rework RNG to use generators instead of generating noises beforehand

modules/rng.py

@@ -0,0 +1,171 @@
+import torch
+
+from modules import devices, rng_philox, shared
+
+
+def randn(seed, shape, generator=None):
+    """Generate a tensor with random numbers from a normal distribution using seed.
+
+    Uses the seed parameter to set the global torch seed; to generate more with that seed, use randn_like/randn_without_seed."""
+
+    manual_seed(seed)
+
+    if shared.opts.randn_source == "NV":
+        return torch.asarray((generator or nv_rng).randn(shape), device=devices.device)
+
+    if shared.opts.randn_source == "CPU" or devices.device.type == 'mps':
+        return torch.randn(shape, device=devices.cpu, generator=generator).to(devices.device)
+
+    return torch.randn(shape, device=devices.device, generator=generator)
+
+
+def randn_local(seed, shape):
+    """Generate a tensor with random numbers from a normal distribution using seed.
+
+    Does not change the global random number generator. You can only generate the seed's first tensor using this function."""
+
+    if shared.opts.randn_source == "NV":
+        rng = rng_philox.Generator(seed)
+        return torch.asarray(rng.randn(shape), device=devices.device)
+
+    local_device = devices.cpu if shared.opts.randn_source == "CPU" or devices.device.type == 'mps' else devices.device
+    local_generator = torch.Generator(local_device).manual_seed(int(seed))
+    return torch.randn(shape, device=local_device, generator=local_generator).to(devices.device)
+
+
+def randn_like(x):
+    """Generate a tensor with random numbers from a normal distribution using the previously initialized genrator.
+
+    Use either randn() or manual_seed() to initialize the generator."""
+
+    if shared.opts.randn_source == "NV":
+        return torch.asarray(nv_rng.randn(x.shape), device=x.device, dtype=x.dtype)
+
+    if shared.opts.randn_source == "CPU" or x.device.type == 'mps':
+        return torch.randn_like(x, device=devices.cpu).to(x.device)
+
+    return torch.randn_like(x)
+
+
+def randn_without_seed(shape, generator=None):
+    """Generate a tensor with random numbers from a normal distribution using the previously initialized genrator.
+
+    Use either randn() or manual_seed() to initialize the generator."""
+
+    if shared.opts.randn_source == "NV":
+        return torch.asarray((generator or nv_rng).randn(shape), device=devices.device)
+
+    if shared.opts.randn_source == "CPU" or devices.device.type == 'mps':
+        return torch.randn(shape, device=devices.cpu, generator=generator).to(devices.device)
+
+    return torch.randn(shape, device=devices.device, generator=generator)
+
+
+def manual_seed(seed):
+    """Set up a global random number generator using the specified seed."""
+    from modules.shared import opts
+
+    if opts.randn_source == "NV":
+        global nv_rng
+        nv_rng = rng_philox.Generator(seed)
+        return
+
+    torch.manual_seed(seed)
+
+
+def create_generator(seed):
+    if shared.opts.randn_source == "NV":
+        return rng_philox.Generator(seed)
+
+    device = devices.cpu if shared.opts.randn_source == "CPU" or devices.device.type == 'mps' else devices.device
+    generator = torch.Generator(device).manual_seed(int(seed))
+    return generator
+
+
+# from https://discuss.pytorch.org/t/help-regarding-slerp-function-for-generative-model-sampling/32475/3
+def slerp(val, low, high):
+    low_norm = low/torch.norm(low, dim=1, keepdim=True)
+    high_norm = high/torch.norm(high, dim=1, keepdim=True)
+    dot = (low_norm*high_norm).sum(1)
+
+    if dot.mean() > 0.9995:
+        return low * val + high * (1 - val)
+
+    omega = torch.acos(dot)
+    so = torch.sin(omega)
+    res = (torch.sin((1.0-val)*omega)/so).unsqueeze(1)*low + (torch.sin(val*omega)/so).unsqueeze(1) * high
+    return res
+
+
+class ImageRNG:
+    def __init__(self, shape, seeds, subseeds=None, subseed_strength=0.0, seed_resize_from_h=0, seed_resize_from_w=0):
+        self.shape = shape
+        self.seeds = seeds
+        self.subseeds = subseeds
+        self.subseed_strength = subseed_strength
+        self.seed_resize_from_h = seed_resize_from_h
+        self.seed_resize_from_w = seed_resize_from_w
+
+        self.generators = [create_generator(seed) for seed in seeds]
+
+        self.is_first = True
+
+    def first(self):
+        noise_shape = self.shape if self.seed_resize_from_h <= 0 or self.seed_resize_from_w <= 0 else (self.shape[0], self.seed_resize_from_h // 8, self.seed_resize_from_w // 8)
+
+        xs = []
+
+        for i, (seed, generator) in enumerate(zip(self.seeds, self.generators)):
+            subnoise = None
+            if self.subseeds is not None and self.subseed_strength != 0:
+                subseed = 0 if i >= len(self.subseeds) else self.subseeds[i]
+                subnoise = randn(subseed, noise_shape)
+
+            if noise_shape != self.shape:
+                noise = randn(seed, noise_shape)
+            else:
+                noise = randn(seed, self.shape, generator=generator)
+
+            if subnoise is not None:
+                noise = slerp(self.subseed_strength, noise, subnoise)
+
+            if noise_shape != self.shape:
+                x = randn(seed, self.shape, generator=generator)
+                dx = (self.shape[2] - noise_shape[2]) // 2
+                dy = (self.shape[1] - noise_shape[1]) // 2
+                w = noise_shape[2] if dx >= 0 else noise_shape[2] + 2 * dx
+                h = noise_shape[1] if dy >= 0 else noise_shape[1] + 2 * dy
+                tx = 0 if dx < 0 else dx
+                ty = 0 if dy < 0 else dy
+                dx = max(-dx, 0)
+                dy = max(-dy, 0)
+
+                x[:, ty:ty + h, tx:tx + w] = noise[:, dy:dy + h, dx:dx + w]
+                noise = x
+
+            xs.append(noise)
+
+        eta_noise_seed_delta = shared.opts.eta_noise_seed_delta or 0
+        if eta_noise_seed_delta:
+            self.generators = [create_generator(seed + eta_noise_seed_delta) for seed in self.seeds]
+
+        return torch.stack(xs).to(shared.device)
+
+    def next(self):
+        if self.is_first:
+            self.is_first = False
+            return self.first()
+
+        xs = []
+        for generator in self.generators:
+            x = randn_without_seed(self.shape, generator=generator)
+            xs.append(x)
+
+        return torch.stack(xs).to(shared.device)
+
+
+devices.randn = randn
+devices.randn_local = randn_local
+devices.randn_like = randn_like
+devices.randn_without_seed = randn_without_seed
+devices.manual_seed = manual_seed