Add EXT_EGL_image_storage extension.
This extension allows the creation of immutable texture EGLImage targets.
These have much simpler semantics than regular texture EGLImage targets
defined by OES_EGL_image and do not exhibit potentially surprising and
undesirable orphaning behavior.
diff --git a/extensions/EXT/EXT_EGL_image_storage.txt b/extensions/EXT/EXT_EGL_image_storage.txt
new file mode 100644
index 0000000..d8614ab
--- /dev/null
+++ b/extensions/EXT/EXT_EGL_image_storage.txt
@@ -0,0 +1,221 @@
+Name
+
+ EXT_EGL_image_storage
+
+Name Strings
+
+ GL_EXT_EGL_image_storage
+
+Contact
+
+ Krzysztof Kosinski (krzysio 'at' google.com)
+
+Contributors
+
+ Krzysztof Kosinski, Google
+ Craig Donner, Google
+ Jesse Hall, Google
+ Jan-Harald Fredriksen, ARM
+ Daniel Koch, Nvidia
+
+Status
+
+ Complete
+
+Version
+
+ February 7, 2018 (version 7)
+
+Number
+
+ #522
+ OpenGL ES Extension #301
+
+Dependencies
+
+ Requires OpenGL 4.2, OpenGL ES 3.0, or ARB_texture_storage.
+
+ Requires EGL 1.4 and either the EGL_KHR_image or EGL_KHR_image_base
+ extensions.
+
+ The EGL_KHR_gl_texture_2D_image, EGL_KHR_gl_texture_cubemap_image,
+ EGL_KHR_gl_texture_3D_image, EGL_KHR_gl_renderbuffer_image,
+ EGL_KHR_vg_parent_image, and EGL_ANDROID_get_native_client_buffer
+ extensions provide additional functionality layered on EGL_KHR_image_base
+ and related to this extension.
+
+ EXT_direct_state_access, ARB_direct_state_access, and OpenGL 4.5 affect
+ the definition of this extension.
+
+ This extension interacts with GL_OES_EGL_image, GL_OES_EGL_image_external,
+ GL_OES_EGL_image_external_essl3, and GL_EXT_EGL_image_array.
+
+ This extension is written based on the wording of the OpenGL ES 3.2
+ Specification.
+
+Overview
+
+ The OpenGL ES extension OES_EGL_image provides a mechanism for creating
+ GL textures sharing storage with EGLImage objects (in other words, creating
+ GL texture EGLImage targets). The extension was written against the
+ OpenGL ES 2.0 specification, which does not have the concept of immutable
+ textures. As a result, it specifies that respecification of a texture by
+ calling TexImage* on a texture that is an EGLImage target causes it to be
+ implicitly orphaned. In most cases, this is not the desired behavior, but
+ rather a result of an application error.
+
+ This extension provides a mechanism for creating texture objects that are
+ both EGLImage targets and immutable. Since immutable textures cannot be
+ respecified, they also cannot accidentally be orphaned, and attempts to do
+ so generate errors instead of resulting in well-defined, but often
+ undesirable and surprising behavior. It provides a strong guarantee that
+ texture data that is intended to be shared will remain shared.
+
+ EGL extension specifications are located in the EGL Registry at
+
+ http://www.khronos.org/registry/egl/
+
+Glossary
+
+ Please see the EGL_KHR_image specification for a list of terms
+ used by this specification.
+
+New Types
+
+ /*
+ * GLeglImageOES is an opaque handle to an EGLImage
+ * Note: GLeglImageOES is also defined in GL_OES_EGL_image
+ */
+ typedef void* GLeglImageOES;
+
+New Procedures and Functions
+
+ void EGLImageTargetTexStorageEXT(enum target, eglImageOES image,
+ const int* attrib_list)
+
+ <If EXT_direct_state_access or an equivalent mechanism is supported:>
+
+ void EGLImageTargetTextureStorageEXT(uint texture, eglImageOES image,
+ const int* attrib_list)
+
+New Tokens
+
+ None.
