JAGPDF in C++ aligning test - c++

Question

Has anyone used jagPDF on c++?
I am trying to learn how to use it from the handbook they provide at http://www.jagpdf.org/doc/index.htm. Unfortunately, all their examples are in Python. Which sometimes is not a big deal to adapt to C++, but sometimes it's confusing.
For example, I am trying to learn how to align text, which in the tutorial is at Text Aligment. Once I find the padding, the function that puts the padding in the line of text is:
canvas.text(txt, [padding / 2.0], [0])
looking in the reference for that function, the translation table is:
[py] text(txt_u, offsets, positions)
[c++] void text(Char const* txt_u, Double const* offsets, UInt offsets_length, Int const* positions, UInt positions_length);
Parameters:
txt_u: zero terminated string.
offsets: glyph offsets expressed in glyph space (i.e. in thousandths of a unit of text space).
offsets_length: number of offsets.
position: associates glyph offsets with glyph indices in txt_u.
positions_length: number of positions.
I have tried several things, but I haven't figure out the two additional input parameters that c++ requires over Python. If someone out there has used jagPDF and knows how to do it in c++, I'd be greatly appreciative.

Answer 1

This is my first touch to JagPDF. There is section Text Alignment, but code is written on Python.
In C++ it should be like:
// line width
pdf::Double line_width = 597.6;
// text to show
pdf::Char *txt = "Everything should be made as simple as possible, but no simpler.";
// calculate text width
pdf::Double text_width = font.advance(txt);
// calculate gap - difference in line_width and text_width
pdf::Double gap = line_width - text_width;
// calculate the text padding
pdf::Double padding = -1000.0 / font.size() * gap;
// create array with paddings - I set all padings, but is used only 1
pdf::Double const pp[] = { padding, padding / 2.0 }; // index 0 for right alignment, 1 for center
// not sure what are positions, but need for function `text()` - set as Doc to zero (0)
pdf::Int const dd[] = { 0};
// get canvas where the text is written
pdf::Canvas canvas = doc.page().canvas();
// start text block
canvas.text_start(0, 480);
// set font
canvas.text_font(font);
// right alignment text
canvas.text(txt, pp, 1, dd, 1);
canvas.text_translate_line(0, font.height());
// center alignment text
canvas.text(txt, &pp[1], 1, dd, 1);
canvas.text_translate_line(0, font.height());
// finish text block
canvas.text_end();
Hope it helps