extensions/IMG/IMG_multisampled_render_to_texture.txt - external/github.com/KhronosGroup/OpenGL-Registry - Git at Google

 Name

     IMG_multisampled_render_to_texture

 Name Strings

     GL_IMG_multisampled_render_to_texture

 Contact

     Georg Kolling, Imagination Technologies (georg.kolling 'at' imgtec.com)

 Status

     Complete

 Version

     Last Modified Date: March 26, 2010
     Revision: 3

 Number

     OpenGL ES Extension #74

 Dependencies

     OpenGL ES 2.0 or OES_framebuffer_object are required. This
     extension is written against the OpenGL ES 2.0 Specification.

 Overview

     This extension introduces functionality to perform multisampled
 	rendering to a color renderable texture, without requiring an
 	explicit resolve of multisample data.

 	Some GPU architectures - such as tile-based renderers - are
 	capable of performing multisampled rendering by storing
 	multisample data in internal high-speed memory and downsampling the
 	data when writing out to external memory after rendering has
 	finished. Since per-sample data is never written out to external
 	memory, this approach saves bandwidth and storage space. In this
 	case multisample data gets discarded, however this is acceptable
 	in most cases.

 	The extension provides a new command, FramebufferTexture2DMultisampleIMG,
 	which attaches a texture level to a framebuffer and enables
 	multisampled rendering to that texture level.

 	When the texture level is used as a source or destination for any
 	operation other than drawing to it, an implicit resolve of
 	multisampled color data is performed. After such a resolve, the
 	multisampled color data is discarded.

 	In order to allow the use of multisampled depth and stencil buffers
 	when performing	multisampled rendering to a texture, the extension
 	also adds the command RenderbufferStorageMultisampleIMG.

 IP Status

     No known IP claims.

 New Procedures and Functions

     void RenderbufferStorageMultisampleIMG(
             enum target, sizei samples,
             enum internalformat,
             sizei width, sizei height);

     void FramebufferTexture2DMultisampleIMG(
             enum target, enum attachment,
             enum textarget, uint texture,
             int level, sizei samples);

 New Tokens

     Accepted by the <pname> parameter of GetRenderbufferParameteriv:

         RENDERBUFFER_SAMPLES_IMG                0x9133

     Returned by CheckFramebufferStatus:

         FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_IMG  0x9134

     Accepted by the <pname> parameter of GetBooleanv, GetIntegerv,
     GetFloatv, and GetDoublev:

         MAX_SAMPLES_IMG                         0x9135

     Accepted by the <pname> parameter of GetFramebufferAttachmentParameteriv:

         TEXTURE_SAMPLES_IMG                     0x9136


 Additions to Section 4.4.3 of the OpenGL ES 2.0 Specification
 (Renderbuffer Objects)

 	Replace the paragraph describing the command RenderbufferStorage
 	with the following:

 		The command
 			void RenderbufferStorageMultisampleIMG( enum target,
 			sizei samples, enum internalformat, sizei width,
 			sizei height );
 		establishes the data storage, format, dimensions, and number of
 		samples of a renderbuffer object's image. target must be RENDERBUFFER.
 		internalformat must be one of the color-renderable, depth-renderable,
 		or stencil-renderable formats described in table 4.5. width and height
 		are the dimensions in pixels of the renderbuffer. If either width or
 		height is greater than the value of MAX_RENDERBUFFER_SIZE, or if
 		samples is greater than the value of MAX_SAMPLES_IMG, then the error
 		INVALID_VALUE is generated. If OpenGL ES is unable to create a data
 		store of the requested size, the error OUT_OF_MEMORY is generated.
 		Upon success, RenderbufferStorageMultisampleIMG deletes any existing
 		data store for the renderbuffer image and the contents of the data
 		store after calling RenderbufferStorageMultisampleIMG are undefined.
 		RENDERBUFFER_WIDTH is set to width, RENDERBUFFER_HEIGHT is set to
 		height, and RENDERBUFFER_INTERNAL_FORMAT is set to internalformat.
 		If samples is zero, then RENDERBUFFER_SAMPLES_IMG is set to zero.
 		Otherwise samples represents a request for a desired minimum number
 		of samples. Since different implementations may support different
 		sample counts for multisampled rendering, the actual number of samples
 		allocated for the renderbuffer image is implementation-dependent.
 		However, the resulting value for RENDERBUFFER_SAMPLES_IMG is
 		guaranteed to be greater than or equal to samples and no more than the
 		next larger sample count supported by the implementation.