+
+Additions to Chapter 8 of the OpenGL ES 3.2 Specification (Textures and
+Samplers)
+
+ - (8.18, p. 210) Insert the following text before the paragraph starting
+ with "After a successful call to any TexStorage* command":
+
+ The command
+
+ void EGLImageTargetTexStorageEXT(enum target, eglImageOES image,
+ const int* attrib_list);
+
+ specifies all levels and properties of a texture (including dimensionality,
+ width, height, format, mipmap levels of detail, and image data) by taking
+ them from the specified eglImageOES <image>. Images specified this way
+ will be EGLImage siblings with the original EGLImage source and any other
+ EGLImage targets.
+
+ <target> must be one of GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY, GL_TEXTURE_3D,
+ GL_TEXTURE_CUBE_MAP, GL_TEXTURE_CUBE_MAP_ARRAY. On OpenGL implementations
+ (non-ES), <target> can also be GL_TEXTURE_1D or GL_TEXTURE_1D_ARRAY.
+ If the implementation supports OES_EGL_image_external, <target> can be
+ GL_TEXTURE_EXTERNAL_OES. <target> must match the type of image data stored
+ in <image>. For instance, if the <image> was created from a GL texture,
+ <target> must match the texture target of the source texture. <image> must
+ be the handle of a valid EGLImage resource, cast into the type eglImageOES.
+ Assuming no errors are generated in EGLImageTargetTexStorageEXT, the newly
+ specified texture object will be an EGLImage target of the specified
+ eglImageOES. <attrib_list> must be NULL or a pointer to the value GL_NONE.
+
+ If <image> is NULL, the error INVALID_VALUE is generated. If <image> is
+ neither NULL nor a valid value, the behavior is undefined, up to and
+ including program termination.
+
+ If the GL is unable to specify a texture object using the supplied
+ eglImageOES <image> (if, for example, <image> refers to a multisampled
+ eglImageOES, or <target> is GL_TEXTURE_2D but <image> contains a cube map),
+ the error INVALID_OPERATION is generated.
+
+ If <attrib_list> is neither NULL nor a pointer to the value GL_NONE, the
+ error INVALID_VALUE is generated.
+
+ <If EXT_direct_state_access or an equivalent mechanism is supported:>
+
+ The command
+
+ void EGLImageTargetTextureStorageEXT(uint texture, eglImageOES image,
+ const int* attrib_list);
+
+ is equivalent to EGLImageTargetTexStorageEXT, but the target texture object
+ is directly specified using the <texture> parameter instead of being taken
+ from the active texture unit.
+
+ - (8.18, p. 210) Replace "After a successful call to any TexStorage*
+ command" with "After a successful call to any TexStorage* or
+ EGLImageTarget*StorageEXT command"
+
+ - (8.18, p. 210) Add the following to the list following the sentence
+ "Using any of the following commands with the same texture will result in
+ an INVALID_OPERATION error being generated, even if it does not affect the
+ dimensions or format:"
+
+ EGLImageTarget*StorageEXT
+
+Issues
+
+ 1. Should this extension provide support for renderbuffers?
+
+ RESOLVED: This seems of limited use, and renderbuffer support specified
+ by OES_EGL_image already uses the immutable storage model, so that would
+ be redundant.
+
+ 2. Should OES_EGL_image be a prerequisite?
+
+ RESOLVED: Supporting both OES_EGL_image and this extension requires
+ more complexity than supporting only this extension and we did not want
+ to rule out such implementations. Therefore, this extension does not
+ require OES_EGL_image.
+
+ 3. Should multisampled texture targets be supported?
+
+ RESOLVED: We are not aware of any EGLImage implementations that support
+ multisampling, so this is omitted.
+
+ 4. What is the interaction with GenerateMipmap?
+
+ RESOLVED: Since immutable textures do not allow respecification,
+ calling GenerateMipmap on a texture created with
+ EGLImageTarget*StorageEXT never causes orphaning.
+
+ 5. What is the purpose of the attrib_list parameter?
