Files
jak-project/goal_src/jak1/engine/physics/trajectory.gc
T

82 lines
3.5 KiB
Common Lisp

;;-*-Lisp-*-
(in-package goal)
(bundles "ENGINE.CGO" "GAME.CGO")
(require "engine/math/vector.gc")
(require "engine/physics/trajectory-h.gc")
(require "engine/debug/debug-h.gc")
;; DECOMP BEGINS
(defmethod eval-position! ((this trajectory) (time float) (result vector))
"Evaluate the position of the object at a give time"
(set! (-> result quad) (-> this initial-position quad))
(+! (-> result x) (* time (-> this initial-velocity x)))
(+! (-> result y) (* time (-> this initial-velocity y)))
(+! (-> result z) (* time (-> this initial-velocity z)))
(+! (-> result y) (* (/ time 2) time (-> this gravity)))
result)
(defmethod eval-velocity! ((this trajectory) (time float) (result vector))
"Evaluate the velocity of the object at a given time"
(set! (-> result quad) (-> this initial-velocity quad))
(+! (-> result y) (* time (-> this gravity)))
result)
(defmethod setup-from-to-duration! ((this trajectory) (from vector) (to vector) (duration float) (grav float))
"Set up a trajectory that goes from->to in the given duration"
(set! (-> this initial-position quad) (-> from quad))
(set! (-> this gravity) grav)
(set! (-> this time) duration)
;; the velocity we need in xz to make it in time
(let ((xz-vel (/ (vector-vector-xz-distance to from) duration)))
;; our velocity will point along from -> to
(vector-! (-> this initial-velocity) to from)
;; but have magnitude that we calculated above.
(vector-xz-normalize! (-> this initial-velocity) xz-vel))
;; solve for the y velocity that makes us land at the right height.
(set! (-> this initial-velocity y) (- (/ (- (-> to y) (-> from y)) duration) (* (/ duration 2) (-> this gravity))))
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(none))
(defmethod setup-from-to-xz-vel! ((this trajectory) (from vector) (to vector) (xz-vel float) (grav float))
"Set up a trajectory that goes from->to with the given velocity"
;; just solve for the duration and use the previous
(let ((duration (/ (vector-vector-xz-distance to from) xz-vel))) (setup-from-to-duration! this from to duration grav))
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(none))
(defmethod setup-from-to-y-vel! ((this trajectory) (from vector) (to vector) (y-vel float) (grav float))
"Set up a trajectory with the given initial y velocity."
(let* ((f0-0 y-vel)
(f1-3 (- (* f0-0 f0-0) (* 2.0 (- (-> from y) (-> to y)) grav)))
(f0-3 900.0))
(when (>= f1-3 0.0)
(let ((f0-4 (sqrtf f1-3))) (set! f0-3 (fmax (/ (- (- y-vel) f0-4) grav) (/ (+ (- y-vel) f0-4) grav)))))
(setup-from-to-duration! this from to f0-3 grav))
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(none))
(defmethod setup-from-to-height! ((this trajectory) (arg0 vector) (arg1 vector) (arg2 float) (arg3 float))
"Setup a trajectory that reaches a given height"
(let* ((f1-2 (+ arg2 (fmax (-> arg0 y) (-> arg1 y))))
(f1-5 (* 2.0 (- (-> arg0 y) f1-2) arg3))
(f0-3 4096.0))
(if (< 0.0 f1-5) (set! f0-3 (sqrtf f1-5)))
(setup-from-to-y-vel! this arg0 arg1 f0-3 arg3))
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(none))
(defmethod debug-draw! ((this trajectory))
"Draw the trajectory"
(let ((prev-pos (new 'stack-no-clear 'vector))
(pos (new 'stack-no-clear 'vector))
(num-segments 10))
(set! (-> pos quad) (-> this initial-position quad))
(dotimes (s2-0 num-segments)
(set! (-> prev-pos quad) (-> pos quad))
(let ((t-eval (* (-> this time) (/ (+ 1.0 (the float s2-0)) (the float num-segments)))))
(eval-position! this t-eval pos))
(add-debug-line #t (bucket-id debug-no-zbuf) prev-pos pos (new 'static 'rgba :r #xff :a #x80) #f (the-as rgba -1))))
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(none))