buffers.h File Reference

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Detailed Description

Frame buffer management functions declarations.

#include "mtypes.h"

Functions
void GLAPIENTRY	_mesa_DrawBuffer (GLenum mode)
	Called by glDrawBuffer().
void GLAPIENTRY	_mesa_DrawBuffersARB (GLsizei n, const GLenum *buffers)
	Called by glDrawBuffersARB; specifies the destination color renderbuffers for N fragment program color outputs.
void	_mesa_drawbuffers (GLcontext *ctx, GLuint n, const GLenum *buffers, const GLbitfield *destMask)
	Helper function to set the GL_DRAW_BUFFER state in the context and current FBO.
void	_mesa_readbuffer (GLcontext *ctx, GLenum buffer, GLint bufferIndex)
	Like.
void GLAPIENTRY	_mesa_ReadBuffer (GLenum mode)
	Called by glReadBuffer to set the source renderbuffer for reading pixels.

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Function Documentation

void GLAPIENTRY _mesa_DrawBuffer

(

GLenum

buffer

)

Called by glDrawBuffer().

Specify which renderbuffer(s) to draw into for the first color output. <buffer> can name zero, one, two or four renderbuffers!

See also:

_mesa_DrawBuffersARB

Parameters:

buffer

buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc.

Note that the behaviour of this function depends on whether the current ctx->DrawBuffer is a window-system framebuffer (Name=0) or a user-created framebuffer object (Name!=0). In the former case, we update the per-context ctx->Color.DrawBuffer state var _and_ the FB's ColorDrawBuffer state. In the later case, we update the FB's ColorDrawBuffer state only.

Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the new FB is a window system FB, we need to re-update the FB's ColorDrawBuffer state to match the context. This is handled in _mesa_update_framebuffer().

See the GL_EXT_framebuffer_object spec for more info.

void _mesa_drawbuffers	(	GLcontext *	ctx,
		GLuint	n,
		const GLenum *	buffers,
		const GLbitfield *	destMask
	)

Helper function to set the GL_DRAW_BUFFER state in the context and current FBO.

All error checking will have been done prior to calling this function so nothing should go wrong at this point.

Parameters:

	ctx	current context
	n	number of color outputs to set
	buffers	array[n] of colorbuffer names, like GL_LEFT.
	destMask	array[n] of BUFFER_BIT_* bitmasks which correspond to the colorbuffer names. (i.e. GL_FRONT_AND_BACK => BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).

void GLAPIENTRY _mesa_DrawBuffersARB	(	GLsizei	n,
		const GLenum *	buffers
	)

Called by glDrawBuffersARB; specifies the destination color renderbuffers for N fragment program color outputs.

See also:

_mesa_DrawBuffer

Parameters:

	n	number of outputs
	buffers	array [n] of renderbuffer names. Unlike glDrawBuffer, the names cannot specify more than one buffer. For example, GL_FRONT_AND_BACK is illegal.

void GLAPIENTRY _mesa_ReadBuffer

(

GLenum

buffer

)

Called by glReadBuffer to set the source renderbuffer for reading pixels.

Parameters:

mode

color buffer such as GL_FRONT, GL_BACK, etc.

void _mesa_readbuffer	(	GLcontext *	ctx,
		GLenum	buffer,
		GLint	bufferIndex
	)

Like.

See also:

_mesa_drawbuffers(), this is a helper function for setting GL_READ_BUFFER state in the context and current FBO.

Parameters:

	ctx	the rendering context
	buffer	GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc.
	bufferIndex	the numerical index corresponding to 'buffer'

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