charcoal/Example/MySimple2DScene.cpp

#include "MySimple2DScene.h"

#include <charcoal/deps.h>
#include <charcoal/constants.h>
#include <charcoal/DrawMode.h>
#include <charcoal/MeshFactory.h>

#include <cmath>
#include <iostream>

MySimple2DScene::MySimple2DScene(Application& application)
	: Scene(application),
	m_shape(MeshFactory<MySimpleShaderProgram::Vertex, MySimpleShaderProgram::Index>::gen(
		DrawMode::DRAW_TRIANGLES,
		MySimpleShaderProgram::Vertex(-50.0f, 50.0f, 0.0f),
		MySimpleShaderProgram::Vertex(50.0f, 150.0f, 0.0f),
		MySimpleShaderProgram::Vertex(-100.0f, -50.0f, 0.0f),
		MySimpleShaderProgram::Vertex(100.0f, -50.0f, 0.0f)
	), DrawMode::DRAW_TRIANGLES),
	m_batch(&m_shape, 2),
	m_camera(m_screen_size)
{}

MySimple2DScene::~MySimple2DScene()
{}

void MySimple2DScene::init()
{
	m_batch.init();
}

void MySimple2DScene::use()
{
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);
}

void MySimple2DScene::unuse()
{

}

void MySimple2DScene::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)TAU * c / intervals;

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

		Poseable& pose = m_batch.get_pose(0);
		pose.update_position(vec3(cos(radians) * 50, 0.0f, 0.0f));
	}

	{
		MySimpleShaderProgram::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;

		Poseable& pose = m_batch.get_pose(1);
		pose.update_position(vec3(0.0f, sin(radians) * 50, 0.0f));
	}

	vec2 camera_translation(0.0f, 0.0f);

	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 * 100.0f);
}

void MySimple2DScene::prerender()
{
	m_camera.prerender();
	m_batch.prerender();
}

void MySimple2DScene::render()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	m_shader_program.use();
	glUniformMatrix4fv(0, 1, GL_FALSE, &m_camera.get_world_to_view_matrix()[0][0]);
	m_batch.render();
}