26 lines
970 B
Python
26 lines
970 B
Python
from collections import defaultdict
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import obj
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def append_triangles(state, vertex_buffer, index_buffer, index_lookup):
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for triangle in state.triangle:
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for p_ix, t_ix, n_ix in triangle:
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position = state.position[p_ix]
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normal = state.normal[n_ix]
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texture = state.texture[t_ix]
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key = (position, normal, texture)
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if key not in index_lookup:
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index = len(vertex_buffer)
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index_lookup[key] = index
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vertex_buffer.append((position, normal, texture))
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index_buffer.append(index_lookup[key])
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def build_faces_by_normal(vertex_buffer, index_buffer):
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by_normal = defaultdict(list)
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for i in range(len(index_buffer) // 3):
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tri = [index_buffer[i * 3 + n] for n in range(3)]
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s = set(vertex_buffer[j][1] for j in tri)
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assert len(s) == 1, s
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normal, = iter(s)
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by_normal[normal].extend(tri)
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return by_normal
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