 		An OpenGL ES implementation may vary its allocation of internal
 		component resolution based on any RenderbufferStorageMultisampleIMG
 		parameter (except target), but the allocation and chosen internal format
 		must not be a function of any other state and cannot be changed once
 		they are established.

 		The command
 			void RenderbufferStorage( enum target, enum internalformat,
 			sizei width, sizei height );
 		is equivalent to calling RenderbufferStorageMultisampleIMG with
 		samples equal to zero.

 	Add the following after the paragraph describing FramebufferTexture2D:

 		The command
 		    void FramebufferTexture2DMultisampleIMG( enum target,
 			enum attachment, enum textarget, uint texture,
 			int level, sizei samples );
 		enables multisampled rendering into the images of a texture object.

 		target, textarget, texture, and level correspond to the same
 		parameters for FramebufferTexture2D and have the same restrictions.
 		attachment must be COLOR_ATTACHMENT0. If samples is greater than the
 		value of MAX_SAMPLES_IMG, then the error INVALID_VALUE is generated.
 		If samples is zero, then TEXTURE_SAMPLES_IMG is set to zero, and
 		FramebufferTexture2DMultisampleIMG behaves like FramebufferTexture2D.

 		Otherwise samples represents a request for a desired minimum number
 		of samples. Since different implementations may support different
 		sample counts for multisampled rendering, the actual number of samples
 		allocated for the image is implementation-dependent. However, the
 		resulting value for TEXTURE_SAMPLES_IMG is guaranteed to be greater
 		than or equal to samples and no more than the next larger sample count
 		supported by the implementation.

 		The implementation allocates an implicit multisample buffer with
 		TEXTURE_SAMPLES_IMG samples and the	same internalformat, width, and
 		height as the specified texture level. This buffer is used as the
 		target for rendering instead of the specified texture level. The
 		buffer is associated with the attachment and gets deleted
 		after the attachment is broken.

 		When the texture level is used as a source or destination for any
 		operation, or when the attachment is broken, an implicit resolve
 		of multisample data from the multisample buffer to the texture level
 		is performed. After such a resolve, the contents of the multisample
 		buffer become undefined.

 		The operations which cause a resolve include:
 			- Drawing with the texture bound to an active texture unit
 			- ReadPixels or CopyTex[Sub]Image* while the texture is
 			  attached to the framebuffer
 			- CopyTex[Sub]Image*, Tex[Sub]Image*,
 			  CompressedTex[Sub]Image* with the specified level as
 			  destination
 			- GenerateMipmap

 Additions to section 4.4.5 of the OpenGL ES 2.0 Specification
 (Framebuffer Completeness)

 	Add the following bullet point after
 		* All attached images have the same width and height.
 		  FRAMEBUFFER_INCOMPLETE_DIMENSIONS
 	on page 116:

 		* The value of RENDERBUFFER_SAMPLES_IMG is the same for all
 		  attached renderbuffers; the value of TEXTURE_SAMPLES_IMG
 		  is the same for all texture attachments; and, if the attached
 		  images are a mix of renderbuffers and textures, the value of
 		  RENDERBUFFER_SAMPLES_IMG matches the value of TEXTURE_-
 		  SAMPLES_IMG.
           FRAMEBUFFER_INCOMPLETE_MULTISAMPLE

 Dependencies on GL and ES profiles, versions, and other extensions

 	None

 Errors

     The error OUT_OF_MEMORY is generated when
     RenderbufferStorageMultisampleIMG cannot create storage of the
     specified size.

