/** CSci-4611 Assignment 5:  Art Render
 */

#ifndef ART_RENDER_APP_H_
#define ART_RENDER_APP_H_

#include <mingfx.h>
using namespace mingfx;

#include "edge_mesh.h"

#include <string>
#include <vector>


/** Main application class for the ArtRender project.*/
class ArtRenderApp : public GraphicsApp {
public:

	ArtRenderApp();
	virtual ~ArtRenderApp();

	/// Rereads the shader programs file their txt files and recompiles them
	void OnReloadBtnPressed();

	/// Switches to gouraud shading
	void OnGouraudBtnPressed();

	/// Switches to phong shading
	void OnPhongBtnPressed();

	/// Switches to an artsy, toon rendering style
	void OnArtsyBtnPressed();

	/// Callbacks used for UniCam camera controls
	void OnLeftMouseDown(const Point2& pos);
	void OnLeftMouseDrag(const Point2& pos, const Vector2& delta);
	void OnLeftMouseUp(const Point2& pos);
	void UpdateSimulation(double dt);

	/// The GUI is setup here
	void InitNanoGUI();

	/// Models and shaders are loaded here, note these cannot be loaded within
	/// the constructor because the OpenGL context is not yet created at the
	/// time the constructor is called.
	void InitOpenGL();

	/// Rendering using shaders goes here.
	void DrawUsingOpenGL();

private:

	void LoadShadersAndTextures();

	// 0 = gouraud, 1 = phong, 2 = artsy
	int shader_style_;

	// 0 for the first model loaded, ...
	int current_model_;

	// filenames, also used as the caption for the buttons
	std::vector<std::string> model_files_;
	// triangle mesh stored for each model file
	std::vector<Mesh> meshes_;
	// the "edge mesh" computed from the triangle mesh for each file
	std::vector<EdgeMesh> edge_meshes_;

	// position for the light source used in the shaders
	Point3 light_pos_;

	// per-vertex gouraud shading
	ShaderProgram gouraud_shaderprog_;

	// standard per-pixel phong shading
	ShaderProgram phong_shaderprog_;

	// toon shading
	ShaderProgram artsy_shaderprog_;
	// textures to use for calculating lighting cutoffs inside the toon shader
	Texture2D diffuse_ramp_;
	Texture2D specular_ramp_;

	// special program to use for drawing silhouette edges with the edge mesh
	ShaderProgram outline_shaderprog_;



	// Unicam stores/sets the view matrix based on mouse interaction since it
	// is in charge of moving around the camera.
	UniCam uni_cam_;
	Matrix4 proj_matrix_;

	// QuickShapes is just used to draw a little yellow sphere at the position
	// of the light.
	QuickShapes quick_shapes_;

	// A list of paths to search for data files (images and shaders)
	std::vector<std::string> search_path_;
};

#endif