lg_mesh.c File Reference

Functions
LG_Mesh *	lg_mesh_load (const char *file_name, LG_LoadMesh_Flags flags)
LG_Mesh *	lg_mesh_new_from_objfile (const char *file_name, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)
LG_Mesh *	lg_mesh_new_from_fbxfile (const char *file_name, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)
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 *file_name, LG_Mesh *mesh)
int	lg_vbo_save_to_file_in_cache (const char *file_name, LG_Mesh *mesh)
int	lg_vbo_load_from_file (const char *file_name, LG_Mesh **mesh)
int	lg_vbo_load_from_file_in_cache (const char *file_name, LG_Mesh **mesh)
int	lg_mesh_reload_mats (LG_Mesh *mesh)
LG_LoadMesh_Flags	lg_loadmesh_flags (zboolean force_reload, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)

Detailed Description

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

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

LG_Mesh *lg_mesh_load(const char *file_name, LG_LoadMesh_Flags flags)
 
// LG_Mesh struct is defined in lg_mesh.h
 
// file_name = OBJ or VBO &co files (= VBO, IBO, and INFO binaries) - only BASENAME is required
 
// Mesh loading flags
typedef struct {
   zboolean        force_reload;   // Force (re)loading and (re)parsing of the OBJ file
   zboolean        invert_z;       // Invert z spatial coord - should be set to TRUE if mesh uses RH coords sys, FALSE if mesh uses LH coords sys
   zboolean        normalize_xyz;
   zboolean        horiz_center;
   zboolean        vert_center;    // Center mesh vertically, if vert_bottom is not set
   zboolean        vert_bottom;    // Set mesh origin vertically at bottom, override vert_center
} LG_LoadMesh_Flags;

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_mesh_load()

LG_Mesh* lg_mesh_load	(	const char *	file_name,
		LG_LoadMesh_Flags	flags
	)

Load OBJ or VBO &co.

=== THIS IS THE NEW ENTRY POINT FOR LOADING MESHES (OBJ, FBX, VBO, IBO, INFO) AND THE ONLY FUNC YOU NEED TO CALL ===

We use the following sequence:

• Try first to load the mesh data (VBO, IBO, and INFO) in the assets/meshes/vbo folder, unless force_reload is set
• If not found, look in the cache/vbo folder
• If not found, load and parse the OBJ file in the assets/meshes/obj folder, then save it to cache

On Android, OBJ files are cached as well

TO AVOID ANY POSSIBLE CONFUSION, ALWAYS FOLLOW THIS:
- PATHS ARE FULL (IE ABSOLUTE) AND INCLUDE THE FILE NAME
- FILE_NAMES ARE BASENAMES (WITH EXTENSION)

Parameters

file_name	Name of OBJ or VBO &co files (= VBO, IBO, and INFO binaries) - only BASENAME is required
flags	Apply to mesh: force_reload, invert_z, normalize_xyz, horiz_center, vert_center, vert_bottom

Returns

Pointer to LG_Mesh if OK, NULL on error

lg_mesh_new_from_objfile()

LG_Mesh* lg_mesh_new_from_objfile	(	const char *	file_name,
		zboolean	invert_z,
		zboolean	normalize_xyz,
		zboolean	horiz_center,
		zboolean	vert_center,
		zboolean	vert_bottom
	)

Create mesh from OBJ file.

Read 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).

Other data is ignored so far.

=== WARNING: MESHES MUST BE PURE-TRIANGULAR ===

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

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

Parameters

file_name	OBJ file name - only BASENAME is required
invert_z	Invert z spatial coord - should be set to TRUE if mesh uses RH coords sys, FALSE if mesh uses LH coords sys
normalize_xyz	Normalize spatial coords
horiz_center	Center mesh horizontally
vert_center	Center mesh vertically, if vert_bottom is not set
vert_bottom	Set mesh origin vertically at bottom, override vert_center

Returns

A new LG_Mesh instance if OK, NULL on error

lg_mesh_new_from_fbxfile()

LG_Mesh* lg_mesh_new_from_fbxfile	(	const char *	file_name,
		zboolean	invert_z,
		zboolean	normalize_xyz,
		zboolean	horiz_center,
		zboolean	vert_center,
		zboolean	vert_bottom
	)

Create mesh from FBX file.

