Question

我想在一个场景上创建一个包含所有图像的场景。我了解如何使用一个图像创建场景。例如：

(define HEIGHT 800)

(define WIDTH 500)

(define (sceneblank x)
  (place-image blank 400 400 (empty-scene WIDTH HEIGHT "black"))
  ;blank being the image

(animate sceneblank)

但是如何连续使用场所图像功能将图像放在那个场景上？

Answer 1

您可以使用嵌套函数在一个场景上放置多个图像，如下所示：

(require 2htdp/image)
(require 2htdp/universe)

(define HEIGHT 800)
(define WIDTH 500)
(define BLANK-SCENE
  (empty-scene WIDTH HEIGHT "black"))

;; This function shows just the circle
(define (add-circle x scene)
  (place-image (circle 50 "solid" "red") x 400 scene))

;; This function shows just the square
(define (add-square x scene)
  (place-image (square 50 "solid" "blue") x 500 scene))

;; This shows both of them
(define (circle+square x)
  (add-circle x (add-square x BLANK-SCENE)))

(animate circle+square)

需要一些关于DrRacket场景的帮助

1 个答案: