#version 330

uniform sampler2D tex;
uniform float gamma, exposure;

in vec2 fragPosScreen;
out vec4 outputColor;

void main() {
	vec4 texColor = texture(tex, fragPosScreen);
	if (texColor.a < 1e-4)
		discard;

	vec3 mapped = texColor.rgb;
	if (exposure < 1e-4)
	 	mapped = mapped / (mapped + vec3(1.0));
	else
		mapped = vec3(1.0) - exp(-mapped * exposure);

	outputColor = vec4(pow(mapped, vec3(1.0/gamma)), 1.0f);
}