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;;; Lisparuga
;;; Copyright © 2020 David Thompson <dthompson2@worcester.edu>
;;;
;;; Lisparuga is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published
;;; by the Free Software Foundation, either version 3 of the License,
;;; or (at your option) any later version.
;;;
;;; Lisparuga is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Lisparuga. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; Enemy actors.
;;
;;; Code:
(define-module (lisparuga enemy)
#:use-module (chickadee audio)
#:use-module (chickadee math)
#:use-module (chickadee math rect)
#:use-module (chickadee math vector)
#:use-module (chickadee scripting)
#:use-module (chickadee render texture)
#:use-module (lisparuga actor)
#:use-module (lisparuga asset)
#:use-module (lisparuga bullets)
#:use-module (lisparuga config)
#:use-module (lisparuga node)
#:use-module (lisparuga node-2d)
#:use-module (oop goops)
#:export (<enemy>
health
points
parting-shots
dead?
fire-parting-shots-maybe
make-utatsugumi))
;;;
;;; Base Enemy
;;;
(define-asset explosion-sound (load-audio (scope-asset "sounds/explosion.wav")))
(define-asset hit-sound (load-audio (scope-asset "sounds/hit.wav")))
(define-class <enemy> (<actor>)
(health #:accessor health #:init-keyword #:health)
(points #:getter points #:init-keyword #:points)
(parting-shots #:getter parting-shots #:init-keyword #:parting-shots)
(fire-parting-shots? #:accessor fire-parting-shots? #:init-form #f))
(define-method (damage (enemy <enemy>) x)
(let ((new-health (max (- (health enemy) x) 0)))
(set! (health enemy) new-health)
(if (zero? new-health)
(audio-play (asset-ref explosion-sound)
#:volume 0.5)
(audio-play (asset-ref hit-sound)
#:volume 0.5))))
(define-method (dead? (enemy <enemy>))
(zero? (health enemy)))
(define (fire-parting-shots-maybe enemy player)
(when (fire-parting-shots? enemy)
(let* ((n (parting-shots enemy))
(ep (position enemy))
(pp (position player))
(angle-to-player
(atan (- (vec2-y pp) (vec2-y ep))
(- (vec2-x pp) (vec2-x ep)))))
(let loop ((i 0))
(when (< i n)
(let ((theta (+ angle-to-player
(- (* (random:uniform) (/ pi 4.0))
(/ pi 8.0)))))
(spawn-bullet (bullet-field enemy)
small-dot
(polarity enemy)
(+ (vec2-x ep)
(- (* (random:uniform) 16.0)
8.0))
(+ (vec2-y ep)
(- (* (random:uniform) 16.0)
8.0))
(* (cos theta) 4.0)
(* (sin theta) 4.0)))
(loop (+ i 1)))))))
(define-method (on-collision (enemy <enemy>) bullet bullet-polarity hitbox)
;; TODO: Distinguish between normal play bullets and homing shots
;; that do more damage.
;;
;; Same polarity = 1 point of damage
;; Opposite polarity = 2 points of damage
(let ((same-polarity? (eq? bullet-polarity (polarity enemy))))
(damage enemy (if same-polarity? 1 2))
(when (and same-polarity? (dead? enemy))
(set! (fire-parting-shots? enemy) #t)))
#t)
(define %enemy-tiles
;; 0: Utatsugumi - white
`((0.0 0.0 24.0 24.0)
;; 1: Utatsugumi - black
(24.0 0.0 24.0 24.0)))
(define (load-enemy-atlas file-name)
(let ((texture (load-image file-name)))
(list->texture-atlas texture %enemy-tiles)))
(define-asset enemy-atlas
(load-enemy-atlas (scope-asset "images/enemies.png")))
;;;
;;; Utatsugumi
;;;
(define-class <utatsugumi> (<enemy>))
(define-method (on-boot (utatsugumi <utatsugumi>))
(attach-to utatsugumi
(make <atlas-sprite>
#:atlas enemy-atlas
#:index (if (eq? 'white (polarity utatsugumi)) 0 1)
#:origin (vec2 12.0 12.0))))
(define (make-utatsugumi polarity x y)
(make <utatsugumi>
#:name (gensym "utatsugumi-")
#:health 1
#:points 20
#:parting-shots 5
#:polarity polarity
#:hitboxes
(list (make-hitbox 'utatsugumi (make-rect -10.0 -10.0 20.0 20.0)))
#:position (vec2 x y)))
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