kicad/common/gal/stroke_font.cpp

630 lines
20 KiB
C++

/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2012 Torsten Hueter, torstenhtr <at> gmx.de
* Copyright (C) 2013 CERN
* @author Maciej Suminski <maciej.suminski@cern.ch>
* Copyright (C) 2016 Kicad Developers, see change_log.txt for contributors.
*
* Stroke font class
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <gal/stroke_font.h>
#include <gal/graphics_abstraction_layer.h>
#include <math/util.h> // for KiROUND
#include <wx/string.h>
#include <gr_text.h>
using namespace KIGFX;
const double STROKE_FONT::INTERLINE_PITCH_RATIO = 1.61;
const double STROKE_FONT::OVERBAR_POSITION_FACTOR = 1.33;
const double STROKE_FONT::UNDERLINE_POSITION_FACTOR = 0.41;
const double STROKE_FONT::BOLD_FACTOR = 1.3;
const double STROKE_FONT::STROKE_FONT_SCALE = 1.0 / 21.0;
const double STROKE_FONT::ITALIC_TILT = 1.0 / 8;
GLYPH_LIST* g_newStrokeFontGlyphs = nullptr; ///< Glyph list
std::vector<BOX2D>* g_newStrokeFontGlyphBoundingBoxes; ///< Bounding boxes of the glyphs
STROKE_FONT::STROKE_FONT( GAL* aGal ) :
m_gal( aGal ), m_glyphs( nullptr ), m_glyphBoundingBoxes( nullptr ), m_maxGlyphWidth( 1.0 )
{
}
bool STROKE_FONT::LoadNewStrokeFont( const char* const aNewStrokeFont[], int aNewStrokeFontSize )
{
if( g_newStrokeFontGlyphs )
{
m_glyphs = g_newStrokeFontGlyphs;
m_glyphBoundingBoxes = g_newStrokeFontGlyphBoundingBoxes;
return true;
}
g_newStrokeFontGlyphs = new GLYPH_LIST;
g_newStrokeFontGlyphs->reserve( aNewStrokeFontSize );
g_newStrokeFontGlyphBoundingBoxes = new std::vector<BOX2D>;
g_newStrokeFontGlyphBoundingBoxes->reserve( aNewStrokeFontSize );
for( int j = 0; j < aNewStrokeFontSize; j++ )
{
GLYPH* glyph = new GLYPH;
double glyphStartX = 0.0;
double glyphEndX = 0.0;
double glyphWidth = 0.0;
std::vector<VECTOR2D>* pointList = nullptr;
int strokes = 0;
int i = 0;
while( aNewStrokeFont[j][i] )
{
if( aNewStrokeFont[j][i] == ' ' && aNewStrokeFont[j][i+1] == 'R' )
strokes++;
i += 2;
}
glyph->reserve( strokes + 1 );
i = 0;
while( aNewStrokeFont[j][i] )
{
VECTOR2D point( 0.0, 0.0 );
char coordinate[2] = { 0, };
for( int k : { 0, 1 } )
coordinate[k] = aNewStrokeFont[j][i + k];
if( i < 2 )
{
// The first two values contain the width of the char
glyphStartX = ( coordinate[0] - 'R' ) * STROKE_FONT_SCALE;
glyphEndX = ( coordinate[1] - 'R' ) * STROKE_FONT_SCALE;
glyphWidth = glyphEndX - glyphStartX;
}
else if( ( coordinate[0] == ' ' ) && ( coordinate[1] == 'R' ) )
{
if( pointList )
pointList->shrink_to_fit();
// Raise pen
pointList = nullptr;
}
else
{
// In stroke font, coordinates values are coded as <value> + 'R',
// <value> is an ASCII char.
// therefore every coordinate description of the Hershey format has an offset,
// it has to be subtracted
// Note:
// * the stroke coordinates are stored in reduced form (-1.0 to +1.0),
// and the actual size is stroke coordinate * glyph size
// * a few shapes have a height slightly bigger than 1.0 ( like '{' '[' )
point.x = (double) ( coordinate[0] - 'R' ) * STROKE_FONT_SCALE - glyphStartX;
#define FONT_OFFSET -10
// FONT_OFFSET is here for historical reasons, due to the way the stroke font
// was built. It allows shapes coordinates like W M ... to be >= 0
// Only shapes like j y have coordinates < 0
point.y = (double) ( coordinate[1] - 'R' + FONT_OFFSET ) * STROKE_FONT_SCALE;
if( !pointList )
{
pointList = new std::vector<VECTOR2D>;
glyph->push_back( pointList );
}
pointList->push_back( point );
}
i += 2;
}
if( pointList )
pointList->shrink_to_fit();
// Compute the bounding box of the glyph
g_newStrokeFontGlyphBoundingBoxes->emplace_back( computeBoundingBox( glyph, glyphWidth ) );
g_newStrokeFontGlyphs->push_back( glyph );
m_maxGlyphWidth = std::max( m_maxGlyphWidth,
g_newStrokeFontGlyphBoundingBoxes->back().GetWidth() );
}
m_glyphs = g_newStrokeFontGlyphs;
m_glyphBoundingBoxes = g_newStrokeFontGlyphBoundingBoxes;
return true;
}
// Static function:
double STROKE_FONT::GetInterline( double aGlyphHeight )
{
// Do not add the glyph thickness to the interline. This makes bold text line-spacing
// different from normal text, which is poor typography.
