lg_textures.c File Reference

Functions
static LG_Texture *	lg_texture_create (int, LG_Path)
static int	lg_texture_add (LG_Texture *)
static void	lg_texture_free (LG_Texture *node)
static int	find_available_tex_unit ()
static void	free_tex_unit (int tex_unit)
void	lg_init_textures_module ()
void	lg_tex_set_min_filter (int v)
void	lg_tex_set_mag_filter (int v)
int	lg_tex_get_min_filter ()
int	lg_tex_get_mag_filter ()
LG_Texture *	lg_texture_new_from_data (lg_tc_format tc_format, int tex_type, LG_Path path, void *data, void **cubemap_data, size_t size, int w, int h, int n_mipmaps)
LG_Texture *	lg_texture_new_from_file (int tex_type, LG_Path path, LG_CubeMap_Paths *cubemap_paths)
SDL_Surface *	lg_sdl_surf_from_file (LG_Path path, int scale_x, int scale_y)
void *	lg_compressed_texdata_from_file (LG_Path path, lg_tc_format *tc_format, size_t *size, int *w, int *h, int *n_mipmaps)
zboolean	lg_test_file_extension (const char *path, const char *ext)
int	lg_get_png_dims (LG_Path path, int *w, int *h)
zboolean	is_lg_tex (LG_Texture *node)
void	lg_texture_remove (LG_Texture *node)
void	lg_texture_remove_all ()
LG_Texture *	lg_texture_first (LG_Texture *node)
LG_Texture *	lg_texture_last (LG_Texture *node)
LG_Texture *	lg_texture_find_by_id (uint32_t id)
int	lg_texture_count_nodes ()
int	lg_texture_count_gl_tex ()
static void	texture_info (const LG_Texture *tex)
void	lg_texture_info (const LG_Texture *tex)
void	lg_texture_info_all ()
void	lg_texture_list_all ()
zboolean	lg_read_pixels_from_screen (void *pixels, Rec2Di r)
zboolean	lg_write_pixels_to_screen (void *pixels, const Rec2Di *dest)
void	lg_texture_unbind (LG_Texture *tex)
void	lg_tex_units_info ()
unsigned int	lg_get_active_tex ()
void	lg_active_tex_info ()
void	lg_free_sdl_surf (SDL_Surface *surf)
int	lg_surf_depth (SDL_Surface *surf)
void	lg_info_out_read_framebuffer ()

Variables
static zboolean	assigned_tex_unit [LG_MAX_TEX_UNITS]
static int	max_tex_units

Detailed Description

=== Handle all texture related stuff ===

We're using a global doubly-linked list.

Vars storing the texture list and the assigned tex units:

• static LG_Texture node0 (in lg_env_instance.c, accessed with lg_texture_get_node0())
• static zboolean assigned_tex_unit[LG_MAX_TEX_UNITS]

These vars are for all libgame and app textures, and are updated by all funcs creating or removing textures.

They are 'private', there is no public API, apart from lg_texture_get_node0().

So, you can/should only use this func to create new textures:

 LG_Texture *lg_texture_new_from_file(int tex_type, LG_Path path, LG_CubeMap_Paths *cubemap_paths)

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

 void lg_texture_remove(LG_Texture *node)

and just ignore the details.

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

*** WARNING: Rendering of DXT1/3 textures with mipmaps is still f**ked up at the moment, so avoid them until it's fixed ***

Function Documentation

lg_init_textures_module()

void lg_init_textures_module

(

)

Must be called at init time in libgame.c

lg_tex_set_min_filter()

void lg_tex_set_min_filter

(

int

v

)

Set global value of GL_TEXTURE_MIN_FILTER

Parameters

new_value

Probably GL_LINEAR or GL_NEAREST

lg_tex_set_mag_filter()

void lg_tex_set_mag_filter

(

int

v

)

Set global value of GL_TEXTURE_MAG_FILTER

Parameters

new_value

Probably GL_LINEAR or GL_NEAREST

lg_tex_get_min_filter()

int lg_tex_get_min_filter

(

)

Get global value of GL_TEXTURE_MIN_FILTER

Returns

Probably GL_LINEAR or GL_NEAREST

lg_tex_get_mag_filter()

int lg_tex_get_mag_filter

(

)

Get global value of GL_TEXTURE_MAG_FILTER

Returns

Probably GL_LINEAR or GL_NEAREST

lg_texture_new_from_data()

LG_Texture * lg_texture_new_from_data	(	lg_tc_format	tc_format,
		int	tex_type,
		LG_Path	path,
		void *	data,
		void **	cubemap_data,
		size_t	size,
		int	w,
		int	h,
		int	n_mipmaps
	)

