Hello Everyone!
I'm learning openGL, and currently i'm making a simple 2D game engine to test what I've learn so far. In order to not say to much, i made a video in which i'm showing you the behavior of the rendering.
Video:
What i was expecting to happen, was the player moving around. When i render only the player, he moves as i would expect. When i add a second Sprite object, instead of the Player, this new sprite object is moving and finally if i add a third Sprite object the third one is moving. And the weird think is that i'm transforming the Vertices of the Player so why the transformation is being applied somewhere else?
Take a look at my code:
Sprite Class
(You mostly need to see the Constructor, the Render Method and the Move Method)
#include "Brain.h"
#include <glm/gtc/matrix_transform.hpp>
#include <vector>
struct Sprite::Implementation
{
//Position.
struct pos pos;
//Tag.
std::string tag;
//Texture.
Texture *texture;
//Model matrix.
glm::mat4 model;
//Vertex Array Object.
VertexArray *vao;
//Vertex Buffer Object.
VertexBuffer *vbo;
//Layout.
VertexBufferLayout *layout;
//Index Buffer Object.
IndexBuffer *ibo;
//Shader.
Shader *program;
//Brains.
std::vector<Brain *> brains;
//Deconstructor.
~Implementation();
};
Sprite::Sprite(std::string image_path, std::string tag, float x, float y)
{
//Create Pointer To Implementaion.
m_Impl = new Implementation();
//Set the Position of the Sprite object.
m_Impl->pos.x = x;
m_Impl->pos.y = y;
//Set the tag.
m_Impl->tag = tag;
//Create The Texture.
m_Impl->texture = new Texture(image_path);
//Initialize the model Matrix.
m_Impl->model = glm::mat4(1.0f);
//Get the Width and the Height of the Texture.
int width = m_Impl->texture->GetWidth();
int height = m_Impl->texture->GetHeight();
//Create the Verticies.
float verticies[] =
{
//Positions //Texture Coordinates.
x, y, 0.0f, 0.0f,
x + width, y, 1.0f, 0.0f,
x + width, y + height, 1.0f, 1.0f,
x, y + height, 0.0f, 1.0f
};
//Create the Indicies.
unsigned int indicies[] =
{
0, 1, 2,
2, 3, 0
};
//Create Vertex Array.
m_Impl->vao = new VertexArray();
//Create the Vertex Buffer.
m_Impl->vbo = new VertexBuffer((void *)verticies, sizeof(verticies));
//Create The Layout.
m_Impl->layout = new VertexBufferLayout();
m_Impl->layout->PushFloat(2);
m_Impl->layout->PushFloat(2);
m_Impl->vao->AddBuffer(m_Impl->vbo, m_Impl->layout);
//Create the Index Buffer.
m_Impl->ibo = new IndexBuffer(indicies, 6);
//Create the new shader.
m_Impl->program = new Shader("Shaders/SpriteShader.shader");
}
//Render.
void Sprite::Render(Window * window)
{
//Create the projection Matrix based on the current window width and height.
glm::mat4 proj = glm::ortho(0.0f, (float)window->GetWidth(), 0.0f, (float)window->GetHeight(), -1.0f, 1.0f);
//Set the MVP Uniform.
m_Impl->program->setUniformMat4f("u_MVP", proj * m_Impl->model);
//Run All The Brains (Scripts) of this game object (sprite).
for (unsigned int i = 0; i < m_Impl->brains.size(); i++)
{
//Get Current Brain.
Brain *brain = m_Impl->brains[i];
//Call the start function only once!
if (brain->GetStart())
{
brain->SetStart(false);
brain->Start();
}
//Call the update function every frame.
brain->Update();
}
//Render.
window->GetRenderer()->Draw(m_Impl->vao, m_Impl->ibo, m_Impl->texture, m_Impl->program);
}
void Sprite::Move(float speed, bool left, bool right, bool up, bool down)
{
if (left)
{
m_Impl->pos.x -= speed;
m_Impl->model = glm::translate(m_Impl->model, glm::vec3(-speed, 0, 0));
}
if (right)
{
m_Impl->pos.x += speed;
m_Impl->model = glm::translate(m_Impl->model, glm::vec3(speed, 0, 0));
}
if (up)
{
m_Impl->pos.y += speed;
m_Impl->model = glm::translate(m_Impl->model, glm::vec3(0, speed, 0));
}
if (down)
{
m_Impl->pos.y -= speed;
m_Impl->model = glm::translate(m_Impl->model, glm::vec3(0, -speed, 0));
}
}
void Sprite::AddBrain(Brain * brain)
{
//Push back the brain object.
m_Impl->brains.push_back(brain);
}
pos *Sprite::GetPos()
{
return &m_Impl->pos;
}
std::string Sprite::GetTag()
{
return m_Impl->tag;
}
int Sprite::GetWidth()
{
return m_Impl->texture->GetWidth();
}
int Sprite::GetHeight()
{
return m_Impl->texture->GetHeight();
}
Sprite::~Sprite()
{
delete m_Impl;
}
//Implementation Deconstructor.
