/*
Konovalov Anton BPI132
USING FREEGLUT!
There is no render scene
*/

#include <cstdlib>
#include <iostream>

using namespace std;

#include <GL/glew.h>
#include "GL/freeglut.h"
#include "shaders.h"

float firBottom[9];
float firUp[9];
float firColor[9];

float firTrunk[12];
float firTrunkColor[12];

float starA[9];
float starB[9];
float starColor[9];

const int figures_count = 5;

UINT uiVBO[figures_count * 2];
UINT uiVAO[figures_count];

CShader shVertex, shFragment;
CShaderProgram spMain;

int initCounter = 0;

void initTriangle(float vertexAr[], float colorAr[]) {

	int index = initCounter++;

	glBindVertexArray(uiVAO[index]);

	glBindBuffer(GL_ARRAY_BUFFER, uiVBO[index * 2]);
	glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(float), vertexAr, GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);

	glBindBuffer(GL_ARRAY_BUFFER, uiVBO[index * 2 + 1]);
	glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(float), colorAr, GL_STATIC_DRAW);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);
}

void initSquare(float vertexAr[], float colorAr[]) {

	int index = initCounter++;

	glBindVertexArray(uiVAO[index]);

	glBindBuffer(GL_ARRAY_BUFFER, uiVBO[index * 2]);
	glBufferData(GL_ARRAY_BUFFER, 12 * sizeof(float), vertexAr, GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);

	glBindBuffer(GL_ARRAY_BUFFER, uiVBO[index * 2 + 1]);
	glBufferData(GL_ARRAY_BUFFER, 12 * sizeof(float), colorAr, GL_STATIC_DRAW);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);
}

bool init_resources(void) {
	glClearColor(0.1f, 0.0f, 0.2f, 1.0f);

	// Setup firbot vertices
	firBottom[0] = -0.4f; firBottom[1] = -0.5f; firBottom[2] = 0.0f;
	firBottom[3] = 0.4f; firBottom[4] = -0.5f; firBottom[5] = 0.0f;
	firBottom[6] = 0.0f; firBottom[7] = 0.0f; firBottom[8] = 0.0f;

	// Setup firup vertices
	firUp[0] = -0.4f; firUp[1] = -0.2f; firUp[2] = 0.0f;
	firUp[3] = 0.4f; firUp[4] = -0.2f; firUp[5] = 0.0f;
	firUp[6] = 0.0f; firUp[7] = 0.3f; firUp[8] = 0.0f;

	// Setup fir color
	firColor[0] = 0.0f; firColor[1] = 1.0f; firColor[2] = 0.2f;
	firColor[3] = 0.0f; firColor[4] = 1.0f; firColor[5] = 0.2f;
	firColor[6] = 0.0f; firColor[7] = 1.0f; firColor[8] = 0.2f;

	// Setup trunk vertices
	firTrunk[0] = -0.1f; firTrunk[1] = -0.5f; firTrunk[2] = 0.0f;
	firTrunk[3] = -0.1f; firTrunk[4] = -0.7f; firTrunk[5] = 0.0f;
	firTrunk[6] = 0.1f; firTrunk[7] = -0.5f; firTrunk[8] = 0.0f;
	firTrunk[9] = 0.1f; firTrunk[10] = -0.7f; firTrunk[11] = 0.0f;

	// Setup trunk color
	firTrunkColor[0] = 0.4f; firTrunkColor[1] = 0.2f; firTrunkColor[2] = 0.1f;
	firTrunkColor[3] = 0.4f; firTrunkColor[4] = 0.2f; firTrunkColor[8] = 0.1f;
	firTrunkColor[6] = 0.4f; firTrunkColor[7] = 0.2f; firTrunkColor[5] = 0.1f;
	firTrunkColor[9] = 0.4f; firTrunkColor[10] = 0.2f; firTrunkColor[11] = 0.1f;

	// Setup starA vertices
	starA[0] = -0.1f; starA[1] = 0.25f; starA[2] = 0.0f;
	starA[3] = 0.1f; starA[4] = 0.25f; starA[5] = 0.0f;
	starA[6] = 0.0f; starA[7] = 0.45f; starA[8] = 0.0f;

	// Setup starB vertices
	starB[0] = -0.1f; starB[1] = 0.4f; starB[2] = 0.0f;
	starB[3] = 0.1f; starB[4] = 0.4f; starB[5] = 0.0f;
	starB[6] = 0.0f; starB[7] = 0.2f; starB[8] = 0.0f;

	// Setup star color
	starColor[0] = 1.0f; starColor[1] = 1.0f; starColor[2] = 0.0f;
	starColor[3] = 1.0f; starColor[4] = 1.0f; starColor[5] = 0.0f;
	starColor[6] = 1.0f; starColor[7] = 1.0f; starColor[8] = 0.0f;


	glGenVertexArrays(figures_count, uiVAO); // Generate two VAOs, one for triangle and one for quad
	glGenBuffers(figures_count * 2, uiVBO); // And four VBOs

	// Setup fir trunk
	initSquare(firTrunk, firTrunkColor);

	// Setup fir bot
	initTriangle(firBottom, firColor);

	// Setup firUp
	initTriangle(firUp, firColor);

	// Setup starA
	initTriangle(starA, starColor);

	// Setup starB
	initTriangle(starB, starColor);


	// Load shaders and create shader program
	shVertex.LoadShader("data\\shaders\\shader.vert", GL_VERTEX_SHADER);
	shFragment.LoadShader("data\\shaders\\shader.frag", GL_FRAGMENT_SHADER);

	spMain.CreateProgram();
	spMain.AddShaderToProgram(&shVertex);
	spMain.AddShaderToProgram(&shFragment);

	spMain.LinkProgram();
	spMain.UseProgram();
	return true;
}

void free_resources() {
	spMain.DeleteProgram();

	shVertex.DeleteShader();
	shFragment.DeleteShader();
}

void draw()
{
	glClear(GL_COLOR_BUFFER_BIT);

	//Rectangle
	glBindVertexArray(uiVAO[0]);
	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

	//Triangles
	for (int i = 1; i < figures_count; i++)
	{
		glBindVertexArray(uiVAO[i]);
		glDrawArrays(GL_TRIANGLES, 0, 3);
	}

	glutSwapBuffers();
}

int main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE);
	glutInitWindowSize(500, 500);
	glutInitWindowPosition(100, 100);
	glutCreateWindow("OpenGL HW1 - Konovalov Anton");

	GLenum glew_status = glewInit();
	if (glew_status != GLEW_OK) {
		cerr << "Error: glewInit: " << glewGetErrorString(glew_status) << endl;
		return EXIT_FAILURE;
	}

	if (!init_resources())
		return EXIT_FAILURE;

	glutDisplayFunc(draw);
	glutMainLoop();

	free_resources();

	return EXIT_SUCCESS;
}