/**
* Heightmap manipulation functionality
*
* A heightmapt is an array of width arrays of height floats
* Width and height is normally mapSize+1 (Number of vertices is one bigger than number of tiles in each direction)
* The default heightmap is g_Map.height (See the Map object)
*
* @warning - Ambiguous naming and potential confusion:
* To use this library use TILE_CENTERED_HEIGHT_MAP = false (default)
* Otherwise TILE_CENTERED_HEIGHT_MAP has nothing to do with any tile centered map in this library
* @todo - TILE_CENTERED_HEIGHT_MAP should be removed and g_Map.height should never be tile centered
*/
/**
* Get the height range of a heightmap
* @param {array} [heightmap=g_Map.height] - The reliefmap the minimum and maximum height should be determined for
* @return {Object} Height range with 2 floats in properties "min" and "max"
*/
function getMinAndMaxHeight(heightmap = g_Map.height)
{
let height = {
"min": Infinity,
"max": -Infinity
};
for (let x = 0; x < heightmap.length; ++x)
for (let y = 0; y < heightmap[x].length; ++y)
{
height.min = Math.min(height.min, heightmap[x][y]);
height.max = Math.max(height.max, heightmap[x][y]);
}
return height;
}
/**
* Rescales a heightmap so its minimum and maximum height is as the arguments told preserving it's global shape
* @param {number} [minHeight=MIN_HEIGHT] - Minimum height that should be used for the resulting heightmap
* @param {number} [maxHeight=MAX_HEIGHT] - Maximum height that should be used for the resulting heightmap
* @param {array} [heightmap=g_Map.height] - A reliefmap
* @todo Add preserveCostline to leave a certain height untoucht and scale below and above that seperately
*/
function rescaleHeightmap(minHeight = MIN_HEIGHT, maxHeight = MAX_HEIGHT, heightmap = g_Map.height)
{
let oldHeightRange = getMinAndMaxHeight(heightmap);
for (let x = 0; x < heightmap.length; ++x)
for (let y = 0; y < heightmap[x].length; ++y)
heightmap[x][y] = minHeight + (heightmap[x][y] - oldHeightRange.min) / (oldHeightRange.max - oldHeightRange.min) * (maxHeight - minHeight);
return heightmap;
}
/**
* Translates the heightmap by the given vector, i.e. moves the heights in that direction.
*
* @param {Vector2D} offset - A vector indicating direction and distance.
* @param {number} [defaultHeight] - The elevation to be set for vertices that don't have a corresponding location on the source heightmap.
* @param {Array} [heightmap=g_Map.height] - A reliefmap
*/
function translateHeightmap(offset, defaultHeight = undefined, heightmap = g_Map.height)
{
if (defaultHeight === undefined)
defaultHeight = getMinAndMaxHeight(heightmap).min;
offset.round();
let sourceHeightmap = clone(heightmap);
for (let x = 0; x < heightmap.length; ++x)
for (let y = 0; y < heightmap[x].length; ++y)
heightmap[x][y] =
sourceHeightmap[x + offset.x] !== undefined &&
sourceHeightmap[x + offset.x][y + offset.y] !== undefined ?
sourceHeightmap[x + offset.x][y + offset.y] :
defaultHeight;
return heightmap;
}
/**
* Get start location with the largest minimum distance between players
* @param {Object} [heightRange] - The height range start locations are allowed
* @param {integer} [maxTries=1000] - How often random player distributions are rolled to be compared
* @param {number} [minDistToBorder=20] - How far start locations have to be away from the map border
* @param {integer} [numberOfPlayers=g_MapSettings.PlayerData.length] - How many start locations should be placed
* @param {array} [heightmap=g_Map.height] - The reliefmap for the start locations to be placed on
* @param {boolean} [isCircular=g_MapSettings.CircularMap] - If the map is circular or rectangular
* @return {Vector2D[]}
*/
function getStartLocationsByHeightmap(heightRange, maxTries = 1000, minDistToBorder = 20, numberOfPlayers = g_MapSettings.PlayerData.length - 1, heightmap = g_Map.height, isCircular = g_MapSettings.CircularMap)
{
let validStartLoc = [];
let mapCenter = g_Map.getCenter();
let mapSize = g_Map.getSize();
