diff --git a/src/lib8/interpolate.rs b/src/lib8/interpolate.rs new file mode 100644 index 0000000..f9a0f76 --- /dev/null +++ b/src/lib8/interpolate.rs @@ -0,0 +1,57 @@ +use num::PrimInt; + +pub fn scale8(i: u8, scale: u8) -> u8 { + // borrowed from FastLED + (i as u16 * scale as u16).wrapping_shr(8) as u8 +} + +pub fn avg7(i: i8, j: i8) -> i8 { + i.unsigned_shr(1).wrapping_add(j.unsigned_shr(1)).wrapping_add(i & 0x1) +} + +pub fn grad8(hash: u8, x: i8, y: i8) -> i8 { + let mut u: i8; + let mut v: i8; + + if hash & 4 != 0 { + u = y; v = x; + } else { + u = x; v = y; + } + + if hash & 1 != 0 { + u = u.wrapping_neg(); + } + if hash & 2 != 0 { + v = v.wrapping_neg(); + } + + return avg7(u, v); +} + +pub fn lerp7by8(a: i8, b: i8, frac: u8) -> i8 { + if b > a { + let delta: u8 = b.wrapping_sub(a) as u8; + let scaled: u8 = scale8(delta as u8, frac); + return a.wrapping_add(scaled as i8); + } else { + let delta: u8 = a.wrapping_sub(b) as u8; + let scaled: u8 = scale8(delta as u8, frac); + return a.wrapping_sub(scaled as i8); + } +} + +pub fn ease8InOutQuad(i: u8) -> u8 { + let j = if i & 0x80 != 0 { + 255 - i + } else { + i + }; + let jj = scale8(j, j); + let jj2 = jj.unsigned_shl(1); + if i & 0x80 == 0 { + return jj2 + } else { + return 255 - jj2; + } +} diff --git a/src/lib8.rs b/src/lib8/mod.rs similarity index 93% rename from src/lib8.rs rename to src/lib8/mod.rs index 60ba524..b95db0b 100644 --- a/src/lib8.rs +++ b/src/lib8/mod.rs @@ -1,12 +1,11 @@ +pub mod interpolate; +pub mod noise; +pub mod trig; + use palette::encoding::srgb::Srgb; use rgb::RGB8; -pub fn scale8(i: u8, scale: u8) -> u8 { - // borrowed from FastLED - (i as u16 * scale as u16).wrapping_shr(8) as u8 -} - pub trait Rgb8Blend { fn saturating_add(self, b: Self) -> Self; } diff --git a/src/lib8/noise.rs b/src/lib8/noise.rs new file mode 100644 index 0000000..0a04834 --- /dev/null +++ b/src/lib8/noise.rs @@ -0,0 +1,59 @@ +use crate::lib8::interpolate::*; + +use num::PrimInt; + +const noise_cube: [u8; 257] = [ + 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, +140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148, +247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, +57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, +74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, +60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54, +65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, +200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, +52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212, +207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, +119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, +129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, +218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, +81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, +184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93, +222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180, +151]; + +const fn P(x: u8) -> u8 { + noise_cube[x as usize] +} + +fn inoise8_raw(x: u16, y: u16) -> u8 { + let X: u8 = x.unsigned_shr(8) as u8; + let Y: u8 = y.unsigned_shr(8) as u8; + + let A: u8 = P(X) + Y; + let AA: u8 = P(A); + let AB: u8 = P(A+1); + let B: u8 = P(X+1) + Y; + let BA: u8 = P(B); + let BB: u8 = P(B+1); + + let mut u: u8 = x as u8; + let mut v: u8 = y as u8; + + let xx: i8 = ((x as u8).unsigned_shr(1) & 0x7f) as i8; + let yy: i8 = ((y as u8).unsigned_shr(1) & 0x7f) as i8; + let N: i8 = 0x80u8 as i8; + + u = ease8InOutQuad(u); + v = ease8InOutQuad(v); + + let X1: i8 = lerp7by8(grad8(P(AA), xx, yy), grad8(P(BA), xx.wrapping_sub(N), yy), u); + let X2: i8 = lerp7by8(grad8(P(AB), xx, yy.wrapping_sub(N)), grad8(P(BB), xx.wrapping_sub(N), yy.wrapping_sub(N)), u); + + return lerp7by8(X1, X2, v) as u8; +} + +pub fn inoise8(x: i16, y: i16) -> u8 { + let mut n: i8 = inoise8_raw(x as u16, y as u16) as i8; + n = n.wrapping_add(64); + return n.saturating_add(n) as u8; +} diff --git a/src/lib8/trig.rs b/src/lib8/trig.rs new file mode 100644 index 0000000..9109103 --- /dev/null +++ b/src/lib8/trig.rs @@ -0,0 +1,32 @@ +use num::PrimInt; + +const b_m16_interleave: [u8; 8] = [0, 49, 49, 41, 90, 27, 117, 10]; + +pub fn sin8(theta: u8) -> u8 { + let mut offset: u8 = theta; + if theta & 0x40 != 0 { + offset = 255 - offset; + } + offset &= 0x3f; + + let mut secoffset: u8 = offset & 0x0f; + if theta & 0x40 != 0 { + secoffset += 1; + } + + let section: u8 = offset.unsigned_shr(4); + let s2: u8 = section * 2; + let b: u8 = b_m16_interleave[s2 as usize]; + let m16: u8 = b_m16_interleave[s2 as usize + 1]; + let mx: u8 = m16.wrapping_mul(secoffset).unsigned_shr(4); + let mut y: i8 = mx as i8 + b as i8; + if theta & 0x80 != 0 { + y = -y; + } + y = y.wrapping_add(128u8 as i8); + return y as u8; +} + +pub fn cos8(theta: u8) -> u8 { + sin8(theta.wrapping_add(64)) +} diff --git a/src/mappings.rs b/src/mappings.rs index 654adb3..26b7bcb 100644 --- a/src/mappings.rs +++ b/src/mappings.rs @@ -1,6 +1,6 @@ use crate::geometry::*; -use crate::lib8::scale8; +use crate::lib8::interpolate::scale8; use std::cmp::max; use std::fmt::{Formatter, Debug};