gfx_utils.h File Reference

Utilities required by other gfx_XXX files. More...

#include <stdio.h>
#include <stdlib.h>

Go to the source code of this file.

Typedefs
typedef void *	rbuf_handle_t
	A handle to a ring buffer object, created using gfxRbufInit() More...

Functions
int	gfxUtilIsCurGLThread (void)
	Checks if the calling thread is the thread that currently holds the GL context. More...
void	gfxUtilSetGLThread (void)
	The calling thread is registered as holding the current GL context. More...
char *	gfxUtilPrependPath (const char *path, char *file)
	Prepends a path string to a filename. More...
char *	gfxUtilGetBinFolderPath (char *bin_path)
	Gets the execution folder of the current program, assumes that program is executing from a folder "bin". More...
const char *	gfxUtilFindResourceDirectory (void)
	Returns the lopcation of the resource directory. More...
FILE *	gfxUtilFindResource (char *resource_name, const char *mode)
	Searches for a file in the RESOURCES_DIRECTORY and returns a FILE * if found. More...
char *	gfxUtilFindResourcePath (char *resource_name)
	Similar to gfxUtilFindResource() only returning the file's path instead of the opened FILE's reference. More...
rbuf_handle_t	gfxRbufInit (size_t item_size, size_t item_count)
	Initialized a ring buffer object with a certain number of objects of a given size. More...
rbuf_handle_t	gfxRbufInitStatic (size_t item_size, size_t item_count, void *buffer)
	Initialized a ring buffer object with a certain number of objects of a given size into a statically allocated buffer. More...
void	gfxRbufFree (rbuf_handle_t rbuf)
	Frees a ring buffer. More...
void	gfxRbufReset (rbuf_handle_t rbuf)
	Resets the ring buffer to it's initial state. More...
int	gfxRbufPutBuffer (rbuf_handle_t rbuf)
	Used when a reference to the next buffer item is already filled, incrementing the next buffer item should an item need to be retrieved. More...
int	gfxRbufPut (rbuf_handle_t rbuf, void *data)
	Fills the next available buffer slot, if a slot is free. More...
int	gfxRbufFPut (rbuf_handle_t rbuf, void *data)
	Fills the next available buffer, overwriting data if the ring buffer is full. More...
void *	gfxRbufGetBuffer (rbuf_handle_t rbuf)
	Returns a reference to the data of the next ring buffer entry. More...
int	gfxRbufGet (rbuf_handle_t rbuf, void *data)
	Returns a copy of the next buffer item's data. More...
unsigned char	gfxRbufEmpty (rbuf_handle_t rbuf)
	Checks if the buffer is empty or not. More...
unsigned char	gfxRbufFull (rbuf_handle_t rbuf)
	Checks if the buffer is full. More...
size_t	gfxRbufSize (rbuf_handle_t rbuf)
	Returns the number of elements currently stored in the ring buffer. More...
size_t	gfxRbufCapacity (rbuf_handle_t rbuf)
	Returns the maximum number of elements that the ring buffer can store. More...

Detailed Description

Utilities required by other gfx_XXX files.

Author

Alex Hoffman

Date

27 August 2019

----------------------------------------------------------------------
Copyright (C) Alexander Hoffman, 2019
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
----------------------------------------------------------------------

Typedef Documentation

rbuf_handle_t

typedef void* rbuf_handle_t

A handle to a ring buffer object, created using gfxRbufInit()

Function Documentation

gfxRbufCapacity()

size_t gfxRbufCapacity

(

rbuf_handle_t

rbuf

)

Returns the maximum number of elements that the ring buffer can store.

Parameters

rbuf	Handle to the ring buffer

Returns

The maximum number of elements that the ring buffer can store

gfxRbufEmpty()

unsigned char gfxRbufEmpty

(

rbuf_handle_t

rbuf

)

Checks if the buffer is empty or not.

Parameters

rbuf	Handle to the ring buffer

Returns

1 if the buffer is empty, 0 otherwise

gfxRbufFPut()

int gfxRbufFPut	(	rbuf_handle_t	rbuf,
		void *	data
	)

Fills the next available buffer, overwriting data if the ring buffer is full.

Parameters

rbuf	Handle to the ring buffer
data	Reference to the data to be copied into the buffer

Returns

0 on success

gfxRbufFree()

void gfxRbufFree

(

rbuf_handle_t

rbuf

)

Frees a ring buffer.

Parameters

rbuf	Handle to the ring buffer

gfxRbufFull()

unsigned char gfxRbufFull

(

rbuf_handle_t

rbuf

)

Checks if the buffer is full.

