implement conways game of life

conway.go

@@ -1,7 +1,8 @@
 package main
 
 import (
-	"github.com/go-resty/resty/v2"
+	"errors"
+	"time"
 )
 
 type Cell struct {
@@ -10,20 +11,96 @@ type Cell struct {
 	live bool
 }
 
-func (c *Cell) NeighborCount() int {
-
+func (c *Cell) NeighborCount(arr [][]Cell) int {
+	count := 0
+	// Iterate through 3x3 neighboring grid
+	for i := -1; i <= 1; i++ {
+		for j := -1; j <= 1; j++ {
+			// Ignore own position
+			if i == 0 && j == 0 {
+				continue
+			}
+			// Get neighbor coordinates
+			nx, ny := c.x+i, c.y+j
+			// Check if neighbor is within bounds
+			if nx < 0 || nx >= len(arr) || ny < 0 || ny >= len(arr[0]) {
+				continue
+			}
+			// Count if neighbor is alive
+			if arr[nx][ny].live {
+				count++
+			}
+		}
+	}
+	return count
 }
 
-func coordinatesToIndex(x int, y int) int {
-	return x + y*width
+func initGrid(width, height int, parent ...[][]Cell) ([][]Cell, error) {
+	exists := len(parent) == 1
+	if exists && len(parent) > 1 {
+		return nil, errors.New("Too many parents specified")
+	}
+
+	// Make first dimension
+	cells := make([][]Cell, width)
+	for i := 0; i < width; i++ {
+		// Make second dimension
+		cells[i] = make([]Cell, height)
+		for j := 0; j < height; j++ {
+			// Make cells
+			cells[i][j].x = i
+			cells[i][j].y = j
+			// If specified, copy state from parent
+			if exists {
+				cells[i][j].live = parent[0][i][j].live
+			}
+		}
+	}
+	return cells, nil
 }
 
-var grid []Cell
+const FPS = 10
 
-func setup(client *resty.Client, url, width int, height int) {
+var grid [][]Cell
 
+func setup(callback func([][]Cell), width, height int) {
+	grid, _ = initGrid(width, height)
+
+	// Prepare
+	ticker := time.NewTicker(time.Second / FPS)
+	done := make(chan bool)
+
+	go func() {
+		for {
+			select {
+			case <-done:
+				return
+			case <-ticker.C:
+				draw(callback)
+			}
+		}
+	}()
 }
 
-func draw() {
-
+func draw(callback func([][]Cell)) {
+	generation, _ := initGrid(len(grid), len(grid[0]), grid)
+	// Iterate through grid
+	for i := 0; i < len(grid); i++ {
+		for j := 0; j < len(grid[0]); j++ {
+			// Count neighbors
+			cout := grid[i][j].NeighborCount(grid)
+			// Get state
+			curr := grid[i][j].live
+			// Apply rules
+			died := curr && (cout < 2 || cout > 3)
+			born := !curr && cout == 3
+			next := curr && !died || born
+			// Set state
+			generation[i][j].live = next
+			//   A * !(A * (B + C)) + !A * D
+			// = A * !B * !C + !A * D
+			// curr && cout >= 2 && cout <= 3 || !curr && cout == 3
+		}
+	}
+	callback(generation)
 }