     If RenderbufferStorageMultisampleEXT is called with a value of
     <samples> that is greater than MAX_SAMPLES_IMG, then the error
     INVALID_VALUE is generated.

     The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
     is called with a <target> that is not FRAMEBUFFER.

     The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
     is called with an <attachment> that is not COLOR_ATTACHMENT0.

     The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
     is called with a <textarget> that is not TEXTURE_2D,
 	TEXTURE_CUBE_MAP_POSITIVE_X, TEXTURE_CUBE_MAP_POSITIVE_Y,
 	TEXTURE_CUBE_MAP_POSITIVE_Z, TEXTURE_CUBE_MAP_NEGATIVE_X,
 	TEXTURE_CUBE_MAP_NEGATIVE_Y, or TEXTURE_CUBE_MAP_NEGATIVE_Z.

 New State

 	Changes to table 6.22, p. 154 (Renderbuffer State)

                                                      Initial
     Get Value                 Type  Get Command      Value   Description  Sec.
     ---------                 ----  ---------------- ------- ------------ -----
     RENDERBUFFER_SAMPLES_IMG  Z+    GetRenderbuffer- 0       Renderbuffer 4.4.3
                                     Parameteriv              samples

 	Changes to table 6.23, p. 155 (Framebuffer State)

                                                        Initial
     Get Value            Type    Get Command           Value   Description     Sec.
     ---------            ------  --------------------- ------- --------------- ----
     TEXTURE_SAMPLES_IMG  n * Z+  GetFramebuffer-       0       Framebuffer     4.4
                                  AttachmentParameteriv         texture samples

 New Implementation Dependent State

     Changes to table 6.17, p. 149 (Implementation Dependent Values)

                                           Minimum
     Get Value         Type    Get Command Value   Description Sec.
     ---------         ----    ----------- ------- ----------- ----
     MAX_SAMPLES_IMG   Z+      GetIntegerv 2       Max. # of   4.4
                                                   samples.

 Sample Code

 	GLsizei width  = ...;
 	GLsizei height = ...;
 	GLint samples;
 	glGetIntegerv(GL_MAX_SAMPLES_IMG, &samples);

 	/* Create multisampled depth renderbuffer */
 	GLuint depthbuffer;
 	glGenRenderbuffers(1, &depthbuffer);
 	glBindRenderbuffer(GL_RENDERBUFFER, depthbuffer);
 	glRenderbufferStorageMultisampleIMG(GL_RENDERBUFFER, samples,
 		GL_DEPTH_COMPONENT16, width, height);
 	glBindRenderbuffer(GL_RENDERBUFFER, 0);

 	/* Create RGBA texture with single mipmap level */
 	GLuint texture;
 	glGenTextures(1, &texture);
 	glBindTexture(GL_TEXTURE_2D, texture);
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,
 		GL_UNSIGNED_SHORT_4_4_4_4, NULL);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 	glBindTexture(GL_TEXTURE_2D, 0);

 	/* Create framebuffer object, attach texture and depth renderbuffer */
 	GLuint framebuffer;
 	glGenFramebuffers(1, &framebuffer);
 	glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
 	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
 		GL_RENDERBUFFER, depthbuffer);
 	glFramebufferTexture2DMultisampleIMG(GL_FRAMEBUFFER,
 		GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0, samples);

 	/* handle unsupported cases */
 	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
 			GL_FRAMEBUFFER_COMPLETE)
 	{
 		...
 	}

 	/* draw to the texture */
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 	...

 	/* Discard the depth renderbuffer contents if possible */
 	if (extension_supported("GL_EXT_discard_framebuffer"))
 	{
 		GLenum discard_attachments[] = { GL_DEPTH_EXT };
 		glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1,
 			discard_attachments);
 	}

 	/* Draw to the default framebuffer using the antialiased texture */
 	/* Color data is implicitly resolved before the texture gets used */
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT |
 		GL_STENCIL_BUFFER_BIT);
 	glBindTexture(GL_TEXTURE_2D, texture);
 	...

