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add pulse width support to other wave types

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This commit is contained in:
Dennis Ranke
2022-03-10 23:05:07 +01:00
parent b626d2609a
commit 29186c806f
5 changed files with 78 additions and 8 deletions
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23
platform/src/ges.cwa
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@@ -67,7 +67,10 @@ export fn gesSnd(t: i32) -> f32 {
if wave < 2 {
if wave {
loop sawLoop {
i!(GesBufferOffset + 128*4) = (phase & 65535) - 32768;
let p = (phase ^ 32768) << 16;
p = ((p ^ (p >> 31)) >> 15) + phaseShift;
p = (p < 0 | p > 65535) * 65535;
i!(GesBufferOffset + 128*4) = (phase ^ p & 65535) - 32768;
phase = phase + phaseInc;
branch_if (i := i + 4) < 64*4: sawLoop;
}
@@ -83,9 +86,12 @@ export fn gesSnd(t: i32) -> f32 {
}
} else {
if wave == 2 {
let scale = pulseWidth + 256;
loop triLoop {
let s = phase << 16;
s = s ^ (s >> 31);
s = (s ^ (s >> 31));
s = (s >> 8) * scale;
s = (s ^ (s >> 31));
i!(GesBufferOffset + 128*4) = (s >> 15) - 32768;
phase = phase + phaseInc;
branch_if (i := i + 4) < 64*4: triLoop;
@@ -93,9 +99,10 @@ export fn gesSnd(t: i32) -> f32 {
} else {
loop noiseLoop {
let s = (phase >> 12) & 4095;
let pulse = ((phase >> 8) & 255) >= pulseWidth;
s = s * 0x6746ba73;
s = s ^ (s >> 15);
i!(GesBufferOffset + 128*4) = (s * 0x83567a92) >> 16;
s = s ^ (s >> 15) * pulse;
i!(GesBufferOffset + 128*4) = (s * 0x83567a92 + (phase << 16)) >> 16;
phase = phase + phaseInc;
branch_if (i := i + 4) < 64*4: noiseLoop;
}
@@ -124,8 +131,12 @@ export fn gesSnd(t: i32) -> f32 {
let ctrl = filter?0x6a;
let note = i32.load16_u(filter * 2, 0x6c);
let inline freq = 440 as f32 * pow(2.0, (note - 69*256) as f32 / (12*256) as f32);
let F = min(4096 as f32, 8192 as f32 * sin(freq * (3.1415 / 44100.0))) as i32;
let Q = 7350 - ctrl * (6530/255);
let F = (8192 as f32 * sin(min(0.25, freq / 44100 as f32) * 3.1415)) as i32;
let Q = 8192 - (ctrl >> 4) * (7000/15);
let Qlimit = (8192*4096/F - F/2) * 3 / 4;
if Q > Qlimit {
Q = Qlimit;
}
let low_out = ctrl & 1;
let high_out = (ctrl >> 1) & 1;
let band_out = (ctrl >> 2) & 1;