+
+ RESOLVED: It allows layered extensions to pass additional data. It is
+ intended to be used similarly to the attrib_list parameter on the
+ EGL functions eglCreateContext and eglCreateImageKHR. Since the new
+ entry points define immutable textures, setting additional values
+ through texture parameters would require more complex validation.
+
+Revision History
+
+ #7 (February 7, 2018) - Amend the explanation of the attrib_list parameter.
+
+ #6 (February 2, 2018) - Add attrib_list parameter to both entry points.
+
+ #5 (January 10, 2018) - Minor wording changes and clean-ups. Moved the
+ discussion of interaction with GenerateMipmap to an issue.
+
+ #4 (December 6, 2017) - Rewritten against the OpenGL ES 3.2 specification.
+ Renamed from KHR to EXT.
+
+ #3 (November 20, 2017) - Added direct state access entry point and corrected
+ references to the OpenGL ES 3.0 specification.
+
+ #2 (November 13, 2017) - Specified the allowed texture targets. Clarified
+ requirements. Clarified interactions with mipmaps.
+
+ #1 (November 1, 2017) - Initial version.
+
diff --git a/extensions/registry.py b/extensions/registry.py
index b8c0630..91eeaf0 100644
--- a/extensions/registry.py
+++ b/extensions/registry.py
@@ -1773,6 +1773,12 @@
'flags' : { 'public' },
'url' : 'extensions/EXT/EXT_EGL_image_external_wrap_modes.txt',
},
+ 'GL_EXT_EGL_image_storage' : {
+ 'number' : 522,
+ 'esnumber' : 301,
+ 'flags' : { 'public' },
+ 'url' : 'extensions/EXT/EXT_EGL_image_storage.txt',
+ },
'GL_EXT_memory_object' : {
'number' : 503,
'esnumber' : 280,
diff --git a/xml/gl.xml b/xml/gl.xml
index 6aa6482..87312fb 100644
--- a/xml/gl.xml
+++ b/xml/gl.xml
@@ -14489,11 +14489,23 @@
<param><ptype>GLeglImageOES</ptype> <name>image</name></param>
</command>
<command>
+ <proto>void <name>glEGLImageTargetTexStorageEXT</name></proto>
+ <param><ptype>GLenum</ptype> <name>target</name></param>
+ <param><ptype>GLeglImageOES</ptype> <name>image</name></param>
+ <param>const <ptype>GLint</ptype>* <name>attrib_list</name></param>
+ </command>
+ <command>
<proto>void <name>glEGLImageTargetTexture2DOES</name></proto>
<param><ptype>GLenum</ptype> <name>target</name></param>
<param><ptype>GLeglImageOES</ptype> <name>image</name></param>
</command>
<command>
+ <proto>void <name>glEGLImageTargetTextureStorageEXT</name></proto>
+ <param><ptype>GLuint</ptype> <name>texture</name></param>
+ <param><ptype>GLeglImageOES</ptype> <name>image</name></param>
+ <param>const <ptype>GLint</ptype>* <name>attrib_list</name></param>
+ </command>
+ <command>
<proto>void <name>glEdgeFlag</name></proto>
<param group="Boolean"><ptype>GLboolean</ptype> <name>flag</name></param>
<vecequiv name="glEdgeFlagv"/>
@@ -42547,6 +42559,15 @@
</extension>
<extension name="GL_EXT_EGL_image_array" supported="gles2">
</extension>
+ <extension name="GL_EXT_EGL_image_storage" supported="gl|glcore|gles2">
+ <require>
+ <type name="GLeglImageOES"/>
+ <command name="glEGLImageTargetTexStorageEXT"/>
+ </require>
+ <require comment="Supported only if GL_EXT_direct_state_access, ARB_direct_state_access, or OpenGL 4.5 are supported">
+ <command name="glEGLImageTargetTextureStorageEXT"/>
+ </require>
+ </extension>
<extension name="GL_EXT_YUV_target" supported="gles2">
<require>
<enum name="GL_SAMPLER_EXTERNAL_2D_Y2Y_EXT"/>
