#include "MyObjectOrientedScene.h"

#include <math.h>

#include "constants.h"

#include "DrawMode.h"
#include "MeshFactory.h"

MyObjectOrientedScene::MyObjectOrientedScene(Application& application)
	: Scene(application),
	m_shape(MeshFactory<MyBatchTestShaderProgram::Vertex, MyBatchTestShaderProgram::Index>::gen(
		DrawMode::DRAW_TRIANGLES,
		MyBatchTestShaderProgram::Vertex(-50.0f, 50.0f, 0.0f),
		MyBatchTestShaderProgram::Vertex(50.0f, 150.0f, 0.0f),
		MyBatchTestShaderProgram::Vertex(-100.0f, -50.0f, 0.0f),
		MyBatchTestShaderProgram::Vertex(100.0f, -50.0f, 0.0f)
	),
	DrawMode::DRAW_TRIANGLES),
	m_batch(&m_shape, 2),
	m_camera(m_screen_size)
{
}

MyObjectOrientedScene::~MyObjectOrientedScene()
{
}

void MyObjectOrientedScene::init()
{
	m_batch.init();
}

void MyObjectOrientedScene::use()
{
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);
}

void MyObjectOrientedScene::unuse()
{

}

void MyObjectOrientedScene::update(float delta_time, clock_t clock)
{
	float brightness;
	float radians;

	clock_t c;
	const clock_t intervals = 512 * CLOCKS_PER_SEC / 100;
	const clock_t half_interval = 256 * CLOCKS_PER_SEC / 100;
	c = clock % intervals;
	if (c < half_interval)
		brightness = (float)c / half_interval;
	else
		brightness = (float)(intervals - c) / half_interval;
	
	radians = (float)egm::TAU * c / intervals;

	{
		MyBatchTestShaderProgram::Color& color = m_batch.get_color(0);
		color.r = brightness;
		color.g = brightness;
		color.b = brightness;
		color.a = 1.0f;

		MyBatchTestShaderProgram::Offset& offset = m_batch.get_offset(0);
		offset.x = 200 * (float)cos(radians);
		offset.y = 0.0f;
		offset.z = 0.0f;
	}
	
	{
		MyBatchTestShaderProgram::Color& color = m_batch.get_color(1);
		color.r = 1.0f - brightness;
		color.g = 1.0f - brightness;
		color.b = 1.0f - brightness;
		color.a = 1.0f;

		MyBatchTestShaderProgram::Offset& offset = m_batch.get_offset(1);
		offset.x = 0.0f;
		offset.y = 200 * (float)sin(radians);
		offset.z = 0.0f;
	}

	vec2 camera_translation;

	if (m_input_manager.is_key_down(GLFW_KEY_W)) camera_translation.y += 1;
	if (m_input_manager.is_key_down(GLFW_KEY_S)) camera_translation.y -= 1;
	if (m_input_manager.is_key_down(GLFW_KEY_A)) camera_translation.x -= 1;
	if (m_input_manager.is_key_down(GLFW_KEY_D)) camera_translation.x += 1;

	m_camera.translate(camera_translation * delta_time);

	m_camera.update_view_projection_matrix();

	// TODO: Make a prerender function or move this to render
	m_batch.prerender();
}

void MyObjectOrientedScene::render()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	m_shader_program.use();
	glUniformMatrix4fv(3, 1, GL_TRUE, &m_camera.get_view_projection_matrix().a.x);
	m_batch.render();
}