let heightConstraint = new HeightConstraint(heightRange.min, heightRange.max);
for (let x = minDistToBorder; x < mapSize - minDistToBorder; ++x)
for (let y = minDistToBorder; y < mapSize - minDistToBorder; ++y)
{
let position = new Vector2D(x, y);
if (heightConstraint.allows(position) && (!isCircular || position.distanceTo(mapCenter)) < mapSize / 2 - minDistToBorder)
validStartLoc.push(position);
}
let maxMinDist = 0;
let finalStartLoc;
for (let tries = 0; tries < maxTries; ++tries)
{
let startLoc = [];
let minDist = Infinity;
for (let p = 0; p < numberOfPlayers; ++p)
startLoc.push(pickRandom(validStartLoc));
for (let p1 = 0; p1 < numberOfPlayers - 1; ++p1)
for (let p2 = p1 + 1; p2 < numberOfPlayers; ++p2)
{
let dist = startLoc[p1].distanceTo(startLoc[p2]);
if (dist < minDist)
minDist = dist;
}
if (minDist > maxMinDist)
{
maxMinDist = minDist;
finalStartLoc = startLoc;
}
}
return finalStartLoc;
}
/**
* Sets the heightmap to a relatively realistic shape
* The function doubles the size of the initial heightmap (if given, else a random 2x2 one) until it's big enough, then the extend is cut off
* @note min/maxHeight will not necessarily be present in the heightmap
* @note On circular maps the edges (given by initialHeightmap) may not be in the playable map area
* @note The impact of the initial heightmap depends on its size and target map size
* @param {number} [minHeight=MIN_HEIGHT] - Lower limit of the random height to be rolled
* @param {number} [maxHeight=MAX_HEIGHT] - Upper limit of the random height to be rolled
* @param {array} [initialHeightmap] - Optional, Small (e.g. 3x3) heightmap describing the global shape of the map e.g. an island [[MIN_HEIGHT, MIN_HEIGHT, MIN_HEIGHT], [MIN_HEIGHT, MAX_HEIGHT, MIN_HEIGHT], [MIN_HEIGHT, MIN_HEIGHT, MIN_HEIGHT]]
* @param {number} [smoothness=0.5] - Float between 0 (rough, more local structures) to 1 (smoother, only larger scale structures)
* @param {array} [heightmap=g_Map.height] - The reliefmap that will be set by this function
*/
function setBaseTerrainDiamondSquare(minHeight = MIN_HEIGHT, maxHeight = MAX_HEIGHT, initialHeightmap = undefined, smoothness = 0.5, heightmap = g_Map.height)
{
g_Map.log("Generating map using the diamond-square algorithm");
initialHeightmap = (initialHeightmap || [[randFloat(minHeight / 2, maxHeight / 2), randFloat(minHeight / 2, maxHeight / 2)], [randFloat(minHeight / 2, maxHeight / 2), randFloat(minHeight / 2, maxHeight / 2)]]);
let heightRange = maxHeight - minHeight;
if (heightRange <= 0)
warn("setBaseTerrainDiamondSquare: heightRange <= 0");
let offset = heightRange / 2;
// Double initialHeightmap width until target width is reached (diamond square method)
let newHeightmap = [];
while (initialHeightmap.length < heightmap.length)
{
newHeightmap = [];
let oldWidth = initialHeightmap.length;
// Square
for (let x = 0; x < 2 * oldWidth - 1; ++x)
{
newHeightmap.push([]);
for (let y = 0; y < 2 * oldWidth - 1; ++y)
{
if (x % 2 == 0 && y % 2 == 0) // Old tile
newHeightmap[x].push(initialHeightmap[x/2][y/2]);
else if (x % 2 == 1 && y % 2 == 1) // New tile with diagonal old tile neighbors
{
newHeightmap[x].push((initialHeightmap[(x-1)/2][(y-1)/2] + initialHeightmap[(x+1)/2][(y-1)/2] + initialHeightmap[(x-1)/2][(y+1)/2] + initialHeightmap[(x+1)/2][(y+1)/2]) / 4);
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
else // New tile with straight old tile neighbors
newHeightmap[x].push(undefined); // Define later
}
}
// Diamond
for (let x = 0; x < 2 * oldWidth - 1; ++x)
{
for (let y = 0; y < 2 * oldWidth - 1; ++y)
{
if (newHeightmap[x][y] !== undefined)
continue;
if (x > 0 && x + 1 < newHeightmap.length - 1 && y > 0 && y + 1 < newHeightmap.length - 1) // Not a border tile
{
newHeightmap[x][y] = (newHeightmap[x+1][y] + newHeightmap[x][y+1] + newHeightmap[x-1][y] + newHeightmap[x][y-1]) / 4;
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
