OpenGL is leaking memory. Which object is not being released? - c++

Question

I'm having problems with my OpenGL rendering. The RAM memory grows absurdly up to the point the entire system freezes. I've identified that if I comment the entire render function, no memory grows at all. Therefore the problem is that my OpenGL render function might be allocating memory for something and I'm not releasing it.
Can you identify what is the problem?
PS: the thing inside the if actually runs one single time, so the allocation of memory it does, occur only one time
This is my OpenGL render function:
void OpenGlVideoQtQuickRenderer::render()
{
if (this->firstRun) {
std::cout << "Creating QOpenGLShaderProgram " << std::endl;
this->firstRun = false;
program = new QOpenGLShaderProgram();
initializeOpenGLFunctions();
//this->m_F = QOpenGLContext::currentContext()->functions();
datas[0] = new unsigned char[width*height]; //Y
datas[1] = new unsigned char[width*height/4]; //U
datas[2] = new unsigned char[width*height/4]; //V
std::cout << program->addShaderFromSourceCode(QOpenGLShader::Fragment, tString2) << std::endl;
std::cout << program->addShaderFromSourceCode(QOpenGLShader::Vertex, vString2) << std::endl;
program->bindAttributeLocation("vertexIn",A_VER);
program->bindAttributeLocation("textureIn",T_VER);
std::cout << "program->link() = " << program->link() << std::endl;
}
program->bind();
glVertexAttribPointer(A_VER, 2, GL_FLOAT, 0, 0, ver);
glEnableVertexAttribArray(A_VER);
glVertexAttribPointer(T_VER, 2, GL_FLOAT, 0, 0, tex);
glEnableVertexAttribArray(T_VER);
unis[0] = program->uniformLocation("tex_y");
unis[1] = program->uniformLocation("tex_u");
unis[2] = program->uniformLocation("tex_v");
glGenTextures(3, texs);
//Y
glBindTexture(GL_TEXTURE_2D, texs[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//U
glBindTexture(GL_TEXTURE_2D, texs[1]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width/2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//V
glBindTexture(GL_TEXTURE_2D, texs[2]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width / 2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texs[0]);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, datas[0]);
glUniform1i(unis[0], 0);
glActiveTexture(GL_TEXTURE0+1);
glBindTexture(GL_TEXTURE_2D, texs[1]);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width/2, height / 2, GL_RED, GL_UNSIGNED_BYTE, datas[1]);
glUniform1i(unis[1],1);
glActiveTexture(GL_TEXTURE0+2);
glBindTexture(GL_TEXTURE_2D, texs[2]);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width / 2, height / 2, GL_RED, GL_UNSIGNED_BYTE, datas[2]);
glUniform1i(unis[2], 2);
glDrawArrays(GL_TRIANGLE_STRIP,0,4);
program->disableAttributeArray(A_VER);
program->disableAttributeArray(T_VER);
program->release();
}

Answer 1

The code is creating three new textures in each frame (glGenTextures) without ever releasing them (glDeleteTextures). Either you delete them at the end of the render method, or even better: You only create the textures once in the first block and then only upload new data to them.
Just for the records: Drawing from CPU memory by specifying the address in glVertexAttribPointer is only valid in OpenGL before Core profile. I highly suggest to use Vertex Buffer Objects instead.