Create a new LG_Texture node from data (either a SDL_Surface or compressed tex data), and ADD IT to the global doubly-linked list

(Completely replace SDL_CreateTextureFromSurface())

Now also reading compressed textures - see lg_astc_loader.c/h and lg_dds_loader.c/h

About mipmaps:

• They are ignored in uncompressed textures, as they are generated with glGenerateMipmap(GL_TEXTURE_2D)
• Skyboxes dont need/want mipmaps, so they also are ignored, if included
• *** WARNING: Rendering of DXT1/3 textures with mipmaps is still f**ked up at the moment, so avoid them until it's fixed ***

Parameters

tc_format	If tc_format == LG_TC_UNCOMPRESSED, data is a SDL_Surface, otherwise data is compressed texture data (LG_TC_DXT1, LG_TC_DXT3, LG_TC_ASTC, LG_TC_ETC1 so far ...)
tex_type	GL_TEXTURE_2D or GL_TEXTURE_CUBE_MAP
path	LG_Path to image file, only used at this point to store info
data	A pointer to compressed texture data or a SDL_Surface - ignored if tex_type == GL_TEXTURE_CUBE_MAP
cubemap_data	Array of 6 compressed tex data or 6 SDL_Surface's - ignored if tex_type == GL_TEXTURE_2D
size	Size - ignored if texture is not compressed
w	Width
h	Height
n_mipmaps	Number of generated mipmaps - WARNING: Original image is considered mipmap level 0, so n_mipmaps must be at least 1

Returns

A pointer to a LG_Texture if OK, NULL on error

lg_texture_new_from_file()

LG_Texture * lg_texture_new_from_file	(	int	tex_type,
		LG_Path	path,
		LG_CubeMap_Paths *	cubemap_paths
	)

Create a new LG_Texture node from a file and ADD IT to the global doubly-linked list

=== You should use this func when creating new textures ===

*** WARNING #1: Rendering of DXT1/3 textures with mipmaps is still f**ked up at the moment, so avoid them until it's fixed ***

*** WARNING #2: stbi_info() doesn't work on Android - used (only) to get jpg file dims, so avoid them until (?) ***

(Seems stb_image is f**ked up on Android and pretty useless, should probably get rid of it)

Parameters

tex_type	GL_TEXTURE_2D or GL_TEXTURE_CUBE_MAP
path	LG_Path to image file - if tex_type == GL_TEXTURE_CUBE_MAP, only used to store path to first image
cubemap_paths	Array of 6 LG_Path to image file - ignored if tex_type == GL_TEXTURE_2D

Returns

A pointer to a LG_Texture if OK, NULL on error

lg_sdl_surf_from_file()

SDL_Surface * lg_sdl_surf_from_file	(	LG_Path	path,
		int	scale_x,
		int	scale_y
	)

For image and NON-compressed tex files

NO scaling is applied if scale_x == 0 or scale_y == 0

Otherwise, scale_x/y apply to env->top_win_logical_w/h, ie

• w = env->top_win_logical_w * scale_x
• h = env->top_win_logical_h * scale_y

Parameters

path	LG_Path to image file
scale_x
scale_y

Returns

A SDL_Surface if OK, NULL on error

lg_compressed_texdata_from_file()

void * lg_compressed_texdata_from_file	(	LG_Path	path,
		lg_tc_format *	tc_format,
		size_t *	size,
		int *	w,
		int *	h,
		int *	n_mipmaps
	)

For compressed tex files

Supported file formats and texture compression formats:

• S3TC -> DDS with DXT1 and DXT3 tex compression (Linux only)
• ASCT
• PKM with ETC1 tex compression
• *** WARNING: Rendering of DXT1/3 textures with mipmaps is still f**ked up at the moment, so avoid them until it's fixed ***

Returned data must be freed afterwards

Parameters

path	LG_Path to compressed tex file
tc_format	Pointer to lg_tc_format
size	Pointer to size
w	Pointer to width
h	Pointer to height
n_mipmaps	Pointer n_mipmaps

Returns

Pointer to compressed data if OK, NULL on error

lg_test_file_extension()

zboolean lg_test_file_extension	(	const char *	path,
		const char *	ext
	)

Test path against file extension (case-insensitive strings comparaison)

NOTE: doesn't search backward for '.' but uses extension string length instead, so extension should include '.', ie ".png", not "png"

Parameters

path	Path string (full or relative, doesn't matter here)
ext	File extension to test against (ie ".png", ".jpg", etc)

