XmobiTea TextureCrop

Editor-only texture cropping window for opening an image file, adjusting board/offset/scale, and saving the baked result.

AI Quick Contract

• This package is Editor-only
• Main window: TextureCropWindowsEditor
• Main menus:
  • XmobiTea Tools/Texture Crop/Show Windows
  • Assets/Texture Crop/Show Windows
• Works with selected Texture2D or Sprite
• Apply overwrites the currently opened file on disk
• Save As writes a new file and reopens it
• The tool edits raw image bytes, not Unity importer metadata
• Current 9-Slice mode is pixel-cropping logic, not Unity sprite border authoring
• Save implementation only handles .png and .jpg, even though the dialog also offers .jpeg and .jpe

What This Package Provides

• fixed-size editor utility window for image cropping
• manual board size and scaling controls
• trim and power-of-two helpers
• undo/redo state stacks
• corner-only 9-Slice crop mode

Exact Editor Behavior

Opening The Tool

Menus:

XmobiTea Tools/Texture Crop/Show Windows
Assets/Texture Crop/Show Windows

Assets/Texture Crop/Show Windows is only valid when the current selection is:

• Texture2D
• Sprite

The asset-path flow opens the selected file from disk and loads it into a temporary Texture2D.

Board Size And Canvas Behavior

Initial/default board size is:

512 x 512

Allowed board-size range is clamped to:

4 .. 8192

The tool keeps separate concepts for:

• source texture pixels
• board width/height
• offset around the board
• scale applied before baking the final texture

Apply

Apply:

1. bakes the current board result through TextureCropUtility.GetLastTexture(...)
2. overwrites the currently opened file path on disk
3. reloads the baked texture into the editor window

This is a destructive in-place save for the opened file.

Save As

Save As:

1. opens a file dialog
2. bakes the current board result
3. writes the new file
4. reopens that file in the editor window

Important quirk: the save dialog offers png,jpg,jpeg,jpe, but actual save code only writes bytes for .png and .jpg.

Practical consequence: choosing .jpeg or .jpe is not a safe documented workflow.

Trim()

Trim() scans for non-transparent bounds and crops the texture to that rectangle.

Important quirk: the code compares pixels against the exact color:

new Color(1, 1, 1, 0)

So this is not a generic "alpha == 0" trim rule. It is an exact transparent-color comparison.

POT()

POT():

1. calls Trim()
2. expands board width and height to the next power of two
3. keeps a minimum dimension of 4

9-Slice

Current 9-Slice mode:

1. enters selection mode
2. captures four corner regions using left/right/top/bottom ratios
3. merges those corners into a new texture
4. runs Trim()
5. runs POT()

Important consequence: this does not write Unity sprite border metadata. It only creates a new pixel texture based on the four corners.

Undo / Redo

Undo and redo are in-memory stacks of cloned Texture2D states.

Practical consequence: large textures can increase memory use while the window stays open.

Required Setup

No runtime or scene setup is required.

This package is editor-only.

Do / Don't

Do

• Do treat this as raw image-file editing.
• Do expect Apply to overwrite the current file.
• Do prefer .png or .jpg when saving.
• Do describe 9-Slice as texture processing, not sprite import configuration.
• Do use the asset-context menu for selected sprites or textures.

Don't

• Don't generate runtime code around this package.
• Don't claim that the tool edits Unity sprite border metadata.
• Don't present .jpeg and .jpe as safe save targets.
• Don't describe Trim() as a generic alpha-only trim without noting the exact transparent-color comparison.

Common Mistakes

Mistake 1: Treating Apply as non-destructive preview

Apply writes back to the current file path.

Mistake 2: Treating 9-Slice as importer border setup

The tool only manipulates pixels.

Mistake 3: Assuming all save extensions from the dialog are implemented

Current save code only handles .png and .jpg.

Mistake 4: Assuming trim checks only alpha

The code compares against exact transparent white (1, 1, 1, 0).

Namespace

using XmobiTea.TextureCrop.Editor;

Package Metadata

• Package name: com.xmobitea.changx.mini-texturecrop
• Unity version: 2022.3+
• License: Apache-2.0