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This is gonna need a bit more work.

Display tooltip at corresponding location in other subplots by manually picking at that location to get the info about the graphic at that location.

Basically:

If system cursor is on subplot A, and we want to display tooltip at same world space location in subplot B:

# system cursor over position in subplot A, get world pos
pos = subplot_A.map_screen_to_world(ev)

# get corresponding screen space position in subplot B
x, y = subplot_B.map_world_to_screen(pos)
# get pick info of this screen pixel
pick = subplot.get_pick_info((x, y))

if pick is None:  # no graphic at this screen pixel in subplot B
    tooltips2.visible = False
    return

# display graphic metadata or anyrelevant info in the tooltip in subplot B
info = pick["graphic"].metadata
tooltips2.display((x, y), str(info))

@clewis7 I'm thinking about changing who "owns" tooltips. Right now Figure owns tooltips and can auto-display them. I'm thinking of a tooltip being owned by each Subplot instead, so we can have a method:

Subplot.display_tooltip(pos: tuple[float, float], space: Literal["world", "screen"], info: str):
    ...

Tooltips are drawn in the overlay render pass which is in screen space, so the tooltip position in the end always has to be in screen space. However it is useful to think of them in world space since that's where the graphics are. It'll just be much easier to know the position of a graphic in world space where you want to show the tooltip, and the Subplot.display_tooltip() will project that pos to screen space under automatically.

@clewis7 I'm thinking about changing who "owns" tooltips. Right now Figure owns tooltips and can auto-display them. I'm thinking of a tooltip being owned by each Subplot instead, so we can have a method:

Subplot.display_tooltip(pos: tuple[float, float], space: Literal["world", "screen"], info: str):
    ...

Tooltips are drawn in the overlay render pass which is in screen space, so the tooltip position in the end always has to be in screen space. However it is useful to think of them in world space since that's where the graphics are. It'll just be much easier to know the position of a graphic in world space where you want to show the tooltip, and the Subplot.display_tooltip() will project that pos to screen space under automatically.

And why would tooltips not be owned by the graphic they correspond to? I could also imagine a property that is image_graphic.tooltip.display = False

And why would tooltips not be owned by the graphic they correspond to? I could also imagine a property that is image_graphic.tooltip.display = False

I didn't think of that! This might be a better way to do it, and customization of tooltips per-graphic makes most sense I think.

I didn't think of that! This might be a better way to do it, and customization of tooltips per-graphic makes most sense I think.

I think then, if you wanted to not display all of the tooltips for graphics in the subplot, you would just need to iterate:

for g in subplot.graphics:
     g.tooltip.display = False 

ok all this stuff works now:

tooltips update on every render, useful when data under the cursor changes:

Tooltips are now enabled on graphics by default, and a cursor can trigger a tooltip to show up in other subplots:

Added more mapping functions, these are explained in the guide:

- ``Subplot.map_screen_to_world((x, y))``
- ``Subplot.map_world_to_screen((x, y, z))``
- ``Graphic.map_model_to_world((x, y, z))``
- ``Graphic.map_world_to_model((x, y, z))``

Need to test a bit, add some more examples maybe, and possibly cleanup some of the code if it can be simplified.

Need to add tests to make sure the right default tooltip display comes up for all graphics.

I should add examples that explain all the spaces (model, world, screen) using a variety of graphics. Show a few points on the graphic and put text that indicates model, world and screen space positions.

• Graphic that isn't rotated or scaled, model and world are same
• Graphic scaled
• Graphic rotated
• Graphic scaled, rotated, translated

Do this with Image, Line and an ellipsoid, should be enough.

@clewis7 you can take a look, but I'm guessing you're deep in CPU design optimizations for the next few days 😆 . I'll summarize everything in this PR later, required quite a bit more than I thought to get this to work.

OK things getting slightly messy, I think this will be better:

• TextBox that can be used to display a textbox anywhere, just text with a rectangle mesh behind it. Lives in the overlay scene.
• Tooltip is a subclass of TextBox. One tooltip instance always exists per subplot. Graphic.tooltip merely sets the tooltip in its subplot.

The PlotArea could also update its tooltip with whatever pick info is under a pixel on every render.

Perhaps the renderer "pointer_move" event could just be used to set the tooltips in each subplot by getting the graphic from the pick_info at that position.

I think things are much simpler now.

• Created TextBox class
• Tooltip which is a light subclass of TextBox
• PlotArea has a Tooltip instance as an attribute. "pointer_move" events will set the tooltip.
• if Tooltip.continuous_mode, then PlotArea will update the tooltip on every render
• Cursor uses Subplot.get_pick_info() to get the graphic, pick info, and set the tooltip in that subplot.

One thing left out is I need to think of how to set the tooltip w.r.t. the transform when it's on the current subplot with a cursor. Figured it out, let the cursor manage tooltips entirely when a subplot is added to it.

~One last thing to figure out, programmatically setting the cursor isn't triggering the tooltip to appear 😩 ~

nevermind it does work, but not on the first render since the canvas is blank

For the examples to demonstrate the different spaces I think I'll make one example for each of these (instead of separate subplots in one Figure) and two sets, one with an image and one with a line:

• no transforms
• translation
• scaling
• rotation
• translation + scaling
• translation + scaling + rotation

@clewis7 finally r4r! And just before midnight here 😂

There is a bug in Volume, will figure out.

Edit: this is a pygfx thing, posted: pygfx/pygfx#1251

Until pygfx/pygfx#1253 is in the next release of pygfx I've kinda disabled tooltips for ImageVolume.