[Solved] sf::Shape::Line not drawing a line

[Naxos]

I'm trying to draw some simple lines using the Line() function of sf::Shape.

However, I get no rendering of lines on the screen.

Here's how I'm doing it at the moment:

Code: [Select]


sf::Shape line;
for(unsigned int i=0;i<layout.size();++i)
{
// get 1st point for line
LayoutPoint p = layout.getPointAt(i);

sprDiamond.SetPosition( p.x, p.y );
App.Draw( sprDiamond );  // this draws no problem

// get 2nd point for line ( % size() because the lines are drawing a 'track' of sorts )
LayoutPoint n = layout.getPointAt( (i+1) % layout.size() );

line.Line( p.x, p.y, n.x, n.y, 10.0f, sf::Color(127,127,127,127) );
App.Draw( line );
}

So I get my positions drawing diamonds, but the lines between each diamond are not being draw.

Am I doing something incorrectly here?

[Nexus]

Nice nickname.

sf::Shape::Line() is a static method which creates a new shape containing a line and returns it. See the documentation. So, you have to assign it to a sf::Shape instance. I guess, you will need a STL container to store multiple lines.

I had problems with this issue at the beginning, too. I think, it's not very clear that the Line() member-function is static. Something like CreateLine() would be more expressive in my opinion.

[Naxos]

Thanks Nexus

I should've noticed that myself, geez.

For the moment I'm just saying:

Code: [Select]

App.Draw( sf::Shape::Line( p.x, p.y, n.x, n.y, 10.0f, sf::Color(127,127,127,127) ) );

And that works. I suppose a container would be more efficient time-wise, but I'll leave it like this unless it starts to affect performance.

Thanks again!

[Nexus]

For a single line, you don't even need a container. But instead of creating the sf::Shape instance every frame, you could declare it anywhere it lasts (for example as a class member, or outside the main loop). Then you just call App.Draw(MyLine); where MyLine is your variable.

Although this won't make a difference in your case, you could keep it in mind for later, if performance becomes more important.