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canvas::Text: add heightForWidth method.

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This commit is contained in:
Thomas Geymayer 2014-06-13 00:04:57 +02:00
parent d3b211e787
commit 36cb7a752b
3 changed files with 295 additions and 0 deletions
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282
simgear/canvas/elements/CanvasText.cxx
View File

@ -40,6 +40,7 @@ namespace canvas
void setFill(const std::string& fill);
void setBackgroundColor(const std::string& fill);
int heightForWidth(int w) const;
osg::Vec2 handleHit(const osg::Vec2f& pos);
virtual osg::BoundingBox computeBound() const;
@ -95,6 +96,281 @@ namespace canvas
setBoundingBoxColor( color );
}
//----------------------------------------------------------------------------
// simplified version of osgText::Text::computeGlyphRepresentation() to
// just calculate the height for a given weight. Glpyh calculations/creating
// is not necessary for this...
int Text::TextOSG::heightForWidth(int w) const
{
if( _text.empty() )
return 0;
osgText::Font* activefont = const_cast<osgText::Font*>(getActiveFont());
if( !activefont )
return -1;
float max_width_safe = _maximumWidth;
const_cast<TextOSG*>(this)->_maximumWidth = w;
SGRecti bb;
osg::Vec2 startOfLine_coords(0.0f,0.0f);
osg::Vec2 cursor(startOfLine_coords);
osg::Vec2 local(0.0f,0.0f);
unsigned int previous_charcode = 0;
unsigned int line_length = 0;
bool horizontal = _layout != VERTICAL;
bool kerning = true;
float hr = _characterHeight;
float wr = hr / getCharacterAspectRatio();
// osg should really care more about const :-/
osgText::String& text = const_cast<osgText::String&>(_text);
typedef osgText::String::iterator TextIterator;
for( TextIterator itr = text.begin(); itr != text.end(); )
{
// record the start of the current line
TextIterator startOfLine_itr = itr;
// find the end of the current line.
osg::Vec2 endOfLine_coords(cursor);
TextIterator endOfLine_itr =
const_cast<TextOSG*>(this)->computeLastCharacterOnLine(
endOfLine_coords, itr, text.end()
);
line_length = endOfLine_itr - startOfLine_itr;
// Set line position to correct alignment.
switch( _layout )
{
case LEFT_TO_RIGHT:
{
switch( _alignment )
{
// nothing to be done for these
//case LEFT_TOP:
//case LEFT_CENTER:
//case LEFT_BOTTOM:
//case LEFT_BASE_LINE:
//case LEFT_BOTTOM_BASE_LINE:
// break;
case CENTER_TOP:
case CENTER_CENTER:
case CENTER_BOTTOM:
case CENTER_BASE_LINE:
case CENTER_BOTTOM_BASE_LINE:
cursor.x() = (cursor.x() - endOfLine_coords.x()) * 0.5f;
break;
case RIGHT_TOP:
case RIGHT_CENTER:
case RIGHT_BOTTOM:
case RIGHT_BASE_LINE:
case RIGHT_BOTTOM_BASE_LINE:
cursor.x() = cursor.x() - endOfLine_coords.x();
break;
default:
break;
}
break;
}
case RIGHT_TO_LEFT:
{
switch( _alignment )
{
case LEFT_TOP:
case LEFT_CENTER:
case LEFT_BOTTOM:
case LEFT_BASE_LINE:
case LEFT_BOTTOM_BASE_LINE:
cursor.x() = 2 * cursor.x() - endOfLine_coords.x();
break;
case CENTER_TOP:
case CENTER_CENTER:
case CENTER_BOTTOM:
case CENTER_BASE_LINE:
case CENTER_BOTTOM_BASE_LINE:
cursor.x() = cursor.x()
+ (cursor.x() - endOfLine_coords.x()) * 0.5f;
break;
// nothing to be done for these
//case RIGHT_TOP:
//case RIGHT_CENTER:
//case RIGHT_BOTTOM:
//case RIGHT_BASE_LINE:
//case RIGHT_BOTTOM_BASE_LINE:
// break;
default:
break;
}
break;
}
case VERTICAL:
{
switch( _alignment )
{
// TODO: current behaviour top baselines lined up in both cases - need to implement
// top of characters alignment - Question is this necessary?
// ... otherwise, nothing to be done for these 6 cases
//case LEFT_TOP:
//case CENTER_TOP:
//case RIGHT_TOP:
// break;
//case LEFT_BASE_LINE:
//case CENTER_BASE_LINE:
//case RIGHT_BASE_LINE:
// break;
case LEFT_CENTER:
case CENTER_CENTER:
case RIGHT_CENTER:
cursor.y() = cursor.y()
+ (cursor.y() - endOfLine_coords.y()) * 0.5f;
break;
case LEFT_BOTTOM_BASE_LINE:
case CENTER_BOTTOM_BASE_LINE:
case RIGHT_BOTTOM_BASE_LINE:
