bmptk::graphics::frame_buffer Class Reference

in-memory frame buffer that can be written in one go More...

#include <graphics.h>

Inheritance diagram for bmptk::graphics::frame_buffer:

Public Member Functions
	frame_buffer (frame &fr)
	construct a frame_buffer from an underlying frame
virtual	~frame_buffer ()
	destruct a frame_buffer, freeing the allocated pixel buffer
void	checked_write (const vector p, const color c)
	write to the pixel buffer
void	flush ()
	write the pixel buffer to the underlying frame
void	clear (const color c=color::white())
	clear the buffer, and rember the color used
Public Member Functions inherited from bmptk::graphics::frame
	frame (const vector size)
	create a frame of specified size
vector	size_get () const
	get the size of the frame
virtual vector	translate_outfrom (const vector p) const
	translate a subframe coordinate to a master frame coordinate
virtual vector	translate_into (const vector p) const
	translate a master frame coordinate to a subframe coordinate
bool	is_valid (vector p)
	whether p is within the frame
color	bg_get ()
	get the backround color
void	write (const vector p, const color c)
	write one pixel, address specified by vector

Additional Inherited Members
Protected Attributes inherited from bmptk::graphics::frame
const vector	size
	frame size
color	bg
	most recently applied background color (as used in clear())

Detailed Description

in-memory frame buffer that can be written in one go

A frame_buffer catches and buffers the writes to the underlying frame in an in-memmory buffer. The flush() call writes the buffer to the underlying frame.

A frame_buffer can be used to prevent flickering while a frame is updated. The downside is the memory use and the extra CPU time for writing the changed pixels to the underlying frame. To do this all buffered pixels must be checked.

Note that buffering the writing to a screen that itself does fancy things (for instance shadowing) can change what appears on a screen because the order in which pixels are written is changed. The safest is to buffer directly above the target screen.

The buffer is allocated on the heap.

Definition at line 827 of file graphics.h.

Constructor & Destructor Documentation

bmptk::graphics::frame_buffer::frame_buffer ( frame &  fr )

inline

construct a frame_buffer from an underlying frame

This constructor allocates the pixel buffer on the heap. The size is the number of pixels in the underlying frame * 4 bytes for each pixel.

Definition at line 860 of file graphics.h.

Member Function Documentation

void bmptk::graphics::frame_buffer::flush ( )

inlinevirtual

write the pixel buffer to the underlying frame

This method writes all changed pixels in the buffer to the underlying frame, and flushes that frame.

Reimplemented from bmptk::graphics::frame.

Definition at line 886 of file graphics.h.

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The documentation for this class was generated from the following file:

• graphics/graphics.h