2.8 KiB
Asset Editor
The Asset Editor finds asset headers in your source — small JSON descriptors inside comments — and turns the data block that follows into an editable bitmap, tilemap, or palette. Edits are written straight back into the source text, preserving the original number base and formatting of each literal.
Asset List
Open the Asset Editor from the sidebar to see every editable asset in your project in one scrolling list. Assets are grouped by file — a heading with the filename, then each asset underneath, in the order it appears in the source.
Each asset shows a line number you can click to jump to that spot in the code (and highlight it), the Asset Header as written in the file, and the editor itself — a picture, a palette, or a tilemap. If something is wrong with an asset, a red error message appears in place of its editor.
Click an asset to start editing; the editor scrolls into view, and your selection is saved in the address bar so you can bookmark or share it. You don't need to understand the header format to edit graphics, but if you want to add or change one, Asset Headers explains it.
Editing images
Assets with a width and height show a grid of thumbnails — one per image. Click the one you want, and a large editor opens beside it.
To paint, just click and drag on the image. Pick a color from the row of swatches below it (each labelled with its palette index). Starting a drag on a pixel that's already the color you picked will erase instead of paint.
The toolbar above the image has quick transforms: flip it horizontally or vertically, rotate it, nudge it in any direction, and copy/paste it. Copy and paste work between any two images in the session, and they keep the palette indices intact, so a tile copied from one asset still looks right in another even if the colors differ.
Editing palettes
Palettes are edited one color at a time. The palette appears as a small table; click any cell to open a color picker. Small, indexed palettes show a grid of swatches to choose from — hover over one to see its value and hex color. Larger, direct-color palettes get color sliders instead. As you change a color, the source code is updated right away.
If more than one palette in your project matches the image's color count, a dropdown appears under the thumbnails. Select a palette to preview it with your image.
Viewing tilemaps
NES nametable assets (map:"nesnt") show the whole tilemap composited
from your project's graphics and palette, as a single preview.
Undo and redo
Use Ctrl/Cmd+Z to undo and Ctrl/Cmd+Shift+Z to redo your edits. The
history starts fresh each time you open the Asset Editor, so undo only
affects the changes you've made in this session.