Problems following a C++/OpenGL Tutorial (importing images) - c++

Question

I need to create a small game using OpenGL and C++ . I am using this tutorial to get started(my aim isn't actually to create the game but to use the code I eventually create).
I finished video 8 (the one linked) but I ran into a problem. My code crashed on the line
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageData.Width, imageData.Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData.Data);
Wen I change the loadAndBufferImage method parameters to something random (hgsjrkbgfdkj works fine) the code doesn't crash but obviously it doesn't load any image. I'm not sure what I am getting wrong. My IDE throws a warning on the glfwReadImage line since it doesn't like variable 3 being NULL (although it runs that line perfectly).
glfwReadImage(fileName, &imageData, NULL);
I'm not sure what I missed out/am doing wrong. Can it be the image? I used one converted via the link provided in the description of the video. The only hing I didn't do in the video was the small image importing part at around 7.40. I am using NetBeans not XCode, and I just imported the rocket.tga file in my resources folder (right click o resources folder, Add Existing Item, added image).
Here is a full copy of my GameWindow.cpp code up till now
#define GLEW_STATIC
#include "GameWindow.h"
#define GL_GLEXT_PROTOTYPES
#include <iostream>
typedef struct {
GLfloat positionCoordinates[3];
GLfloat textureCoordinates[2];
} VertexData;
#define Square_Size 100
VertexData vertices[] = {
{{0.0f, 0.0f, 0.0f},{0.0f,0.0f}},
{{Square_Size, 0.0f, 0.0f}, {1.0f,0.0f}},
{{Square_Size, Square_Size, 0.0f}, {1.0f,1.0f}},
{{0.0f, Square_Size, 0.0f}, {0.0f,1.0f}}
};
void GameWindow::setRunning(bool newRunning) {
_running = newRunning;
}
bool GameWindow::getRunning() {
return _running;
}
GLuint GameWindow::loadAndBufferImage(const char *fileName){
GLFWimage imageData;
glfwReadImage(fileName, &imageData, NULL);
GLuint textureBufferID;
glGenTextures(1, &textureBufferID);
glBindTexture(GL_TEXTURE_2D, textureBufferID);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageData.Width, imageData.Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData.Data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glfwFreeImage(&imageData);
return textureBufferID;
}
GameWindow::GameWindow(bool running):_running(running), _height(800), _width(800*16/9) {
glClearColor(1.0f,1.0f,1.0f,1.0f);
glViewport(0.0f, 0.0f, _width, _height);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glMatrixMode(GL_PROJECTION);
gluOrtho2D(0,_width,0,_height);
glMatrixMode(GL_MODELVIEW);
glGenBuffers(1, &_vertexBufferID);
glBindBuffer(GL_ARRAY_BUFFER, _vertexBufferID);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(VertexData), (GLvoid *) offsetof(VertexData,positionCoordinates));
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL_FLOAT, sizeof(VertexData), (GLvoid *) offsetof(VertexData, textureCoordinates));
_textureBufferID = loadAndBufferImage("rocket.tga");
}
void GameWindow::render() {
glClear(GL_COLOR_BUFFER_BIT);
glDrawArrays(GL_QUADS, 0, 4);
glfwSwapBuffers();
}
void GameWindow::update() {
}
I am using an oldish version of GLFW I think. Around version 2.7 because I couldn't get the new ones to work. Once again, not really relevant though I think.

Answer 1

Use imageData.Format for format in glTexImage2D():
glTexImage2D
(
GL_TEXTURE_2D,
0,
GL_RGBA,
imageData.Width,
imageData.Height,
0,
imageData.Format, // instead of GL_RGBA
GL_UNSIGNED_BYTE,
imageData.Data
);
Otherwise if imageData.Format == GL_RGB and you lie and say it's GL_RGBA instead then OpenGL will happily read right off the end of imageData.Data looking for RGBA tuples that aren't there.