Manipulating individual tiles in an SVG pattern - svg

Question

I'm trying to create an interactive grid for a web game (HTML, JS, etc.), in which every cell should change it's fill on hover/click. I need both a regular square grid, and a triangular grid. I want it to be vector based so that it will scale nicely to fit different screen sizes. I thought the easiest way would be to create a pattern and fill it on a rectangle. This is the code I have so far:
<pattern id="baseTile" width="10" height="10" patternUnits="userSpaceOnUse">
<path id="tile" d="M 0,0 L 0,10 10,10 10,0 Z" fill="none" stroke="gray" stroke-width="1"/>
</pattern>
For the square, and this for the triangular grid:
<pattern id="baseTile" width="10" height="10" patternUnits="userSpaceOnUse">
<path d="M 5,0 L 10,2.5 10,7.5 5,10 0,7.5 0,2.5 Z" fill="none" stroke="gray" stroke-width=".1" />
<path d="M 5,0 L 5,10" fill="none" stroke="gray" stroke-width=".1" />
<path d="M 0,2.5 L 10,7.5" fill="none" stroke="gray" stroke-width=".1" />
<path d="M 0,7.5 L 10,2.5" fill="none" stroke="gray" stroke-width=".1" />
<path d="M 0,0 L 0,2.5 M 0,7.5 L 0,10" fill="none" stroke="gray" stroke-width=".1" />
<path d="M 10,0 L 10,2.5 M 10,7.5 L 10,10" fill="none" stroke="gray" stroke-width=".1" />
</pattern>
They produce the grids I need, but I don't know how to target each cell individually. I'm guessing since I've found no information on this, it's just not possible, and some other solution other than should be used. Any ideas?
Edit:
I want to be able to cycle through different fills on mouse click. For the square grid, I'm using the code I found here: http://bl.ocks.org/bunkat/2605010 but for the triangular lattice, I have absolutely no idea where to begin. That's why I thought of .
PS: I should probably add I have no programming experience, I'm trying to make a nonogram game to teach myself some Javascript.

Answer 1

Patterns are purely decorative. Targetting a single tile within a pattern would be like targetting a single colour within a gradient. Better not to think about them as distinct "tiles", and instead think of it as a sheet of repeating wallpaper.
So what to do? Well, you are going to need a distinct element for each piece that you want to be able to manipulate. But since they are mostly the same, you'll want to use <use> elements to repeat the graphics. You'll need to do a bit of math to figure out how to position the triangles just right, but no worse than what you had to do to figure out that pattern. It will of course be easiest to create the elements with a loop in your JS script, although you could hard code the original elements in a <defs> section.
Moreover, you don't specify what you want to do with the individual cells. If you are going to be changing their appearance, it might help to remember that you can set styles on the <use> element and these will be inherited by the re-used graphics. So if you don't set fill/stroke directly, you can change them by styling the <use>, instead of having a separate, differently coloured template to swap in.