Delacroix and GIMP
Delacroix combines GIMP's well-tried image engine with a Mac interface of its own. It is not GIMP for macOS: it uses GIMP 3.2.6's engine so that the pixels and the files are right, and follows the Mac, and Affinity's way of working, everywhere else.
This page is for people who know GIMP: what stays the same, and what is different.
Architecture
| GIMP 3.2 | Delacroix | |
|---|---|---|
| Interface | GTK 3 | Swift, AppKit and SwiftUI |
| Canvas | Drawn by the CPU | Drawn with Metal; the layer stack is composited on the GPU |
| Engine | GIMP core over GEGL and babl | The same core, vendored without GTK, over GEGL and babl |
| Text | Pango and FreeType | Core Text, with the fonts installed on the Mac |
| Plug-ins | Separate processes, through the PDB | None; the operations are built in |
What Is Different
The canvas is drawn on the GPU
In Delacroix the layer stack is composited on the GPU with GIMP's own layer-mode maths. Changing a layer's opacity, mode or visibility redraws at once, without waiting for the engine. Brush dabs and gradient previews appear straight away while the engine paints behind them. Pinch to zoom, two-finger panning and two-finger rotation (hold ⇧ for 15° steps) are smooth at any size.
Personas instead of one toolbox
GIMP shows all of its tools in one toolbox. Delacroix divides them into five personas (Raster, Vector, Liquify, Export and Pixel), each with its own tools, panes and layout. See Personas.
One tool, several modes
Several of GIMP's tools are modes of one Delacroix tool:
- Move (
V) picks and moves objects; GIMP's Move tool is its GIMP Move mode in the Raster persona. - The Lasso includes the Magnetic Lasso (GIMP's Scissors Select).
- The Wand includes Select by Colour (All Matching).
- Clone includes Perspective Clone.
- The Brush paints with GIMP's tips or with MyPaint, depending on the brush you choose.
Filters that stay editable
In GIMP 3, filters can stay editable on a layer. Delacroix builds on that: turn on Keep editable in a filter's dialog and the filter becomes an effect in the Effects pane, where you can change, reorder, hide or bake it at any time. Layer styles save sets of effects to reuse.
Vector work like Affinity Designer
GIMP's vector support is centred on paths and, in 3.2, vector layers with one fill and one stroke. In Delacroix:
- A vector layer is a container of shapes, each with its own fill and stroke.
- The Pen draws curve objects, as Affinity Designer's does.
- Shapes stay live until you convert them to curves.
- Booleans can stay live as compounds.
- Dropping a layer on another's thumbnail makes it a mask, and dropping it on another's name clips it.
GIMP still opens every shape as a vector layer. See Vector and SF Symbols.
A Mac application
- Mac menus and shortcuts:
⌘,for Settings,⌘Hto hide, and all shortcuts changeable in Settings ▸ Shortcuts. - Search and Run a Command… (
⌘/) finds any menu item or tool. - Light and dark appearance follow the system.
- Text uses Core Text and the Mac's font menus.
Things Delacroix adds
The Pixel persona and its working palette, the Develop pane, artboards, symbols, SF Symbols templates, the Freeform Gradient and the Dither Brush, slices with output presets, global colours, snapshots, macros, and the Send Feedback tool.
What Stays GIMP's
The interface is the Mac's, but the data is GIMP's:
- The same pixels. Painting, filters, layer modes and file saving run through the vendored GIMP 3.2.6 engine.
- XCF in both directions. Layers, groups, masks, layer modes, paths, vector layers, text and metadata pass cleanly between Delacroix and GIMP 3.2 on Linux, Windows or the Mac.
- No lock-in. Features GIMP doesn't have are kept next to the GIMP data. The status bar shows how compatible the document is, and File ▸ GIMP Compatibility… tells you what would be lost and how to avoid it. See Files and Formats.