VEX Creator

Authoring tool for VEX .vfrag files — a single file bundling a GLSL ES 1.00 fragment shader together with its background textures (compressed) that the VEX loads and runs.

Requirements

• The .vfrag extension — and updating a VEX over MIDI — needs a NerdSEQ firmware ≥ 3.03 and VEX ≥ 3.3.
• MIDI features need Chrome or Edge and a secure context (https:// or localhost).

Steps

• Load a shader — drop a .frag/.glsl file (or paste into the editor). It must be a GLSL ES 1.00 fragment shader using gl_FragColor and the VEX's built-in uniforms (u_resolution, u_time, u_texture1…4, …).
• Load a .vfrag — dropping a .vfrag (or picking a Template…) unpacks it: its shader fills the editor and its textures/sprites load into the slots below, replacing whatever was loaded before. A plain shader is the exception — it carries no images, so your textures and sprites are kept.
• New… — start over: back to the default shader with no textures and no sprites. It asks first, and it cannot be undone.
• Add textures — drop an image onto any of the four slots (u_texture1…4). Each shows a thumbnail; pick its pixel format (RGB565 for opaque backgrounds, RGBA for alpha). Images over 1024 px on either axis are auto-scaled down (aspect preserved) — the VEX's hard texture limit.
• Invert — the half-circle button at the bottom right of every texture thumbnail and every sprite cell flips that image's colours. It is lossless and reversible: clicking it again hands back the untouched original, bit for bit, however often you toggle. Only RGB is inverted — transparent stays transparent — and a chroma-keyed colour is inverted with it, so keyed pixels stay keyed.
• Save .vfrag — the shader is compile-checked as GLES2, images are converted and LZ4-compressed, and the bundle downloads. Only slots you actually filled are written.

Recording the preview

• Record (under the preview) captures the live preview to a video file — exactly what plays, including modulator moves and u_mouse drags. Press it again (Stop) to end the take; a Save as dialog then asks where to put the file. Cancel it and the clip is kept behind a Save recording… button rather than lost.
• The dropdown next to it picks the format from what your browser can encode — MP4 (H.264) on recent Chrome/Edge, WebM otherwise. The clip's size is the preview box's own pixel size, so it changes with the window, the aspect buttons and the split position; the aspect buttons are therefore locked while recording (a mid-take resolution change would corrupt the file).

Editing a tilemap

• Click a vex_tile[…] value to pick a sprite for that one entry from the atlas grid.
• Click the vex_tile name itself to open the whole array as a COLS × ROWS map showing the sprite in every cell. Click any cell to pick its sprite — the id is written straight into the array and you're back on the map. Close it with Ready, a click outside, or Esc. Cells with no vex_tile[n] = … in the source are dashed and not editable.
• The grid size comes from the shader's #define COLS / #define ROWS; without them it falls back to the number of assignments per source line.

MIDI

• MIDI connects automatically on startup (if the browser grants access). Use the MIDI ▾ menu or click the round DIN-plug button to reconnect/disconnect. The plug shows green when connected.
• Update VEX (next to the preview's countdown bar) sends the shader/textures/sprites to the VEX over MIDI SysEx — disabled until MIDI is connected. The first update sends the whole bundle (.uvfrag); later updates send only what changed since (.ufrag/.utex/.uspr). Check Auto to update automatically a couple seconds after any change. The bar shows upload progress and the ETA.
• Start on NerdSEQ sends a tiny <name>.svex file (the Filename field, e.g. tilemap.svex) telling the NerdSEQ to start this project in the slot picked in the dropdown (Slot 1…8). It carries the slot byte plus the project name — no shader — so it works even while the shader has a compile error.