khanat-client/addons/zylann.hterrain/tools/texture_editor/display_normal.shader

28 lines
618 B
GLSL

shader_type canvas_item;
uniform float u_strength = 1.0;
uniform bool u_flip_y = false;
vec3 unpack_normal(vec4 rgba) {
vec3 n = rgba.xzy * 2.0 - vec3(1.0);
// Had to negate Z because it comes from Y in the normal map,
// and OpenGL-style normal maps are Y-up.
n.z *= -1.0;
return n;
}
vec3 pack_normal(vec3 n) {
n.z *= -1.0;
return 0.5 * (n.xzy + vec3(1.0));
}
void fragment() {
vec4 col = texture(TEXTURE, UV);
vec3 n = unpack_normal(col);
n = normalize(mix(n, vec3(-n.x, n.y, -n.z), 0.5 - 0.5 * u_strength));
if (u_flip_y) {
n.z = -n.z;
}
col.rgb = pack_normal(n);
COLOR = vec4(col.rgb, 1.0);
}