A sample Play window. The center icon is surrounded by 6 others with combined bit flags of 246. In 47-state joining, the corners with flags 2 and 128 don't count, so the real state displayed is 116.
Version 2
by Lummox JR
IconCutter is a utility designed to create icons suitable for autojoining from a template you supply.
Autojoining icons may be used to create effects such as walls that have continuous edges instead of individual blocks, puddles and ponds that have realistic-looking boundaries instead of square tiles, tables that adjust to fit any shape you want, and more.
Throughout the following text, numbers that refer to different join states can be considered as combinations of bits. Bit 0 (value 1) is north, bit 1 (2) is northeast, bit 2 (4) east, bit 3 (8) southeast, and so on clockwise.
For more information on how to use autojoining effects in your games, see Dream Tutor: All Together Now at BYONDscape.
To begin using IconCutter, the first thing you'll need is an icon to use
as a template. sourceicons.dmi, included in the project, is a
good example. It has icon states 0, 17, 68, 85, and 255, which make it useful
for 47-state autojoining. State 0 is all outer edges: It's
for tiles that won't join to any other. State 17 is for joining to the north
and south; notice it has edges to either side. State 68 is the same east and
west. 85's edges are inside corners, which is what you get when joining in
all 4 cardinal directions but not diagonally. And finally, 255 is for tiles
completely surrounded by other tiles; it has no edges at all.
The way IconCutter works is by breaking these templates up into 4 corners each, and developing all the possible autojoin states from those corners. For example, state 1 would be an icon that joins to the north only; its bottom half needs outside corners like you see in state 0, and its top half needs to join north with edges on either side, like you see in state 17. So IconCutter builds state 1 by taking the top half of 17 and the bottom of 0.
To get good results out of IconCutter, your template icons should be made so that each can be split into 4 16×16 corners and mixed with other corners. For example, if you made water tiles and used a different pattern for each icon in the template, the corners wouldn't match up well; state 5--which uses the corners of 0, 17, 68, and 85--would be one of many finished icons that showed a seam between the corners.
IconCutter can do more than one kind of joining at a time. To put multiple autojoining icons in the same file, all you need to do is give them different state names followed by numbers. For example, you could have trees0, trees17, etc., and then also have sand0, sand17, sand68.... IconCutter would properly apply your requested autojoin type to create trees1, trees4, and so on, while also making icons for the sand series.
The numbers you need depend on the kind of joining you wish to do. You must have 0, 17, 68, and 85 at the very least. If that's all you have, it's suited for 16-state joining. For 47-state joining, which is more common (because it's more versatile), you also need 255 for the filled corners. In addition, IconCutter supports other join types including 161-state (which requires states 187 and 238) and 256-state (which uses all of the above as well as 170).
Once you have your template icon, you're ready to cut it. Open IconCutter
and click the Load link that appears in your browser. A list of the joinable
states will appear, with options for you to choose from. In the case of
sourceicons.dmi, you'll see that the default state ("") is a
good candidate for 47-state joining.
Go down the list and choose the join type you want for each series. You can choose a lower value like 16, or a higher value. If you choose to autojoin for more states, like using a 47-state template to build a 161-state icon, IconCutter will fill in as best it can from what you provide. There's no point using a higher value if you don't have to, though, as it just makes a larger file.
You can also select no joining, if you don't plan to use autojoining for a template set that might support it.
Once you're ready, click any one of the "Join now" buttons. The icons will then be sliced and diced into their new form. If you're ready to save at this point, click the Save link at the top of the page, and IconCutter will prompt you for a file name. Save the new icon as anything you like.
You can still keep working on the same set, if you change your mind about something, or you can load a new icon and start again.
A sample Play window. The center icon is surrounded by 6 others with combined bit flags of 246. In 47-state joining, the corners with flags 2 and 128 don't count, so the real state displayed is 116.
To see your joined icon in action, you can click the Play link to play around with it. A popup window will appear with a 3×3 grid of icons. The center grid cell will show your icon, and other icons around it may be turned on or off. Your icon in the center will adjust accordingly. Below you will see the bitflags that the surrounding icons represent, as well as the actual state displayed for the center icon.