Parameters

rbuf	Handle to the ring buffer

Returns

1 if the buffer is full, 0 otherwise

gfxRbufGet()

int gfxRbufGet	(	rbuf_handle_t	rbuf,
		void *	data
	)

Returns a copy of the next buffer item's data.

Parameters

rbuf	Handle to the ring buffer
data	A reference to the allocated memory region into which the data should be copied

Returns

0 on success

gfxRbufGetBuffer()

void* gfxRbufGetBuffer

(

rbuf_handle_t

rbuf

)

Returns a reference to the data of the next ring buffer entry.

Because only a reference is returned the contents of the buffer entry cannot be guarenteed

Parameters

rbuf	Handle to the ring buffer

Returns

A reference to the next item in the buffer's data

gfxRbufInit()

rbuf_handle_t gfxRbufInit	(	size_t	item_size,
		size_t	item_count
	)

Initialized a ring buffer object with a certain number of objects of a given size.

Parameters

item_size	The size, in bytes, of each ring buffer item
item_count	The maximum number of items to be stored in the ring buffer

Returns

A handle to the created ring buffer, else NULL

gfxRbufInitStatic()

rbuf_handle_t gfxRbufInitStatic	(	size_t	item_size,
		size_t	item_count,
		void *	buffer
	)

Initialized a ring buffer object with a certain number of objects of a given size into a statically allocated buffer.

Parameters

item_size	The size, in bytes, of each ring buffer item
item_count	The maximum number of items to be stored in the ring buffer
buffer	Reference to the statically allocated memory region that is to be used for storing the ring buffer

Returns

A handle to the created ring buffer, else NULL

gfxRbufPut()

int gfxRbufPut	(	rbuf_handle_t	rbuf,
		void *	data
	)

Fills the next available buffer slot, if a slot is free.

Parameters

rbuf	Handle to the ring buffer
data	Reference to the data to be copied into the buffer

Returns

0 on success

gfxRbufPutBuffer()

int gfxRbufPutBuffer

(

rbuf_handle_t

rbuf

)

Used when a reference to the next buffer item is already filled, incrementing the next buffer item should an item need to be retrieved.

Parameters

rbuf	Handle to the ring buffer

Returns

0 on success

gfxRbufReset()

void gfxRbufReset

(

rbuf_handle_t

rbuf

)

Resets the ring buffer to it's initial state.

Parameters

rbuf	Handle to the ring buffer

gfxRbufSize()

size_t gfxRbufSize

(

rbuf_handle_t

rbuf

)

Returns the number of elements currently stored in the ring buffer.

Parameters

rbuf	Handle to the ring buffer

Returns

Number of elements stored in the ring buffer

gfxUtilFindResource()

FILE* gfxUtilFindResource	(	char *	resource_name,
		const char *	mode
	)

Searches for a file in the RESOURCES_DIRECTORY and returns a FILE * if found.

Parameters

resource_name	Name of the file to be found
mode	The reading mode to be used when opening the file, eg. "rw"

Returns

FILE reference if found, otherwise NULL

gfxUtilFindResourceDirectory()

const char* gfxUtilFindResourceDirectory

(

void

)

Returns the lopcation of the resource directory.

Returns

String reference if found, otherwise NULL

gfxUtilFindResourcePath()

char* gfxUtilFindResourcePath

(

char *

resource_name

)

Similar to gfxUtilFindResource() only returning the file's path instead of the opened FILE's reference.

The found filename is stored in a statically allocated buffer and can be overwritten by subsequent calls to the functions

Parameters

resource_name

Name of the file to be found

Returns

Reference to the statically allocated filename, else NULL

gfxUtilGetBinFolderPath()

char* gfxUtilGetBinFolderPath

(

char *

bin_path

)

Gets the execution folder of the current program, assumes that program is executing from a folder "bin".

Parameters

bin_path

The program's binary's location, usually argv[0]

Returns

char * String of the folder's absolute location

gfxUtilIsCurGLThread()

int gfxUtilIsCurGLThread

(

void

)

Checks if the calling thread is the thread that currently holds the GL context.

Returns

0 if the current thread does hold the GL context, -1 otherwise.

gfxUtilPrependPath()

char* gfxUtilPrependPath	(	const char *	path,
		char *	file
	)

Prepends a path string to a filename.

Parameters

path	Path string to be prepended
file	Filename to which the path string should be prepended

Returns

char * to the complete compiled path

gfxUtilSetGLThread()

void gfxUtilSetGLThread

(

void

)

The calling thread is registered as holding the current GL context.