tilemap-to-convexes

Merge solid polygons and decompose into convexes.

#### Example

Make a tilemap:

``typescript
const gridSize = 32;
const tiles: { x: number, y: number }[][] = [];

function addRect(x: number, y: number) {
x *= gridSize;
y *= gridSize;
tiles.push([
{x: x, y: y},
{x: x + gridSize, y: y},
{x: x + gridSize, y: y + gridSize},
{x: x, y: y + gridSize}
]);
}

function addSlopeBR(x: number, y: number) {
x *= gridSize;
y *= gridSize;
tiles.push([
{x: x, y: y},
{x: x + gridSize, y: y},
{x: x + gridSize, y: y + gridSize}
]);
}

function addSlopeBL(x: number, y: number) {
x *= gridSize;
y *= gridSize;
tiles.push([
{x: x, y: y},
{x: x + gridSize, y: y},
{x: x, y: y + gridSize}
]);
}

function addSlopeTL(x: number, y: number) {
x *= gridSize;
y *= gridSize;
tiles.push([
{x: x, y: y},
{x: x + gridSize, y: y + gridSize},
{x: x, y: y + gridSize}
]);
}

function addSlopeTR(x: number, y: number) {
x *= gridSize;
y *= gridSize;
tiles.push([
{x: x + gridSize, y: y},
{x: x + gridSize, y: y + gridSize},
{x: x, y: y + gridSize}
]);
}

addRect(4, 0);
addRect(5, 0);
addRect(4, 1);
addRect(5, 1);

addRect(-2, 0);
addRect(-1, 0);
addRect(0, 0);
addRect(1, 0);

addRect(-2, 1);
addRect(1, 1);

addRect(-2, 2);
addRect(1, 2);

addRect(-2, 3);
addRect(-1, 3);
addRect(0, 3);
addRect(1, 3);

addSlopeBR(-3, 3);
addSlopeBR(-2, 4);
addSlopeBR(-1, 5);

addSlopeBL(0, 5);
addSlopeBL(1, 4);
addSlopeBL(2, 3);

addSlopeTL(-1, 4);
addSlopeTR(0, 4);

`

![](1.png)

Decompose into convexes:

`typescript
const mergePolygons = new MergePolygons();
tiles.forEach(tile => mergePolygons.addPolygon(...tile)); // vertices need to be in counterclockwise order
const convexes = mergePolygons.getConvexes();
``