Added a scene manager module.

examples/README.md

@@ -34,3 +34,7 @@ This example shows how to create an animated character that follows the mouse.
 ## [Timer](timer.d)
 
 This example shows how to use the timer structure of Popka.
+
+## [Scene](scene.d)
+
+This example shows how to use the scene manager of Popka.

examples/scene.d

@@ -0,0 +1,75 @@
+/// This example shows how to use the scene manager of Popka.
+import popka;
+
+// The game variables.
+auto sceneManager = SceneManager();
+
+// The first scene.
+struct Scene1 {
+    mixin extendScene;
+
+    float counter = 0;
+
+    void ready() {
+        println("Entering scene 1.");
+        setBackgroundColor(gray1);
+    }
+
+    bool update(float dt) {
+        if (Keyboard.space.isPressed) {
+            sceneManager.enter!Scene2();
+        }
+
+        counter += 5 * dt;
+
+        drawDebugText("Press enter to change scene.", resolution * Vec2(0.5), DrawOptions(Hook.center));
+        drawDebugText("Scene 1\nCounter: {}".format(cast(int) counter), Vec2(8));
+        return false;
+    }
+
+    void finish() {
+        println("Exiting scene 1.");
+    }
+}
+
+// The second scene.
+struct Scene2 {
+    mixin extendScene;
+
+    void ready() {
+        println("Entering scene 2.");
+        setBackgroundColor(gray2);
+    }
+
+    bool update(float dt) {
+        if (Keyboard.space.isPressed) {
+            sceneManager.enter!Scene1();
+        }
+
+        drawDebugText("Press enter to change scene.", resolution * Vec2(0.5), DrawOptions(Hook.center));
+        drawDebugText("Scene 2\nNo counter here.", Vec2(8));
+        return false;
+    }
+
+    void finish() {
+        println("Exiting scene 2.");
+    }
+}
+
+void ready() {
+    lockResolution(320, 180);
+    // Enter the first scene. This will call the ready function of that scene.
+    sceneManager.enter!Scene1();
+}
+
+bool update(float dt) {
+    // Update the current scene.
+    return sceneManager.update(dt);
+}
+
+void finish() {
+    // Free the scene manager. This will call the finish function of the current scene.
+    sceneManager.free();
+}
+
+mixin runGame!(ready, update, finish);

scripts/header.d

@@ -10,7 +10,7 @@ enum header = "// ---
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---";
 
 int main(string[] args) {

source/popka/dialogue.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 // TODO: The DialogueCommandRunner should work with gc functions too. Think about how to do it.

source/popka/engine.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 // TODO: Test the resources code and the tag thing.
@@ -157,6 +157,33 @@ struct DrawOptions {
     Color color    = white;        /// The color of the drawn object.
     Hook hook      = Hook.topLeft; /// An value representing the origin point of the drawn object when origin is set to zero.
     Flip flip      = Flip.none;    /// An value representing flipping orientations.
+
+    @safe @nogc nothrow:
+
+    /// Initializes the options with the given scale.
+    this(Vec2 scale) {
+        this.scale = scale;
+    }
+
+    /// Initializes the options with the given rotation.
+    this(float rotation) {
+        this.rotation = rotation;
+    }
+
+    /// Initializes the options with the given color.
+    this(Color color) {
+        this.color = color;
+    }
+
+    /// Initializes the options with the given hook.
+    this(Hook hook) {
+        this.hook = hook;
+    }
+
+    /// Initializes the options with the given flip.
+    this(Flip flip) {
+        this.flip = flip;
+    }
 }
 
 /// A structure representing a camera.

source/popka/package.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 module popka;
@@ -11,6 +11,7 @@ module popka;
 public import joka;
 public import popka.dialogue;
 public import popka.engine;
+public import popka.scene;
 public import popka.sprite;
 public import popka.tilemap;
 public import popka.timer;

source/popka/rl/package.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 /// The `rl` module provides access to the raylib library.

source/popka/rl/raylib.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 /// The `rayib` module provides access to the raylib.h functions.

source/popka/rl/rlgl.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 /// The `rlgl` module provides access to the rlgl.h functions.

source/popka/scene.d

@@ -0,0 +1,87 @@
+// ---
+// Copyright 2024 Alexandros F. G. Kapretsos
+// SPDX-License-Identifier: MIT
+// Email: alexandroskapretsos@gmail.com
+// Project: https://github.com/Kapendev/popka
+// Version: v0.0.22
+// ---
+
+// TODO: Update all the doc comments here.
+
+/// The `scene` module provides a simple scene manager.
+module popka.scene;
+
+import stdc = joka.stdc;
+import popka.engine;
+
+struct Scene {
+    void delegate() ready;
+    bool delegate(float dt) update;
+    void delegate() finish;
+}
+
+struct SceneManager {
+    Scene* scene;
+    Scene* nextScene;
+
+    @trusted @nogc nothrow
+    void enter(T)() {
+        if (nextScene) return;
+        auto temp = cast(T*) stdc.malloc(T.sizeof);
+        *temp = T();
+        temp.prepare();
+        nextScene = cast(Scene*) temp;
+    }
+
+    bool update(float dt) {
+        if (nextScene) {
+            if (scene) {
+                if (scene.finish) scene.finish();
+                stdc.free(scene);
+            }
+            scene = nextScene;
+            nextScene = null;
+            if (scene.ready) scene.ready();
+            if (scene.update) return scene.update(dt);
+            return true;
+        }
+        if (scene && scene.update) return scene.update(dt);
+        return true;
+    }
+
+    void free() {
+        if (scene) {
+            if (scene.finish) scene.finish();
+            stdc.free(scene);
+            scene = null;
+        }
+        if (nextScene) {
+            stdc.free(nextScene);
+            nextScene = null;
+        }
+    }
+}
+
+mixin template extendScene() {
+    Scene base;
+
+    @safe @nogc nothrow
+    void prepare() {
+        auto base = mixin("&", this.tupleof[0].stringof);
+        static if (hasMember!(typeof(this), "ready")) {
+            base.ready = &this.ready;
+        } else {
+            base.ready = null;
+        }
+        static if (hasMember!(typeof(this), "update")) {
+            base.update = &this.update;
+        } else {
+            base.update = null;
+        }
+        static if (hasMember!(typeof(this), "finish")) {
+            base.finish = &this.finish;
+        } else {
+            base.finish = null;
+        }
+    }
+}

source/popka/sprite.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 // TODO: Think about gaps in an atlas texture.

source/popka/tilemap.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 // TODO: Think about gaps in an atlas texture.

source/popka/timer.d

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 // Email: alexandroskapretsos@gmail.com
 // Project: https://github.com/Kapendev/popka
-// Version: v0.0.21
+// Version: v0.0.22
 // ---
 
 // TODO: Update all the doc comments here.
@@ -11,7 +11,7 @@
 /// The `timer` module provides a simple and extensible timer.
 module popka.timer;
 
-import popka.engine;
+import joka.math;
 
 @safe @nogc nothrow: