framebuffer.c File Reference

#include "glheader.h"
#include "imports.h"
#include "buffers.h"
#include "context.h"
#include "depthstencil.h"
#include "macros.h"
#include "mtypes.h"
#include "fbobject.h"
#include "framebuffer.h"
#include "renderbuffer.h"
#include "texobj.h"

Functions
static void	compute_depth_max (struct gl_framebuffer *fb)
	Functions for allocating/managing framebuffers and renderbuffers.
struct gl_framebuffer *	_mesa_create_framebuffer (const GLvisual *visual)
	Create and initialize a gl_framebuffer object.
struct gl_framebuffer *	_mesa_new_framebuffer (GLcontext *ctx, GLuint name)
	Allocate a new gl_framebuffer object.
void	_mesa_initialize_framebuffer (struct gl_framebuffer *fb, const GLvisual *visual)
	Initialize a gl_framebuffer object.
void	_mesa_destroy_framebuffer (struct gl_framebuffer *fb)
	Deallocate buffer and everything attached to it.
void	_mesa_free_framebuffer_data (struct gl_framebuffer *fb)
	Free all the data hanging off the given gl_framebuffer, but don't free the gl_framebuffer object itself.
void	_mesa_reference_framebuffer (struct gl_framebuffer **ptr, struct gl_framebuffer *fb)
	Set *ptr to point to fb, with refcounting and locking.
void	_mesa_resize_framebuffer (GLcontext *ctx, struct gl_framebuffer *fb, GLuint width, GLuint height)
	Resize the given framebuffer's renderbuffers to the new width and height.
void	_mesa_resizebuffers (GLcontext *ctx)
	XXX THIS IS OBSOLETE - drivers should take care of detecting window size changes and act accordingly, likely calling _mesa_resize_framebuffer().
void GLAPIENTRY	_mesa_ResizeBuffersMESA (void)
static void	update_framebuffer_size (GLcontext *ctx, struct gl_framebuffer *fb)
	Examine all the framebuffer's renderbuffers to update the Width/Height fields of the framebuffer.
void	_mesa_update_draw_buffer_bounds (GLcontext *ctx)
	Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
void	_mesa_update_framebuffer_visual (struct gl_framebuffer *fb)
	The glGet queries of the framebuffer red/green/blue size, stencil size, etc.
void	_mesa_update_depth_buffer (GLcontext *ctx, struct gl_framebuffer *fb, GLuint attIndex)
	Update the framebuffer's _DepthBuffer field using the renderbuffer found at the given attachment index.
void	_mesa_update_stencil_buffer (GLcontext *ctx, struct gl_framebuffer *fb, GLuint attIndex)
	Update the framebuffer's _StencilBuffer field using the renderbuffer found at the given attachment index.
static void	update_color_draw_buffers (GLcontext *ctx, struct gl_framebuffer *fb)
	Update the (derived) list of color drawing renderbuffer pointers.
static void	update_color_read_buffer (GLcontext *ctx, struct gl_framebuffer *fb)
	Update the (derived) color read renderbuffer pointer.
static void	update_framebuffer (GLcontext *ctx, struct gl_framebuffer *fb)
	Update a gl_framebuffer's derived state.
void	_mesa_update_framebuffer (GLcontext *ctx)
	Update state related to the current draw/read framebuffers.
GLboolean	_mesa_source_buffer_exists (GLcontext *ctx, GLenum format)
	Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels, glCopyTex[Sub]Image, etc) exists.
GLboolean	_mesa_dest_buffer_exists (GLcontext *ctx, GLenum format)
	As above, but for drawing operations.

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Function Documentation

struct gl_framebuffer* _mesa_create_framebuffer

(

const GLvisual *

visual

)

[read]

Create and initialize a gl_framebuffer object.

This is intended for creating _window_system_ framebuffers, not generic framebuffer objects ala GL_EXT_framebuffer_object.

See also:

_mesa_new_framebuffer

GLboolean _mesa_dest_buffer_exists	(	GLcontext *	ctx,
		GLenum	format
	)

As above, but for drawing operations.

XXX could do some code merging w/ above function.

void _mesa_destroy_framebuffer

(

struct gl_framebuffer *

fb

)

Deallocate buffer and everything attached to it.

Typically called via the gl_framebuffer->Delete() method.

void _mesa_free_framebuffer_data

(

struct gl_framebuffer *

fb

)

Free all the data hanging off the given gl_framebuffer, but don't free the gl_framebuffer object itself.

void _mesa_initialize_framebuffer	(	struct gl_framebuffer *	fb,
		const GLvisual *	visual
	)

Initialize a gl_framebuffer object.

Typically used to initialize window system-created framebuffers, not user-created framebuffers.

See also:

_mesa_create_framebuffer

struct gl_framebuffer* _mesa_new_framebuffer	(	GLcontext *	ctx,
		GLuint	name
	)			[read]

Allocate a new gl_framebuffer object.

