GLM::Projection questions

I am trying to understand projection with glm, the textbooks and references I use refers to gluProject, however I use GLM for everything and it is deprecated for the version of OpenGL (4) I use.

I am writing a shader that renders a volumetric light (Final post FX where i draw a quad), so i need to project into 2D space from 3D.

This is my attempt to use glm :: project over gluProject

Code :

glm::vec3 screenCoords = glm::project(
glm::vec3(m_pos),
view*model,
proj,
glm::vec4( 0, 0, m_windowWidth, m_windowHeight)
);

**m_pos** is the position of the light.

**view** is the view of the camera (from glm::lookAt)

**model** is mat4(1), i was unsure about this one

**proj** is the view projection of the camera.
Code :

glm::perspective<float>(70.0f, (float)m_windowWidth/
m_windowHeight, 0.1f, 1000.0f);

then final code before i draw the scene, normalize the vectors then update the vec2 uniform for light position.

Code :

screenCoords = glm :: normalize(screenCoords);
m_engine->postFXShader().setUniform("lightPositionOnScreen", vec2(screenCoords.x, screenCoords.y));

Shader code (Fragment)

Code :

#version 420
in vec2 UV;
out vec3 color;
uniform sampler2D renderedTexture;
uniform vec2 lightPositionOnScreen;
int NUM_SAMPLES = 100;
float density = 1.0;
float illuminationDecay = 0.75;
float weight = 0.010;
float decay = 0.99;
vec3 LightBeam()
{
vec3 sampler;
vec2 uvLocal = UV.xy;
vec2 light = lightPositionOnScreen;
//light.xy = (light.xy + vec2(1.0, 1.0)) / 2.0;
vec2 deltaTexCoord = uvLocal.xy - light.xy;
deltaTexCoord.xy *= 1.0 / (float(NUM_SAMPLES) * density);
vec3 color = texture2D(renderedTexture, uvLocal.xy ).xyz;
for(int i=0; i<NUM_SAMPLES; ++i)
{
uvLocal.xy -= deltaTexCoord.xy;
sampler = texture2D(renderedTexture, uvLocal.xy ).xyz;
sampler *= illuminationDecay * weight;
color += sampler;
illuminationDecay *= decay;
}
return color;
}
void main() {
color = LightBeam();
}

The result i see is good, but when i rotate the camera it appears like the rays rotate incorrectly in terms of camera rotation, so i wanted to post my code here, in case i made any obvious mistakes using glm.