实现aoi九宫格算法

grid.go

@@ -0,0 +1,112 @@
+package aoi
+
+import "sync"
+
+// Grid 格子
+type Grid struct {
+	GID      int      //格子ID
+	Entities sync.Map //当前格子内的实体
+}
+
+// GridManger AOI九宫格实现矩形
+type GridManger struct {
+	StartX    int // X区域左边界坐标
+	StartY    int // Y区域上边界坐标
+	AreaWidth int // 格子宽度(长=宽)
+	GridCount int // 格子数量
+	grids     map[int]*Grid
+}
+
+func NewGrid(gid int) *Grid {
+	return &Grid{
+		GID: gid,
+	}
+}
+
+func NewGridManger(startX, startY, areaWidth, gridCount int) AOI {
+	manager := &GridManger{
+		StartX:    startX,
+		StartY:    startY,
+		AreaWidth: areaWidth,
+		GridCount: gridCount,
+		grids:     make(map[int]*Grid),
+	}
+
+	for y := 0; y < gridCount; y++ {
+		for x := 0; x < gridCount; x++ {
+			//格子编号：ID = IDy *nx + IDx  (利用格子坐标得到格子编号)
+			gID := y*gridCount + x
+			manager.grids[gID] = NewGrid(gID)
+		}
+	}
+
+	return manager
+}
+
+func (g *GridManger) gridWidth() int {
+	return g.AreaWidth / g.GridCount
+}
+
+// GetGIDByPos 通过横纵坐标获取对应的格子ID
+func (g *GridManger) GetGIDByPos(entity *Entity) int {
+	gx := (int(entity.X) - g.StartX) / g.gridWidth()
+	gy := (int(entity.Y) - g.StartY) / g.gridWidth()
+
+	return gy*g.GridCount + gx
+}
+
+// GetSurroundGrids 根据格子的gID得到当前周边的九宫格信息
+func (g *GridManger) GetSurroundGrids(gID int) (grids []*Grid) {
+	if _, ok := g.grids[gID]; !ok {
+		return
+	}
+	grids = append(grids, g.grids[gID])
+
+	// 根据gID, 得到格子所在的坐标
+	x, y := gID%g.GridCount, gID/g.GridCount
+
+	// 分别将这8个方向的方向向量按顺序写入x, y的分量数组
+	dx := []int{-1, -1, -1, 0, 0, 1, 1, 1}
+	dy := []int{-1, 0, 1, -1, 1, -1, 0, 1}
+
+	surroundGID := make([]int, 0)
+	for i := 0; i < 8; i++ {
+		newX := x + dx[i]
+		newY := y + dy[i]
+
+		if newX >= 0 && newX < g.GridCount && newY >= 0 && newY < g.GridCount {
+			surroundGID = append(surroundGID, newY*g.GridCount+newX)
+		}
+	}
+
+	for _, gID := range surroundGID {
+		grids = append(grids, g.grids[gID])
+	}
+
+	return
+}
+
+func (g *GridManger) Add(entity *Entity) {
+	ID := g.GetGIDByPos(entity)
+	grid := g.grids[ID]
+	grid.Entities.Store(entity.Name, entity)
+}
+
+func (g *GridManger) Delete(entity *Entity) {
+	ID := g.GetGIDByPos(entity)
+	grid := g.grids[ID]
+	grid.Entities.Delete(entity.Name)
+}
+
+func (g *GridManger) Search(entity *Entity) (result []*Entity) {
+	ID := g.GetGIDByPos(entity)
+	grids := g.GetSurroundGrids(ID)
+	for _, grid := range grids {
+		grid.Entities.Range(func(_, value interface{}) bool {
+			result = append(result, value.(*Entity))
+			return true
+		})
+	}
+
+	return
+}