Shader code
shader_type canvas_item;
uniform float hue_shift: hint_range(0.0, 1.0) = 0.0;
vec4 shift_hue(in vec4 color, in float shift) {
// The unit gray vector in RGB color space.
vec3 gray = vec3(0.57735);
// Project color onto gray axis.
vec3 projection = gray * dot(gray, color.rgb);
// Vector from gray axis to original color.
vec3 U = color.rgb - projection;
// Vector perpendicular to gray axis and U.
vec3 V = cross(gray, U);
// Rotate U and V around the gray axis.
vec3 shifted = U * cos(shift * 2.0 * PI) + V * sin(shift * 2.0 * PI) + projection;
return vec4(shifted, color.a);
}
void fragment() {
COLOR = shift_hue(texture(TEXTURE, UV), hue_shift);
}
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Tags
Color,
hue,
shift