16-state joining is the simplest kind: It doesn't care about connections between corners. It has 16 states because each of the 4 sides may be connected or not, which is simply 2×2×2×2. Although IconCutter describes this as "unfilled corners", really your icons can look however you want. For many things you can get a good effect out of just 16 states.
The most obvious uses for 16-state joining include roads and pipes.
47-state joining is the most common, because it is the most useful. It can show edges anywhere. The only restriction is that it may not join a corner unless both sides next to that corner are also joined. 47 seems like a strange number, but that's really what it works out to. Mathematically, having 4 sides and 4 corners could mean up to 256 connections, which is where 256-state joining comes in, but the restriction on how corners can be joined means that certain combinations just don't work. Only 47 do.
This kind of join can be used for most items: Walls, terrain, water.
To reduce a set of bit flags to a valid 47-state form, use this formula:
flags &= ((flags << 1) & ((flags << 7) | (flags >> 1))) | 85161-state "incomplete corner" joining is unique but of limited practicality for most games. It's a hybrid between 47-state and 256-state joins. It can reduce the "squaring" effect of 47-state joining to further round out inside corners, and it can be used to create edges that terminate instead of flowing into the next icon. The difference between this and 47-state joining is that a corner can have a connection as long as either side next to it is also connected.
Templates for 161-state joining need states 187 (connections north, south, and in all diagonal directions) and 238 (connections east, west, and all diagonals).
I discovered this join type when trying to make autojoining railings for a game. Graphically it made no sense for a railing to continue into a set of stairs if the staircase was going down; I wanted the railing to have a nice post at the end instead. So I created a rule for this: If the stairs next to this tile go down, count the corner tiles next to the stairs as connected.
This join type is useful for realistic liquid, terrain, or cavern walls. The incomplete corners "anticipate" a curve, so you can draw part of the curve in the incomplete corner, and part in the inside corner (state 85), instead of having the inside corner draw a single curve constrained by small space.
To reduce a set of bit flags to a valid 161-state form, use this formula:
flags &= (flags << 1) | (flags << 7) | (flags >> 1) | 85This type allows corner connections to be independent of the sides. It is almost useless because generally, any time you'd want to connect the corners of two tiles, you would want some kind of smooth transition into the tiles to either side. An exception would be a game like ACWraith's Webcrawl, where the connection is just a 1-pixel line.
To make a 256-state template, you need states 187 and 238 as you would in 161-state joining, as well as 170. State 170 should show connections to all of the corners, but none of the sides.
This join type is a hybrid between 16-state and 161-state joining. Partial corners are allowed, but the difference between inside and filled corners is meaningless. A corner is only considered connected if one and only one side next to it is also connected.
Templates for 82-state joining need states 187 and 238, but not 255.
To reduce a set of bit flags to a valid 82-state form, use this formula:
flags &= (flags << 1) ^ (flags << 7) | (flags >> 1) | 85Foomer invented a subset of 47-state joins which only uses 13 states. This allows for much smaller icon files and more artistic freedom, but places some restrictions on how the icons are used. Generally icon sets of this sort aren't built by IconCutter, but by hand. However, IconCutter can create them.
There are only 13 valid states in Foomerian joining: a single outside or inside corner, a side, or completely filled. To place the icons correctly, each must be part of a 2×2 block. Also in any given 3×3 block, there may not be two empty corner tiles, since this would require the center icon to have two inside corners.
Another type of join based on this, Neo-Foomerian joining, uses 15 states. It has the same restrictions except for one: it allows icons with two inside corners. This form is a little easier to work with when building maps, but it does remove some of the artistic design advantages of a 13-state join in that it's harder to make by hand. (Many icon sets designed for original 13-state joining can be converted to 15-state by cutting the inside corner icons diagonally and combining them to create states 119 and 221.)
The source icon for a Foomerian join should have states 0, 17, 68, 85, and 255, but of those only state 255 will appear in the final output. The other states will be used to build the valid ones.