ImGui

This is yet another continuation of my game engine project (Part 1, Part 2)

This week I wanted to check out ImGui which is a nice C++ GUI library targeted towards use in internal tools and embedded systems. I've known about ImGui for a couple years now but never used it before.

Before I could start integrating ImGui I needed to finish my work from last week. I had started implementing my postprocessing stack but never actually finished it. I last left it in a weird state where I could only use one postprocessing effect at a time, using zero or more would crash the application (The reason for this is that I hadn't implemented proper double buffering, and made an assumption about which buffer the result was rendered in).
With this out of the way I get started with ImGui, and I was pleasantly surprised at how easy it was! I spent more time fighting with visual studio than fighting with the actual library (vs refused to recompile objs.. whyyyyy,,,,)
Once I had a basic example running I just integrated it into my game loop and almost got it going to the first try.

After this I spent most of my time just studying the provided samples and copy-pasting writing simple editor windows. It's quite satisfying to see it all coming together!

Not only does it look good, actually creating the gui is also incredibly easy. I would like to share a complete example of how my vignette is currently implemented, GUI code and all.
C++:

class Vignette : public Effect {
public:
	float radius = 1.;
	float density = 1.;
	float falloff = 2.;

	Vignette() : Effect("vignette", "Vignette") { }

	void onEditorGui() {
		ImGui::SliderFloat("Radius", &radius, 0, 2);
		ImGui::SliderFloat("Density", &density, .1f, 10);
		ImGui::SliderFloat("Falloff", &falloff, 1., 32);
	}

	void onBind() {
		shader.setFloat("radius", radius);
		shader.setFloat("density", density);
		shader.setFloat("falloff", falloff);
	}
};

Shader:

out vec4 FragColor;
  
in vec2 TexCoords;

uniform sampler2D screenTexture;

uniform float radius;
uniform float density;
uniform float falloff;

void main()
{ 
    vec2 center = TexCoords-.5;

    vec2 uv = TexCoords;
    // ugly aspect ratio fix
    uv.x*=800./600.;

    vec3 col = texture(screenTexture, TexCoords).rgb;
    float vignette = 1-max(0,pow(length(center)/radius, falloff) * density);
    col *= vignette;

    FragColor = vec4(col,1);
}