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make use of nontrapping-fptoint, add tunnel.cwa as reference

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This commit is contained in:
Dennis Ranke
2022-01-02 16:34:11 +01:00
parent acea5cb6e0
commit 10ba7ed3bb
6 changed files with 24 additions and 14 deletions
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13
examples/rust/tunnel.rs
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@@ -27,15 +27,6 @@ fn sqrt(v: f32) -> f32 {
unsafe { core::intrinsics::sqrtf32(v) }
}
fn ftoi(v: f32) -> i32 {
// The compiler is allowed to do bad things to our code if this
// ever results in a value that doesn't fit in an i32.
// (the joy of undefined behavior)
// But that would trap in wasm anyway, so we don't really
// care.
unsafe { v.to_int_unchecked() }
}
#[no_mangle]
pub fn upd() {
let mut i: i32 = 0;
@@ -43,9 +34,9 @@ pub fn upd() {
let t = time() * 63.;
let x = (i % 320 - 160) as f32;
let y = (i / 320 - 120) as f32;
let d = 40000 as f32 / sqrt(x * x + y * y + 1.);
let d = 40000 as f32 / sqrt(x * x + y * y);
let u = atan2(x, y) * 512. / 3.141;
let c = (ftoi(d + t * 2.) ^ ftoi(u + t)) as u8 >> 4;
let c = ((d + t * 2.) as i32 ^ (u + t) as i32) as u8 >> 4;
unsafe {
*((120 + i) as *mut u8) = c;
}