egutierrez
10ac4c74db
mesh_obj_parse (pure) + mesh_obj_load (impure file helper). Soporta v / vn / f (tris y quads). Genera normales per-face si faltan (flat shading). Quads se parten en 2 tris; n-gons (>4) se descartan silenciosamente. Indices 1-based positivos y negativos. issue 0029
30 lines
1.0 KiB
C++
30 lines
1.0 KiB
C++
#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <vector>
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namespace fn::gfx {
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// CPU-side mesh: positions interleaved with normals stride 3 floats each,
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// indexed by `indices`.
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struct Mesh {
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std::vector<float> positions; // x,y,z stride=3 (count = num_vertices*3)
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std::vector<float> normals; // x,y,z stride=3 (same length as positions)
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std::vector<uint32_t> indices; // tri-list (count multiple of 3)
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};
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// Parse Wavefront .obj from a text buffer. Pure: no I/O.
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// Supports: v, vn, f (triangles and quads). Ignores: vt, mtllib, usemtl, o, g, s.
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// If the file has no vn, normals are generated per-face (flat shading).
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// Quads in `f` are split into 2 triangles (fan). N-gons (>4 verts) are not supported.
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//
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// Returns an empty Mesh ({}, {}, {}) on parse failure (no vertices found).
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Mesh mesh_obj_parse(const char* obj_text, size_t len);
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// Read file from disk and parse. IMPURE (file I/O).
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// Returns empty Mesh on read or parse failure.
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Mesh mesh_obj_load(const char* path);
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} // namespace fn::gfx
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