else if (x < newHeightmap.length - 1 && y > 0 && y < newHeightmap.length - 1) // Left border
{
newHeightmap[x][y] = (newHeightmap[x+1][y] + newHeightmap[x][y+1] + newHeightmap[x][y-1]) / 3;
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
else if (x > 0 && y > 0 && y < newHeightmap.length - 1) // Right border
{
newHeightmap[x][y] = (newHeightmap[x][y+1] + newHeightmap[x-1][y] + newHeightmap[x][y-1]) / 3;
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
else if (x > 0 && x < newHeightmap.length - 1 && y < newHeightmap.length - 1) // Bottom border
{
newHeightmap[x][y] = (newHeightmap[x+1][y] + newHeightmap[x][y+1] + newHeightmap[x-1][y]) / 3;
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
else if (x > 0 && x < newHeightmap.length - 1 && y > 0) // Top border
{
newHeightmap[x][y] = (newHeightmap[x+1][y] + newHeightmap[x-1][y] + newHeightmap[x][y-1]) / 3;
newHeightmap[x][y] += (newHeightmap[x][y] - minHeight) / heightRange * randFloat(-offset, offset);
}
}
}
initialHeightmap = clone(newHeightmap);
offset /= Math.pow(2, smoothness);
}
// Cut initialHeightmap to fit target width
let shift = [Math.floor((newHeightmap.length - heightmap.length) / 2), Math.floor((newHeightmap[0].length - heightmap[0].length) / 2)];
for (let x = 0; x < heightmap.length; ++x)
for (let y = 0; y < heightmap[0].length; ++y)
heightmap[x][y] = newHeightmap[x + shift[0]][y + shift[1]];
return heightmap;
}
/**
* Meant to place e.g. resource spots within a height range
* @param {array} [heightRange] - The height range in which to place the entities (An associative array with keys "min" and "max" each containing a float)
* @param {array} [avoidPoints=[]] - An array of objects of the form { "x": int, "y": int, "dist": int }, points that will be avoided in the given dist e.g. start locations
* @param {Object} [avoidClass=undefined] - TileClass to be avoided
* @param {integer} [minDistance=30] - How many tile widths the entities to place have to be away from each other, start locations and the map border
* @param {array} [heightmap=g_Map.height] - The reliefmap the entities should be distributed on
* @param {integer} [maxTries=2 * g_Map.size] - How often random player distributions are rolled to be compared (256 to 1024)
* @param {boolean} [isCircular=g_MapSettings.CircularMap] - If the map is circular or rectangular
*/
function getPointsByHeight(heightRange, avoidPoints = [], avoidClass = undefined, minDistance = 20, maxTries = 2 * g_Map.size, heightmap = g_Map.height, isCircular = g_MapSettings.CircularMap)
{
const points = [];
const placements = clone(avoidPoints);
const validVertices = [];
const r = 0.5 * (heightmap.length - 1); // Map center x/y as well as radius
for (let x = minDistance; x < heightmap.length - minDistance; ++x)
for (let y = minDistance; y < heightmap[x].length - minDistance; ++y)
{
if (avoidClass &&
(avoidClass.has(Math.max(x - 1, 0), y) ||
avoidClass.has(x, Math.max(y - 1, 0)) ||
avoidClass.has(Math.min(x + 1, avoidClass.size - 1), y) ||
avoidClass.has(x, Math.min(y + 1, avoidClass.size - 1))))
continue;
if (heightmap[x][y] > heightRange.min && heightmap[x][y] < heightRange.max && // Has correct height
(!isCircular || r - Math.euclidDistance2D(x, y, r, r) >= minDistance)) // Enough distance to the map border
validVertices.push({ "x": x, "y": y, "dist": minDistance });
}
for (let tries = 0; tries < maxTries; ++tries)
{
const point = pickRandom(validVertices);
if (placements.every(p => Math.euclidDistance2D(p.x, p.y, point.x, point.y) > Math.max(minDistance, p.dist)))
{
points.push(point);
placements.push(point);
}
}
return points;
}
/**
* Returns an approximation of the heights of the tiles between the vertices, a tile centered heightmap
* A tile centered heightmap is one smaller in width and height than an ordinary heightmap
* It is meant to e.g. texture a map by height (x/y coordinates correspond to those of the terrain texture map)
* Don't use this to override g_Map height (Potentially breaks the map)!