Sprite::Implementation::~Implementation()
{
delete texture;
delete vao;
delete vbo;
delete layout;
delete ibo;
delete program;
}
Renderer Class
#include "Renderer.h"
#include "Error.h"
Renderer::Renderer()
{
}
Renderer::~Renderer()
{
}
void Renderer::Draw(VertexArray * vao, IndexBuffer * ibo, Texture *texture, Shader * program)
{
vao->Bind();
ibo->Bind();
program->Bind();
if (texture != NULL)
texture->Bind();
GLCall(glDrawElements(GL_TRIANGLES, ibo->GetCount(), GL_UNSIGNED_INT, NULL));
}
void Renderer::Clear(float r, float g, float b)
{
GLCall(glClearColor(r, g, b, 1.0));
GLCall(glClear(GL_COLOR_BUFFER_BIT));
}
void Renderer::Update(GLFWwindow *window)
{
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
}
Shader Code
#shader vertex
#version 330 core
layout(location = 0) in vec4 aPos;
layout(location = 1) in vec2 aTexCoord;
out vec2 t_TexCoord;
uniform mat4 u_MVP;
void main()
{
gl_Position = u_MVP * aPos;
t_TexCoord = aTexCoord;
}
#shader fragment
#version 330 core
out vec4 aColor;
in vec2 t_TexCoord;
uniform sampler2D u_Texture;
void main()
{
aColor = texture(u_Texture, t_TexCoord);
}
Also i'm pretty sure that every time i'm hitting the up, down, left and right arrows on the keyboard, i'm changing the model Matrix of the Player and not the others.
Window Class:
#include "Window.h"
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "Error.h"
#include "Renderer.h"
#include "Scene.h"
#include "Input.h"
//Global Variables.
int screen_width, screen_height;
//On Window Resize.
void OnWindowResize(GLFWwindow *window, int width, int height);
//Implementation Structure.
struct Window::Implementation
{
//GLFW Window.
GLFWwindow *GLFW_window;
//Renderer.
Renderer *renderer;
//Delta Time.
double delta_time;
//Frames Per Second.
int fps;
//Scene.
Scene *scnene;
//Input.
Input *input;
//Deconstructor.
~Implementation();
};
//Window Constructor.
Window::Window(std::string title, int width, int height)
{
//Initializing width and height.
screen_width = width;
screen_height = height;
//Create Pointer To Implementation.
m_Impl = new Implementation();
//Try initializing GLFW.
if (!glfwInit())
{
std::cout << "GLFW could not be initialized!" << std::endl;
std::cout << "Press ENTER to exit..." << std::endl;
std::cin.get();
exit(-1);
}
//Setting up OpenGL Version 3.3 Core Profile.
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
/* Create a windowed mode window and its OpenGL context */
m_Impl->GLFW_window = glfwCreateWindow(width, height, title.c_str(), NULL, NULL);
if (!m_Impl->GLFW_window)
{
std::cout << "GLFW could not create a window!" << std::endl;
std::cout << "Press ENTER to exit..." << std::endl;
std::cin.get();
glfwTerminate();
exit(-1);
}
/* Make the window's context current */
glfwMakeContextCurrent(m_Impl->GLFW_window);
//Initialize GLEW.
if(glewInit() != GLEW_OK)
{
std::cout << "GLEW could not be initialized!" << std::endl;
std::cout << "Press ENTER to exit..." << std::endl;
std::cin.get();
glfwTerminate();
exit(-1);
}
//Enabling Blending.
GLCall(glEnable(GL_BLEND));
GLCall(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
//Setting the ViewPort.
GLCall(glViewport(0, 0, width, height));
//**********Initializing Implementation**********//
m_Impl->renderer = new Renderer();
m_Impl->delta_time = 0.0;
m_Impl->fps = 0;
m_Impl->input = new Input(this);
//**********Initializing Implementation**********//
//Set Frame Buffer Size Callback.
glfwSetFramebufferSizeCallback(m_Impl->GLFW_window, OnWindowResize);
}
//Window Deconstructor.
