Add Spine Atlas support to embedded AnimationEditor

[vchelaru]

[profexorgeek]

Bugs

• Camera should not snap when pushing middle mouse button
• Duplicate names should not be allowed when renaming

Here's my list of features specific to Gunboki (but probably relevant to most projects)

• User can add a texture atlas to FRB outside of the context of an entity (directly in Global Content)
• User can add an animation chain list to FRB outside of the context of an entity (directly in Global Content)
• User can load from and save to either format (.achx or .atlas)
• User can work from one format (achx) and "Save" saves to that format but "Export" allows saving to a different format without changing the file context the editor is editing (this allows you to save two versions of the same texture mapping easily)
• User can rapidly create named spritesheet sections with one or multiple frames
• Frame dimensions can be manually entered
• Frame dimensions can be visually resized
• Frame can be visually dragged
• Frame can snap to a user-selected increment when visually resizing
• Grid is shown at the appropriate size when snapping is enabled
• Zooming zoomes in/out based on cursor position
• Middle mouse press can drag the canvas
• User can copy/paste frames into an animation
• User can copy/paste entire animations
• User can reorder animations
• User can delete an animation
• User can set individual frame duration
• Read/write .aeproperties file which includes information like snapping
• User can select multiple animations intuitively with CTRL and SHIFT
• User can reorder multiple animations at once
• User can delete multiple animations at once
• When exporting to a different file format, the target file may be in a different place relative to the image files it references. Image paths in the exported file should be updated to correctly reference the target image file when exporting.

Optional Features (some of these are probably bugfixes)

• The editor can be used in standalone mode
• When an animation ends with a number that has prepended zeroes, the number is correctly incremented when duplicating (0006 -> 0007, not 0006 -> 7)
• Animations can be sorted alphabetically
• User can set whole animation duration and each frame is updated
• If the resize box is a single pixel, the drag handle is intelligently selected in the drag direction such that no dimension can be negative
• User can select N animations, see all of their frames on the spritesheet, and drag all of them at once (really useful for resizing or rearranging spritesheets)
• Magic wand selection works*
• Magic wand can snap to the "next biggest square snap increment in each dimension" (a 12x26 pixel selection snaps to 16x32 if 16 is set as the snap size)*
• Holding a modifier key while clicking with the magic wand will auto create new animation chains with auto-generated names such as "auto_001"*
• A preview pane exists above the list of animations and auto-zooms to fill its frame*
• User can page through animations with a key (tab?) and when paging through, the chain name is automatically focused and selected*
• [SUPER STRETCH GOAL] The editor can be embedded in FRB games in headless mode that you can bind to your own VMs and UI.

* Imagine creating tens or hundreds of new items on a spritesheet, then rapidly magic wand clicking to map all of them to frames that are automatically sized to the snap increment. Then pressing tab to page through the chains and quickly typing in chain names based on the preview image. This would be an incredibly fast way to create and name hundreds of chains.

Testing Notes/Bugs

• When a new frame is created in a new chain, the frame duration shouldn't default to zero, it should probably be something like 0.1f
• Animation whole chain should be draggable, the current AE supports this. Note that the existing optional bullet is to drag multiple animation chains, which is a nice to have. But being able to drag a whole chain with all the frames at once is a common scenario and should exist in the MVP
• Clicking an animation chain should either focus the chain or not move the camera at all. Right now it moves the camera to 0,0 which is worse than not moving it at all. (UPDATE: it only resets the camera sometimes. I tried to capture this on video, see comment below)

[profexorgeek]

This is an image from discord discussion with a recommended UI wireframe:

[profexorgeek]

This video shows a couple of minor bugs. I was specifically trying to repro what is making the camera occasionally reset to focus at 0,0 which is why there's a lot of just random clicking...

• At about 0:40 I copy/paste an animation chain but the pasted version has no frames
• At about 1:28 the camera resets to 0,0 on the spritesheet

animation-editor-minor-bugs.mp4