Method RebuildColourIndexIfNecessary

src/smallmap_gui.cpp:745–765

* Rebuilds the colour indices used for fast access to the smallmap contour colours based on the heightlevel. */

	 * Rebuilds the colour indices used for fast access to the smallmap contour colours based on the heightlevel.
	 */
	void RebuildColourIndexIfNecessary()
	{
		/* Rebuild colour indices if necessary. */
		if (SmallMapWindow::map_height_limit == _settings_game.construction.map_height_limit) return;

		for (auto &heightmap_scheme : _heightmap_schemes) {
			/* The heights go from 0 up to and including maximum. */
			size_t heights = _settings_game.construction.map_height_limit + 1;
			heightmap_scheme.height_colours.resize(heights);

			for (size_t z = 0; z < heights; z++) {
				size_t access_index = (heightmap_scheme.height_colours_base.size() * z) / heights;

				/* Choose colour by mapping the range (0..max heightlevel) on the complete colour table. */
				heightmap_scheme.height_colours[z] = heightmap_scheme.height_colours_base[access_index];
			}
		}

		SmallMapWindow::map_height_limit = _settings_game.construction.map_height_limit;
		BuildLandLegend();
	}

	/**
	 * Get the number of rows in the legend from the number of columns. Those