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iterate on reading order
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@kermitt2
kermitt2 committed Aug 22, 2020
1 parent d0c8739 commit 12a6488
Showing 1 changed file with 107 additions and 76 deletions.
183 changes: 107 additions & 76 deletions src/XmlAltoOutputDev.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -5708,7 +5708,7 @@ void TextPage::dump(GBool noLineNumbers, GBool fullFontName, vector<bool> lineNu
paragraph->setXMax(paragraph->getXMin() + maxBlockLineWidth);

// adding previous block to the page element
if(readingOrder)
if(readingOrder && num == 1)
lastBlockInserted = addBlockInReadingOrder(paragraph, lineFontSize, lastBlockInserted);
else
blocks->append(paragraph);
Expand Down Expand Up @@ -5778,7 +5778,7 @@ void TextPage::dump(GBool noLineNumbers, GBool fullFontName, vector<bool> lineNu
paragraph->setYMax(paragraph->getYMin() + blockHeight);

// adding previous block to the page element
if(readingOrder)
if(readingOrder && num == 1)
lastBlockInserted = addBlockInReadingOrder(paragraph, lineFontSize, lastBlockInserted);
else
blocks->append(paragraph);
Expand Down Expand Up @@ -5811,7 +5811,7 @@ void TextPage::dump(GBool noLineNumbers, GBool fullFontName, vector<bool> lineNu
endPage = gFalse;

if (paragraph != NULL) {
if(readingOrder)
if(readingOrder && num == 1)
lastBlockInserted = addBlockInReadingOrder(paragraph, lineFontSize, lastBlockInserted);
else
blocks->append(paragraph);
Expand Down Expand Up @@ -6353,100 +6353,131 @@ void TextPage::dump(GBool noLineNumbers, GBool fullFontName, vector<bool> lineNu
}

// PL: Insert a block in the page's block list according to the reading order
GBool TextPage::addBlockInReadingOrder(TextParagraph * block, double fontSize, GBool lastInserted) {
// lastInserted: true if the previously added block has been inserted and not appended
GBool TextPage::addBlockInReadingOrder(TextParagraph *block, double fontSize, GBool lastInserted) {
// if Y_pos of the block to be inserted is less than Y_pos of the existing block
// (i.e. block is located above)
// and, in case of vertical overlap,
// X_pos + width of the block to be inserted is less than X_pos of this existing block
// (i.e. block is on the left and the surfaces of the block are not overlaping -
// 2 columns case)
// then the block order is before the existing block
GBool notInserted = gTrue;
int indexLowerBlock = 0, insertIndex= 0;
//GBool insertable = gFalse;
int indexLowerBlock = 0, indexUpperBlock = 0;
// default insert place is at the end of the block list, so append
int insertIndex = blocks->getLength();
GBool firstLowerBlock = gFalse;
GBool noVerticalOverlap = gTrue;
GBool firstUpperBlock = gFalse;
GBool verticalOverlap = gFalse;
double page_middle = pageWidth/2;
// we get the first child of the current page node
unsigned long nbChildren = blocks->getLength();
if (nbChildren > 0) {
// coordinates of the block to be inserted
double blockX = block->getXMin();
double blockY = block->getYMin();

double blockHeight = block->getYMax() - block->getYMin();
double blockWidth = block->getXMax() - block->getXMin();

//cout << "to be inserted: " << nodeblock->name << ", X: " << blockX << ", Y: " << blockY << ", H: " << blockHeight << ", W: " << blockWidth << endl;

TextParagraph * par;
// we get all the block nodes in the XML tree corresponding to the page
for (int i = 0; i <= blocks->getLength()-1 && notInserted; i++) {
par = (TextParagraph *) blocks->get(i);
double currentY = par->getYMin();

double currentX = par->getXMin();

double currentWidth = par->getXMax() - par->getXMin();
double currentHeight = par->getYMax() - par->getXMin();

if((currentY <= blockY && currentY + currentHeight >= blockY) ||
(blockY + blockHeight > currentY && blockY + blockHeight < currentY + currentHeight)){
noVerticalOverlap = gFalse;
if (block->getXMax() == 0 || block->getYMax() == 0) {
double maxLineWidth = 0.0;
double maxLineY = 0.0;
// fix missing xmax or ymax at block level (usually single line block)
for (int lineIdx = 0; lineIdx < block->lines->getLength(); lineIdx++) {
TextLine *line = (TextLine *) block->lines->get(lineIdx);
if (line->getYMax() > maxLineY)
maxLineY = line->getYMax();
if (line->getXMax() - line->getXMin() > maxLineWidth)
maxLineWidth = line->getXMax() - line->getXMin();
}
if (block->getXMax() == 0)
block->setXMax(block->getXMin() + maxLineWidth);
if (block->getYMax() == 0)
block->setYMax(maxLineY);
}

if (currentY < blockY)
continue;

if (blockY < currentY) {
if (blockY + blockHeight < currentY) {
// coordinates of the block to be inserted
double x = block->getXMin();
double y = block->getYMin();
double w = block->getXMax() - block->getXMin();
double h = block->getYMax() - block->getYMin();