return ( aGlyphHeight * INTERLINE_PITCH_RATIO );
}
BOX2D STROKE_FONT::computeBoundingBox( const GLYPH* aGLYPH, double aGlyphWidth ) const
{
VECTOR2D min( 0, 0 );
VECTOR2D max( aGlyphWidth, 0 );
for( const std::vector<VECTOR2D>* pointList : *aGLYPH )
{
for( const VECTOR2D& point : *pointList )
{
min.y = std::min( min.y, point.y );
max.y = std::max( max.y, point.y );
}
}
return BOX2D( min, max - min );
}
void STROKE_FONT::Draw( const UTF8& aText, const VECTOR2D& aPosition, double aRotationAngle )
{
if( aText.empty() )
return;
// Context needs to be saved before any transformations
m_gal->Save();
m_gal->Translate( aPosition );
m_gal->Rotate( -aRotationAngle );
// Single line height
int lineHeight = KiROUND( GetInterline( m_gal->GetGlyphSize().y ) );
int lineCount = linesCount( aText );
const VECTOR2D& glyphSize = m_gal->GetGlyphSize();
// align the 1st line of text
switch( m_gal->GetVerticalJustify() )
{
case GR_TEXT_VJUSTIFY_TOP:
m_gal->Translate( VECTOR2D( 0, glyphSize.y ) );
break;
case GR_TEXT_VJUSTIFY_CENTER:
m_gal->Translate( VECTOR2D( 0, glyphSize.y / 2.0 ) );
break;
case GR_TEXT_VJUSTIFY_BOTTOM:
break;
default:
break;
}
if( lineCount > 1 )
{
switch( m_gal->GetVerticalJustify() )
{
case GR_TEXT_VJUSTIFY_TOP:
break;
case GR_TEXT_VJUSTIFY_CENTER:
m_gal->Translate( VECTOR2D(0, -( lineCount - 1 ) * lineHeight / 2) );
break;
case GR_TEXT_VJUSTIFY_BOTTOM:
m_gal->Translate( VECTOR2D(0, -( lineCount - 1 ) * lineHeight ) );
break;
}
}
m_gal->SetIsStroke( true );
//m_gal->SetIsFill( false );
if( m_gal->IsFontBold() )
m_gal->SetLineWidth( m_gal->GetLineWidth() * BOLD_FACTOR );
// Split multiline strings into separate ones and draw them line by line
size_t begin = 0;
size_t newlinePos = aText.find( '\n' );
while( newlinePos != aText.npos )
{
size_t length = newlinePos - begin;
drawSingleLineText( aText.substr( begin, length ) );
m_gal->Translate( VECTOR2D( 0.0, lineHeight ) );
begin = newlinePos + 1;
newlinePos = aText.find( '\n', begin );
}
// Draw the last (or the only one) line
if( !aText.empty() )
drawSingleLineText( aText.substr( begin ) );
m_gal->Restore();
}
void STROKE_FONT::drawSingleLineText( const UTF8& aText )
{
double xOffset;
double yOffset;
VECTOR2D baseGlyphSize( m_gal->GetGlyphSize() );
double overbar_italic_comp = computeOverbarVerticalPosition() * ITALIC_TILT;
if( m_gal->IsTextMirrored() )
overbar_italic_comp = -overbar_italic_comp;
// Compute the text size
VECTOR2D textSize = computeTextLineSize( aText );
double half_thickness = m_gal->GetLineWidth()/2;
// Context needs to be saved before any transformations
m_gal->Save();
// First adjust: the text X position is corrected by half_thickness
// because when the text with thickness is draw, its full size is textSize,
// but the position of lines is half_thickness to textSize - half_thickness
// so we must translate the coordinates by half_thickness on the X axis
// to place the text inside the 0 to textSize X area.
