lg_mesh.c File Reference

Functions
LG_Mesh *	lg_mesh_load (const char *relative_path, LG_LoadMesh_Flags flags)
LG_Mesh *	lg_mesh_load_easy (const char *relative_path, zboolean force_reload_objs, LG_LoadMesh_Flags flags1)
LG_Mesh *	lg_mesh_new_from_objfile (const char *relative_path, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)
LG_Mesh *	lg_mesh_new_from_fbxfile (const char *relative_path, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)
void	lg_mesh_free (LG_Mesh *mesh)
int	lg_bmesh_save_to_file (const char *full_path, LG_Mesh *mesh)
int	lg_bmesh_load_from_file (const char *full_path, LG_Mesh **mesh)
int	lg_mesh_reload_mats (LG_Mesh *mesh)
void	lg_serialize_LG_Material_64_to_32 (Serializable_LG_Material *s_mat, LG_Material *mat)
void	lg_unserialize_LG_Material_32_to_64 (LG_Material *mat, Serializable_LG_Material *s_mat)
void	lg_serialize_LG_Mesh_64_to_32 (Serializable_LG_Mesh *s_mesh, LG_Mesh *mesh)
void	lg_unserialize_LG_Mesh_32_to_64 (LG_Mesh *mesh, Serializable_LG_Mesh *s_mesh)
LG_LoadMesh_Flags	lg_loadmesh_flags (zboolean save_to_assets, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom)
void	lg_mesh_info (LG_Mesh *mesh)
char *	lg_replace_file_extension (const char *path, const char *new_ext)

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 *relative_path, LG_LoadMesh_Flags flags)
 
// LG_Mesh struct is defined in lg_mesh.h
 
// relative_path = relative path of mesh file, with extension OBJ or FBX or BMESH, expected to be in predefined locations
 
// Mesh loading flags
typedef struct {
   zboolean        save_to_assets;         // Save to assets as BMESH, otherwise to cache - on Android, should always be set to FALSE as you can't write to assets
   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).

NEW CONVENTIONS FOR PATHS / FILE NAMES AS FUNC ARGS:

- full_path      -> absolute path, include file name
- relative_path  -> relative path, include file name = sub_dir1/sub_dir2/.../file_name
- file_name      -> basename only, always with extension

Function Documentation

lg_mesh_load()

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

Load OBJ or FBX or BMESH mesh file

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

• Valid extensions are OBJ, FBX, and BMESH
• Expected to be in predefined locations

If OBJ or FBX file successfully loaded, then successfully saved as BMESH, will set mesh name ext as BMESH

WARNING: FBX support is not complete yet

Parameters

relative_path	Relative path of mesh file, with extension OBJ or FBX or BMESH, expected to be in predefined locations
flags	Apply to mesh: save_to_assets, invert_z, normalize_xyz, horiz_center, vert_center, vert_bottom

Returns

Pointer to LG_Mesh if OK, NULL on error

lg_mesh_load_easy()

LG_Mesh * lg_mesh_load_easy	(	const char *	relative_path,
		zboolean	force_reload_objs,
		LG_LoadMesh_Flags	flags1
	)

Helper func which will call lg_mesh_load()

If force_reload_objs is set to TRUE, look only for OBJ or FBX files - if found, parse them and save them as BMESH files

Otherwise, look first for BMESH files - if not found, look for OBJ or FBX files - if found, parse them and save them as BMESH files

Example use:

LG_LoadMesh_Flags flags1 = lg_loadmesh_flags(SAVE_TO_ASSETS, FALSE, NORMALIZE_XYZ, HORIZ_CENTER, FALSE, VERT_BOTTOM);
zboolean force_reload_objs = TRUE; // Easier than deleting all files in assets/meshes/bmesh/
 
LG_Mesh *cottage_mesh = lg_mesh_load_easy("cottage.bmesh", force_reload_objs, flags1);
if (cottage_mesh == NULL) exit(-1);
 
LG_Mesh *cottage3_mesh = lg_mesh_load_easy("cottage3.bmesh", force_reload_objs, flags1);
if (cottage3_mesh == NULL) exit(-1);
 
LG_Mesh *tree2_mesh = lg_mesh_load_easy("tree2.bmesh", force_reload_objs, flags1);
if (tree2_mesh == NULL) exit(-1);
 
LG_Mesh *old_house2_mesh = lg_mesh_load_easy("old_house2.bmesh", force_reload_objs, flags1);
if (old_house2_mesh == NULL) exit(-1);
 
LG_Mesh *windmill1_mesh = lg_mesh_load_easy("windmill1.bmesh", force_reload_objs, flags1);
if (windmill1_mesh == NULL) exit(-1);

Parameters

relative_path	Relative path of mesh file (extension is not checked), expected to be in predefined locations
force_reload_objs	Setting force_reload_objs to TRUE is easier than deleting all files in assets/meshes/bmesh/
flags	LG_LoadMesh_Flags You can use LG_LoadMesh_Flags flags1 = lg_loadmesh_flags(zboolean save_to_assets, zboolean invert_z, zboolean normalize_xyz, zboolean horiz_center, zboolean vert_center, zboolean vert_bottom) and these macros, which are all set to TRUE: SAVE_TO_ASSETS, INVERT_Z, NORMALIZE_XYZ, 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 *	relative_path,
		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).