Window::~Window()
{
delete m_Impl;
}
//Window Main Loop.
void Window::MainLoop()
{
//Time Variables.
double start_time = 0, end_time = 0, old_time = 0, total_time = 0;
//Frames Counter.
int frames = 0;
/* Loop until the user closes the window */
while (!glfwWindowShouldClose(m_Impl->GLFW_window))
{
old_time = start_time; //Total time of previous frame.
start_time = glfwGetTime(); //Current frame start time.
//Calculate the Delta Time.
m_Impl->delta_time = start_time - old_time;
//Get Frames Per Second.
if (total_time >= 1)
{
m_Impl->fps = frames;
total_time = 0;
frames = 0;
}
//Clearing The Screen.
m_Impl->renderer->Clear(0, 0, 0);
//Render The Scene.
if (m_Impl->scnene != NULL)
m_Impl->scnene->Render(this);
//Updating the Screen.
m_Impl->renderer->Update(m_Impl->GLFW_window);
//Increasing frames counter.
frames++;
//End Time.
end_time = glfwGetTime();
//Total time after the frame completed.
total_time += end_time - start_time;
}
//Terminate GLFW.
glfwTerminate();
}
//Load Scene.
void Window::LoadScene(Scene * scene)
{
//Set the scene.
m_Impl->scnene = scene;
}
//Get Delta Time.
double Window::GetDeltaTime()
{
return m_Impl->delta_time;
}
//Get FPS.
int Window::GetFPS()
{
return m_Impl->fps;
}
//Get Width.
int Window::GetWidth()
{
return screen_width;
}
//Get Height.
int Window::GetHeight()
{
return screen_height;
}
//Get Input.
Input * Window::GetInput()
{
return m_Impl->input;
}
Renderer * Window::GetRenderer()
{
return m_Impl->renderer;
}
GLFWwindow * Window::GetGLFWindow()
{
return m_Impl->GLFW_window;
}
//Implementation Deconstructor.
Window::Implementation::~Implementation()
{
delete renderer;
delete input;
}
//OnWindowResize
void OnWindowResize(GLFWwindow *window, int width, int height)
{
screen_width = width;
screen_height = height;
//Updating the ViewPort.
GLCall(glViewport(0, 0, width, height));
}
Brain Class
#include "Brain.h"
#include "Sprite.h"
#include "Window.h"
struct Brain::Implementation
{
//Just A Flag.
bool started;
//Window Pointer.
Window *window;
//Sprite Pointer.
Sprite *sprite;
};
Brain::Brain(Window *window, Sprite *sprite)
{
//Create Pointer To Implementation.
m_Impl = new Implementation();
//Initialize Implementation.
m_Impl->started = true;
m_Impl->window = window;
m_Impl->sprite = sprite;
}
Brain::~Brain()
{
//Delete Pointer To Implementation.
delete m_Impl;
}
void Brain::Start()
{
}
void Brain::Update()
{
}
Window * Brain::GetWindow()
{
return m_Impl->window;
}
Sprite * Brain::GetSprite()
{
return m_Impl->sprite;
}
bool Brain::GetStart()
{
return m_Impl->started;
}
void Brain::SetStart(bool value)
{
m_Impl->started = value;
}
Script Class (Its a Brain Subclass!!!)
#include "Script.h"
Script::Script(Window *window, Sprite *sprite) : Brain(window, sprite)
{
}
Script::~Script()
{
}
void Script::Start()
{
std::cout << "Game Started!" << std::endl;
}
void Script::Update()
{
Input *input = this->GetWindow()->GetInput();
Sprite *sp = this->GetSprite();
//Move this sprite.
this->GetSprite()->Move(200 * this->GetWindow()->GetDeltaTime(),
input->GetKeyDown("left"),
input->GetKeyDown("right"),
input->GetKeyDown("up"),
input->GetKeyDown("down"));
std::cout << sp->GetTag().c_str() << ".x = " << sp->GetPos()->x << ", " << sp->GetTag().c_str() << ".y = " << sp->GetPos()->y << std::endl;
}
Main:
#include "SpaceShooterEngine.h"
#include "Script.h"
int main()
{
Window w("title", 600,600);
Scene *scene = new Scene();
Sprite *player = new Sprite("Resources/Images/player.png", "Player", 100,100);
Sprite *other = new Sprite("Resources/Images/cherno.png", "Other", 400, 100);
Sprite *other2 = new Sprite("Resources/Images/cherno.png", "Other", 300, 400);
Brain *brain = new Script(&w, player);
player->AddBrain(brain);
scene->AddSprite(player);
scene->AddSprite(other);
scene->AddSprite(other2);
w.LoadScene(scene);
w.MainLoop();
return 0;
}
I literally can't find what is wrong. If you need more code, ask me to post it. I will also attach all the source files.