**Porymap is a cross-platform map editor for the Gen 3 pret decompilation projects. Its primary functions are to allow editing map tiles, collision, events, connections, and properties. Porymap provides additional functionality, such as tileset editing and region map editing. Downloadable releases are available for Windows and Mac, and Linux users can build it from source.**
Those familiar with traditional Gen 3 binary ROM hacking can think of it as the Advance Map equivalent for the decompilation projects. Porymap supports the same features as Advance Map, so Advance Map users shouldn't have much difficulty learning how to use Porymap. There are many usability improvements in Porymap. The most notable is undo/redo when painting map tiles.
Porymap reads and writes files in the decompilation projects. It **does not** read or write ROM files. **Therefore, it is highly recommended to use Git for version control when working with Porymap.**
Before using Porymap, you must have your decompilation project setup. Porymap supports the `pokeemerald <https://github.com/pret/pokeemerald>`_, `pokeruby <https://github.com/pret/pokeruby>`_, and `pokefirered <https://github.com/pret/pokefirered>`_ decompilation projects. See their respective ``INSTALL.md`` files to get setup, and make sure you can successfully compile the ROM.
The first thing we'll do is open a Gen 3 decompilation project with *File -> Open Project…* (``Ctrl+O``). A folder selection dialog will pop up. Choose the location of your existing decompilation project. After doing so, Porymap will take a few seconds to load the project, and the main window should now be displaying the first map. (In ``pokeemerald``, it's Petalburg City.)
Now, let's make our first basic edit using Porymap. We'll use the Pencil Tool to draw some more flowers on the grass in Petalburg City. First, make sure the Pencil Tool is selected. You can click the Pencil Tool button, press the ``N`` shortcut, or select *Tools -> Pencil*. The various painting Tool buttons are found on the left side of the toolbar above the map area.
..figure:: images/introduction/tool-buttons.png
:alt:Tool Buttons
Tool Buttons
Next, select the flower metatile from the Metatile Selection panel by left-clicking on it. The flower is metatile 0x4 in the General tileset.