attempt at porting mattdesl's 2d pixel perfect shadows

Game.cpp

#include "Game.hpp"

#include <iostream>

#include <GL/glew.h>
#include <GLFW/glfw3.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

#include "Shader.hpp"
#include "Geometry.hpp"

Game::Game(GLFWwindow *window) : window{window} {
	glfwGetWindowSize(window, &windowWidth, &windowHeight);

	light.x = 0.0f;
	light.y = 100.0f;
	light.size = 256;

	prepareResources();
}

Game::~Game(){

}

void Game::prepareResources() {
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_CULL_FACE);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

	shader = new Shader("shaders/simple.vert", "shaders/simple.frag");
	shadowShader = new Shader("shaders/simple.vert", "shaders/shadow.frag");
	shadowRenderShader = new Shader("shaders/simple.vert", "shaders/shadowRender.frag");
	shader->prepareShader();
	shadowRenderShader->prepareShader();
	shadowShader->prepareShader();

	float vertices[] = {
		0,0,0, 0,0,
		80,0,0, 0,1,
		80,80,0, 1,1
	};

	float square[] = {
		0,0,0, 0,0,
		1,0,0, 1,0,
		1,1,0, 1,1,
		
		0,0,0, 0,0,
		1,1,0, 1,1,
		0,1,0, 0,1
	};

	geometry = new Geometry(&vertices[0], sizeof(vertices), 3, GL_TRIANGLES);
	unitSquare = new Geometry(&square[0], sizeof(square), 6, GL_TRIANGLES);

	view  = glm::lookAt(glm::vec3(0,0,5), glm::vec3(0,0,0), glm::vec3(0,1,0));
	projection = glm::ortho(-windowWidth/2.0f, windowWidth/2.0f, -windowHeight/2.0f, windowHeight/2.0f, 0.1f, 100.0f);

	// OCCLUDERS
	// create & bind fbo
	glGenFramebuffers(1, &occlusionFbo);
	glBindFramebuffer(GL_FRAMEBUFFER, occlusionFbo);

	// attach a texture
	glGenTextures(1, &occlusionTexture);
	glBindTexture(GL_TEXTURE_2D, occlusionTexture);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, light.size, light.size, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, occlusionTexture, 0);

	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE)
		std::cout << "Fraembuffer is complete\n";
	else
		std::cout << "Fraembuffer is NOT complete\n";


	// SHADOWMAP
	// create & bind fbo
	glGenFramebuffers(1, &shadowFbo);
	glBindFramebuffer(GL_FRAMEBUFFER, shadowFbo);

	// attach a texture
	glGenTextures(1, &shadowTexture);
	glBindTexture(GL_TEXTURE_1D, shadowTexture);

	glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, light.size, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_T, GL_REPEAT);

	glFramebufferTexture1D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_1D, shadowTexture, 0);

	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE)
		std::cout << "Fraembuffer is complete\n";
	else
		std::cout << "Fraembuffer is NOT complete\n";

	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	shader->useProgram();
}

void Game::tick(float dt) {
	// generate occlusion map
	glBindFramebuffer(GL_FRAMEBUFFER, occlusionFbo);
	glClearColor(0, 0, 0, 0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	shader->useProgram();
	shader->setVec3("color", glm::vec3(0,0,0));
	shader->setMat4("model", glm::mat4(1));
	shader->setMat4("view", view);
	shader->setMat4("projection", glm::ortho(light.x - light.size/2, light.x + light.size/2, light.y - light.size/2, light.y + light.size/2));

	glBindVertexArray(geometry->VAO);
	glDrawArrays(geometry->type, 0, geometry->vertexCount);

	// generate shadow map
	glBindFramebuffer(GL_FRAMEBUFFER, shadowFbo);
	glClearColor(0, 0, 0, 0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	shadowShader->useProgram();
	shadowShader->setVec2("resolution", light.size, light.size);
	shadowShader->setInt("u_texture", 0);

	shadowShader->setVec3("color", glm::vec3(0,0,0));
	shadowShader->setMat4("model", glm::scale(glm::mat4(1), glm::vec3(light.size, 1, 0)));
	shadowShader->setMat4("view", view);
	shadowShader->setMat4("projection", glm::ortho(light.x - light.size/2, light.x + light.size/2, light.y - light.size/2, light.y + light.size/2));

	glBindTexture(GL_TEXTURE_2D, occlusionTexture);
	glBindVertexArray(unitSquare->VAO);
	glDrawArrays(unitSquare->type, 0, unitSquare->vertexCount);

	glBindTexture(GL_TEXTURE_2D, 0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	// draw shadows
	shadowRenderShader->useProgram();
	glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	shadowRenderShader->setVec2("resolution", light.size, light.size);
	shadowRenderShader->setInt("u_texture", 0);
	shadowRenderShader->setVec3("color", glm::vec3(1,1,1));
	shadowRenderShader->setMat4("model",
		glm::translate(
			glm::scale(glm::mat4(1), glm::vec3(light.size, light.size, 0)),
			glm::vec3(light.x - light.size/2, light.y - light.size/2, 0))
		);
	shadowRenderShader->setMat4("view", view);
	shadowRenderShader->setMat4("projection", projection);

	glBindTexture(GL_TEXTURE_2D, shadowTexture);

	glBindVertexArray(unitSquare->VAO);
	glDrawArrays(unitSquare->type, 0, unitSquare->vertexCount);

	// draw scene
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glBindTexture(GL_TEXTURE_2D, 0);

	shader->useProgram();

	shader->setVec3("color", glm::vec3(1,0,0));
	shader->setMat4("model", glm::mat4(1));
	shader->setMat4("view", view);
	shader->setMat4("projection", projection);
	shader->setInt("tex", 0);

	glBindVertexArray(geometry->VAO);
	glDrawArrays(geometry->type, 0, geometry->vertexCount);

}

Where can I get full source?