chore: auto-commit (43 archivos)

- .mcp.json - bash/functions/infra/write_mcp_jupyter_config.md - bash/functions/infra/write_mcp_jupyter_config.sh - cpp/CMakeLists.txt - cpp/apps/chart_demo - cpp/apps/shaders_lab - cpp/functions/gfx/gl_framebuffer.cpp - cpp/functions/gfx/gl_framebuffer.h - cpp/functions/gfx/gl_framebuffer.md - cpp/functions/gfx/mesh_gpu.md - ... Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-30 17:28:47 +02:00
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+---
+group: mesh-3d
+description: "Carga, parse y upload a GPU de meshes 3D (OBJ, GLB/glTF 2.0). Flujo CPU→GPU para apps ImGui."
+---
+
+# mesh-3d — Capability Group
+
+Cluster de funciones para cargar geometria 3D desde disco o memoria (CPU) y subirla a GPU con OpenGL. El flujo canonico es: **loader → `fn::gfx::Mesh` → `mesh_gpu_upload`**.
+
+## Funciones
+
+| ID | Firma corta | Que hace |
+|---|---|---|
+| `gltf_load_mesh_cpp_gfx` | `Mesh gltf_load_mesh_from_file(path)` | Carga primer mesh de un GLB 2.0. Genera normales si faltan. |
+| `mesh_obj_load_cpp_gfx` | `Mesh mesh_obj_load(path); Mesh mesh_obj_parse(buf, len)` | Carga/parsea Wavefront .obj. Genera normales por face si faltan. |
+| `mesh_gpu_cpp_gfx` | `MeshGpu mesh_gpu_upload(mesh); void mesh_gpu_destroy(gpu)` | Sube `fn::gfx::Mesh` CPU a VAO+VBO+EBO OpenGL. |
+
+## Struct compartido
+
+```cpp
+// cpp/functions/gfx/mesh_obj_load.h
+namespace fn::gfx {
+struct Mesh {
+    std::vector<float>    positions;  // xyz stride=3
+    std::vector<float>    normals;    // xyz stride=3, mismo length que positions
+    std::vector<uint32_t> indices;    // tri-list, multiplo de 3
+};
+}
+```
+
+## Ejemplo canonico end-to-end
+
+```cpp
+#include "gfx/gltf_load_mesh.h"   // gltf_load_mesh_from_file
+#include "gfx/mesh_obj_load.h"    // Mesh (struct)
+#include "gfx/mesh_gpu.h"         // mesh_gpu_upload, mesh_gpu_destroy
+
+// -- Cargar desde GLB (ej. output de TripoSR/trimesh) --
+auto cpu = fn::gfx::gltf_load_mesh_from_file("model.glb");
+if (cpu.positions.empty()) {
+    fprintf(stderr, "load failed: %s\n", fn::gfx::gltf_load_last_error());
+    return;
+}
+
+// -- Alternativamente desde OBJ --
+// auto cpu = fn::gfx::mesh_obj_load("model.obj");
+
+// -- Subir a GPU (requiere contexto GL activo) --
+auto gpu = fn::gfx::mesh_gpu_upload(cpu);
+if (!gpu.ok()) return;
+
+// -- Render --
+glUseProgram(prog);
+glBindVertexArray(gpu.vao);
+glDrawElements(GL_TRIANGLES, gpu.index_count, GL_UNSIGNED_INT, 0);
+glBindVertexArray(0);
+
+// -- Cleanup --
+fn::gfx::mesh_gpu_destroy(gpu);
+```
+
+## Shader esperado (layout)
+
+```glsl
+#version 330 core
+layout(location = 0) in vec3 a_pos;
+layout(location = 1) in vec3 a_normal;
+```
+
+## Fronteras
+
+- Sin texturas/UV — mesh viewer usa color uniforme o shading por normal.
+- Sin animaciones ni skinning.
+- `gltf_load_mesh`: solo GLB binario (no .gltf+.bin separado, no data-URI base64). Solo primer mesh/primitive.
+- `mesh_obj_load`: solo tris y quads; N-gons ignorados.
+- `mesh_gpu`: asume contexto OpenGL 3.3+ activo. Sin streaming (GL_STATIC_DRAW).
+
+## Prerequisitos
+
+- `mesh_gpu_upload` requiere contexto GL activo (llama a `glGenVertexArrays`, etc.).
+- `gltf_load_mesh` requiere `cpp/vendor/nlohmann/json.hpp`.
+- `mesh_obj_load` solo stdlib — sin dependencias extra.