bendns' repos / fimg
fast image operations
Diffstat (limited to 'src/pixels/blending.rs')
-rw-r--r--src/pixels/blending.rs127
1 files changed, 0 insertions, 127 deletions
diff --git a/src/pixels/blending.rs b/src/pixels/blending.rs
deleted file mode 100644
index cecc742..0000000
--- a/src/pixels/blending.rs
+++ /dev/null
@@ -1,127 +0,0 @@
-//! module for pixel blending ops
-#![allow(redundant_semicolons)]
-use super::{Floatify, Unfloatify, convert::PFrom, float, unfloat};
-use atools::prelude::*;
-
-/// Trait for blending pixels together.
-pub trait Blend<const W: usize> {
- /// blends self with another pixel
- fn blend(&mut self, with: [u8; W]);
-}
-
-pub(crate) fn blend_alpha_and_color(a: u8, color: [u8; 3], onto: &mut [u8; 3]) {
- if a == 0 {
- return;
- }
- if a == 255 {
- *onto = color;
- return;
- }
-
- let [br, bg, bb] = *onto;
- let [fr, fg, fb] = color;
-
- onto[0] = lerp(br, fr, a);
- onto[1] = lerp(bg, fg, a);
- onto[2] = lerp(bb, fb, a);
-
- // onto.copy_from_slice(&fg.zip(bg).map(|(f, b)| a * (f - b) + b));
-}
-
-fn lerp(ba: u8, fo: u8, a: u8) -> u8 {
- ((fo as i32 - ba as i32) * a as i32 / 256 + ba as i32) as u8
-}
-
-impl Blend<4> for [u8; 4] {
- #[lower::apply(algebraic)]
- fn blend(&mut self, fg: [u8; 4]) {
- if fg[3] == 0 {
- return;
- }
- if fg[3] == 255 {
- *self = fg;
- return;
- }
- let fg = fg.float();
- let bg = self.float();
- let a = bg[3] + fg[3] - bg[3] * fg[3];
- if a == 0.0 {
- return;
- };
- self[..3].copy_from_slice(
- &fg.init()
- .zip(bg.init())
- .map(|(f, b)| (f * fg[3] + b * bg[3] * (1.0 - fg[3])) / a)
- .unfloat(),
- );
- self[3] = unfloat(a)
- }
-}
-
-impl Blend<3> for [u8; 3] {
- fn blend(&mut self, with: [u8; 3]) {
- *self = with;
- }
-}
-
-impl Blend<4> for [u8; 3] {
- fn blend(&mut self, with: [u8; 4]) {
- let mut us: [u8; 4] = PFrom::pfrom(*self);
- us.blend(with);
- *self = PFrom::pfrom(us);
- }
-}
-
-impl Blend<2> for [u8; 2] {
- #[lower::apply(algebraic)]
- fn blend(&mut self, with: [u8; 2]) {
- let bg = self.float();
- let fg = with.float();
-
- let a = bg[1] + fg[1] - bg[1] * fg[1];
- if a == 0.0 {
- return;
- }
- *self = [
- // SAFETY: no u8 can do transform bad
- (fg[0] * fg[1] + bg[0] * bg[1] * (unsafe { (1.0) } - fg[1])) / a,
- a,
- ]
- .unfloat()
- }
-}
-
-impl Blend<1> for [u8; 1] {
- fn blend(&mut self, with: [u8; 1]) {
- *self = with;
- }
-}
-
-#[cfg(test)]
-mod blend {
- use super::*;
-
- macro_rules! blend {
- ([$($a:literal),+] + [$($b:literal),+] = $what:expr) => {
- let mut a = [$($a,)+];
- a.blend([$($b,)+]);
- assert_eq!(a, $what);
- };
-}
-
- #[test]
- fn test_blend_rgba() {
- blend!([255, 255, 255, 255] + [255, 255, 255, 255] = [255, 255, 255, 255]);
- blend!([255, 255, 255, 0] + [255, 255, 255, 255] = [255, 255, 255, 255]);
- blend!([255, 255, 255, 255] + [255_u8, 255, 255, 0] = [255, 255, 255, 255]);
- blend!([255, 255, 255, 0] + [255_u8, 255, 255, 0] = [255, 255, 255, 0]);
- }
-
- #[test]
- fn test_blend_ya() {
- blend!([255, 255] + [255, 255] = [255, 255]);
- blend!([255, 0] + [255, 255] = [255, 255]);
- blend!([255, 255] + [255, 0] = [255, 255]);
- blend!([255, 0] + [255, 0] = [255, 0]);
- }
-}