How do I add light to my textures?

Question

How do I add light to my textures using this? I have this

GLfloat ka = 1.0;
glm::vec3 ia = glm::vec3(0.5f, 0.5f, 0.5f);

and in the fragment shader

out vec4 color;

in VS_OUT
{
    vec2 tc;
    vec3 normals;
} 

fs_in;


layout(binding=0)uniform sampler2D tex; 


void main(void)
{
color= texture(tex, fs_in.tc);
}

We were given this example but I don't understand what to do.

out vec4 color;
uniform vec3 materialColor;
uniform vec3 ia; // Ambient colour
uniform float ka; // Ambient constant
void main(void){
color = vec4( ka * ia , 1.0);
}

Help?

Answer 1

Just multiply the two expressions you already have:

color= texture(tex, fs_in.tc) * vec4( ka * ia , 1.0);

This tints the colour of the texture by the colour and intensity of the ambient light.

This is shown in nearly every example shader and definitely in every single "how to get started with glsl shaders" tutorial on the net, so it does not look like you researched this at all. Please take the time to do a bit more legwork and reading before posting a question here in future.