 Conformance Tests

     No conformance test has been defined yet

 Issues


 Revision History

     Revision 3, 2010/03/26
       - Set enums to undefined

     Revision 2, 2010/03/24
       - Removed error condition for glReadPixels and glCopyTexImage2D

     Revision 1, 2010/01/05
       - First draft of extension
	Name

	IMG_multisampled_render_to_texture

	Name Strings

	GL_IMG_multisampled_render_to_texture

	Contact

	Georg Kolling, Imagination Technologies (georg.kolling 'at' imgtec.com)

	Status

	Complete

	Version

	Last Modified Date: March 26, 2010
	Revision: 3

	Number

	OpenGL ES Extension #74

	Dependencies

	OpenGL ES 2.0 or OES_framebuffer_object are required. This
	extension is written against the OpenGL ES 2.0 Specification.

	Overview

	This extension introduces functionality to perform multisampled
	rendering to a color renderable texture, without requiring an
	explicit resolve of multisample data.

	Some GPU architectures - such as tile-based renderers - are
	capable of performing multisampled rendering by storing
	multisample data in internal high-speed memory and downsampling the
	data when writing out to external memory after rendering has
	finished. Since per-sample data is never written out to external
	memory, this approach saves bandwidth and storage space. In this
	case multisample data gets discarded, however this is acceptable
	in most cases.

	The extension provides a new command, FramebufferTexture2DMultisampleIMG,
	which attaches a texture level to a framebuffer and enables
	multisampled rendering to that texture level.

	When the texture level is used as a source or destination for any
	operation other than drawing to it, an implicit resolve of
	multisampled color data is performed. After such a resolve, the
	multisampled color data is discarded.

	In order to allow the use of multisampled depth and stencil buffers
	when performing multisampled rendering to a texture, the extension
	also adds the command RenderbufferStorageMultisampleIMG.

	IP Status

	No known IP claims.

	New Procedures and Functions

	void RenderbufferStorageMultisampleIMG(
	enum target, sizei samples,
	enum internalformat,
	sizei width, sizei height);

	void FramebufferTexture2DMultisampleIMG(
	enum target, enum attachment,
	enum textarget, uint texture,
	int level, sizei samples);

	New Tokens

	Accepted by the <pname> parameter of GetRenderbufferParameteriv:

	RENDERBUFFER_SAMPLES_IMG 0x9133

	Returned by CheckFramebufferStatus:

	FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_IMG 0x9134

	Accepted by the <pname> parameter of GetBooleanv, GetIntegerv,
	GetFloatv, and GetDoublev:

	MAX_SAMPLES_IMG 0x9135

	Accepted by the <pname> parameter of GetFramebufferAttachmentParameteriv:

	TEXTURE_SAMPLES_IMG 0x9136


	Additions to Section 4.4.3 of the OpenGL ES 2.0 Specification
	(Renderbuffer Objects)

	Replace the paragraph describing the command RenderbufferStorage
	with the following:

	The command
	void RenderbufferStorageMultisampleIMG( enum target,
	sizei samples, enum internalformat, sizei width,
	sizei height );
	establishes the data storage, format, dimensions, and number of
	samples of a renderbuffer object's image. target must be RENDERBUFFER.
	internalformat must be one of the color-renderable, depth-renderable,
	or stencil-renderable formats described in table 4.5. width and height
	are the dimensions in pixels of the renderbuffer. If either width or
	height is greater than the value of MAX_RENDERBUFFER_SIZE, or if
	samples is greater than the value of MAX_SAMPLES_IMG, then the error
	INVALID_VALUE is generated. If OpenGL ES is unable to create a data
	store of the requested size, the error OUT_OF_MEMORY is generated.
	Upon success, RenderbufferStorageMultisampleIMG deletes any existing
	data store for the renderbuffer image and the contents of the data
	store after calling RenderbufferStorageMultisampleIMG are undefined.
	RENDERBUFFER_WIDTH is set to width, RENDERBUFFER_HEIGHT is set to
	height, and RENDERBUFFER_INTERNAL_FORMAT is set to internalformat.
	If samples is zero, then RENDERBUFFER_SAMPLES_IMG is set to zero.
	Otherwise samples represents a request for a desired minimum number
	of samples. Since different implementations may support different
	sample counts for multisampled rendering, the actual number of samples
	allocated for the renderbuffer image is implementation-dependent.
	However, the resulting value for RENDERBUFFER_SAMPLES_IMG is
	guaranteed to be greater than or equal to samples and no more than the
	next larger sample count supported by the implementation.

