egutierrez
44e189c5cc
mesh_gpu_upload sube positions+normals interleaved (stride 6 floats, location 0=a_pos, location 1=a_normal) + EBO uint32. mesh_gpu_destroy libera todo. GL_STATIC_DRAW (mesh inmutable post-upload). issue 0029
69 lines
2.1 KiB
Markdown
69 lines
2.1 KiB
Markdown
---
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name: mesh_gpu
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kind: function
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lang: cpp
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domain: gfx
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version: "1.0.0"
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purity: impure
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signature: "MeshGpu mesh_gpu_upload(const Mesh&); void mesh_gpu_destroy(MeshGpu&)"
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description: "Sube un Mesh CPU a OpenGL como VAO + VBO interleaved (pos.xyz, normal.xyz) + EBO uint32. Layout: location 0 = a_pos vec3, location 1 = a_normal vec3, stride 6 floats."
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tags: [opengl, mesh, vao, vbo, ebo, gpu, gfx]
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uses_functions: [mesh_obj_load_cpp_gfx]
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uses_types: []
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returns: []
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returns_optional: false
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error_type: "error_go_core"
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imports: [GL/gl.h, GL/glext.h]
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tested: false
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tests: []
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test_file_path: ""
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file_path: "cpp/functions/gfx/mesh_gpu.cpp"
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framework: opengl
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params:
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- name: mesh
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desc: "Mesh CPU con positions/normals (mismo length, stride 3) e indices uint32. Si esta vacio o invalido, upload devuelve MeshGpu{} (ok()==false)."
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- name: mesh_gpu
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desc: "MeshGpu (vao/vbo/ebo, index_count). destroy libera todo y pone IDs a 0."
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output: "mesh_gpu_upload: MeshGpu listo para draw con glDrawElements(GL_TRIANGLES, index_count, GL_UNSIGNED_INT, 0). Si !ok(), no hubo upload."
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---
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# mesh_gpu
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CRUD GPU minimal para `Mesh`. Asume contexto OpenGL 3.3+ activo.
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## Layout de attribs
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```glsl
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#version 330 core
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layout(location = 0) in vec3 a_pos;
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layout(location = 1) in vec3 a_normal;
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```
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Stride = `6 * sizeof(float)`, sin padding.
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## Uso tipico
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```cpp
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auto cpu = fn::gfx::mesh_obj_load("model.obj");
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auto gpu = fn::gfx::mesh_gpu_upload(cpu);
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if (!gpu.ok()) { /* falla */ return; }
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// Draw:
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glUseProgram(prog);
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glBindVertexArray(gpu.vao);
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glDrawElements(GL_TRIANGLES, gpu.index_count, GL_UNSIGNED_INT, 0);
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glBindVertexArray(0);
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// Cleanup:
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fn::gfx::mesh_gpu_destroy(gpu);
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```
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## Validacion de input
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`mesh_gpu_upload` exige que `mesh.normals.size() == mesh.positions.size()`. `mesh_obj_parse` siempre genera normales (per-face si faltan) → invariante natural.
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## Notas
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- Indices son `GL_UNSIGNED_INT` (32-bit) para soportar meshes grandes sin tener que decidir formato dinamicamente.
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- `GL_STATIC_DRAW`: el assumption es que la malla no cambia post-upload. Si necesitas streaming, crear otro helper con `GL_DYNAMIC_DRAW`.
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