Aseprite Source Code

If you are here is because you want to learn about Aseprite source code. We'll try to write in these README.md files a summary of each module/library.

Modules & Libraries

Aseprite is separated in the following layers/modules:

Level 0: Completely independent modules

These libraries are easy to be used and embedded in other software because they don't depend on any other component.

• clip: Clipboard library.
• fixmath: Fixed point operations (original code from Allegro code by Shawn Hargreaves).
• flic: Library to load/save FLI/FLC files.
• laf/base: Core/basic stuff, multithreading, utf8, sha1, file system, memory, etc.
• laf/gfx: Abstract graphics structures like point, size, rectangle, region, color, etc.
• observable: Signal/slot functions.
• scripting: JavaScript engine.
• steam: Steam API wrapper to avoid static linking to the .lib file.
• undo: Generic library to manage a history of undoable commands.

Level 1

• cfg (base): Library to load/save .ini files.
• gen (base): Helper utility to generate C++ files from different XMLs.
• net (base): Networking library to send HTTP requests.
• laf/os (base, gfx, wacom): OS input/output.

Level 2

• doc (base, fixmath, gfx): Document model library.
• ui (base, gfx, os): Portable UI library (buttons, windows, text fields, etc.)
• updater (base, cfg, net): Component to check for updates.

Level 3

• dio (base, doc, fixmath, flic): Load/save sprites/documents.
• filters (base, doc, gfx): Effects for images.
• render (base, doc, gfx): Library to render documents.
• view (base, doc): Abstract timeline/range view/helpers.

Level 4

• app (base, doc, dio, filters, fixmath, flic, gfx, pen, render, scripting, os, ui, undo, updater, view)
• desktop (base, doc, dio, render): Integration with the desktop (Windows Explorer, Finder, GNOME, KDE, etc.)

Level 5

• main (app, base, os, ui)

Debugging Tricks

When Aseprite is compiled with ENABLE_DEVMODE, you have the following extra commands/features available:

• F5: On Windows shows the amount of used memory.
• F1: Switch between new/old/shader renderers.
• Ctrl+F1: Switch/test Screen/UI Scaling values.
• Ctrl+Alt+Shift+Q: crashes the application in case that you want to test the anticrash feature or your need a memory dump file.
• Ctrl+Alt+Shift+R: recover the active document from the data recovery store.
• aseprite.ini: [perf] show_render_time=true shows a performance clock in the Editor.

In Debug mode (_DEBUG):

• TRACEARGS: in debug mode, it prints in the terminal/console each given argument

In release mode you can use a similar function:

• PRINTARGS prints in the terminal/console each given argument

Trace Macros

You can uncomment/enable some special macros to debug specific features when you are trying to fix a part of the program:

• src/ui/manager.cpp:
  • REPORT_MESSAGES: Prints a string each time a message is removed from the queue, and is sent to a widget. You can enable specific flags to debug mouse/paint/timer messages:
    • REPORT_MOUSE_MESSAGES
    • REPORT_PAINT_MESSAGES
    • REPORT_TIMER_MESSAGES
  • REPORT_FOCUS_MOVEMENT: Prints the list of widgets that participate in the focus movement.
  • LIMIT_DISPATCH_TIME: Limit the amount of time we can pump UI messages until we ask for new events to the OS.
  • GARBAGE_TRACE: Prints debug messages to keep track when a deferDelete() is finally executed.
  • CAPTURE_TRACE: Prints debug messages when the mouse is captured/released.
• src/ui/message.h:
  • DEBUG_PAINT_MESSAGES: Prints a blue rectangle on the screen before sending the final kPaintMessage.
• src/ui/widget.cpp:
  • PAINT_BASELINE: Paints a dotted line where the baseline is located for every single widget.

Detect Platform

You can check the platform using some laf macros:

#if LAF_WINDOWS
  // ...
#elif LAF_MACOS
  // ...
#elif LAF_LINUX
  // ...
#endif

Or using platform-specific macros:

#ifdef _WIN32
  #ifdef _WIN64
    // Windows x64
  #else
    // Windows x86
  #endif
#elif defined(__APPLE__)
    // macOS
#else
    // Linux
#endif