//cout << "to be inserted: " << " X: " << x << ", Y: " << y << ", H: " << h << ", W: " << w << ", X_max: " << block->getXMax() << ", Y_max: " << block->getYMax() << endl;

// check if the block is centered on the page
GBool centered = gFalse;
if ( (block->getXMin() < page_middle) &&
(block->getXMax() > page_middle) ) {
int left_size = page_middle - block->getXMin();
int right_size = block->getXMax() - page_middle;
//cout << "centered: " << std::abs(left_size-right_size) << endl;
if (std::abs(left_size-right_size) < 20) {
centered = gTrue;
}
}

TextParagraph * currentBlock;
// we get all the block nodes corresponding to the page, starting from the lower/last present block
// to prioritize the stream order when it is valid
//for (int i = 0; i < blocks->getLength(); i++) {
for (int i = blocks->getLength()-1; i >= 0; i--) {
currentBlock = (TextParagraph *)blocks->get(i);
double c_x = currentBlock->getXMin();
double c_y = currentBlock->getYMin();
double c_w = currentBlock->getXMax() - currentBlock->getXMin();
double c_h = currentBlock->getYMax() - currentBlock->getYMin();

//cout << "current: " << " X: " << c_x << ", Y: " << c_y << ", H: " << c_h << ", W: " << c_w << endl;

if (y > c_y) {
// if block is centered in the middle of the line, we don't consider column constraints
if (centered) {
break;
} else if (x+w < c_x) {
// although lower, block to be added is entirely on the left of current,
// so before in reading order
insertIndex = i;
} else {
break;
}
}

if(!notInserted)
continue;
// we keep the first block under it, if no overlap put it above
if(!firstLowerBlock) {
indexLowerBlock = i;
firstLowerBlock = gTrue;
}
// we don't have any vertical overlap
// check the X-pos, the block cannot be on the right of the current block
// check if the
if ((blockX <= currentX + currentWidth && blockX >= currentX) ||
(blockX <= currentX + currentWidth && blockX + blockWidth > currentX)||
blockX < currentX + currentWidth +fontSize * maxColSpacing
) {
// we can insert the block before the current block
insertIndex = i;
notInserted = false;
}
} else
noVerticalOverlap = gFalse;
if (
((y <= c_y+c_h) && (y+h > c_y+c_h)) ||
((y <= c_y) && (y+h > c_y))
) {
verticalOverlap = gTrue;
}
// we have vertical overlap, check position on X axis

/*double currentHeight = 0;
attrValue = xmlGetProp(cur_node, (const xmlChar*)ATTR_HEIGHT);
if (attrValue != NULL) {
currentHeight = atof((const char*)attrValue);
xmlFree(attrValue);
if ((y+h < c_y) || verticalOverlap ) {
// we are entirely above current block, no vertical overlap
// so we might want to insert the block just above it
// we need to check the column and general horizontal constraints

// if block is centered in the middle of the line, we don't consider column constraints

if (centered) {
insertIndex = i;
} else if ((x > c_x + c_w) && (x+w < (pageWidth*1.2)/2) ) {
// the block to be inserted is on the right of the current block
// block is after current, we stop going up
break;
} else
insertIndex = i;

// we don't have any vertical overlap
// check the X-pos, the block cannot be on the right of the current block
// check if the
/*if ((x <= c_x+c_w && x >= c_x) ||
(x <= c_x+c_w && x+w > c_x) ||
x < c_x+c_w + fontSize * maxColSpacing
) {
// we can insert the block before the current block
insertIndex = i;
insertable = gTrue;
break;
}*/
}
}
if((lastInserted || noVerticalOverlap) && firstLowerBlock){
insertIndex = indexLowerBlock;
notInserted = false;
}
/*if (notInserted && (blockX + blockWidth < currentX)) {
// does not work for multi column sections one after the other
xmlNodePtr result = xmlAddPrevSibling(cur_node, nodeblock);
notInserted = false;
}*/
}

if (notInserted) {
blocks->append(block);
return gFalse;
} else {
blocks->insert(insertIndex, block); // beware, the order can be the opposite if next block in next column..
return gTrue;
}
blocks->insert(insertIndex, block);
return insertIndex;
}

void TextPage::addImageInlineNode(xmlNodePtr nodeline,
Expand Down

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