File size: 11,324 Bytes
c8c00f0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
from dataclasses import dataclass

import torch
from torch import Tensor, nn
import numpy as np

from flux.modules.layers import (DoubleStreamBlock, EmbedND, LastLayer,
                                 MLPEmbedder, SingleStreamBlock,
                                 timestep_embedding)


@dataclass
class FluxParams:
    in_channels: int
    out_channels: int
    vec_in_dim: int
    context_in_dim: int
    hidden_size: int
    mlp_ratio: float
    num_heads: int
    depth: int
    depth_single_blocks: int
    axes_dim: list[int]
    theta: int
    qkv_bias: bool
    guidance_embed: bool


class Flux(nn.Module):
    """
    Transformer model for flow matching on sequences.
    """

    def __init__(self, params: FluxParams):
        super().__init__()

        self.params = params
        self.in_channels = params.in_channels
        self.out_channels = params.out_channels
        if params.hidden_size % params.num_heads != 0:
            raise ValueError(
                f"Hidden size {params.hidden_size} must be divisible by num_heads {params.num_heads}"
            )
        pe_dim = params.hidden_size // params.num_heads
        if sum(params.axes_dim) != pe_dim:
            raise ValueError(f"Got {params.axes_dim} but expected positional dim {pe_dim}")
        self.hidden_size = params.hidden_size
        self.num_heads = params.num_heads
        self.pe_embedder = EmbedND(dim=pe_dim, theta=params.theta, axes_dim=params.axes_dim)
        self.img_in = nn.Linear(self.in_channels, self.hidden_size, bias=True)
        self.time_in = MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size)
        self.vector_in = MLPEmbedder(params.vec_in_dim, self.hidden_size)
        self.guidance_in = (
            MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size) if params.guidance_embed else nn.Identity()
        )
        self.txt_in = nn.Linear(params.context_in_dim, self.hidden_size)

        self.double_blocks = nn.ModuleList(
            [
                DoubleStreamBlock(
                    self.hidden_size,
                    self.num_heads,
                    mlp_ratio=params.mlp_ratio,
                    qkv_bias=params.qkv_bias,
                )
                for _ in range(params.depth)
            ]
        )

        self.single_blocks = nn.ModuleList(
            [
                SingleStreamBlock(self.hidden_size, self.num_heads, mlp_ratio=params.mlp_ratio)
                for _ in range(params.depth_single_blocks)
            ]
        )

        self.final_layer = LastLayer(self.hidden_size, 1, self.out_channels)
        self._sequential_offload = False

    def enable_sequential_cpu_offload(self):
        self._sequential_offload = True

    def forward(
        self,
        img: Tensor,
        img_ids: Tensor,
        txt: Tensor,
        txt_ids: Tensor,
        timesteps: Tensor,
        y: Tensor,
        guidance: Tensor | None = None,
        info = None,
        ref_img: Tensor | None = None,        # ← NEW
        ref_img_ids: Tensor | None = None,    # ← NEW
    ) -> Tensor:
        if img.ndim != 3 or txt.ndim != 3:
            raise ValueError("Input img and txt tensors must have 3 dimensions.")

        # Ensure inputs match the model's dtype (NF4 can silently upcast to float32)
        target_dtype = self.img_in.weight.dtype
        img = img.to(target_dtype)
        txt = txt.to(target_dtype)
        if y.dtype != target_dtype:
            y = y.to(target_dtype)

        # running on sequences img
        img = self.img_in(img)
        original_img_seq_len = img.shape[1]   # ← REMEMBER: how many original img tokens

        vec = self.time_in(timestep_embedding(timesteps, 256))
        if self.params.guidance_embed:
            if guidance is None:
                raise ValueError("Didn't get guidance strength for guidance distilled model.")
            vec = vec + self.guidance_in(timestep_embedding(guidance, 256))
        vec = vec + self.vector_in(y)
        txt = self.txt_in(txt)

        # ═══════════════════════════════════════════════════════
        # NEW: Concatenate reference tokens into image stream
        # ═══════════════════════════════════════════════════════
        if ref_img is not None and ref_img_ids is not None:
            ref = self.img_in(ref_img)        # project reference patches same way
            img = torch.cat([img, ref], dim=1)
            img_ids = torch.cat([img_ids, ref_img_ids], dim=1)

        if ref_img is not None:
            print(f"[Flux.forward] Attending to {ref_img.shape[1]} ref tokens + {original_img_seq_len} img tokens")
        # ═══════════════════════════════════════════════════════

        ids = torch.cat((txt_ids, img_ids), dim=1)
        pe = self.pe_embedder(ids)
        inject_pe = pe.clone()
        if not info['inverse']:
            # Defensive clamp: GSAM indices may exceed seq_len for non-16-divisible images
            seq_len = pe.shape[2]

