Moving Camera on X axis glm::lookat() - c++

Question

I'm trying to make a 2D camera on OpenGl using the function glm::lookat(). The problem is that once everything is rendered, I can't move the camera. I'm only trying to move it on an horizontal way.
glm::mat4 projection = glm::ortho(0.0f, static_cast<GLfloat>(this->Width), static_cast<GLfloat>(this->Height), 0.0f, 0.1f, 500.0f);
glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);
glm::mat4 view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);

Answer 1

glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
So, something like:
void Update()
{
static glm::vec3 cameraPos(0,0,-1);
cameraPos.x += 0.1f;
... etc
}
(Though, I'd suggest creating a Camera class, or at least storing the vec3 outside of this method, for anything beyond experimentation.) Everything else should work fine.
Typically, you'd also want to take into account the time difference between frames. There are many ways to measure this - whatever gl framework you're using probably provides a function for it - but you're probably running at 60Hz, so assume the time between frames is 16.6ms. In which case, you might
float velocity = 10; // units per second
glm::vec3 cameraPos(0,0,-3);
float deltaT = 16.6e-3f; // 16 milliseconds
void Update()
{
cameraPos.x += velocity * deltaT;
glm::lookAt(cameraPos, .....);
}
You might run into a situation where everything renders the first frame, then disappears. In that case, drop the velocity to zero to make sure everything is working as it was before, then try some really small velocity values (like 0.001). It depends on how big your geometry is, distance from camera, and a bunch of other stuff. A camera Z of -3 is pretty small, might try backing it off some more while you're working this out.
Good luck!