m_gal->Translate( VECTOR2D( half_thickness, 0 ) );
// Adjust the text position to the given horizontal justification
switch( m_gal->GetHorizontalJustify() )
{
case GR_TEXT_HJUSTIFY_CENTER:
m_gal->Translate( VECTOR2D( -textSize.x / 2.0, 0 ) );
break;
case GR_TEXT_HJUSTIFY_RIGHT:
if( !m_gal->IsTextMirrored() )
m_gal->Translate( VECTOR2D( -textSize.x, 0 ) );
break;
case GR_TEXT_HJUSTIFY_LEFT:
if( m_gal->IsTextMirrored() )
m_gal->Translate( VECTOR2D( -textSize.x, 0 ) );
break;
default:
break;
}
if( m_gal->IsTextMirrored() )
{
// In case of mirrored text invert the X scale of points and their X direction
// (m_glyphSize.x) and start drawing from the position where text normally should end
// (textSize.x)
xOffset = textSize.x - m_gal->GetLineWidth();
baseGlyphSize.x = -baseGlyphSize.x;
}
else
{
xOffset = 0.0;
}
// The overbar is indented inward at the beginning of an italicized section, but
// must not be indented on subsequent letters to ensure that the bar segments
// overlap.
bool last_had_overbar = false;
bool in_overbar = false;
bool in_super_or_subscript = false;
VECTOR2D glyphSize = baseGlyphSize;
// Allocate only once (for performance)
std::vector<VECTOR2D> ptListScaled;
int char_count = 0;
yOffset = 0;
for( UTF8::uni_iter chIt = aText.ubegin(), end = aText.uend(); chIt < end; ++chIt )
{
// Handle tabs as locked to the nearest 4th column (counting in spaces)
// The choice of spaces is somewhat arbitrary but sufficient for aligning text
if( *chIt == '\t' )
{
// We align to the 4th column. This is based on the monospace font used in the text input
// boxes. Here, we take the widest character as our baseline spacing and make tab stops
// at each fourth of this widest character
char_count = ( char_count / 4 + 1 ) * 4 - 1;
xOffset = m_maxGlyphWidth * baseGlyphSize.x * char_count;
glyphSize = baseGlyphSize;
yOffset = 0;
// Tab ends an overbar
in_overbar = false;
}
else if( *chIt == '~' )
{
if( ++chIt == end )
break;
if( *chIt == '~' )
{
// double ~ is really a ~ so go ahead and process the second one
// so what's a triple ~? It could be a real ~ followed by an overbar, or
// it could be an overbar followed by a real ~. The old algorithm did the
// former so we will too....
}
else
{
in_overbar = !in_overbar;
}
}
else if( *chIt == '^' )
{
auto lookahead = chIt;
if( ++lookahead != end && *lookahead == '{' )
{
// process superscript
chIt = lookahead;
in_super_or_subscript = true;
glyphSize = baseGlyphSize * 0.8;
yOffset = -baseGlyphSize.y * 0.3;
continue;
}
}
else if( *chIt == '_' )
{
auto lookahead = chIt;
if( ++lookahead != end && *lookahead == '{' )
{
// process subscript
chIt = lookahead;
in_super_or_subscript = true;
glyphSize = baseGlyphSize * 0.8;
yOffset = baseGlyphSize.y * 0.1;
continue;
}
}
else if( *chIt == '}' && in_super_or_subscript )
{
in_super_or_subscript = false;
glyphSize = baseGlyphSize;
yOffset = 0;
continue;
}
// Overbar syntax is less precise so we have to have some special cases
else if( in_overbar && ( *chIt == ' ' || *chIt == '}' || *chIt == ')' ) )
{
in_overbar = false;
}
// Index into bounding boxes table
int dd = (signed) *chIt - ' ';
if( dd >= (int) m_glyphBoundingBoxes->size() || dd < 0 )
{
int substitute = *chIt == '\t' ? ' ' : '?';
dd = substitute - ' ';
}
const GLYPH* glyph = m_glyphs->at( dd );
const BOX2D& bbox = m_glyphBoundingBoxes->at( dd );
if( in_overbar )
{
double overbar_start_x = xOffset;
double overbar_start_y = - computeOverbarVerticalPosition();
double overbar_end_x = xOffset + glyphSize.x * bbox.GetEnd().x;
double overbar_end_y = overbar_start_y;
if( !last_had_overbar )
{
if( m_gal->IsFontItalic() )
overbar_start_x += overbar_italic_comp;
last_had_overbar = true;
}
VECTOR2D startOverbar( overbar_start_x, overbar_start_y );
VECTOR2D endOverbar( overbar_end_x, overbar_end_y );
m_gal->DrawLine( startOverbar, endOverbar );
}
else
{
last_had_overbar = false;
}
if( m_gal->IsFontUnderlined() )
{
double vOffset = computeUnderlineVerticalPosition();
VECTOR2D startUnderline( xOffset, - vOffset );
VECTOR2D endUnderline( xOffset + glyphSize.x * bbox.GetEnd().x, - vOffset );
m_gal->DrawLine( startUnderline, endUnderline );
}
for( const std::vector<VECTOR2D>* ptList : *glyph )
{
int ptCount = 0;
ptListScaled.clear();
for( const VECTOR2D& pt : *ptList )
{
VECTOR2D scaledPt( pt.x * glyphSize.x + xOffset, pt.y * glyphSize.y + yOffset );
if( m_gal->IsFontItalic() )
{
// FIXME should be done other way - referring to the lowest Y value of point
// because now italic fonts are translated a bit
if( m_gal->IsTextMirrored() )
scaledPt.x += scaledPt.y * STROKE_FONT::ITALIC_TILT;
else
scaledPt.x -= scaledPt.y * STROKE_FONT::ITALIC_TILT;
}
ptListScaled.push_back( scaledPt );
ptCount++;
}
m_gal->DrawPolyline( &ptListScaled[0], ptCount );
}
char_count++;
xOffset += glyphSize.x * bbox.GetEnd().x;
}
m_gal->Restore();
}
double STROKE_FONT::ComputeOverbarVerticalPosition( double aGlyphHeight ) const
{
// Static method.
