Draw tiles on grid, show current tile at mouse pos, load-texture once

src/game.clj

@@ -1,23 +1,51 @@
 (ns game
+  (:gen-class)
   (:require
    [engine]
    [rl :as rl]))
 
-(def screen-width 900)
-(def screen-height 500)
+(def ^:const screen-width 1280)
+(def ^:const screen-height 630)
+(def ^:const cell-size 16)
+(def ^:const rows (/ screen-width cell-size))
+(def ^:const cols (quot screen-height cell-size))
 
 (set! *warn-on-reflection* true)
 ;; (set! *unchecked-math* :warn-on-boxed)
 
+;; Colors
+(def color-ground (rl/color-seg 0xE8CFA6))
+(def color-tint-gray (rl/color-seg 0 0 0 100))
+
+(defonce texture-cache (atom {}))
+
+(defn load-texture-once [path]
+  (or (@texture-cache path)
+      (let [t (rl/load-texture path)]
+        (swap! texture-cache assoc path t)
+        t)))
+
+(defn idx [row col] (+ (* row cols) col))
+(defn tile-at  [game r c] (aget ^objects (:grid game) (idx r c)))
+(defn set-tile! [game r c tile] (aset ^objects (:grid game) (idx r c) tile))
+
 (defn init-game [config]
   {:editor-mode false
-   :color-idx 0})
+   :color-idx 0
+   ;; :event-queue []
+   ;; TODO: Once we have a proper ID system for the cells, use int-array for performance
+   :grid (object-array (* rows cols))
+   :texture (load-texture-once "source-assets/Sprout Lands - Sprites - premium pack/Sprout Lands - Sprites - premium pack/Tilesets/ground tiles/New tiles/Grass_Hill_Tiles_v2.png")})
 
 (defn handle-game-input [config game]
+  (let [game (assoc game :event-queue [])]
     (when (rl/key-pressed? rl/key-r))
+    (when (rl/mouse-button-pressed? rl/mouse-button-left)
+      (let [{mx :x my :y} (rl/get-mouse-position)]
+        (set-tile! game (quot my cell-size) (quot mx cell-size) [3 3])))
     (cond-> game
       (rl/key-pressed? rl/key-space)
-    (update :editor-mode not)))
+      (update :editor-mode not))))
 
 (defn update-game [config game]
   (if (:editor-mode game)
@@ -25,16 +53,33 @@
     ())
   game)
 
+(defn draw-tile! [game row-idx col-idx x y scale]
+  (let [src-rect (rl/rect-seg (* col-idx cell-size) (* row-idx cell-size) cell-size cell-size)
+        dst-x (* (quot x (* cell-size scale)) cell-size scale)
+        dst-y (* (quot y (* cell-size scale)) cell-size scale)
+        dst-rect (rl/rect-seg dst-x dst-y (* cell-size scale) (* cell-size scale))]
+    (rl/draw-texture-pro!* (:seg (:texture game)) src-rect dst-rect (rl/vec2-seg 0 0) (float 0.0) rl/white)))
+
+(def scale 4.0)
 (defn draw-game [config game]
-  (rl/clear-background!* rl/cornflower-blue)
+  (rl/clear-background!* color-ground)
+  (doseq [row (range rows)
+          col (range cols)]
+    (when-let [[tx ty] (tile-at game row col)]
+      (draw-tile! game tx ty (* col cell-size) (* row cell-size) scale)))
+  (let [{mx :x my :y :as mouse-pos} (rl/get-mouse-position)]
+    (draw-tile! game 3 3 mx my scale))
   (when (:editor-mode game)
-    (rl/draw-rectangle!* 0 0 screen-width screen-height (rl/color-seg 0 0 0 100))
+    (rl/draw-rectangle!* 0 0 screen-width screen-height color-tint-gray)
     (rl/draw-rectangle!* (/ screen-width 2) (/ screen-height 2) 100 100 rl/white)
     (rl/draw-text!* "EDIT MODE" (- screen-width 100) 10 16 rl/green)))
 
 (defn watch-game [config game]
   {:color-idx (:color-idx game)})
 
+(defn unload-game [game]
+  (rl/unload-texture! (:texture game)))
+
 (defn -main [& _args]
   (engine/run-game!
    {:title       "Siam Farmer"
@@ -45,8 +90,11 @@
     :input       #'handle-game-input
     :update      #'update-game
     :draw        #'draw-game
-    :watch-fn    #'watch-game}))
+    :watch-fn    #'watch-game
+    :unload      #'unload-game}))
 
 (comment
   (future (-main))
+  (reset! @#'engine/game-state (init-game {}))
+  (swap! @#'engine/game-state :assoc {})
   :-)