Revert "Revert "Grid" (#6)" (#7)

This reverts commit a645805.

Author: alexapostolu

include/object.hpp

@@ -0,0 +1,60 @@
+#pragma once
+
+#include "SDL.h"
+
+#include <array>
+#include <vector>
+#include <forward_list>
+
+namespace king {
+
+struct Object
+{
+protected:
+	void pan_point(SDL_FPoint& point, float dx, float dy);
+};
+
+class Farmhouse : private Object
+{
+public:
+	Farmhouse(SDL_Renderer* renderer, std::array<SDL_Vertex, 4> const& _grid_snap_vertices);
+	~Farmhouse();
+
+public:
+	void pan(float dx, float dy);
+	/*
+	 * @returns True if mouse is pressed over the object
+	 */
+	bool mouse_pressed(float mx, float my);
+	void drag(float mx, float my, std::forward_list<Farmhouse> const& farmhouses);
+	void mouse_released();
+	void zoom(SDL_MouseWheelEvent const& wheel);
+	void render(SDL_Renderer* renderer);
+
+	bool isPointInObject(int px, int py) const;
+	bool isPolygonInObject(std::array<SDL_Vertex, 4> const& _vertices) const;
+
+public:
+	inline static Farmhouse* drag_ptr = nullptr;
+
+public:
+	// Display
+	SDL_Texture* texture;
+	int texture_width, texture_height;
+	SDL_Colour clr;
+
+	// Position
+	std::array<SDL_Vertex, 4> grid_snap_vertices;
+	std::array<SDL_Vertex, 4> absolute_vertices;
+
+	// Movement
+	float start_mouse_drag_x, start_mouse_drag_y;
+	// If the movement ends at an invalid location, reset the position to original
+	std::array<SDL_Vertex, 4> start_grid_snap_vertices;
+	std::array<SDL_Vertex, 4> start_absolute_vertices;
+
+	// Scaling
+	float old_scale;
+};
+
+} // namespace king

src/CMakeLists.txt

@@ -1,4 +1,4 @@
-add_executable(kingdoms main.cpp ${SDL_fontcache_DIR}/SDL_FontCache.c)
+add_executable(kingdoms main.cpp object.cpp ${SDL_fontcache_DIR}/SDL_FontCache.c)
 
 # Specify the SDL2 and SDL2_ttf library directories
 target_link_libraries(kingdoms