return aGlyphHeight * OVERBAR_POSITION_FACTOR;
}
double STROKE_FONT::computeOverbarVerticalPosition() const
{
// Compute the Y position of the overbar. This is the distance between
// the text base line and the overbar axis.
return ComputeOverbarVerticalPosition( m_gal->GetGlyphSize().y );
}
double STROKE_FONT::computeUnderlineVerticalPosition() const
{
// Compute the Y position of the underline. This is the distance between
// the text base line and the underline axis.
return - m_gal->GetGlyphSize().y * UNDERLINE_POSITION_FACTOR;
}
VECTOR2D STROKE_FONT::computeTextLineSize( const UTF8& aText ) const
{
return ComputeStringBoundaryLimits( aText, m_gal->GetGlyphSize(), m_gal->GetLineWidth() );
}
VECTOR2D STROKE_FONT::ComputeStringBoundaryLimits( const UTF8& aText, const VECTOR2D& aGlyphSize,
double aGlyphThickness ) const
{
VECTOR2D string_bbox;
int line_count = 1;
double maxX = 0.0, curX = 0.0;
double curScale = 1.0;
bool in_overbar = false;
bool in_super_or_subscript = false;
for( UTF8::uni_iter it = aText.ubegin(), end = aText.uend(); it < end; ++it )
{
if( *it == '\n' )
{
curX = 0.0;
maxX = std::max( maxX, curX );
++line_count;
continue;
}
// Handle tabs as locked to the nearest 4th column (counting in spaces)
// The choice of spaces is somewhat arbitrary but sufficient for aligning text
if( *it == '\t' )
{
double spaces = m_glyphBoundingBoxes->at( 0 ).GetEnd().x;
double addlSpace = 3.0 * spaces - std::fmod( curX, 4.0 * spaces );
// Add the remaining space (between 0 and 3 spaces)
curX += addlSpace;
// Tab ends an overbar
in_overbar = false;
}
else if( *it == '~' )
{
if( ++it == end )
break;
if( *it == '~' )
{
// double ~ is really a ~ so go ahead and process the second one
// so what's a triple ~? It could be a real ~ followed by an overbar, or
// it could be an overbar followed by a real ~. The old algorithm did the
// former so we will too....
}
else
{
// single ~ toggles overbar
in_overbar = !in_overbar;
}
}
else if( *it == '^' || *it == '_' )
{
auto lookahead = it;
if( ++lookahead != end && *lookahead == '{' )
{
// process superscript
it = lookahead;
in_super_or_subscript = true;
curScale = 0.8;
continue;
}
}
else if( *it == '}' && in_super_or_subscript )
{
in_super_or_subscript = false;
curScale = 1.0;
continue;
}
// Overbar syntax is less precise so we have to have some special cases
else if( in_overbar && ( *it == ' ' || *it == '}' || *it == ')' ) )
{
in_overbar = false;
}
// Index in the bounding boxes table
int dd = (signed) *it - ' ';
if( dd >= (int) m_glyphBoundingBoxes->size() || dd < 0 )
{
int substitute = *it == '\t' ? ' ' : '?';
dd = substitute - ' ';
}
const BOX2D& box = m_glyphBoundingBoxes->at( dd );
curX += box.GetEnd().x * curScale;
}
string_bbox.x = std::max( maxX, curX ) * aGlyphSize.x;
string_bbox.x += aGlyphThickness;
string_bbox.y = line_count * GetInterline( aGlyphSize.y );
// For italic correction, take in account italic tilt
if( m_gal->IsFontItalic() )
string_bbox.x += string_bbox.y * STROKE_FONT::ITALIC_TILT;
return string_bbox;
}