            # Initialize accumulated lists for tracking all processed IDs
            accumulated_target_ids = []
            accumulated_ref_ids = []
            for artifact_data in info['artifact_data']:
                if artifact_data['artifact_type'] == 'addition' and info['addition']:
                    ref_ids = artifact_data['reference_patch_indices'].copy()
                    target_ids = artifact_data['target_patch_indices'].copy()
                    ref_ids = [max(0, min(int(i), seq_len - 1)) for i in ref_ids]
                    target_ids = [max(0, min(int(i), seq_len - 1)) for i in target_ids]
                    if len(target_ids) > 0 and len(ref_ids) > 0:
                        inject_pe[:,:,target_ids,:,:,:] = inject_pe[:,:,ref_ids,:,:,:]

                    # Accumulate IDs
                    if info['inject']:
                        accumulated_target_ids.extend(target_ids)
                        accumulated_ref_ids.extend(ref_ids)

                elif artifact_data['artifact_type'] == 'removal' and info['removal']:
                    ref_ids = artifact_data['reference_patch_indices'].copy()
                    target_ids = artifact_data['target_patch_indices'].copy()

                    ref_ids = [max(0, min(int(i), seq_len - 1)) for i in ref_ids]
                    target_ids = [max(0, min(int(i), seq_len - 1)) for i in target_ids]

                    # ref_ids = get_closest_patch_inds(info['patch_h'], info['patch_w'], target_ids, ref_ids)
                    if len(target_ids) > 0 and len(ref_ids) > 0:
                        inject_pe[:,:,target_ids,:,:,:] = inject_pe[:,:,ref_ids,:,:,:]
                    # Accumulate IDs (after target_ids modification)
                    if info['inject']:
                        accumulated_target_ids.extend(target_ids)
                        accumulated_ref_ids.extend(ref_ids)

                elif artifact_data['artifact_type'] == 'distortion' and info['distortion']:
                    ref_ids = artifact_data['reference_patch_indices'].copy()
                    target_ids = artifact_data['target_patch_indices'].copy()
                    ref_ids = [max(0, min(int(i), seq_len - 1)) for i in ref_ids]
                    target_ids = [max(0, min(int(i), seq_len - 1)) for i in target_ids]

                    if len(ref_ids) == 0:
                        # For distortion with no reference patches, shuffle target patches
                        ref_ids = target_ids.copy()
                        np.random.shuffle(ref_ids)
                    # Ensure target_ids and ref_ids are different for distortion
                    if len(target_ids) > 0 and len(ref_ids) > 0:
                        inject_pe[:,:,target_ids,:,:,:] = inject_pe[:,:,ref_ids,:,:,:]
                    # Accumulate IDs (after any ref_ids modification)
                    if info['inject']:
                        accumulated_target_ids.extend(target_ids)
                        accumulated_ref_ids.extend(ref_ids)

                elif artifact_data['artifact_type'] == 'fusion' and info['fusion']:
                    ref_ids = artifact_data['reference_patch_indices'].copy()
                    target_ids = artifact_data['target_patch_indices'].copy()
                    ref_ids = [max(0, min(int(i), seq_len - 1)) for i in ref_ids]
                    target_ids = [max(0, min(int(i), seq_len - 1)) for i in target_ids]

                    # np.random.shuffle(ref_ids)
                    if len(target_ids) > 0 and len(ref_ids) > 0:
                        inject_pe[:,:,target_ids,:,:,:] = inject_pe[:,:,ref_ids,:,:,:]
                        
                    # Accumulate IDs
                    if info['inject']:
                        accumulated_target_ids.extend(target_ids)
                        accumulated_ref_ids.extend(ref_ids)

            info['patch_ids'] = accumulated_target_ids
            info['patch_ref_ids'] = accumulated_ref_ids 
        info['timesteps'] = timesteps


        if self._sequential_offload:
            for block in self.double_blocks:
                block = block.to(img.device)
                img, txt = block(img=img, txt=txt, vec=vec, pe=inject_pe, info=info)
                block = block.cpu()
                torch.cuda.empty_cache()
        else:
            for block in self.double_blocks:
                img, txt = block(img=img, txt=txt, vec=vec, pe=inject_pe, info=info)

        cnt = 0
        img = torch.cat((txt, img), 1) 
        info['type'] = 'single'
        if self._sequential_offload:
            for block in self.single_blocks:
                block = block.to(img.device)
                info['id'] = cnt
                if cnt < 19:
                    img, info = block(img, vec=vec, pe=inject_pe, info=info)
                else:
                    img, info = block(img, vec=vec, pe=pe, info=info)
                block = block.cpu()
                torch.cuda.empty_cache()
                cnt += 1
        else:
            for block in self.single_blocks:
                info['id'] = cnt
                if cnt < 19:
                    img, info = block(img, vec=vec, pe=inject_pe, info=info)
                else:
                    img, info = block(img, vec=vec, pe=pe, info=info)
                cnt += 1
            

        # ═══════════════════════════════════════════════════════
        # MODIFIED: Extract only ORIGINAL img tokens
        # Before: img = img[:, txt.shape[1] :, ...]  (gets img + ref)
        # After:  img = img[:, txt.shape[1] : txt.shape[1] + original_img_seq_len, ...]
        # ═══════════════════════════════════════════════════════
        img = img[:, txt.shape[1] : txt.shape[1] + original_img_seq_len, ...]

        img = self.final_layer(img, vec)  # (N, T, patch_size ** 2 * out_channels)
        return img, info