Image maps and mission maps
Introduction
One of the map types Hedgewars supports are maps that were previously drawn by an artist. These are called “image maps” because they use an image file (PNG). The looks of such maps are distinctly defined and are not subject to randomized values.
Additionally, these image maps allow Lua-script to be associated with them in order to enable adding specific gameplay changes and map behavior, these are called “mission maps”.
Summary
Put all map files into
Data/Maps/<YOUR MAP NME>
.
Files:
-
map.png
: Map in PNG format
-
preview.png
: Preview image of map. 256×128 PNG image
-
map.cfg
: Map configuration.
- First line: Default theme
- Second line: Maximum recommended number of hedgehogs
-
mask.png
: Optional map mask for custom land types
-
map.lua
: Optional Lua script for mission maps
Location
All maps are automatically loaded from the
Hedgewars data directory.
In this directory there has to be a folder for every map, named after the desired map name.
Examples:
- Data/Maps/MyVeryOwnMap
- Data/Maps/Ropes
- Data/Maps/Sheep
- etc.
Mission maps
Missions may use preset maps that aren't located in the Data/Maps directory.
A mission may contain in the same directory with mission's lua script a .hwp file.
This file is a zip file with an altered extension from .zip to .hwp and it contains the directory Maps/some_name.
In the some_name directory the files map.cfg, map.png and mask.png are located. See the Basic Files section for more on these files.
The name of the .hwp file should be the same with the mission script.
In the mission script’s
onGameInit
, map should be set to some_name. See LuaEvents for more about
onGameInit
.
Files
Within the folder of every map the following files are expected to be there:
Basic files
map.cfg
Configuration file.
- First line is the name of the default theme used by the map (for background and clouds, flakes, water, etc). Select a theme that fits to your map
- Second line is max. number of hedgehogs supported. If the second line is not provided, it is assumed to be 18. Note that Hedgewars currently does not support games with more than 64 hedgehogs
map.png
Image of visible land area.
- 32-bit PNG with alpha channel
- Usually width/length ratio of 2:1
- Typical size: 2048 x 1024
- Max size: no limit, 0.9.18+. 4096 x 2048 or less in 0.9.17 and earlier. There are a few practical limits to map size that should be examined for people trying to make very large maps.
- SDL 1.2 - SDL 1.2 can only load maps that are <=16,384px wide, and <=65,536px high. SDL 1.2 rect is only capable of handling a map that is <=32768 high, while behaviour in Hedgewars 0.9.20 or lower forces <=16,384 if using a mask.png without a map.png.
- SDL 2.0 - SDL 2.0 failed to load a 999,936x512 map. A 499,968x512 map succeeded. Those would use ~244MiB/~122MiB of your graphics card with Blurry Land enabled, and ~977MiB/~488MiB without it.
- GIMP. GIMP 2.8 can only create PNGs that are 262,144px wide or high - is an arbitrary hardcoded sanity check. GIMP 2.10 allows 524,288 wide or high.
- libpng - libpng can only load maps that are < 1 million px wide or high, with default configuration.
- Graphics card. This is the big one. Your graphics card probably has anywhere from 256MiB to 2GiB of vRAM. If blurry land is enabled and the map has a typical amount of empty space, you can make a map w/ ~2x the pixels as a card has vRAM. But. Most people don't like using Blurry Land, so best to limit to ~½ the pixels as a card has vRAM. Targetting support for people on 256MiB of vRAM, that means a 2:1 rectangular map should not be larger than 16,384x8192 which coincidentally fits in the SDL 1.2 width limit.
- There is also a completely arbitrary check in game for widths/height < ~billion pixels which avoids possible integer issues, and a limit on size in pixels of 6 billion or so, which was just a basic sanity limit. However given the limitations above, these are not likely to be reached.
- If there is no mask.png, this image will also be used for deciding what pixels are subject to collision: alpha value not equal to 0 (so below max transparency) will be considered land
- As of 0.9.19+, map.png is optional if a mask.png is provided. If there is no map.png, the theme will be used to decorate the map. No objects will be added to white areas. Use black if you want objects.
preview.png
Preview image of the map to show how the map would actually look like in the game, minus the background. Usually this is just a smaller version of
map.png
, so in most cases you can just downscale
map.png
to get your preview.
This should really just be a preview, and nothing else. No logos, text, theme background or other distractions that don't exist on the map.
Optional files (for advanced features and adjustments)
mask.png
Image defining the collision areas of the map.
- Pixels with alpha value = 0 will not be subject to collision
- White (255, 255, 255) pixels will be terrain, no background texture will be shown when it is destroyed.
- Black (0, 0, 0) pixels will be terrain with background texture applied (Note: Adding any black pixels removes erasure protection from areas where the map.png is solid but the mask.png is transparent) - 0.9.17+
- Red (255, 0, 0) pixels will be indestructible terrain (regardless of game mode settings)
- Blue (0, 0, 255) pixels will be ice - 0.9.17+
- Green (0, 255, 0) pixels are bouncy (since 0.9.20) and block portals (since 0.9.18). This mask can be used normally for maps or theme objects. If bouncing is implemented and the green pixels should only block portals, place a dotted line of single red or black or white pixels 3 pixels above the green, spaced 3 pixels apart each. This will keep most objects from interacting with the green, but prevent portal spawning.
It is recommended that your file only consists of pixels which have one of the values above. This ensures that the masks works properly for your map and avoids unexpected behaviour. Also, it makes your file significantly smaller. Here is a simple guide describing how you can ensure that.
Examples:
(Transparent areas may not be recognizeable as such in your browser/image preview program, so open e.g. in
Gimp)
map.lua
A Lua script to be used together with the map.
See the LuaGuide for more information on Hedgewars’ scripting support.
Image format
- PNG, 8-bit/color RGBA (so 32 bit)
- Gamma correction and colour profiles should not be applied, in order to ensure the map is loaded identically on macOS as it is on other operating systems by SDL. To ensure this happens, please run in the command-line (requires Pngcrush):
pngcrush -rem gAMA -rem cHRM -rem iCCP -rem sRGB old/map.png new/map.png
(Pngcrush is a command-line tool which can be found on
http://pmt.sourceforge.net/pngcrush/)
or be sure your image editing software has these options disabled.
Editing software recommendations
Images
A vector based drawing software is recommended for creating the maps.
(Reasons for that: Edges are usually automatically smoothed on export; Easier to meet Hedgewars Graphics rules, style constraints, guidelines; Images are easier to change, adjust and maintain style)
If you don't have one, check out the free open-source Inkscape: There are various Inkscape tutorials online, so you should be able to get started easily.
Sharing image maps
You can only play a game with a custom image map against other players online if all participating players have the image map installed under the same name.
If any player does not have the image map installed, the game will fail to start and an error message is displayed.
If you wish, you can post your custom-made image map in the Content Creations forum.