* @param {array} [heightmap=g_Map.height] - A reliefmap the tile centered version should be build from
*/
function getTileCenteredHeightmap(heightmap = g_Map.height)
{
let max_x = heightmap.length - 1;
let max_y = heightmap[0].length - 1;
let tchm = [];
for (let x = 0; x < max_x; ++x)
{
tchm[x] = new Float32Array(max_y);
for (let y = 0; y < max_y; ++y)
tchm[x][y] = 0.25 * (heightmap[x][y] + heightmap[x + 1][y] + heightmap[x][y + 1] + heightmap[x + 1][y + 1]);
}
return tchm;
}
/**
* Returns a slope map (same form as the a heightmap with one less width and height)
* Not normalized. Only returns the steepness (float), not the direction of incline.
* The x and y coordinates of a tile in the terrain texture map correspond to those of the slope map
* @param {array} [inclineMap=getInclineMap(g_Map.height)] - A map with the absolute inclination for each tile
*/
function getSlopeMap(inclineMap = getInclineMap(g_Map.height))
{
let max_x = inclineMap.length;
let slopeMap = [];
for (let x = 0; x < max_x; ++x)
{
let max_y = inclineMap[x].length;
slopeMap[x] = new Float32Array(max_y);
for (let y = 0; y < max_y; ++y)
slopeMap[x][y] = Math.euclidDistance2D(0, 0, inclineMap[x][y].x, inclineMap[x][y].y);
}
return slopeMap;
}
/**
* Returns an inclination map corresponding to the tiles between the heightmaps vertices:
* array of heightmap width-1 arrays of height-1 vectors (associative arrays) of the form:
* { "x": x_slope, "y": y_slope } - A 2D vector pointing to the highest incline (with the length the inclination in the vector's direction).
* The x and y coordinates of a tile in the terrain texture map correspond to those of the inclination map.
* @param {array} [heightmap=g_Map.height] - The reliefmap the inclination map is to be generated from.
*/
function getInclineMap(heightmap)
{
heightmap = (heightmap || g_Map.height);
let max_x = heightmap.length - 1;
let max_y = heightmap[0].length - 1;
let inclineMap = [];
for (let x = 0; x < max_x; ++x)
{
inclineMap[x] = [];
for (let y = 0; y < max_y; ++y)
{
let dx = heightmap[x + 1][y] - heightmap[x][y];
let dy = heightmap[x][y + 1] - heightmap[x][y];
let next_dx = heightmap[x + 1][y + 1] - heightmap[x][y + 1];
let next_dy = heightmap[x + 1][y + 1] - heightmap[x + 1][y];
inclineMap[x][y] = { "x": 0.5 * (dx + next_dx), "y": 0.5 * (dy + next_dy) };
}
}
return inclineMap;
}
function getGrad(wrapped = true, scalarField = g_Map.height)
{
let vectorField = [];
let max_x = scalarField.length;
let max_y = scalarField[0].length;
if (!wrapped)
{
max_x -= 1;
max_y -= 1;
}
for (let x = 0; x < max_x; ++x)
{
vectorField.push([]);
for (let y = 0; y < max_y; ++y)
{
vectorField[x].push({
"x": scalarField[(x + 1) % max_x][y] - scalarField[x][y],
"y": scalarField[x][(y + 1) % max_y] - scalarField[x][y]
});
}
}
return vectorField;
}
function splashErodeMap(strength = 1, heightmap = g_Map.height)
{
let max_x = heightmap.length;
let max_y = heightmap[0].length;
let dHeight = getGrad(heightmap);
for (let x = 0; x < max_x; ++x)
{
let next_x = (x + 1) % max_x;
let prev_x = (x + max_x - 1) % max_x;
for (let y = 0; y < max_y; ++y)
{
let next_y = (y + 1) % max_y;
let prev_y = (y + max_y - 1) % max_y;
let slopes = [-dHeight[x][y].x, -dHeight[x][y].y, dHeight[prev_x][y].x, dHeight[x][prev_y].y];
let sumSlopes = 0;
for (let i = 0; i < slopes.length; ++i)
if (slopes[i] > 0)
sumSlopes += slopes[i];
let drain = [];
for (let i = 0; i < slopes.length; ++i)
{
drain.push(0);
if (slopes[i] > 0)
drain[i] += Math.min(strength * slopes[i] / sumSlopes, slopes[i]);
}
let sumDrain = 0;
for (let i = 0; i < drain.length; ++i)
sumDrain += drain[i];
// Apply changes to maps
heightmap[x][y] -= sumDrain;
heightmap[next_x][y] += drain[0];
heightmap[x][next_y] += drain[1];
heightmap[prev_x][y] += drain[2];
heightmap[x][prev_y] += drain[3];
}
}
return heightmap;
}