Returns

TRUE if path FILE EXTENSION == EXT, FALSE otherwise

lg_get_png_dims()

int lg_get_png_dims	(	LG_Path	path,
		int *	w,
		int *	h
	)

Get PNG image dimensions

Parameters

path	LG_Path to image file
w	Width
h	Height

Returns

LG_OK if OK

is_lg_tex()

zboolean is_lg_tex

(

LG_Texture *

node

)

Check if a LG_Texture node is valid, ie non NULL and with a valid signature

Parameters

node	A LG_Texture node

Returns

TRUE if OK, FALSE otherwise

lg_texture_remove()

void lg_texture_remove

(

LG_Texture *

node

)

Remove node from list AND free node and all associated resources (including the GL texture), if != <node0>

=== You should use this func when done with a texture ===

WARNING: Must be a valid texture and need a valid GL context, or will segfault

Anyways, lg_texture_remove_all() is always called by lg_quit() so you shouldn't worry too much about memory leaks

Parameters

node	A LG_Texture node

Returns

TRUE if removed, FALSE on error

lg_texture_remove_all()

void lg_texture_remove_all

(

)

Remove all nodes (but <node0>) from list, freeing all resources (including GL textures)

WARNING:

• This func should be called very carefully, unless you know exactly what you are doing
• This func is always called by lg_quit()
• Need a valid GL context

Returns

The num of removed nodes

lg_texture_first()

LG_Texture * lg_texture_first

(

LG_Texture *

node

)

Return first node

Parameters

node	A LG_Texture node

Returns

First node of the list

lg_texture_last()

LG_Texture * lg_texture_last

(

LG_Texture *

node

)

Return last node

Parameters

node	A LG_Texture node

Returns

Last node of the list

lg_texture_find_by_id()

LG_Texture * lg_texture_find_by_id

(

uint32_t

id

)

Return first found occurence

Parameters

id	A LG_Texture id

Returns

Found LG_Texture node or NULL if not found

lg_texture_count_nodes()

int lg_texture_count_nodes

(

)

Count all nodes - doesn't check if node->id is a valid GL texture

Include <node0>

Returns

Number of nodes of the list

lg_texture_count_gl_tex()

int lg_texture_count_gl_tex

(

)

Count all nodes - check if node->id is a valid GL texture

Doesn't include <node0>

Returns

Number of nodes of the list

lg_texture_info()

void lg_texture_info

(

const LG_Texture *

tex

)

Print out texture info

Parameters

tex	A LG_Texture

lg_texture_info_all()

void lg_texture_info_all

(

)

Print out texture info for all nodes

lg_texture_list_all()

void lg_texture_list_all

(

)

Print out a list of all textures (id and rel_path_in_assets)

lg_read_pixels_from_screen()

zboolean lg_read_pixels_from_screen	(	void *	pixels,
		Rec2Di	r
	)

Store a v-flipped image (don't ask me why it's v-flipped)

From some doc somewhere: "Only two format/type parameter pairs are accepted. GL_RGBA/GL_UNSIGNED_BYTE is always accepted, and the other acceptable pair can be discovered by querying GL_IMPLEMENTATION_COLOR_READ_FORMAT and GL_IMPLEMENTATION_COLOR_READ_TYPE."

Parameters

pixels	A pixel buffer
r	A Rec2Di

Returns

TRUE if OK

lg_write_pixels_to_screen()

zboolean lg_write_pixels_to_screen	(	void *	pixels,
		const Rec2Di *	dest
	)

'Un-flip' the image provided by lg_read_pixels_from_screen()

If NULL, dest is the entire rendering target

Parameters

pixels	A pixel buffer
dest	A Rec2Di

Returns

TRUE if OK

lg_texture_unbind()

void lg_texture_unbind

(

LG_Texture *

tex

)

Unbind texture

lg_tex_units_info()

void lg_tex_units_info

(

)

Print out texture units info

lg_get_active_tex()

unsigned int lg_get_active_tex

(

)

Returns

The active texture unit

lg_active_tex_info()

void lg_active_tex_info

(

)

Print out active texture unit info

lg_free_sdl_surf()

void lg_free_sdl_surf

(

SDL_Surface *

surf

)

Free SDL_Surface if not NULL

Parameters

surf	Addr of SDL_Surface

lg_surf_depth()

int lg_surf_depth

(

SDL_Surface *

surf

)

Surface depth of a SDL_Surface

Parameters

surf	Addr of SDL_Surface

Returns

Surface depth

lg_info_out_read_framebuffer()

void lg_info_out_read_framebuffer

(

)

Print out current bound read framebuffer info