/*
* Inkscape::Text::Layout::ScanlineMaker - text layout engine shape measurers
*
* Authors:
* Richard Hughes <cyreve@users.sf.net>
*
* Copyright (C) 2005 Richard Hughes
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "Layout-TNG-Scanline-Maker.h"
#include "livarot/Shape.h"
#include "livarot/float-line.h"
#include <limits>
namespace Inkscape {
namespace Text {
// *********************** infinite version
Layout::InfiniteScanlineMaker::InfiniteScanlineMaker(double initial_x, double initial_y, Layout::Direction block_progression)
{
_current_line_height.setZero();
switch (block_progression) {
case LEFT_TO_RIGHT:
case RIGHT_TO_LEFT:
_x = initial_y;
_y = initial_x;
break;
default:
_x = initial_x;
_y = initial_y;
break;
}
_negative_block_progression = block_progression == RIGHT_TO_LEFT || block_progression == BOTTOM_TO_TOP;
}
Layout::InfiniteScanlineMaker::~InfiniteScanlineMaker()
{
}
std::vector<Layout::ScanlineMaker::ScanRun> Layout::InfiniteScanlineMaker::makeScanline(Layout::FontMetrics const &line_height)
{
std::vector<ScanRun> runs(1);
runs[0].x_start = _x;
runs[0].x_end = std::numeric_limits<float>::max(); // we could use DBL_MAX, but this just seems safer
runs[0].y = _y;
_current_line_height = line_height;
return runs;
}
void Layout::InfiniteScanlineMaker::completeLine()
{
if (_negative_block_progression)
_y -= _current_line_height.emSize();
else
_y += _current_line_height.emSize();
_current_line_height.setZero();
}
void Layout::InfiniteScanlineMaker::setNewYCoordinate(double new_y)
{
_y = new_y;
}
bool Layout::InfiniteScanlineMaker::canExtendCurrentScanline(Layout::FontMetrics const &line_height)
{
_current_line_height = line_height;
return true;
}
void Layout::InfiniteScanlineMaker::setLineHeight(Layout::FontMetrics const &line_height)
{
_current_line_height = line_height;
}
// *********************** real shapes version
Layout::ShapeScanlineMaker::ShapeScanlineMaker(Shape const *shape, Layout::Direction block_progression)
{
if (block_progression == TOP_TO_BOTTOM) {
_rotated_shape = const_cast<Shape*>(shape);
_shape_needs_freeing = false;
} else {
Shape *temp_rotated_shape = new Shape;
_shape_needs_freeing = true;
temp_rotated_shape->Copy(const_cast<Shape*>(shape));
switch (block_progression) {
case BOTTOM_TO_TOP: temp_rotated_shape->Transform(Geom::Affine(1.0, 0.0, 0.0, -1.0, 0.0, 0.0)); break; // reflect about x axis
case LEFT_TO_RIGHT: temp_rotated_shape->Transform(Geom::Affine(0.0, 1.0, 1.0, 0.0, 0.0, 0.0)); break; // reflect about y=x
case RIGHT_TO_LEFT: temp_rotated_shape->Transform(Geom::Affine(0.0, -1.0, 1.0, 0.0, 0.0, 0.0)); break; // reflect about y=-x
default: break;
}
_rotated_shape = new Shape;
_rotated_shape->ConvertToShape(temp_rotated_shape);
delete temp_rotated_shape;
}
_rotated_shape->CalcBBox(true);
_bounding_box_top = _rotated_shape->topY;
_bounding_box_bottom = _rotated_shape->bottomY;
_y = _rasterizer_y = _bounding_box_top;
_current_rasterization_point = 0;
_rotated_shape->BeginRaster(_y, _current_rasterization_point);
_negative_block_progression = block_progression == RIGHT_TO_LEFT || block_progression == BOTTOM_TO_TOP;
}
Layout::ShapeScanlineMaker::~ShapeScanlineMaker()
{
_rotated_shape->EndRaster();
if (_shape_needs_freeing)
delete _rotated_shape;
}
std::vector<Layout::ScanlineMaker::ScanRun> Layout::ShapeScanlineMaker::makeScanline(Layout::FontMetrics const &line_height)
{
if (_y > _bounding_box_bottom)
return std::vector<ScanRun>();
if (_y < _bounding_box_top)
_y = _bounding_box_top;
FloatLigne line_rasterization;
FloatLigne line_decent_length_runs;
float line_text_height = (float)(line_height.emSize());
if (line_text_height == 0.0)
line_text_height = 0.001; // Scan() doesn't work for zero height so this will have to do
_current_line_height = (float)line_height.emSize();
// I think what's going on here is that we're moving the top of the scanline to the given position...
_rotated_shape->Scan(_rasterizer_y, _current_rasterization_point, _y, line_text_height);
// ...then actually retreiving the scanline (which alters the first two parameters)
_rotated_shape->Scan(_rasterizer_y, _current_rasterization_point, _y + line_text_height , &line_rasterization, true, line_text_height);
// sanitise the raw rasterisation, which could have weird overlaps
line_rasterization.Flatten();
// line_rasterization.Affiche();
// cut out runs that cover less than 90% of the line
line_decent_length_runs.Over(&line_rasterization, 0.9 * line_text_height);
if (line_decent_length_runs.runs.empty())
{
if (line_rasterization.runs.empty())
return std::vector<ScanRun>(); // stop the flow
// make up a pointless run: anything that's not an empty vector
std::vector<ScanRun> result(1);
result[0].x_start = line_rasterization.runs[0].st;
result[0].x_end = line_rasterization.runs[0].st;
result[0].y = _negative_block_progression ? - _y : _y;
return result;
}
// convert the FloatLigne to what we use: vector<ScanRun>
std::vector<ScanRun> result(line_decent_length_runs.runs.size());
for (unsigned i = 0 ; i < result.size() ; i++) {
result[i].x_start = line_decent_length_runs.runs[i].st;
result[i].x_end = line_decent_length_runs.runs[i].en;
result[i].y = _negative_block_progression ? - _y : _y;
}
return result;
}
void Layout::ShapeScanlineMaker::completeLine()
{
_y += _current_line_height;
}
double Layout::ShapeScanlineMaker::yCoordinate()
{
if (_negative_block_progression) return - _y;
return _y;
}
void Layout::ShapeScanlineMaker::setNewYCoordinate(double new_y)
{
_y = (float)new_y;
if (_negative_block_progression) _y = - _y;
// what will happen with the rasteriser if we move off the shape?
// it's not an important question because <flowSpan> doesn't have a y attribute
}
bool Layout::ShapeScanlineMaker::canExtendCurrentScanline(Layout::FontMetrics const &/*line_height*/)
{
//we actually could return true if only the leading changed, but that's too much effort for something that rarely happens
return false;
}
void Layout::ShapeScanlineMaker::setLineHeight(Layout::FontMetrics const &line_height)
{
_current_line_height = line_height.emSize();
}
}//namespace Text
}//namespace Inkscape