	An OpenGL ES implementation may vary its allocation of internal
	component resolution based on any RenderbufferStorageMultisampleIMG
	parameter (except target), but the allocation and chosen internal format
	must not be a function of any other state and cannot be changed once
	they are established.

	The command
	void RenderbufferStorage( enum target, enum internalformat,
	sizei width, sizei height );
	is equivalent to calling RenderbufferStorageMultisampleIMG with
	samples equal to zero.

	Add the following after the paragraph describing FramebufferTexture2D:

	The command
	void FramebufferTexture2DMultisampleIMG( enum target,
	enum attachment, enum textarget, uint texture,
	int level, sizei samples );
	enables multisampled rendering into the images of a texture object.

	target, textarget, texture, and level correspond to the same
	parameters for FramebufferTexture2D and have the same restrictions.
	attachment must be COLOR_ATTACHMENT0. If samples is greater than the
	value of MAX_SAMPLES_IMG, then the error INVALID_VALUE is generated.
	If samples is zero, then TEXTURE_SAMPLES_IMG is set to zero, and
	FramebufferTexture2DMultisampleIMG behaves like FramebufferTexture2D.

	Otherwise samples represents a request for a desired minimum number
	of samples. Since different implementations may support different
	sample counts for multisampled rendering, the actual number of samples
	allocated for the image is implementation-dependent. However, the
	resulting value for TEXTURE_SAMPLES_IMG is guaranteed to be greater
	than or equal to samples and no more than the next larger sample count
	supported by the implementation.

	The implementation allocates an implicit multisample buffer with
	TEXTURE_SAMPLES_IMG samples and the same internalformat, width, and
	height as the specified texture level. This buffer is used as the
	target for rendering instead of the specified texture level. The
	buffer is associated with the attachment and gets deleted
	after the attachment is broken.

	When the texture level is used as a source or destination for any
	operation, or when the attachment is broken, an implicit resolve
	of multisample data from the multisample buffer to the texture level
	is performed. After such a resolve, the contents of the multisample
	buffer become undefined.

	The operations which cause a resolve include:
	- Drawing with the texture bound to an active texture unit
	- ReadPixels or CopyTex[Sub]Image* while the texture is
	attached to the framebuffer
	- CopyTex[Sub]Image, Tex[Sub]Image,
	CompressedTex[Sub]Image* with the specified level as
	destination
	- GenerateMipmap

	Additions to section 4.4.5 of the OpenGL ES 2.0 Specification
	(Framebuffer Completeness)

	Add the following bullet point after
	* All attached images have the same width and height.
	FRAMEBUFFER_INCOMPLETE_DIMENSIONS
	on page 116:

	* The value of RENDERBUFFER_SAMPLES_IMG is the same for all
	attached renderbuffers; the value of TEXTURE_SAMPLES_IMG
	is the same for all texture attachments; and, if the attached
	images are a mix of renderbuffers and textures, the value of
	RENDERBUFFER_SAMPLES_IMG matches the value of TEXTURE_-
	SAMPLES_IMG.
	FRAMEBUFFER_INCOMPLETE_MULTISAMPLE

	Dependencies on GL and ES profiles, versions, and other extensions

	None

	Errors

	The error OUT_OF_MEMORY is generated when
	RenderbufferStorageMultisampleIMG cannot create storage of the
	specified size.

