tilt
442  if( m_gal->IsFontItalic() )
443  string_bbox.x += string_bbox.y * STROKE_FONT::ITALIC_TILT;
444 
445  return string_bbox;
446 }
Class UTF8 is an 8 bit string that is assuredly encoded in UTF8, and supplies special conversion supp...
Definition: utf8.h:73
virtual void DrawPolyline(const std::deque< VECTOR2D > &aPointList)
Draw a polyline.
static constexpr std::string::size_type npos
Definition: utf8.h:155
EDA_TEXT_HJUSTIFY_T GetHorizontalJustify() const
Returns current text horizontal justification setting.
static double GetInterline(double aGlyphHeight, double aGlyphThickness)
Compute the distance (interline) between 2 lines of text (for multiline texts).
EDA_TEXT_VJUSTIFY_T GetVerticalJustify() const
Returns current text vertical justification setting.
std::pair< UTF8, std::vector< bool > > ProcessOverbars(const UTF8 &aText)
Processes a text to extract the raw text and overbar flags.
Definition: text_utils.cpp:27
double computeOverbarVerticalPosition() const
Compute the vertical position of an overbar, sometimes used in texts.
Class CAIRO_GAL is the cairo implementation of the graphics abstraction layer.
Definition: class_module.h:58
static int KiROUND(double v)
Round a floating point number to an integer using "round halfway cases away from zero".
Definition: common.h:120
static const double BOLD_FACTOR
Factor that determines relative line width for bold text.
Definition: stroke_font.h:182
const Vec GetEnd() const
Definition: box2.h:193
GLYPH_LIST m_glyphs
Glyph list.
Definition: stroke_font.h:120
std::string substr(size_t pos=0, size_t len=npos) const
Definition: utf8.h:182
VECTOR2D ComputeStringBoundaryLimits(const UTF8 &aText, const VECTOR2D &aGlyphSize, double aGlyphThickness) const
Compute the boundary limits of aText (the bounding box of all shapes).
std::vector< BOX2D > m_glyphBoundingBoxes
Bounding boxes of the glyphs.
Definition: stroke_font.h:121
void Compute(const Container &aPointList)
Compute the bounding box from a given list of points.
Definition: box2.h:89
bool LoadNewStrokeFont(const char *const aNewStrokeFont[], int aNewStrokeFontSize)
Load the new stroke font.
Definition: stroke_font.cpp:49
static const double ITALIC_TILT
Tilt factor for italic style (the is is the scaling factor on dY relative coordinates to give a tilst...
Definition: stroke_font.h:189
virtual void DrawLine(const VECTOR2D &aStartPoint, const VECTOR2D &aEndPoint)
Draw a line.
uni_iter ubegin() const
Function ubegin returns a uni_iter initialized to the start of "this" UTF8 byte sequence.
Definition: utf8.h:285
virtual void SetLineWidth(float aLineWidth)
Set the line width.
virtual void Rotate(double aAngle)
Rotate the context.
BOX2I boundingBox(T aObject)
boundingBox template method
Definition: shape_index.h:59
GAL * m_gal
Pointer to the GAL.
Definition: stroke_font.h:119
bool IsFontBold() const
Returns true if current font has &#39;bold&#39; attribute enabled.
VECTOR2< double > VECTOR2D
Definition: vector2d.h:586
bool empty() const
Definition: utf8.h:108
std::string::size_type find(char c) const
Definition: utf8.h:110
BOX2D computeBoundingBox(const GLYPH &aGlyph, const VECTOR2D &aGlyphBoundingX) const
Compute the bounding box of a given glyph.
VECTOR2D computeTextLineSize(const UTF8 &aText) const
Compute the X and Y size of a given text.
const VECTOR2D & GetGlyphSize() const
static const double INTERLINE_PITCH_RATIO
Factor that determines the pitch between 2 lines.
Definition: stroke_font.h:192
unsigned linesCount(const UTF8 &aText) const
Returns number of lines for a given text.
Definition: stroke_font.h:169
class uni_iter is a non-mutating iterator that walks through unicode code points in the UTF8 encoded ...
Definition: utf8.h:207
void Draw(const UTF8 &aText, const VECTOR2D &aPosition, double aRotationAngle)
Draw a string.
STROKE_FONT(GAL *aGal)
Constructor.
Definition: stroke_font.cpp:43
uni_iter uend() const
Function uend returns a uni_iter initialized to the end of "this" UTF8 byte sequence.
Definition: utf8.h:294
static const double STROKE_FONT_SCALE
Scale factor for a glyph
Definition: stroke_font.h:185
void drawSingleLineText(const UTF8 &aText)
Draws a single line of text.
virtual void Restore()
Restore the context.
#define max(a, b)
Definition: auxiliary.h:86
#define FONT_OFFSET
size_t i
Definition: json11.cpp:597
double ComputeOverbarVerticalPosition(double aGlyphHeight, double aGlyphThickness) const
Compute the vertical position of an overbar, sometimes used in texts.
static const double OVERBAR_POSITION_FACTOR
Factor that determines relative vertical position of the overbar.
Definition: stroke_font.h:179
bool IsFontItalic() const
Returns true if current font has &#39;italic&#39; attribute enabled.
virtual void Save()
Save the context.
std::deque< std::deque< VECTOR2D > > GLYPH
Definition: stroke_font.h:43
float GetLineWidth() const
Get the line width.
bool IsTextMirrored() const
Returns true if text should displayed mirrored.
virtual void Translate(const VECTOR2D &aTranslation)
Translate the context.
virtual void SetIsStroke(bool aIsStrokeEnabled)
Enable/disable stroked outlines.
int getInterline() const
Returns a single line height using current settings.
Class GAL is the abstract interface for drawing on a 2D-surface.