cursor.y() = cursor.y() - (line_length * _characterHeight);
break;
case LEFT_BOTTOM:
case CENTER_BOTTOM:
case RIGHT_BOTTOM:
cursor.y() = 2 * cursor.y() - endOfLine_coords.y();
break;
default:
break;
}
break;
}
}
if( itr != endOfLine_itr )
{
for(;itr != endOfLine_itr;++itr)
{
unsigned int charcode = *itr;
osgText::Glyph* glyph = activefont->getGlyph(_fontSize, charcode);
if( glyph )
{
float width = (float) (glyph->getWidth()) * wr;
float height = (float) (glyph->getHeight()) * hr;
if( _layout == RIGHT_TO_LEFT )
{
cursor.x() -= glyph->getHorizontalAdvance() * wr;
}
// adjust cursor position w.r.t any kerning.
if( kerning && previous_charcode )
{
switch( _layout )
{
case LEFT_TO_RIGHT:
{
osg::Vec2 delta( activefont->getKerning( previous_charcode,
charcode,
_kerningType ) );
cursor.x() += delta.x() * wr;
cursor.y() += delta.y() * hr;
break;
}
case RIGHT_TO_LEFT:
{
osg::Vec2 delta( activefont->getKerning( charcode,
previous_charcode,
_kerningType ) );
cursor.x() -= delta.x() * wr;
cursor.y() -= delta.y() * hr;
break;
}
case VERTICAL:
break; // no kerning when vertical.
}
}
local = cursor;
osg::Vec2 bearing( horizontal ? glyph->getHorizontalBearing()
: glyph->getVerticalBearing() );
local.x() += bearing.x() * wr;
local.y() += bearing.y() * hr;
// set up the coords of the quad
osg::Vec2 upLeft = local + osg::Vec2(0.f, height);
osg::Vec2 lowLeft = local;
osg::Vec2 lowRight = local + osg::Vec2(width, 0.f);
osg::Vec2 upRight = local + osg::Vec2(width, height);
// move the cursor onto the next character.
// also expand bounding box
switch( _layout )
{
case LEFT_TO_RIGHT:
cursor.x() += glyph->getHorizontalAdvance() * wr;
bb.expandBy(lowLeft.x(), lowLeft.y());
bb.expandBy(upRight.x(), upRight.y());
break;
case VERTICAL:
cursor.y() -= glyph->getVerticalAdvance() * hr;
bb.expandBy(upLeft.x(), upLeft.y());
bb.expandBy(lowRight.x(), lowRight.y());
break;
case RIGHT_TO_LEFT:
bb.expandBy(lowRight.x(), lowRight.y());
bb.expandBy(upLeft.x(), upLeft.y());
break;
}
previous_charcode = charcode;
}
}
// skip over spaces and return.
while( itr != text.end() && *itr == ' ' )
++itr;
if( itr != text.end() && *itr == '\n' )
++itr;
}
else
{
++itr;
}
// move to new line.
switch( _layout )
{
case LEFT_TO_RIGHT:
{
startOfLine_coords.y() -= _characterHeight * (1.0 + _lineSpacing);
cursor = startOfLine_coords;
previous_charcode = 0;
break;
}
case RIGHT_TO_LEFT:
{
startOfLine_coords.y() -= _characterHeight * (1.0 + _lineSpacing);
cursor = startOfLine_coords;
previous_charcode = 0;
break;
}
case VERTICAL:
{
startOfLine_coords.x() += _characterHeight * (1.0 + _lineSpacing)
/ getCharacterAspectRatio();
cursor = startOfLine_coords;
previous_charcode = 0;
break;
}
}
}
const_cast<TextOSG*>(this)->_maximumWidth = max_width_safe;
return bb.height();
}
//----------------------------------------------------------------------------
osg::Vec2 Text::TextOSG::handleHit(const osg::Vec2f& pos)
{
@ -369,6 +645,12 @@ namespace canvas
}
#endif
//----------------------------------------------------------------------------
int Text::heightForWidth(int w) const
{
return _text->heightForWidth(w);
}
//----------------------------------------------------------------------------
osg::Vec2 Text::getNearestCursor(const osg::Vec2& pos) const
{

1
simgear/canvas/elements/CanvasText.hxx
View File

@ -46,6 +46,7 @@ namespace canvas
void setFont(const char* name);
void setAlignment(const char* align);
int heightForWidth(int w) const;
osg::Vec2 getNearestCursor(const osg::Vec2& pos) const;
protected:

12
simgear/math/SGRect.hxx
View File

@ -113,6 +113,18 @@ class SGRect
void setTop(T t) { _min.y() = t; }
void setBottom(T b) { _max.y() = b; }
/**
* Expand rectangle to include the given position
*/
void expandBy(T x, T y)
{
if( x < _min.x() ) _min.x() = x;
if( x > _max.x() ) _max.x() = x;
if( y < _min.y() ) _min.y() = y;
if( y > _max.y() ) _max.y() = y;
}
/**
* Move rect by vector
*/