Water terrain code has undocumented WML-Code

[pipapopinguin]

I am working on terrain-related add-ons and I've found code in a water-macro from the dev-team:

Code: Select all

#define NEW:WAVES TERRAINLIST ADJACENT LAYER IMAGESTEM
    [terrain_graphics]
        map="
,  2
*,   2
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={TERRAINLIST}
            set_no_flag=waves_convex-@R0-@R5,waves_convex-@R0-@R1
        [/tile]
        [tile]
            pos=2
            type={ADJACENT}
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]

    [terrain_graphics]
        map="
,  2
*,   2
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={ADJACENT}
            set_no_flag=waves_concave-@R0-@R5,waves_concave-@R0-@R1
        [/tile]
        [tile]
            pos=2
            type={TERRAINLIST}
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]

    # These 4 rules draw very special convex-concave combination rules in 3-way
    # sand-water-other corners
    [terrain_graphics]
        map="
,  2
*,   3
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={TERRAINLIST}
            no_draw=yes
        [/tile]
        [tile]
            pos=2
            type={ADJACENT}
        [/tile]
        [tile]
            pos=3
            type=!,{TERRAINLIST},{ADJACENT}
            no_draw=yes
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]
    [terrain_graphics]
        map="
,  2
*,   3
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={ADJACENT}
            no_draw=yes
        [/tile]
        [tile]
            pos=2
            type=!,{TERRAINLIST},{ADJACENT}
            no_draw=yes
        [/tile]
        [tile]
            pos=3
            type={TERRAINLIST}
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R1.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]
    [terrain_graphics]
        map="
,  2
*,   3
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={TERRAINLIST}
            no_draw=yes
        [/tile]
        [tile]
            pos=2
            type=!,{TERRAINLIST},{ADJACENT}
            no_draw=yes
        [/tile]
        [tile]
            pos=3
            type={ADJACENT}
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-convex-A[01~13].png~MASK(terrain/masks/7hex-@R0.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]
    [terrain_graphics]
        map="
,  2
*,   3
,  1
*,   *
,  *"
        [tile]
            pos=1
            type={ADJACENT}
            no_draw=yes
        [/tile]
        [tile]
            pos=2
            type={TERRAINLIST}
        [/tile]
        [tile]
            pos=3
            type=!,{TERRAINLIST},{ADJACENT}
            no_draw=yes
        [/tile]

        rotations=tr,r,br,bl,l,tl

        [image]
            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R5.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]
    [/terrain_graphics]
#enddef

And the interesting part is:

Code: Select all

        [image]
            name={IMAGESTEM}-concave-A[01~13].png~MASK(terrain/masks/7hex-@R0-@R5.png):200
            random_start=no
            layer={LAYER}
            center=90,144
            base=90,144
            is_water=yes
        [/image]

is_water isn't documented on the TerrainGraphicsWML, so my question is, what exactly does it do and how does it function? Are there any other key words I can put in into [terrain_graphics] or [image]?

My game version is 1.16 and the macro is in new-macros.cfg inside the terrain-graphics folder.

[Celtic_Minstrel]

That relates to the preference to disable animated water. An image with that key will cease to animate if you turn off animated water.