fn_registry/cpp/functions/gfx/mesh_gpu.md

name, kind, lang, domain, version, purity, signature, description, tags, uses_functions, uses_types, returns, returns_optional, error_type, imports, tested, tests, test_file_path, file_path, framework, params, output

name	kind	lang	domain	version	purity	signature	description	tags	uses_functions	uses_types	returns	returns_optional	error_type	imports	tested	tests	test_file_path	file_path	framework	params	output
mesh_gpu	function	cpp	gfx	1.0.0	impure	MeshGpu mesh_gpu_upload(const Mesh&); void mesh_gpu_destroy(MeshGpu&)	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.	opengl mesh vao vbo ebo gpu gfx	mesh_obj_load_cpp_gfx			false	error_go_core	GL/gl.h GL/glext.h	false			cpp/functions/gfx/mesh_gpu.cpp	opengl	name desc mesh Mesh CPU con positions/normals (mismo length, stride 3) e indices uint32. Si esta vacio o invalido, upload devuelve MeshGpu{} (ok()==false). name desc mesh_gpu MeshGpu (vao/vbo/ebo, index_count). destroy libera todo y pone IDs a 0.	mesh_gpu_upload: MeshGpu listo para draw con glDrawElements(GL_TRIANGLES, index_count, GL_UNSIGNED_INT, 0). Si !ok(), no hubo upload.

mesh_gpu

CRUD GPU minimal para Mesh. Asume contexto OpenGL 3.3+ activo.

Layout de attribs

#version 330 core
layout(location = 0) in vec3 a_pos;
layout(location = 1) in vec3 a_normal;

Stride = 6 * sizeof(float), sin padding.

Uso tipico

auto cpu = fn::gfx::mesh_obj_load("model.obj");
auto gpu = fn::gfx::mesh_gpu_upload(cpu);
if (!gpu.ok()) { /* falla */ return; }

// Draw:
glUseProgram(prog);
glBindVertexArray(gpu.vao);
glDrawElements(GL_TRIANGLES, gpu.index_count, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);

// Cleanup:
fn::gfx::mesh_gpu_destroy(gpu);

Validacion de input

mesh_gpu_upload exige que mesh.normals.size() == mesh.positions.size(). mesh_obj_parse siempre genera normales (per-face si faltan) → invariante natural.

Notas

• Indices son GL_UNSIGNED_INT (32-bit) para soportar meshes grandes sin tener que decidir formato dinamicamente.
• GL_STATIC_DRAW: el assumption es que la malla no cambia post-upload. Si necesitas streaming, crear otro helper con GL_DYNAMIC_DRAW.