### COMPUTER SCIENCE LESSONS

GRAPHIC PROGRAMS
LESSONS
Cartisian Plane Code
Copy and Paste the code below into DrScheme and Execute.
 ```;;=======================TEACH PACK COORDINATE PLANE====================| ;;--------------------> Canvas Size <--------------------- (define L 400) ;; Length of Canvas (define M (/ L 2)) ;; Middle (start L L) ;; Starts a drawing canvas ;;------------------- > X-AXIS and Y-AXIS <------------------ (draw-solid-line (make-posn M 0) (make-posn M L)) (draw-solid-line (make-posn 0 M) (make-posn L M)) ;;---------------------> Drawing Commands <--------------------------- ;;line: posn posn color -> true ;;Draws a line given the start and end points and a color on a cartesian plane (define (line start end color) (draw-solid-line (make-posn (+ (posn-x start)M) (- M (posn-y start))) (make-posn (+ (posn-x end) M) (- M (posn-y end))) color)) ;;circle: posn number color -> true ;;Draws a circle given the center point, radius and a color on a cartesian plane (define (circle center radius color) (draw-circle (make-posn (+ M(posn-x center)) (- M (posn-y center))) radius color)) ;;disk: posn number color -> true ;;Draws a solid-disk given the center point, radius and a color on a cartesian plane (define (disk center radius color) (draw-solid-disk (make-posn (+ M(posn-x center)) (- M (posn-y center))) radius color)) ;;rect: posn number number color -> true ;;Draws a solid-rectangle given the top-left corner point, the length, width and color (define (rect corner L H color) (draw-solid-rect (make-posn (+ M (posn-x corner)) (- M (posn-y corner))) L H color)) ;;=======================END OF TEACH PACK COORDINATE PLANE=========================| ;;--------------------> Grid Line Markers <----------------- (line (make-posn -5 100) (make-posn +5 100) 'black) (line (make-posn 100 -5) (make-posn 100 +5) 'blue) (line (make-posn -5 -100) (make-posn +5 -100)'green) (line (make-posn -100 -5) (make-posn -100 +5) 'red) ;;--------------------> Sample Object <------------------ (circle (make-posn 0 0) 80 'red) (disk (make-posn 30 30) 15 'blue) (disk (make-posn -30 30) 15 'blue) (rect (make-posn -40 -30) 80 5 'red) ;;-------------------> YOUR PRACTICE FOR MASTERY <------------- Following the above examples, add personality to the face. PLAN ON GRAPH PAPER FIRST!! ```