VAO isn't rendering my simple triangle, what could be causing this? - c++

Question

I've already looked all over the internet for the past couple days and I cannot find a fix to this problem. I believe I've got the basic debugging stuff setup yet I get no errors telling me what I've done wrong. This is my first attempt at a renderer, and I'm also trying to use a OOP/DOD (Data oriented design) structure. I think the error is just something small that I am blind to, or I'm completely doing this wrong... please help if you can.
Also I'm using shaders, EBOs, VBOs, linking to a VAO (I think)
Additional information: I'm using SDL + GLAD(opengl 4.6, core)
If you need me to reply with anything else that could help you help me, let me know.
Here is my console output:
screenshot
All I see on the window: screenshot
Here are my files (that might have the error):
vertex shader
#version 460 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;
out vec3 ourColor;
void main()
{
gl_Position = vec4(aPos, 1.0);
ourColor = aColor;
}
fragment shader
#version 460 core
out vec4 FragColor;
in vec3 ourColor;
void main()
{
FragColor = vec4(ourColor, 1.0f);
}
main.cpp (the window)
#include <loader.h>
using namespace testProgram;
int close(SDL_Window* window, SDL_GLContext glContext) {
IMG_Quit();
SDL_DestroyWindow(window);
SDL_GL_DeleteContext(glContext);
SDL_Quit();
return 0;
}
// Simple debugger callback, will most likely modify in the future.
static void APIENTRY openglCallbackFunction(
GLenum source,
GLenum type,
GLuint id,
GLenum severity,
GLsizei length,
const GLchar* message,
const void* userParam
){
(void)source; (void)type; (void)id;
(void)severity; (void)length; (void)userParam;
fprintf(stderr, "%s\n", message);
if (severity==GL_DEBUG_SEVERITY_HIGH) {
fprintf(stderr, "Aborting...\n");
abort();
}
}
std::vector<GLfloat> vertices {
// positions // colors
0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // bottom left
0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f // top
};
std::vector<GLuint> indices {
0, 1, 2
};
std::vector<int> vertexAttribSizes {
3
};
int main(int argc, char* argv[]) {
// Variables
bool quit = false;
// Initializations
SDL_Init(SDL_INIT_EVERYTHING);
IMG_Init(IMG_INIT_PNG);
setGLAttributes();
// Creating the window
SDL_Window* window = SDL_CreateWindow("test", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, winW, winH, flags);
SDL_GLContext glContext = SDL_GL_CreateContext(window);
SDL_GL_MakeCurrent(window, glContext);
SDL_Surface* icon = IMG_Load("images/icon.png");
setIcon(window, icon);
// Setting up OpenGL
if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress)) {
printf("Failed to initialize GLAD\n");
return -1;
}
glViewport(0, 0, winW, winH);
// Enable the debug callback
glEnable(GL_DEBUG_OUTPUT);
glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
glDebugMessageCallback(openglCallbackFunction, nullptr);
glDebugMessageControl
(
GL_DONT_CARE,
GL_DONT_CARE,
GL_DONT_CARE,
0, NULL, true
);
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
Renderer::Queue queue;
Renderer::Shader shader;
Renderer::Object object;
shader.Update("CUT OUT THE DIRECTORY FOR THIS POST (because it doesn't matter)", "CUT OUT THE DIRECTORY FOR THIS POST (because it doesn't matter)");
object.Update(vertices, indices, shader.id, "triangle", vertexAttribSizes);
object.Attach(queue);
while(!quit) {
SDL_Event event;
mouseX = event.motion.x;
mouseY = event.motion.y;
while (SDL_PollEvent(&event) != 0) {
inputCollection(event, quit);
}
SDL_SetWindowHitTest(window, hitCallback, 0);
glClearColor(0.085f, 0.085f, 0.085f, 0.f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
queue.Render();
SDL_GL_SwapWindow(window);
}
// Closes all processes
object.Detach(queue);
close(window, glContext);
return 0;
}
renderer.h (it is included in loader.h, which is included in main.cpp. loader.h I believe doesn't contain the issue, so I dont want to pollute this post with even more code haha)
// Includes
#include <glad/glad.h>
#include <stdio.h>
#include <algorithm>
#include <string>
#include <vector>
#include <iostream>
#include <fstream>
#include <ctype.h>
#include <fstream>
#include <cstring>
#include <sstream>
// Renderer
namespace Renderer {
class Shader {
private:
// Read the shader's source code.
std::string readFile(const char* _path);
// Check the shader.
bool checkShader(GLuint &_shader);
// Check the program.
bool checkProgram(GLuint &_program);
public:
const char* vertexPath;
const char* fragmentPath;
GLuint id;
void Update(const char* _vertexPath, const char* _fragmentPath); // Update the shader's parameters.
void Use() { glUseProgram(id); } // Use the shader.