NO-OP on Android as BMESH files should be used instead

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

relative_path	Relative path of OBJ file (with extension OBJ), expected to be in OBJ_DIR predefined location
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 *	relative_path,
		zboolean	invert_z,
		zboolean	normalize_xyz,
		zboolean	horiz_center,
		zboolean	vert_center,
		zboolean	vert_bottom
	)

Create mesh from FBX file.

Parameters

relative_path	Relative path of FBX file (with extension OBJ), expected to be in FBX_DIR predefined location
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_bmesh_save_to_file()

int lg_bmesh_save_to_file	(	const char *	full_path,
		LG_Mesh *	mesh
	)

Save mesh in BINARY MESH (.bmesh) format. Don't add suffix BINARY_MESH_EXT, as it's done automagically.

BINARY MESH (.bmesh) file format
================================
- Header = Serializable_LG_Mesh
           -> header_size = lg_align_up_to_next_4_bytes_boundary((void *)sizeof(Serializable_LG_Mesh))
- VBO data block - aligned to 4 bytes boundaries
   -> starting at header_size
- IBO data block - aligned to 4 bytes boundaries
   -> starting at header_size + lg_align_up_to_next_4_bytes_boundary((void *)(uint64_t)mesh->vbo_size)

Parameters

full_path	BMESH file full path
mesh	Pointer to a LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_bmesh_load_from_file()

int lg_bmesh_load_from_file	(	const char *	full_path,
		LG_Mesh **	mesh
	)

Load mesh from BINARY MESH (.bmesh) file. Don't add suffix BINARY_MESH_EXT, as it's done automagically.

BINARY MESH (.bmesh) file format
================================
- Header = Serializable_LG_Mesh
           -> header_size = lg_align_up_to_next_4_bytes_boundary((void *)sizeof(Serializable_LG_Mesh))
- VBO data block - aligned to 4 bytes boundaries
   -> starting at header_size
- IBO data block - aligned to 4 bytes boundaries
   -> starting at header_size + lg_align_up_to_next_4_bytes_boundary((void *)(uint64_t)mesh->vbo_size)

Parameters

full_path	BMESH file full path
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 not loaded from OBJ file.

Parameters

mesh	Pointer to a LG_Mesh

Returns

LG_OK if OK, error code otherwise

lg_serialize_LG_Material_64_to_32()

void lg_serialize_LG_Material_64_to_32	(	Serializable_LG_Material *	s_mat,
		LG_Material *	mat
	)

Serialize a LG_Material instance

Parameters

s_mat	Pointer to a Serializable_LG_Material
mat	Pointer to a Serializable_LG_Material

lg_unserialize_LG_Material_32_to_64()

void lg_unserialize_LG_Material_32_to_64	(	LG_Material *	mat,
		Serializable_LG_Material *	s_mat
	)

Unserialize a LG_Material instance

Parameters

mat	Pointer to a Serializable_LG_Material
s_mat	Pointer to a Serializable_LG_Material

lg_serialize_LG_Mesh_64_to_32()

void lg_serialize_LG_Mesh_64_to_32	(	Serializable_LG_Mesh *	s_mesh,
		LG_Mesh *	mesh
	)

Serialize a LG_Mesh instance

Parameters

s_mesh	Pointer to a Serializable_LG_Mesh
mesh	Pointer to a LG_Mesh

lg_unserialize_LG_Mesh_32_to_64()

void lg_unserialize_LG_Mesh_32_to_64	(	LG_Mesh *	mesh,
		Serializable_LG_Mesh *	s_mesh
	)

Unserialize a LG_Mesh instance

Parameters

mesh	Pointer to a LG_Mesh
s_mesh	Pointer to a Serializable_LG_Mesh

lg_loadmesh_flags()

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

Mesh loading flags.

See lg_mesh_load().

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

• SAVE_TO_ASSETS
• INVERT_Z
• NORMALIZE_XYZ
• VERT_CENTER
• VERT_BOTTOM

Parameters

save_to_assets	Save to assets as BMESH, otherwise to cache - on Android, should always be set to FALSE as you can't write to assets
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

lg_mesh_info()

void lg_mesh_info

(

LG_Mesh *

mesh

)

Print out LG_Mesh info.

Parameters

mesh

lg_replace_file_extension()

char * lg_replace_file_extension	(	const char *	path,
		const char *	new_ext
	)

Replace file extension with another extension, ie 'bla_bla/hello.old_ext' -> 'bla_bla/hello.new_ext'

Extension must not include leading dot

Remove trailing dot if new_ext is empty string

Returned new path must be freed after use (dynamically allocated)

lg_replace_file_extension('hello.vbo', 'blob') = 'hello.blob'
lg_replace_file_extension('bla_bla_1/bla_bla_2.vbo', 'blob') = 'bla_bla_1/bla_bla_2.blob'
lg_replace_file_extension('bla_bla_1/bla_bla_2.v', 'z') = 'bla_bla_1/bla_bla_2.z'
lg_replace_file_extension('hello1.hello2.vbo', 'blob') = 'hello1.hello2.blob'
lg_replace_file_extension('v.1', '2') = 'v.2'
lg_replace_file_extension('v1', '2') = 'v1.2'
lg_replace_file_extension('bla_bla_1/bla_bla_1', '2') = 'bla_bla_1/bla_bla_1.2'
lg_replace_file_extension('.1', '2') = '.2'
lg_replace_file_extension('vbo.1', '') = 'vbo'
lg_replace_file_extension('v.1', '') = 'v'
lg_replace_file_extension('1.', '2') = '1.2'
lg_replace_file_extension('1.', '') = '1'

Parameters

path
new_ext

Returns

New path with swapped extension