feat: implemented scrolling ground

src/scrolling_ground.cpp

@@ -0,0 +1,32 @@
+#include "scrolling_ground.hpp"
+#include "core/sprite.hpp"
+#include <SDL2/SDL.h>
+
+#define NUM_SPRITES 2u
+
+ScrollingGround::ScrollingGround()
+: ce::Node2D("scrolling_ground") {
+    this->sprites[0] = this->create_child<ce::Sprite>("background_1", "background");
+    this->sprites[0]->set_global_transform(this->get_global_transform()
+        .scaled({10.f, 10.f})
+    );
+    this->sprites[1] = this->create_child<ce::Sprite>("background_2", "background");
+    this->sprites[1]->set_global_transform(this->sprites[1]->get_global_transform()
+        .scaled({10.f, 10.f})
+        .translated({
+            .x = 0.f,
+            .y = this->sprites[1]->get_size().y * 10.f
+        })
+    );
+}
+
+void ScrollingGround::_tick(double const &delta) {
+    ce::Transform trans;
+    for(size_t i{0u}; i < NUM_SPRITES; ++i) {
+        trans = this->sprites[i]->get_global_transform()
+            .translated({0.f, float(this->SPEED * delta)});
+        if(trans.position.y >= this->sprites[i]->get_size().y)
+            trans.position.y -= this->sprites[i]->get_size().y * 2;
+        this->sprites[i]->set_global_transform(trans);
+    }
+}

src/scrolling_ground.hpp

@@ -0,0 +1,17 @@
+#ifndef SCROLLING_GROUND_HPP
+#define SCROLLING_GROUND_HPP
+
+#include "core/node2d.hpp"
+namespace ce {
+class Sprite;
+}
+
+class ScrollingGround : public ce::Node2D {
+    float const SPEED{10.f};
+    ce::Sprite *sprites[2]{nullptr, nullptr};
+public:
+    ScrollingGround();
+    virtual void _tick(double const &delta) override;
+};
+
+#endif // !SCROLLING_GROUND_HPP