if-statement in GLSL [SOLVED]

OpenGL Development
#1

I’ve been trying to implement the bloom effect, and it’s really, really easy to understand and implement. Except that I just can’t implement it, because there seems to be something hinky going on with my fragment shader. I’ve got multiple render targets. I’m rendering to GL_COLOR_ATTACHMENT0 and GL_COLOR_ATTACHMENT1. I’m using framebuffers to render to textures.

Before I explain my problem, here’s my fragment shader code:


#version 400 core

in vec4 passColour;
in vec3 passNormals;
in vec3 toLightVectors[16];
in vec3 passCamDir;

layout (location = 0) out vec4 outColour;
layout (location = 1) out vec4 brightColour;

void main(void){
	vec3 surfaceNormal = normalize(passNormals);
	float diffuse = 0; 
	float specular = 0;
	for(int i = 0; i < 16; i++){
		vec3 surfaceToLightVector = normalize(toLightVectors[i]);
		diffuse += max(dot(surfaceNormal, surfaceToLightVector), 0.02);
		float angle = dot(reflect(-surfaceToLightVector, surfaceNormal), passCamDir); 
		float spec = pow(max(angle, 0.02), 4);
		specular += spec;
	}
	outColour = (diffuse + specular) * passColour;

        float brightness = dot(outColour.rgb, vec3(0.2126, 0.7152, 0.0722)); 
        if(brightness > 1.0){
    	        brightColour = vec4(outColour.rgb, 1.0);
        }

}

You can ignore the diffuse and specular lighting calculations at the top. Take a look at the last few lines, where I declare a variable called “brightness” and I use an if statement to determine if the brightness level of the fragment is exceeding 1.0.

GL_COLOR_ATTACHMENT0 is where I render the entire scene normally, with the lighting and everything. GL_COLOR_ATTACHMENT1 is where all the fragments that are brighter than 1.0 are rendered. brightColour is the colour output for GL_COLOR_ATTACHMENT1, but for some reason it’s rendering all of the fragments to GL_COLOR_ATTACHMENT1, even the ones that are definitely not brighter than 1.0

So my first thought was that there’s something up with the if statement. And there was.

Here are a list of conditions that I tried in the if statement:

brightness > 100.0 == true
brightness > 10000.0 == true
brightness < 0.0 && brightness > 1.0 == true (how is this even possible???)

So there’s definitely something wrong here. But I just can’t figure out what the heck’s going on. The most relevant answer that I got on the Internet is completely irrelevant (which means I can’t get any answers or clues). I tried several different ways to figure out what’s wrong, but I couldn’t figure anything out.

I can’t fix a problem if I don’t even know what the problem is, so I’d appreciate any help you guys can offer.

I also checked if 1 == 2, because I couldn’t think of anything else. 1 == 2 is still false, but I just don’t see how brightness < 0 && brightness > 1 can be true.

I’m not asking for an answer, I just need a push in the right direction.

#2

`How did you check the conditions?

#3

I just replaced the condition in the if statement in the code above.

#4

OK, I figured it out. It’s been working the whole time, but it made it seem as though it was all normal because the dark fragments were being discarded, making it seem as though it was just the diffuse and specular lighting making those regions dark. But in actuality, those regions were being discarded and they weren’t being rendered at all.