Class: SDL2::RWops

Inherits:
Struct
  • Object
show all
Defined in:
lib/sdl2/rwops.rb,
lib/sdl2/rwops.rb

Overview

“This is the read/write operation structure – very basic”

size    - " Return the size of the file in this rwops, or -1 if unkown
seek    - "Seek to \c offset relative to \c whence, one of stdio's whence values:
            RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
            return the final offset in the data stream, or -1 on error.
read    - "Read up to \cc maxnum objects each of size \cc size from the data
            stream to the area pointed at by \cc ptr.
            Return the number of objects read, or 0 at error or end of file.
write   - "Write eactly \cc num objects each of size \cc size from the area
            pointed at by \cc ptr to data stream.
            Return the number of objects written, or 0 at error or end of file.
close   - "Close and free an allocated SDL_RWops structure.
            Return 0 if successful or -1 on write error when flushing data.

Defined Under Namespace

Classes: AndroidIO, Hidden, Mem, STDIO, Unkown, WindowsIO

Constant Summary collapse

SEEK_SET =

“Seek from the beginning of data”

0
SEEK_CUR =

“Seek relative to current read point”

1
SEEK_END =

“Seek relative to the end of data”

2

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Struct

#==, cast, create, #free, #initialize, #to_s, #update_members

Methods included from StructHelper

#member_readers, #member_writers

Constructor Details

This class inherits a constructor from SDL2::Struct

Class Method Details

.from_file(file_name, mode) ⇒ Object

Create RWOps from file name



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# File 'lib/sdl2/rwops.rb', line 109

def self.from_file(file_name, mode)
  SDL2.rw_from_file!(file_name, mode)
end

.release(pointer) ⇒ Object

Release this structure using SDL_FreeRW



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# File 'lib/sdl2/rwops.rb', line 93

def self.release(pointer)
  SDL2.free_rw(pointer)
end

Instance Method Details

#close ⇒ Object

“Close and free an allocated SDL_RWops structure.”

"\return 0 if successful or -1 on write error when flushing data."



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# File 'lib/sdl2/rwops.rb', line 155

def close
  self[:close].call(self)
end

#read(pointer, size, n) ⇒ Object

“Read up to \c maxnum objects each of size \c size from the data

stream to the area pointed at by \c ptr."
"\return the number of objects read, or 0 at error or end of file."



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# File 'lib/sdl2/rwops.rb', line 139

def read(pointer, size, n)
  self[:read].call(self, pointer, size, n)
end

#seek(offset, whence) ⇒ Object

“Seek to \c offset in the data stream, or -1 on error.” “\return the number of objects read, or 0 at error or end of file”



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# File 'lib/sdl2/rwops.rb', line 124

def seek(offset, whence)
  self[:seek].call(self, offset, whence)
end

#size ⇒ Object

“Return the size of the file in this rwops, or -1 if unkown”



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# File 'lib/sdl2/rwops.rb', line 117

def size
  self[:size].call
end

#tell ⇒ Object

BadQuanta: “I suppose this returns the current position” SDL_rwops.h:186.



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# File 'lib/sdl2/rwops.rb', line 131

def tell
  self[:seek].call(self, 0, SEEK_CUR)
end

#write(pointer, size, n) ⇒ Object

“Write exactly \c num objects each of size \c size from the area

pointed at by \c ptr to data stream."

"\return the number of objects written, or 0 at error or end of file."



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# File 'lib/sdl2/rwops.rb', line 148

def write(pointer, size, n)
  self[:write].call(self, pointer, size, n)
end