Decal layer editing
The decal edit panel can be opened from the slot overview panel, by either clicking the 'edit' entry or the image for the decal layer. The 'D' hotkey can also be used to open the decal panel from the slot overview panel.
TODO : screenshot of panel
At the very top of the panel, the ID of the currently selected slot to which this decal layer belongs, is shown.
Under the active slot, the name of the current sprite used as the image for this layer is shown, in the default set_style_sprite format.
Under the sprite name, the sprite itself is shown (the size of this preview depends on the default gridsize for the active compatibility mode), with next to it 3 selectors to change the set, style and tile of this sprite. To change the image, you can either click the arrow buttons to cycle through all available sets, styles or tiles for the active compatibility mode. If you place the mouse cursor over the 'set', 'style' or 'tile' words, you can also use the arrow keys to cycle through the available images.
Further there is also a selector for the hue, opacity and brightness (which can also be controlled with arrow keys, similar to the image selectors), two toggles to turn vertical or horizontal flip on or off and a rotate button that allows to cycle through four orientations : north (N), east (E), south (S) and west (W). X and Y offsets can be changed to adjust the position of the decal image relative to the top left corner of the slot it belongs to. These values can range from -31 to +32. The cissors icon can be used to toggle cutoff on or off - if this option is set to 'off', images with an offset can spill over into neighbouring slots. If this option is set to 'on' instead, the part of an image that would overlap a neighbouring slot will be cut off instead.
At the bottom of the panel, there are options to copy the entire decal layer, or paste previously copied decal layer data into this layer. It's also possible to delete this layer, or return to the selected grid overview or the editor main menu.