snake/snake.go

175 lines
3.9 KiB
Go

package main
import (
"github.com/gdamore/tcell/v2"
)
// initSnake Initialize the snake
func initSnake(snakex int, snakey int) Snake {
var x, y int = snakex, snakey
snake := Snake{
head: Position{
x: x,
y: y,
},
tail: []Position{
{
x: x - 3,
y: y,
},
{
x: x - 2,
y: y,
},
{
x: x - 1,
y: y,
},
},
length: 3,
direction: 1,
}
return snake
}
func drawSnake(screen tcell.Screen, style tcell.Style, snake *Snake) {
var tail []rune
// Reverse tail, chop of the excesses,
snake.tail = ReverseSlice(snake.tail)
if len(snake.tail) > snake.length {
snake.tail = snake.tail[:snake.length]
}
// reverse it back to the original order, replace the tail in `snake`
snake.tail = ReverseSlice(snake.tail)
for i, j := range snake.tail {
// The Tail end
if i == 0 {
left := getDirection(j, snake.tail[i+1])
right := getDirection(j, snake.tail[i+1])
tail = append(tail, getLineType(left, right))
// The Bit behind the head
} else if i == len(snake.tail)-1 {
left := getDirection(j, snake.tail[i-1])
right := getDirection(j, snake.head)
tail = append(tail, getLineType(left, right))
// The body of the snake
} else {
left := getDirection(j, snake.tail[i-1])
right := getDirection(j, snake.tail[i+1])
tail = append(tail, getLineType(left, right))
}
}
// Draw the body
for i, segment := range snake.tail {
screen.SetContent(segment.x, segment.y, tail[i], nil, style)
}
// Draw the head, make sure it is on top of everything
screen.SetContent(snake.head.x, snake.head.y, '0', nil, style)
}
func snakeDirection(press int, snake *Snake) {
if press == Left {
snake.head.x--
snake.tail = append(snake.tail, Position{x: snake.head.x + 1, y: snake.head.y})
snake.direction = press
} else if press == Right {
snake.head.x++
snake.tail = append(snake.tail, Position{x: snake.head.x - 1, y: snake.head.y})
snake.direction = press
} else if press == Up {
snake.head.y--
snake.tail = append(snake.tail, Position{x: snake.head.x, y: snake.head.y + 1})
snake.direction = press
} else if press == Down {
snake.head.y++
snake.tail = append(snake.tail, Position{x: snake.head.x, y: snake.head.y - 1})
snake.direction = press
}
}
// Check if a pos hits the tail
func hitsTail(snake *Snake, x int, y int) bool {
var hit bool = false
for _, segment := range snake.tail {
if segment.x == x && segment.y == y {
hit = true
}
}
return hit
}
func ReverseSlice[T comparable](s []T) []T {
var r []T
for i := len(s) - 1; i >= 0; i-- {
r = append(r, s[i])
}
return r
}
func validateDirection(snake *Snake, direction int) bool {
if snake.direction == direction {
return true
} else if snake.direction == Left && direction == Right {
return false
} else if snake.direction == Right && direction == Left {
return false
} else if snake.direction == Up && direction == Down {
return false
} else if snake.direction == Down && direction == Up {
return false
} else {
return true
}
}
func getDirection(from Position, to Position) int {
var direction int
if from.x-to.x == 1 {
direction = Left
} else if from.x-to.x == -1 {
direction = Right
} else if from.y-to.y == 1 {
direction = Up
} else if from.y-to.y == -1 {
direction = Down
}
return direction
}
func getLineType(from int, to int) rune {
var lineType rune
if (from == Left && to == Down) || (from == Down && to == Left) {
lineType = '┐'
} else if (from == Up && to == Right) || (from == Right && to == Up) {
lineType = '└'
} else if (from == Left && to == Right) || (from == Right && to == Left) {
lineType = '─'
} else if (from == Left && to == Up) || (from == Up && to == Left) {
lineType = '┘'
} else if (from == Right && to == Down) || (from == Down && to == Right) {
lineType = '┌'
} else if (from == Up && to == Down) || (from == Down && to == Up) {
lineType = '│'
}
return lineType
}