rmgen heightmap image import

[elexis]

While it is a rightfully demanded feature to open terrain maps created in atlas from a random map script, it would also be handy to open an image file of a heightmap directly from rmgen without creating a PMP file thereof.

The rmgen script can then be tought to interpolate, set the waterheight and so forth. This way one can keep the original data source and if needed replace it while the code and map generation still works. (It means if such a replacement is needed or benefitial, artistic value of the terrain is not lost).

See #4816 for loading Atlas terrain PMP files from random map scripts.

[elexis]

For instance if someone decides that we actually wanted a slightly different chunk of the map (square to circular map conversion), the entire artwork in atlas would be lost, but if there was no artwork in atlas but rmgen doing the same, it can't be lost.

[elexis]

blue marble data

[elexis]

In 21113:

Allow random map scripts to load heightmap image files, fixes #5018.

Move the atlas heightmap import code to MapIO.cpp and reuse it.
Implements what rP18523 and rP20525 wanted to be.

[elexis]

In 21133:

Implement JS random map library counterpart to rP21131 and rP21113, refs #4816, #5018.

Refactors the heightmap and terrainmap copying code from rP18523 and the bicubic interpolation code from rP18710 / rP18925 which were unused since rP20362.

[elexis]

In 21135:

Red Sea random map replica, based on the original map by _kali created in rP18523 deleted in rP20362, refs #4816, #5018, D957.

Uses an unadulterated, easily exchangeable, well compressed topography image of the NASA Blue Marble series in the public domain,
instead of a heavily tuned and not so well licensed NASA SRTM v4.1 image encoded in JSON.
Circular intead of a square map shape.
Randomized, height- and slope-based terrain texture painting, refs #5004.

[elexis]

In 21157:

Mediterranean random map replica of _kali's map in rP18523, refs #5018, D957.

[elexis]

In 21175:

Implement SmoothingPainter for random maps, fixes #5027.

This allows only specific regions of the map to be smoothened, especially important on imported digital elevation models.
It uses the Inverse Distance Weighting / Shepard's method as mentioned by Imarok and formerly implemented in the Pyrenean Sierra map by wraitii in rP12248.

Supersedes the globalSmoothHeightmap function in FeXoRs heightmap library, refs #3764.
Drop the heightmap argument to be consistent with the other painters.
If painting on arbitrary heightmaps is wished, the createArea mechanism, all Placers, Painters, Constraints and Areas can and should support that.

Update the HeightmapPainter from rP21133 to not break if TILE_CENTERED_HEIGHT_MAP is enabled (i.e. numVertices = numTiles), refs #5018.
Use that mode on Mediterranean and Red Sea.
Drop the disabling of bicubic interpolation in the HeightmapPainter instead of extending it to this feature.

Inevitable smoothing performance improvement for Belgian Uplands (from 45 to 15 seconds per call), even if it implies a somewhat different outcome, refs #5011.

[elexis]

In 21227:

convertHeightmap1Dto2D helper function which allows extracting a subset of a heightmap image.
Could become superseded by the C++ counterpart returning a 2D array instead, refs #5018, #4816.

One more DiskPlacer from rP21225.

[elexis]

In 21330:

Elephantine random map script, refs #5040.
Uses OpenStreetMap polygons for the shape of the water, refs #5018.

Proposed by: Sundiata, wowgetoffyourcellphone

[elexis]

In 21403:

Add translateHeightmap function which allows repositioning of an imported heightmap before copying it to the map, refs #3764, #5018, #4816.

Inline some variables and return the heightmap in the heightmap library functions, so that one can apply multiple transformations within the same statement.

[elexis]

In 21814:

Fix rP21113 compatibility with zipped mods, refs #5018.

Differential Revision: ​https://code.wildfiregames.com/D1480
Reviewed By: Itms

[elexis]

In 22892:

Use all three color channels when loading heightmaps following rP21113, refs #5018.

Removes wrong debug leftover line from rP21113 and unneeded clamp from rP12308.

Differential Revision: ​https://code.wildfiregames.com/D1816
Patch By: Angen
Comments By: Vladislav