From e61233513f97cfc3fdd5a4dbc68a75f006352e4c Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Tue, 3 May 2016 22:44:03 -0400
Subject: Render explosions.

---
 game.scm | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

(limited to 'game.scm')

diff --git a/game.scm b/game.scm
index a848392..7f6aecf 100644
--- a/game.scm
+++ b/game.scm
@@ -257,7 +257,7 @@
     (add-enemy-bullets world bullets)))
 
 (define (explosion-active? explosion current-time)
-  (> (- current-time (explosion-time explosion)) 120))
+  (< (- current-time (explosion-time explosion)) 15))
 
 
 ;;;
@@ -670,6 +670,9 @@ each time KEY is pressed."
 (define-signal enemy-tileset
   (load-tileset/live "assets/images/enemies.png" 16 16))
 
+(define-signal explosion-tileset
+  (load-tileset/live "assets/images/explosion.png" 16 16))
+
 (define-signal player-sprite
   (signal-map-maybe (lambda (world tileset)
                       (make-sprite
@@ -717,6 +720,7 @@ each time KEY is pressed."
 
 (define bullet-rect (make-rect -8 -8 16 16))
 (define enemy-rect (make-rect -8 -8 16 16))
+(define explosion-rect (make-rect -8 -8 16 16))
 
 (define (render-bullets bullets tileset batch)
   (lambda (context)
@@ -771,6 +775,19 @@ each time KEY is pressed."
       (move (player-position player)
             (render-sprite sprite))))
 
+(define (render-explosions explosions tileset batch time)
+  (lambda (context)
+    (with-sprite-batch batch context
+      (for-each (lambda (explosion)
+                  (let* ((start-time (explosion-time explosion))
+                         (rect (rect-move explosion-rect
+                                          (explosion-position explosion)))
+                         ;; 3 frames of animation.
+                         (frame (min 2 (floor (/ (- time start-time) 5))))
+                         (tex (tileset-ref tileset frame)))
+                    (sprite-batch-add! batch context tex rect)))
+                explosions))))
+
 (define-signal scene
   (signal-let ((fps-text fps-text)
                (score-text score-text)
@@ -783,28 +800,33 @@ each time KEY is pressed."
                (player-sprite player-sprite)
                (bullet-tileset bullet-tileset)
                (enemy-tileset enemy-tileset)
+               (explosion-tileset explosion-tileset)
                (batch batch)
                (world world)
                (time timer))
     (if (and framebuffer framebuffer-sprite batch bullet-tileset
-             enemy-tileset player-sprite)
+             enemy-tileset player-sprite explosion-tileset)
         (let ((player (actor-ref (world-player world))))
           (render-begin
            (with-framebuffer framebuffer
              (with-camera camera
                (render-begin
                 background
+                (render-explosions (world-explosions world)
+                                   explosion-tileset
+                                   batch
+                                   time)
                 (render-bullets (world-player-bullets world)
                                 bullet-tileset
                                 batch)
                 (render-player player player-sprite time)
-                (render-bullets (world-enemy-bullets world)
-                                bullet-tileset
-                                batch)
                 (render-enemies (world-enemies world)
                                 enemy-tileset
                                 batch
                                 time)
+                (render-bullets (world-enemy-bullets world)
+                                bullet-tileset
+                                batch)
                 (with-color font-color
                   (render-begin
                    (if display-fps?
-- 
cgit v1.2.3