Hi,

I’m trying to make 3 different stage, first drawing only then add lighting and finally texture.

So that I can switch among 3 modes, can this be achieved by one single shader? or it has to be separated?

Many thanks!

**[Drawing + No Lighting]**

I couldn’t figure this out yet

**[Drawing + Lighting]**

**[Drawing + Lighting + Texture]**

**[Vertex Shader]**

```
#version 450 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
out VS_OUT {
vec3 FragPos;
vec3 Normal;
vec2 TexCoords;
} vs_out;
uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
void main() {
vs_out.FragPos = vec3(model * vec4(aPos, 1.0));
vs_out.TexCoords = aTexCoords;
mat3 normalMatrix = transpose(inverse(mat3(model)));
vs_out.Normal = normalize(normalMatrix * aNormal);
gl_Position = projection * view * model * vec4(aPos, 1.0);
}
```

**[Fragment Shader]**

```
#version 450 core
layout (location = 0) out vec4 FragColor;
layout (location = 1) out vec4 BrightColor;
in VS_OUT {
vec3 FragPos;
vec3 Normal;
vec2 TexCoords;
} fs_in;
struct Light {
vec3 Position;
vec3 Color;
};
uniform Light lights[4];
uniform sampler2D diffuseTexture;
uniform bool withLight;
uniform bool withTexture;
uniform vec3 viewPos;
out vec4 FragColor;
void main() {
vec3 color;
if (withTexture)
color = texture(diffuseTexture, fs_in.TexCoords).rgb;
else
color = vec3(0.45, 0.45, 0.45);
vec3 normal = normalize(fs_in.Normal);
// Ambient
vec3 ambient = 0.0 * color;
// Lighting
vec3 lighting = vec3(0.0);
vec3 viewDir = normalize(viewPos - fs_in.FragPos);
for (int i = 0; i < 4; i++) {
// Diffuse
vec3 lightDir = normalize(lights[i].Position - fs_in.FragPos);
float diff = max(dot(lightDir, normal), 0.0);
vec3 result = lights[i].Color * diff * color;
// Attenuation (use quadratic as we have gamma correction)
float distance = length(fs_in.FragPos - lights[i].Position);
result *= 1.0 / (distance * distance);
lighting += result;
}
vec3 result = ambient + lighting;
// Check whether result is higher than some threshold, if so, output as threshold color
float brightness = dot(result, vec3(0.2126, 0.7152, 0.0722));
if (brightness > 1.0)
BrightColor = vec4(result, 1.0);
else
BrightColor = vec4(0.0, 0.0, 0.0, 1.0);
FragColor = vec4(result, 1.0);
}
```