add precaching for painting

main.go

@@ -87,14 +87,18 @@ func createSocket(pixelmatrix [][][4]uint32, xstart, ystart int) net.Conn {
 }
 
 func paint(conn net.Conn, pixelmatrix [][][4]uint32, xstart, ystart int) {
-	for {
-		for x, row := range pixelmatrix {
-			for y, pixel := range row {
-				if pixel[3] != 0 {
-					msg := fmt.Sprintf("PX %d %d %02x%02x%02x\n", xstart+x, ystart+y, pixel[0], pixel[1], pixel[2])
-					conn.Write([]byte(msg))
-				}
+	var prerender [][]byte
+	for x, row := range pixelmatrix {
+		for y, pixel := range row {
+			if pixel[3] != 0 {
+				msg := fmt.Sprintf("PX %d %d %02x%02x%02x\n", xstart+x, ystart+y, pixel[0], pixel[1], pixel[2])
+				prerender = append(prerender, []byte(msg))
 			}
 		}
 	}
+	for {
+		for _, data := range prerender {
+			conn.Write(data)
+		}
+	}
 }