lg_mesh.c File Reference

Functions
LG_Mesh *	lg_load_vbo (const char *path, zboolean force_reload_obj, zboolean do_normalize_xyz)
LG_Mesh *	lg_mesh_new_from_objfile (const char *path, zboolean do_normalize_xyz)
void	lg_mesh_free (LG_Mesh *mesh)
void	lg_mesh_info (LG_Mesh *mesh)
int	lg_obj_file_save_to_cache (void *asset_buf, const char *file_name, size_t size, size_t *written_size)
void *	lg_obj_file_open_from_cache (const char *file_name)
int	lg_vbo_save_to_file (const char *path, LG_Mesh *mesh)
int	lg_vbo_load_from_file (const char *path, LG_Mesh **mesh)

Detailed Description

This module deals with meshes, ie data that will feed VBOs and IBOs for fast and efficient drawing.

=== MESHES MUST BE PURE-TRIANGULAR ===

 Using MeshLab filters:
    remeshing, simplification and reconstruction
            turn into a pure-triangle mesh
 Also:
    normals, curvatures and orientation
            transform: translate, center, set origin
                    -> center on layer bbox
    normals, curvatures and orientation
            transform: scale, normalize
                    -> scale to unit bbox

At the moment, read only a limited set of data from WAVEFRONT OBJ files: vertex/index values for v (coords), vt (texture coords), vn (normals), f (triangular faces), mtllib, usemtl (materials/textures stuff), plus newmtl, and map_K* (in MTL files).

Will create a Vertex_uv_n VBO (see lg_vertex.h).

You can/should only use this func to load meshes:

 LG_Mesh *lg_load_vbo(const char *path, zboolean force_reload_obj, zboolean do_normalize_xyz)

and you can/should only use this func when done with a mesh:

 void       lg_mesh_free(LG_Mesh *)

and just ignore the details.

(Use everything here only if you know what you're doing).

Function Documentation

lg_load_vbo()

LG_Mesh* lg_load_vbo	(	const char *	path,
		zboolean	force_reload_obj,
		zboolean	do_normalize_xyz
	)

Load VBO &co

=== This is the entry point for loading meshes (obj, vbo, ibo) ===

THIS WHOLE MODULE WORKS GREAT BUT NEED TO FIND A MORE DESCRIPTIVE AND ACCURATE NAME FOR THIS FUNC (AND OTHERS AS WELL ?)

We use a cache mechanism:

• Try first to load the mesh data (VBO, IBO, and info) from cache
• If it doesn't exist, load and parse the obj file, then save it to cache

All mesh data is saved

On Android, obj files are cached as well

Parameters

path	Path to obj file
force_reload_obj
do_normalize_xyz

Returns

A LG_Mesh instance if OK, NULL on error

lg_mesh_new_from_objfile()

LG_Mesh* lg_mesh_new_from_objfile	(	const char *	path,
		zboolean	do_normalize_xyz
	)

Create mesh from obj file

Parameters

path
do_normalize_xyz

Returns

A new LG_Mesh instance if OK, NULL on error

lg_mesh_free()

void lg_mesh_free

(

LG_Mesh *

mesh

)

Free mesh

Parameters

mesh

lg_mesh_info()

void lg_mesh_info

(

LG_Mesh *

mesh

)

Print out LG_Mesh info

Parameters

mesh

lg_obj_file_save_to_cache()

int lg_obj_file_save_to_cache	(	void *	asset_buf,
		const char *	file_name,
		size_t	size,
		size_t *	written_size
	)

Save obj file to cache

lg_obj_file_open_from_cache()

void* lg_obj_file_open_from_cache

(

const char *

file_name

)

Load obj file from cache

lg_vbo_save_to_file()

int lg_vbo_save_to_file	(	const char *	path,
		LG_Mesh *	mesh
	)

Actually save mesh with VBO and IBO in binary form, so should find a more accurate name. Don't add suffix LG_MESH_INFO_EXT, LG_MESH_VBO_EXT, LG_MESH_IBO_EXT to path, it's done automagically. Only the basename of path is used. All binary files are saved in the cache.

lg_vbo_load_from_file()

int lg_vbo_load_from_file	(	const char *	path,
		LG_Mesh **	mesh
	)

Same as above but for reading binary files