This is the default function for ctx->Driver.NewFramebuffer(). This is for allocating user-created framebuffers, not window-system framebuffers!

See also:

_mesa_create_framebuffer

void _mesa_reference_framebuffer	(	struct gl_framebuffer **	ptr,
		struct gl_framebuffer *	fb
	)

Set *ptr to point to fb, with refcounting and locking.

void _mesa_resize_framebuffer	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb,
		GLuint	width,
		GLuint	height
	)

Resize the given framebuffer's renderbuffers to the new width and height.

This should only be used for window-system framebuffers, not user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object). This will typically be called via ctx->Driver.ResizeBuffers() or directly from a device driver.

Note:

it's possible for ctx to be null since a window can be resized without a currently bound rendering context.

void _mesa_resizebuffers

(

GLcontext *

ctx

)

XXX THIS IS OBSOLETE - drivers should take care of detecting window size changes and act accordingly, likely calling _mesa_resize_framebuffer().

GL_MESA_resize_buffers extension.

When this function is called, we'll ask the window system how large the current window is. If it's a new size, we'll call the driver's ResizeBuffers function. The driver will then resize its color buffers as needed, and maybe call the swrast's routine for reallocating swrast-managed depth/stencil/accum/etc buffers.

Note:

This function should only be called through the GL API, not from device drivers (as was done in the past).

void GLAPIENTRY _mesa_ResizeBuffersMESA

(

void

)

GLboolean _mesa_source_buffer_exists	(	GLcontext *	ctx,
		GLenum	format
	)

Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels, glCopyTex[Sub]Image, etc) exists.

Parameters:

format

a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA, GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.

Returns:

GL_TRUE if buffer exists, GL_FALSE otherwise

void _mesa_update_depth_buffer	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb,
		GLuint	attIndex
	)

Update the framebuffer's _DepthBuffer field using the renderbuffer found at the given attachment index.

If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer, create and install a depth wrapper/adaptor.

Parameters:

	fb	the framebuffer whose _DepthBuffer field to update
	attIndex	indicates the renderbuffer to possibly wrap

void _mesa_update_draw_buffer_bounds

(

GLcontext *

ctx

)

Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.

These values are computed from the buffer's width and height and the scissor box, if it's enabled.

Parameters:

ctx

the GL context.

void _mesa_update_framebuffer

(

GLcontext *

ctx

)

Update state related to the current draw/read framebuffers.

void _mesa_update_framebuffer_visual

(

struct gl_framebuffer *

fb

)

The glGet queries of the framebuffer red/green/blue size, stencil size, etc.

are satisfied by the fields of ctx->DrawBuffer->Visual. These can change depending on the renderbuffer bindings. This function updates the given framebuffer's Visual from the current renderbuffer bindings.

This may apply to user-created framebuffers or window system framebuffers.

Also note: ctx->DrawBuffer->Visual.depthBits might not equal ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits. The former one is used to convert floating point depth values into integer Z values.

void _mesa_update_stencil_buffer	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb,
		GLuint	attIndex
	)

Update the framebuffer's _StencilBuffer field using the renderbuffer found at the given attachment index.

If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer, create and install a stencil wrapper/adaptor.

Parameters:

	fb	the framebuffer whose _StencilBuffer field to update
	attIndex	indicates the renderbuffer to possibly wrap

static void compute_depth_max

(

struct gl_framebuffer *

fb

)

[static]

Functions for allocating/managing framebuffers and renderbuffers.

Also, routines for reading/writing renderbuffer data as ubytes, ushorts, uints, etc. Compute/set the _DepthMax field for the given framebuffer. This value depends on the Z buffer resolution.

static void update_color_draw_buffers	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb
	)			[static]

Update the (derived) list of color drawing renderbuffer pointers.

Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers writing colors.

static void update_color_read_buffer	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb
	)			[static]

Update the (derived) color read renderbuffer pointer.

Unlike the DrawBuffer, we can only read from one (or zero) color buffers.

static void update_framebuffer	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb
	)			[static]

Update a gl_framebuffer's derived state.

Specifically, update these framebuffer fields: _ColorDrawBuffers _NumColorDrawBuffers _ColorReadBuffer _DepthBuffer _StencilBuffer

If the framebuffer is user-created, make sure it's complete.

The following functions (at least) can effect framebuffer state: glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT, glRenderbufferStorageEXT.

static void update_framebuffer_size	(	GLcontext *	ctx,
		struct gl_framebuffer *	fb
	)			[static]

Examine all the framebuffer's renderbuffers to update the Width/Height fields of the framebuffer.

If we have renderbuffers with different sizes, set the framebuffer's width and height to the min size. Note: this is only intended for user-created framebuffers, not window-system framebuffes.

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