Where is the mouse?

[negester]

This is my first post. I'm an experienced Lua programmer but a Löve newbie.

1. Wish list item: getting and setting the shape of the mouse cursor.

2. Given a fair number of polygon-shaped objects, maybe overlapping, inside which of these is the mouse cursor? Any better way than just searching through all of them every time?

[nevon]

1. There is an SDL function that does that, but it's pretty shit. I'd recommend you simply hide the cursor and draw an image at the mouse coordinates instead.

2. To find if the mouse is inside a convex polygon, you could use a right-of-test. vrld gave an excellent explanation for that here. The physics module provides a method for checking if a point is inside a shape, so that's also an option.

If you have thousands of polygons, that might be too slow - in which case you'll have to sort some of them out, perhaps using a quadtree.

[Taehl]

The shape of the cursor? You mean, you want to change its appearance? Then just hide the cursor with love.mouse.setVisible(false), then draw your own cursor with love.graphics.draw(newCursor, love.mouse.getX(), love.mouse.getY()).

[josefnpat]

The shape of the cursor? You mean, you want to change its appearance? Then just hide the cursor with love.mouse.setVisible(false), then draw your own cursor with love.graphics.draw(newCursor, love.mouse.getX(), love.mouse.getY()).

Thank you! Learn something new every day.

[TechnoCat]

The shape of the cursor? You mean, you want to change its appearance? Then just hide the cursor with love.mouse.setVisible(false), then draw your own cursor with love.graphics.draw(newCursor, love.mouse.getX(), love.mouse.getY()).

There are some love.run optimizations (fixes?) that need to be done in order to do this properly.
Just make it handle events before love.update instead of after love.draw. Then the cursorImage will feel more responsive. Otherwise, there is at least a whole millisecond of sleep before you get each event (mouse position, keyboard keys, etc.).

Code: Select all

function love.run() --LOVE 0.7.2

    if love.load then love.load(arg) end

    local dt = 0

    -- Main loop time.
    while true do
        if love.timer then
            love.timer.step()
            dt = love.timer.getDelta()
        end
        -- Process events.
        if love.event then
            for e,a,b,c in love.event.poll() do
                if e == "q" then
                    if not love.quit or not love.quit() then
                        if love.audio then
                            love.audio.stop()
                        end
                        return
                    end
                end
                love.handlers[e](a,b,c)
            end
        end
        if love.update then love.update(dt) end -- will pass 0 if love.timer is disabled
        if love.graphics then
            love.graphics.clear()
            if love.draw then love.draw() end
        end

        if love.timer then love.timer.sleep(1) end
        if love.graphics then love.graphics.present() end

    end

end

[Taehl]

Come to think of it... Is there any reason it's not done that way in the default love.run?

[thelinx]

That is the default behaviour in 0.8.0.

[hryx]

That is the default behaviour in 0.8.0.

So it is! And if you don't believe him, here's proof.

I'm gonna shove this in the wiki entry next to the 0.7.2 version. The 0.6.x parts should get removed since they're pretty irrelevant now and take up space. If anyone needs to know really old versions of love.run they can look in the code repository history.