};
class Queue {
public:
GLuint VAO;
void listObjects(); // List all objects in the queue (BY NAME, INDEX IS THE ID FOR ALL VALUES/PARAMETERS)
GLuint getObject(std::string objName); // Grab an object from the queue (BY NAME, INDEX IS THE ID FOR ALL VALUES/PARAMETERS) [Returns the id of the object]
bool findObject(std::string objName); // Returns true or false if the object is found.
void Render(); // Render all objects in the queue. (Sets VAOs)
std::vector<std::vector<GLfloat>> vertices;
std::vector<std::vector<int>> indices;
std::vector<std::vector<int>> vertexAttribs;
std::vector<int> shaderProgramIDs;
std::vector<std::string> names;
};
class Object {
public:
GLuint VBO, EBO;
std::vector<GLfloat> vertices;
std::vector<int> indices;
std::vector<int> vertexAttribSizes; // This is the sizes of the vertex attributes, not the values.
GLuint shaderProgramID;
std::string name;
// Set the object's parameters.
void Update(
std::vector<GLfloat> _vertices,
std::vector<GLuint> _indices,
int _shaderProgramID,
std::string _name,
std::vector<int> _vertexAttribSizes
);
void Attach(Queue &queue);
void Detach(Queue &queue);
};
};
renderer.cpp
#include <renderer.h>
using namespace Renderer;
// List all objects in the queue.
void Queue::listObjects() {
for (auto name : names) {
std::cout << name << std::endl;
}
}
// Returns true or false if the object is found.
bool Queue::findObject(std::string objName) {
auto index = std::find(names.begin(), names.end(), objName);
if (index != names.end()) {
return true;
} else {
return false;
}
}
// Returns the object id.
GLuint Queue::getObject(std::string objName) {
auto index = std::find(names.begin(), names.end(), objName);
if (findObject(objName)) {
return index - names.begin();
} else {
return -1;
}
}
// Renders all objects linked to the current queue.
void Queue::Render() {
for (int i = 0; i < names.size(); i++) {
glUseProgram(shaderProgramIDs[i]);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, indices[i].size(), GL_UNSIGNED_INT, 0);
}
}
std::string Shader::readFile(const char* _path) {
std::string content;
std::ifstream fileStream(_path, std::ios::in);
if (!fileStream.is_open()) {
std::cerr << "Could not read file " << _path << ". File does not exist." << std::endl;
return "";
}
std::string line = "";
while (!fileStream.eof()) {
std::getline(fileStream, line);
content.append(line + "\n");
}
fileStream.close();
return content;
}
bool Shader::checkShader(GLuint &_shader) {
GLint success;
glGetShaderiv(_shader, GL_COMPILE_STATUS, &success);
if(!success) {
GLint maxLength = 0;
glGetShaderiv(_shader, GL_INFO_LOG_LENGTH, &maxLength);
std::vector<GLchar> errorLog(maxLength);
glGetShaderInfoLog(_shader, maxLength, &maxLength, &errorLog[0]);
std::cout << "Shader compilation failed: " << std::endl;
std::cout << &errorLog[0] << std::endl;
return false;
}
return true;
}
bool Shader::checkProgram(GLuint &_program) {
GLint success;
glGetProgramiv(_program, GL_LINK_STATUS, &success);
if(!success) {
GLint maxLength = 0;
glGetProgramiv(_program, GL_INFO_LOG_LENGTH, &maxLength);
std::vector<GLchar> errorLog(maxLength);
glGetProgramInfoLog(_program, maxLength, &maxLength, &errorLog[0]);
std::cout << "Program linking failed: " << std::endl;
std::cout << &errorLog[0] << std::endl;
return false;
}
return true;
}
void Shader::Update(
const char* _vertexPath,
const char* _fragmentPath
){
GLuint vertex, fragment;
vertex = glCreateShader(GL_VERTEX_SHADER);
fragment = glCreateShader(GL_FRAGMENT_SHADER);
vertexPath = _vertexPath;
fragmentPath = _fragmentPath;
std::string vertexString = readFile(_vertexPath);