	If RenderbufferStorageMultisampleEXT is called with a value of
	<samples> that is greater than MAX_SAMPLES_IMG, then the error
	INVALID_VALUE is generated.

	The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
	is called with a <target> that is not FRAMEBUFFER.

	The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
	is called with an <attachment> that is not COLOR_ATTACHMENT0.

	The error INVALID_ENUM is generated if FramebufferTexture2DMultisampleIMG
	is called with a <textarget> that is not TEXTURE_2D,
	TEXTURE_CUBE_MAP_POSITIVE_X, TEXTURE_CUBE_MAP_POSITIVE_Y,
	TEXTURE_CUBE_MAP_POSITIVE_Z, TEXTURE_CUBE_MAP_NEGATIVE_X,
	TEXTURE_CUBE_MAP_NEGATIVE_Y, or TEXTURE_CUBE_MAP_NEGATIVE_Z.

	New State

	Changes to table 6.22, p. 154 (Renderbuffer State)

	Initial
	Get Value Type Get Command Value Description Sec.
	--------- ---- ---------------- ------- ------------ -----
	RENDERBUFFER_SAMPLES_IMG Z+ GetRenderbuffer- 0 Renderbuffer 4.4.3
	Parameteriv samples

	Changes to table 6.23, p. 155 (Framebuffer State)

	Initial
	Get Value Type Get Command Value Description Sec.
	--------- ------ --------------------- ------- --------------- ----
	TEXTURE_SAMPLES_IMG n * Z+ GetFramebuffer- 0 Framebuffer 4.4
	AttachmentParameteriv texture samples

	New Implementation Dependent State

	Changes to table 6.17, p. 149 (Implementation Dependent Values)

	Minimum
	Get Value Type Get Command Value Description Sec.
	--------- ---- ----------- ------- ----------- ----
	MAX_SAMPLES_IMG Z+ GetIntegerv 2 Max. # of 4.4
	samples.

	Sample Code

	GLsizei width = ...;
	GLsizei height = ...;
	GLint samples;
	glGetIntegerv(GL_MAX_SAMPLES_IMG, &samples);

	/* Create multisampled depth renderbuffer */
	GLuint depthbuffer;
	glGenRenderbuffers(1, &depthbuffer);
	glBindRenderbuffer(GL_RENDERBUFFER, depthbuffer);
	glRenderbufferStorageMultisampleIMG(GL_RENDERBUFFER, samples,
	GL_DEPTH_COMPONENT16, width, height);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	/* Create RGBA texture with single mipmap level */
	GLuint texture;
	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D, texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,
	GL_UNSIGNED_SHORT_4_4_4_4, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glBindTexture(GL_TEXTURE_2D, 0);

	/* Create framebuffer object, attach texture and depth renderbuffer */
	GLuint framebuffer;
	glGenFramebuffers(1, &framebuffer);
	glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
	GL_RENDERBUFFER, depthbuffer);
	glFramebufferTexture2DMultisampleIMG(GL_FRAMEBUFFER,
	GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0, samples);

	/* handle unsupported cases */
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
	GL_FRAMEBUFFER_COMPLETE)
	{
	...
	}

	/* draw to the texture */
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT);
	...

	/* Discard the depth renderbuffer contents if possible */
	if (extension_supported("GL_EXT_discard_framebuffer"))
	{
	GLenum discard_attachments[] = { GL_DEPTH_EXT };
	glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1,
	discard_attachments);
	}

	/* Draw to the default framebuffer using the antialiased texture */
	/* Color data is implicitly resolved before the texture gets used */
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT \|
	GL_STENCIL_BUFFER_BIT);
	glBindTexture(GL_TEXTURE_2D, texture);
	...

	Conformance Tests

	No conformance test has been defined yet

	Issues


	Revision History

	Revision 3, 2010/03/26
	- Set enums to undefined

	Revision 2, 2010/03/24
	- Removed error condition for glReadPixels and glCopyTexImage2D

	Revision 1, 2010/01/05
	- First draft of extension