chlorospingus/chloroway
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Properly use premultiplied alpha

Browse Source
This commit is contained in:
Chlorospingus
2025-05-28 14:34:21 -07:00
parent 3bcccb2e87
commit 1eff2cd4f7
6 changed files with 69 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
src/graphics/drawable.rs
View File

@@ -1,34 +1,51 @@
use crate::wayland::{shm::ShmPool, wl_shm::wl_buffer};
pub fn rgb_blend(col1: u32, col2: u32, diff: f64) -> u32 {
let r1 = (col1 & 0x00ff0000) >> 16;
let g1 = (col1 & 0x0000ff00) >> 8;
let b1 = col1 & 0x000000ff;
let r2 = (col2 & 0x00ff0000) >> 16;
let g2 = (col2 & 0x0000ff00) >> 8;
let b2 = col2 & 0x000000ff;
let r3 = if r1 < r2 {
r1 + ((r2 - r1) as f64 * diff) as u32
} else {
r1 - ((r1 - r2) as f64 * diff) as u32
};
let g3 = if g1 < g2 {
g1 + ((g2 - g1) as f64 * diff) as u32
} else {
g1 - ((g1 - g2) as f64 * diff) as u32
};
let b3 = if b1 < b2 {
b1 + ((b2 - b1) as f64 * diff) as u32
} else {
b1 - ((b1 - b2) as f64 * diff) as u32
};
(r3 << 16) + (g3 << 8) + b3
pub fn premultiply(color: u32) -> u32 {
let a = (color & 0xff000000) >> 24;
let r = (color & 0x00ff0000) >> 16;
let g = (color & 0x0000ff00) >> 8;
let b = (color & 0x000000ff) >> 0;
let alpha = (a as f64 / 0xff as f64);
(a << 24) +
(((r as f64*alpha) as u32) << 16) +
(((g as f64*alpha) as u32) << 8) +
(((b as f64*alpha) as u32) << 0)
}
pub fn color_blend(col1: u32, col2: u32, diff: f64) -> u32 {
let a1 = (col1 & 0xff000000) >> 24;
let r1 = (col1 & 0x00ff0000) >> 16;
let g1 = (col1 & 0x0000ff00) >> 8;
let b1 = (col1 & 0x000000ff) >> 0;
let a2 = (col2 & 0xff000000) >> 24;
((a2 + ((a1 as f64/0xff as f64)*(0xff - a2) as f64*(1.0-diff)) as u32) << 24) + rgb_blend(col1, col2, diff * (a1 as f64 / 0xff as f64))
let r2 = (col2 & 0x00ff0000) >> 16;
let g2 = (col2 & 0x0000ff00) >> 8;
let b2 = (col2 & 0x000000ff) >> 0;
(((a1 as f64 + (a2 as f64 - a1 as f64) * diff).round() as u32) << 24) +
(((r1 as f64 + (r2 as f64 - r1 as f64) * diff).round() as u32) << 16) +
(((g1 as f64 + (b2 as f64 - g1 as f64) * diff).round() as u32) << 8 ) +
(((b1 as f64 + (g2 as f64 - b1 as f64) * diff).round() as u32) << 0 )
}
pub fn color_over(over: u32, under: u32) -> u32 {
let a_over = (over & 0xff000000) >> 24;
let a_under = (under & 0xff000000) >> 24;
if a_over == 0xff || a_under == 0 {
return over;
}
if a_over == 0 {
return under;
}
let r_over = (over & 0x00ff0000) >> 16;
let r_under = (under & 0x00ff0000) >> 16;
let g_over = (over & 0x0000ff00) >> 8;
let g_under = (under & 0x0000ff00) >> 8;
let b_over = (over & 0x000000ff) >> 0;
let b_under = (under & 0x000000ff) >> 0;
((a_over + (a_under as f64 * (0xff - a_over) as f64 / 0xff as f64) as u32).min(0xff) << 24).min(0xff) +
((r_over + (r_under as f64 * (0xff - a_over) as f64 / 0xff as f64) as u32).min(0xff) << 16).min(0xff) +
((g_over + (g_under as f64 * (0xff - a_over) as f64 / 0xff as f64) as u32).min(0xff) << 8) +
((b_over + (b_under as f64 * (0xff - a_over) as f64 / 0xff as f64) as u32).min(0xff) << 0)
}
pub trait Drawable : Send {