Very Simple Letterbox Shader

A simple shader that replicates a letterbox effect.

Shader code
/* Simple Godot Letterbox Shader - Kanjo (CC0) */
shader_type canvas_item;

uniform float squishedness = 0.0;

void fragment() {
	if (SCREEN_UV.y < squishedness * 0.5 || SCREEN_UV.y > 1.0 - (squishedness * 0.5)) COLOR = vec4(0, 0, 0, 1);
}

/* Better solution (credit to Beebe Ray in comments) */
shader_type canvas_item;

uniform float squishedness = 0.0;

void fragment() {
	COLOR = mix(
		vec4(vec3(0.0), 1.0),
		texture(SCREEN_TEXTURE, SCREEN_UV),
		step(squishedness * 0.5, SCREEN_UV.y) - step(1.0 - squishedness * 0.5, SCREEN_UV.y)
	);
}
Tags
cinematic, letterbox
The shader code and all code snippets in this post are under CC0 license and can be used freely without the author's permission. Images and videos, and assets depicted in those, do not fall under this license. For more info, see our License terms.

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Beebe Ray
Beebe Ray
11 months ago

One line instead.

COLOR = mix(
vec4(vec3(0.0), 1.0),
texture(SCREEN_TEXTURE, SCREEN_UV),
step(squishedness, SCREEN_UV.y) - step(1.0-squishedness, SCREEN_UV.y)
);
Last edited 11 months ago by k2kra
snesmocha
snesmocha
11 months ago
Reply to  Beebe Ray

ah yes, the classic commenter does better xd