Parameters

file_name	FBX file name - only BASENAME is required
invert_z	Invert z spatial coord - should be set to TRUE if mesh uses RH coords sys, FALSE if mesh uses LH coords sys
normalize_xyz	Normalize spatial coords
horiz_center	Center mesh horizontally
vert_center	Center mesh vertically, if vert_bottom is not set
vert_bottom	Set mesh origin vertically at bottom, override vert_center

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.

Parameters

asset_buf	Mem buffer
file_name	OBJ file name - only BASENAME is required
size
written_size

Returns

LG_OK if OK, error code otherwise

lg_obj_file_open_from_cache()

void* lg_obj_file_open_from_cache

(

const char *

file_name

)

Open OBJ file from cache.

NOTE: this func is meant to be used with lg_obj2vbo().

Parameters

file_name

The OBJ file name

Returns

Opened stream if OK, NULL on error

lg_vbo_save_to_file()

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

Save mesh VBO and IBO in binary format, plus LG_Mesh struct instance as INFO -> file_name.obj.vbo, file_name.obj.ibo, and file_name.obj.info. Don't add suffix LG_MESH_INFO_EXT, LG_MESH_VBO_EXT, LG_MESH_IBO_EXT to path, as it's done automagically. Only the basename of path is used. All binary files are saved in the assets vbo folder.

Parameters

file_name	OBJ file name - only BASENAME is required
mesh	Pointer to a LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_vbo_save_to_file_in_cache()

int lg_vbo_save_to_file_in_cache	(	const char *	file_name,
		LG_Mesh *	mesh
	)

Save mesh VBO and IBO in binary format, plus LG_Mesh struct instance as INFO -> file_name.obj.vbo, file_name.obj.ibo, and file_name.obj.info. Don't add suffix LG_MESH_INFO_EXT, LG_MESH_VBO_EXT, LG_MESH_IBO_EXT to path, as it's done automagically. Only the basename of path is used. All binary files are saved in the cache/vbo folder.

Parameters

file_name	OBJ file name - only BASENAME is required
mesh	Pointer to a LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_vbo_load_from_file()

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

Same as above but for reading binary files in the assets vbo folder.

Parameters

file_name	OBJ file name - only BASENAME is required
mesh	Pointer to an array of pointers to LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_vbo_load_from_file_in_cache()

int lg_vbo_load_from_file_in_cache	(	const char *	file_name,
		LG_Mesh **	mesh
	)

Same as above but for reading binary files in the vbo_cache folder.

Parameters

file_name	OBJ file name - only BASENAME is required
mesh	Pointer to an array of pointers to LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_mesh_reload_mats()

int lg_mesh_reload_mats

(

LG_Mesh *

mesh

)

Reload materials textures correctly, when mesh is loaded from cache.

Parameters

mesh	Pointer to a LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_loadmesh_flags()

LG_LoadMesh_Flags lg_loadmesh_flags	(	zboolean	force_reload,
		zboolean	invert_z,
		zboolean	normalize_xyz,
		zboolean	horiz_center,
		zboolean	vert_center,
		zboolean	vert_bottom
	)

Mesh loading flags.

See lg_load_vbo().

You can use these helper, which are all set to TRUE:

• FORCE_RELOAD
• INVERT_Z
• NORMALIZE_XYZ
• VERT_CENTER
• VERT_BOTTOM

Parameters

force_reload	Force (re)loading and (re)parsing of the OBJ file
invert_z	Invert z spatial coord - should be set to TRUE if mesh uses RH coords sys, FALSE if mesh uses LH coords sys
normalize_xyz
horiz_center
vert_center	Center mesh vertically, if vert_bottom is not set
vert_bottom	Set mesh origin vertically at bottom, override vert_center

Returns

A LG_LoadMesh_Flags