Episode 36: Verlet Integration Part 1
author |
Steve Losh <steve@stevelosh.com> |
date |
Fri, 08 Jul 2016 15:49:50 +0000 |
parents |
9122a5749085 |
children |
8b18b0cb32bb |
(in-package #:coding-math.2d.demo)
;;;; Config
(setf *bypass-cache* t)
(defparameter *width* 600)
(defparameter *height* 400)
(defparameter *center-x* (/ *width* 2))
(defparameter *center-y* (/ *height* 2))
(defvar *shift* nil)
(defvar *control* nil)
(defvar *command* nil)
(defvar *option* nil)
;;;; Utils
(defmacro with-setup (&body body)
`(with-fps
(background (gray 1))
,@body))
(defun oob-p (p &optional (r 0.0))
(or (outsidep (- 0 r) (+ *width* r) (vec-x p))
(outsidep (- 0 r) (+ *height* r) (vec-y p))))
(defun real-time ()
(/ (get-internal-real-time) internal-time-units-per-second))
(defun random-location ()
(make-random-vec *width* *height*))
(defun random-location-centered ()
(make-vec (random-range (- *center-x*) *center-x*)
(random-range (- *center-y*) *center-y*)))
;;;; Sketch
(defun draw-particle (p)
(circle (particle-x p) (particle-y p) (particle-radius p)))
(defun draw-line (p1 p2)
(with-vecs ((x1 y1) p1 (x2 y2) p2)
(line x1 y1 x2 y2)))
(defun draw-circle (p &optional (radius 5))
(if (listp p)
(circle (getf p :x) (getf p :y) (or (getf p :radius) radius))
(circle (vec-x p) (vec-y p) radius)))
(defun draw-square (p radius)
(rect (- (vec-x p) radius)
(- (vec-y p) radius)
(* 2 radius)
(* 2 radius)))
(defun draw-point (p)
(point (vec-x p) (vec-y p)))
(defun draw-polygon (points)
(when points
;; why is this fucked?
(apply #'polygon
(iterate (for p :in points)
(collect (vec-x p))
(collect (vec-y p))))))
(defun draw-triangle (p1 p2 p3)
#+sketch-polygon-fn-is-fucked (polygon (vec-x p1) (vec-y p1)
(vec-x p2) (vec-y p2)
(vec-x p3) (vec-y p3))
(let ((vertices (list (vec-to-list p1)
(vec-to-list p2)
(vec-to-list p3))))
(sketch::draw-shape :triangles vertices vertices)))
(defstruct (point
(:constructor make-point (x y old-x old-y)))
x y old-x old-y)
(defun update-point (point)
(with-slots (x y old-x old-y) point
(let* ((friction 0.999)
(bounce 0.9)
(gravity 0.2)
(vx (* friction (- x old-x)))
(vy (* friction (- y old-y))))
(setf old-x x
old-y y)
(incf x vx)
(incf y vy)
(decf y gravity)
(macrolet ((wrap ((cur old vel) comp bound)
`(when (,comp ,cur ,bound)
(setf ,cur ,bound
,old (+ ,cur (* bounce ,vel))))))
(wrap (x old-x vx) > *width*)
(wrap (x old-x vx) < 0)
(wrap (y old-y vy) > *height*)
(wrap (y old-y vy) < 0)))))
(defun render-point (point)
(with-slots (x y) point
(draw-circle (make-vec x y) 5)))
(defsketch cm
((width *width*) (height *height*) (y-axis :up) (title "Coding Math 2D")
(copy-pixels nil)
(mouse (make-vec 0 0))
(frame 0)
(start-time (real-time))
(current-time 0)
(previous-time 0)
(total-time 0)
;; Data
(points (list (make-point 100 100 95 95)))
;; Pens
(particle-pen (make-pen :fill (gray 0.9) :stroke (gray 0.4)))
(black-pen (make-pen :stroke (rgb 0 0 0) :fill (rgb 0.4 0.4 0.4) :weight 1 :curve-steps 50))
(red-pen (make-pen :stroke (rgb 0.6 0 0) :fill (rgb 0.9 0 0) :weight 1 :curve-steps 50))
(green-pen (make-pen :stroke (rgb 0 0.6 0) :fill (rgb 0 0.9 0) :weight 1 :curve-steps 50))
(blue-pen (make-pen :stroke (rgb 0 0 0.6) :fill (rgb 0 0 0.9) :weight 1 :curve-steps 50))
)
(setf previous-time current-time
current-time (real-time))
(incf total-time (- current-time previous-time))
(incf frame)
;;
(with-setup
(in-context
(mapc #'update-point points)
(mapc #'render-point points)
))
;;
)
;;;; Mouse
(defun mousemove (instance x y)
(with-slots (mouse) instance
(setf mouse (make-vec x (- *height* y)))
;;
;;
)
)
(defun mousedown-left (instance x y)
(declare (ignorable instance x y))
)
(defun mousedown-right (instance x y)
(declare (ignorable instance x y))
)
(defun mouseup-left (instance x y)
(declare (ignorable instance x y))
)
(defun mouseup-right (instance x y)
(declare (ignorable instance x y))
)
(defmethod kit.sdl2:mousemotion-event ((window cm) ts b x y xrel yrel)
(declare (ignore ts b xrel yrel))
(mousemove window x y))
(defmethod kit.sdl2:mousebutton-event ((window cm) state ts button x y)
(declare (ignore ts))
(funcall (case state
(:mousebuttondown
(case button
(1 #'mousedown-left)
(3 #'mousedown-right)))
(:mousebuttonup
(case button
(1 #'mouseup-left)
(3 #'mouseup-right))))
window x y))
;;;; Keyboard
(defun keydown (instance scancode)
(declare (ignorable instance))
(scancode-case scancode
(:scancode-space (sketch::prepare instance))
(:scancode-lshift (setf *shift* t))
(:scancode-lctrl (setf *control* t))
(:scancode-lgui (setf *command* t))
(:scancode-lalt (setf *option* t))
;;
;;
))
(defun keyup (instance scancode)
(declare (ignorable instance))
(scancode-case scancode
(:scancode-lshift (setf *shift* nil))
(:scancode-lctrl (setf *control* nil))
(:scancode-lgui (setf *command* nil))
(:scancode-lalt (setf *option* nil))
(:scancode-space nil)))
(defmethod kit.sdl2:keyboard-event ((instance cm) state timestamp repeatp keysym)
(declare (ignore timestamp repeatp))
(cond
((eql state :keyup) (keyup instance (sdl2:scancode-value keysym)))
((eql state :keydown) (keydown instance (sdl2:scancode-value keysym)))
(t nil)))
;;;; Run
; (defparameter *demo* (make-instance 'cm))