3DS Junkdraw

3DS Junkdraw
General
Author	haloopdy
Type	Other Apps
Version	0.5.0
License	MIT License
Last Updated	2026/05/30
Links
Download
Website
Source

An extremely simple drawing app for the 3DS. Focus is simplicity and ease of reimplementation.

Features

• Paginated drawing capable of storing hundreds of pages per file.
• 8 banks of 64 color palettes (which means no anti-aliasing or alpha-blending).
• Optional RGB color sliders.
• 2 layers with 1-bit transparency.
• Button controls.
• Quick swap between pen/eraser/slowpen.
• Saving/loading.
• PNG + GIF export.
• Animation mode with onion skin + basic gif export.

Controls

Start - Menu

Select - Change layers

L - Color picker

A - Pencil tool

B - Eraser tool

Up/Down - Zoom in/out

Left/Right - Change brush width

R+L - Change palette (the default is the one that starts with bright red followed by black)

R+Left/Right - Really change brush width

R+Up/Down - Change page (can have thousands)

R+L+Up/Down - Really change page (not advised)

R+B - Undo

R+A - Redo

Changelog

V0.5.0 2026/05/30

• NEW DATA FORMAT: when loading drawings from previous versions, the data will automatically be converted to the new format. You must use the new format, and conversion is nearly instantaneous
• Edit menu: you can now perform various page-based actions in the new edit menu
  • Copy/paste (even on top of existing strokes)
  • Swap pages
  • "Shift" pages (think drag to rearrange in other programs)
  • Delete pages
• New (optional) alternate control scheme: toggle buttons:
  • A swaps through tools
  • X undo
  • Y redo
  • B switch to secondary color (new! not available on default mode)
• ZL/ZR now duplicates of L/R (in case your buttons don't work)
• Greatly shortened (5x) the time it takes to scan to page. This means for larger saves (50% or more usage) you will notice GREATLY reduced wait times for later pages to begin rendering. It should be nearly instant for all pages now
• Greatly increased performance of linedraw function. This VASTLY improves performance on old 3ds, and should now match the performance of the new 3ds. In practice, this means scrolling through pages should no longer lag under most circumstances
  • Note: the optimized linedraw function is SLIGHTLY (very VERY slightly) different, and if you pixel-peep, you may notice 1 pixel inconsistencies in incredibly few instances. I have many dozens of drawings that I've checked and I couldn't tell any differences at 1x zoom, but looking very closely, some parts have a missing pixel. This may impact pixel art far more than normal art; if any drawings have been ruined, I recommend downgrading to the last stable release 0.4.3 and exporting your art before upgrading.

V0.4.4_pre3 2026/05/23

• You can now set a page loop point. This means:
  • Navigating pages will loop as you jump through them in both directions; useful for animations
  • Onion skinning will wrap around at the loop point, so frame 1 will show the shadows from the end of the loop (also useful for animations)
• The GIF export will loop at your set loop point, meaning you can leave scraps past the loop point (notes or otherwise) for yourself
• Gif export now lets you set the frame time all the way up to 2000ms (from the old max of 200ms). To make it easier, one of the menu options lets you bump the frame time by 100ms
• Moved "session-only" (ie non-permanent) settings into their own menu to make it more obvious which are saved on application exit and which aren't
• Export options moved into sub-menu, removed duplicate option for canvas size (is set by session options)

V0.4.4_pre2 2026/05/19

• Added a full grayscale palette (for all shades of pure gray possible with 5 bits) plus sepia tones.
• Added HTTP server to easily download last exported image for current session.

V0.4.4 pre 2025/08/11

• Add settings persistence.

V0.4.3 2025/08/11

• Add undo/redo:
  • Press R+B to undo, R+A to redo.
  • Undo buffer count shown as U: on top screen.
  • Undo buffer cleared if you change pages.
  • Image is redrawn for each undo for simplicity, may take a while on complex drawings. You can spam the button to undo multiple times even while the image is redrawing.

v0.4.2 2025/01/26

• This release skips over 0.4.1 and has the following new features:
  • The palette has an extra section on the right to house the last 32 colors used on a page, the "history". It's per-page so new pages have no color history, and old pages (even before the update) will still show a valid color history.
  • There's now an RGB color picker option, available in the options menu. You can now select any arbitrary color using basic sliders.
  • Added 2 new palettes, trying to round out the selection of colors through palettes.

v0.4 2024/09/17

• Added multiple draw modes to facilitate animation (see "Options"). These are "Normal", "Animation", and "Small Animation".
• Added onion skin up to 3 layers deep (not including your current page) with a settable darkness.
• Added gif export.
• Added layer visibility (but it's not simple; you have to go through the options menu).
• Disable home + sleep in critical places to prevent crashes + freezes when going back to the home menu. These are mainly in menus, where the menu title will turn red if you try to press home to indicate that it was blocked.
• Added slow pen; press Y to use. Same look as regular pen, but lags behind cursor to create a sort-of "stabilization" effect. In reality, it's just a lag brush.
• Enable new 3DS mode on startup to increase speed. Mostly only noticeable with very large drawings (maybe over 50% full).
• Add option to disable new 3DS mode (and potentially other things in the future) with "Power Saving" option in menu.

v0.3.3 2024/07/23

• Fixed segmentation faults occurring on real hardware.
  • Issue was not present in earlier versions, accidentally added a NULL check when struct wasn't initialized, forgot this isn't Go.
• Removed old source code.
• Refactored even more to remove unnecessary code.

v0.3.2 2024/07/22

• DO NOT USE: segmentation fault on real hardware.
• Fixed strange rendering bugs that would rarely occur (like phantom strokes that looked legitimate but were in the wrong place or color).
• Files will load on the last used page for convenience.
• Very large rewrite of parsing/drawing system. Significantly simplified.

v0.3.1 2024/07/11

• Small QOL update:
  • PNG export now in menu, where everyone (including myself) expects it to be.
  • Clarify how to change pages.
  • Ignore ALL rects outside of texture.
  • Auto-close palette when color chosen.
  • Add screenshot to readme.

v0.3.0 2024/07/10

• Completely refactor all code to fix one issue:
  • Screen size reduced to 1000x1000 (from 1024x1024).
  • Can now safely draw on left and top edges of screen.
  • Remove multiplayer features (system still setup to support it, just don't want to do it now).
  • Add additional debug messages on boot.

v0.2.2 2024/07/08

• First "release" with modifications to get around citro2d bugs:
  • Draw on a "large" paginated canvas.
  • Simple save/load system.
  • Export to png (R+select).
  • 2 layers, 64 colors.
  • Created with the goal of multiplayer probably won't implement it though.

External links

• GitHub - https://github.com/randomouscrap98/3ds_junkdraw/
• GBAtemp - https://gbatemp.net/threads/3ds-junk-draw.658158/