std::string fragmentString = readFile(_fragmentPath);
const char *vertexSource = vertexString.c_str();
const char *fragmentSource = fragmentString.c_str();
glShaderSource(vertex, 1, &vertexSource, NULL);
glCompileShader(vertex);
checkShader(vertex);
glShaderSource(fragment, 1, &fragmentSource, NULL);
glCompileShader(fragment);
checkShader(fragment);
this->id = glCreateProgram();
glAttachShader(this->id, vertex);
glAttachShader(this->id, fragment);
glLinkProgram(this->id);
checkProgram(this->id);
glDeleteShader(vertex);
glDeleteShader(fragment);
}
void Object::Attach(Queue &queue) {
queue.names.push_back(this->name);
GLuint id = queue.getObject(this->name);
queue.shaderProgramIDs.insert(queue.shaderProgramIDs.begin()+id, this->shaderProgramID);
queue.vertices.insert(queue.vertices.begin()+id, this->vertices);
queue.indices.insert(queue.indices.begin()+id, this->indices);
queue.vertexAttribs.insert(queue.vertexAttribs.begin()+id, this->vertexAttribSizes);
glGenBuffers(1, &this->VBO);
glGenBuffers(1, &this->EBO);
glGenVertexArrays(1, &queue.VAO);
glBindVertexArray(queue.VAO);
glBindBuffer(GL_ARRAY_BUFFER, this->VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(this->vertices), &this->vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(this->indices), &this->indices, GL_STATIC_DRAW);
int stride = 3;
for (int i = 0; i < this->vertexAttribSizes.size(); i++) {
stride+=this->vertexAttribSizes[i];
}
// Positions
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, stride * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
// Other attributes
int totalSize = 3;
for (int i = 0; i < this->vertexAttribSizes.size(); i++) {
glVertexAttribPointer(i+1, this->vertexAttribSizes[i], GL_FLOAT, GL_FALSE, stride * sizeof(float), (void*)(totalSize * sizeof(float)));
glEnableVertexAttribArray(i+1);
totalSize+=this->vertexAttribSizes[i];
}
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
void Object::Detach(Queue &queue) {
GLuint id = queue.getObject(this->name);
queue.names.erase(std::remove(queue.names.begin(), queue.names.end(), this->name), queue.names.end());
queue.vertices.erase(queue.vertices.begin()+id, queue.vertices.begin()+id+this->vertices.size());
queue.indices.erase(queue.indices.begin()+id, queue.indices.begin()+id+this->indices.size());
queue.vertexAttribs.erase(queue.vertexAttribs.begin()+id, queue.vertexAttribs.begin()+id+this->vertexAttribSizes.size());
glDeleteBuffers(1, &this->VBO);
glDeleteBuffers(1, &this->EBO);
}
void Object::Update(
std::vector<GLfloat> _vertices,
std::vector<GLuint> _indices,
int _shaderProgramID,
std::string _name,
std::vector<int> _vertexAttribSizes
){
// TODO: Clear all vectors, also detach and reattach automatically.
for (int i = 0; i < _vertices.size(); i++) {
vertices.push_back(_vertices[i]);
}
for (int i = 0; i < _indices.size(); i++) {
indices.push_back(_indices[i]);
}
for (int i = 0; i < _vertexAttribSizes.size(); i++) {
vertexAttribSizes.push_back(_vertexAttribSizes[i]);
}
shaderProgramID = _shaderProgramID;
name = _name;
}

Answer 1

glBindBuffer(GL_ARRAY_BUFFER, this->VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(this->vertices), &this->vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(this->indices), &this->indices, GL_STATIC_DRAW);
this->vertices is a std::vector. You are uploading raw pointer values where there should be actual data in the buffer.
glBindBuffer(GL_ARRAY_BUFFER, this->VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * this->vertices.size(), this->vertices.data(), GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int) * this->indices.size(), this->indices.data(), GL_STATIC_DRAW);