Reimplementing features from two commits back + fixes for significant graphical bugs

1 files changed, 56 insertions, 5 deletions

diff --git a/player.fnl b/player.fnl
index 250b70c..b26c310 100644
--- a/player.fnl
+++ b/player.fnl
@@ -15,23 +15,65 @@
 ;;;; You should have received a copy of the GNU General Public License along
 ;;;; with slime-the-world. If not, see <http://www.gnu.org/licenses/>.
 
+(local lume (require :lib.lume))
+
 (local draw (require :draw))
 
+(local gravity 128)
+
+;; Returns a pair, (x, y) that represents the player's next position, assuming
+;; that it did /not/ collide with anything. The role of collision detection, and
+;; further, setting the player's position, is on the world.
+(fn next-position [player dt]
+  (let [x (+ (. player :x-pos) (* dt (. player :x-vel)))
+        y (+ (. player :y-pos) (* dt (. player :y-vel)))]
+    (values x y)))
+
+(fn next-x-vel [player dt]
+  (let [last-x-vel (. player :x-vel)
+        moving-right (. player :action :right)
+        moving-left (. player :action :left)
+        abs-x-vel (. player :goal-x-vel)
+        goal-x-vel (if moving-right abs-x-vel moving-left (- abs-x-vel) 0)]
+    (lume.lerp last-x-vel goal-x-vel dt)))
+
+(fn next-y-vel [player dt]
+  (let [last-y-vel (. player :y-vel)
+        jumping (. player :action :jump)
+        grounded (. player :grounded)
+        jumping-y-vel (- last-y-vel (. player :goal-y-vel))]
+    (if (and jumping grounded) jumping-y-vel
+        grounded 0
+        :else (+ (. player :y-vel) (* gravity dt)))))
+
+(fn impact-bottom [player]
+  (tset player :grounded true))
+
+(fn impact-top [player])
+
+(fn impact-left [player])
+
+(fn impact-right [player])
+
 (fn move-right [player]
   (tset player :orientation :right)
   (tset player :action :right true)
   (tset player :action :left false)
   (tset player :x-vel (/ (. player :x-vel) 2)))
 
+(fn stop-right [player]
+  (tset player :action :right false)
+  (tset player :x-vel (/ (. player :x-vel) 2)))
+
 (fn move-left [player]
   (tset player :orientation :left)
   (tset player :action :left true)
   (tset player :action :right false)
   (tset player :x-vel (/ (. player :x-vel) 2)))
 
-(fn position-at [player x y]
-  (tset player :x-pos x)
-  (tset player :y-pos y))
+(fn stop-left [player]
+  (tset player :action :left false)
+  (tset player :x-vel (/ (. player :x-vel) 2)))
 
 (local player-sheet
        {:img (love.graphics.newImage "art/swanky.png")
@@ -40,7 +82,8 @@
         :padding-x 8 :padding-y 10})
 
 (fn draw-player [player x y]
-  (draw.tile x y player-sheet 0 0))
+  (let [x-offset (if (= (. player :orientation) :left) 4 0)]
+    (draw.tile x y player-sheet x-offset 0)))
 
 ;; Returns a new player object.
 (fn new-player []
@@ -67,9 +110,17 @@
             :right false
             :left false}
 
-   :position-at position-at
+   :next-position next-position
+   :next-x-vel next-x-vel
+   :next-y-vel next-y-vel
+   :impact-bottom impact-bottom
+   :impact-top impact-top
+   :impact-left impact-left
+   :impact-right impact-right
    :move-right move-right
+   :stop-right stop-right
    :move-left move-left
+   :stop-left stop-left
 
    :draw draw-player})