Updates to ANGLE_depth_texture
Trac #20959
- fix a number of incorrect error values
- disallow multi-level depth textures
git-svn-id: https://angleproject.googlecode.com/svn/trunk@1132 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/extensions/ANGLE_depth_texture.txt b/extensions/ANGLE_depth_texture.txt
index 48ba830..1ffc0a8 100644
--- a/extensions/ANGLE_depth_texture.txt
+++ b/extensions/ANGLE_depth_texture.txt
@@ -11,6 +11,7 @@
Nicolas Capens, TransGaming
Kenneth Russell, Google
Vangelis Kokkevis, Google
+ Gregg Tavares, Google
Contributors to OES_depth_texture
Contributors to OES_packed_depth_stencil
@@ -24,8 +25,8 @@
Version
- Last Modifed Date: May 30, 2012
- Revision: #2
+ Last Modifed Date: June 4, 2012
+ Revision: #3
Number
@@ -50,7 +51,8 @@
provide the ability to load existing data via TexImage2D or
TexSubImage2D. This extension also allows implementation
variability in which components from a sampled depth texture
- contain the depth data.
+ contain the depth data. Depth textures created with this
+ extension only support 1 level.
New Procedures and Functions
@@ -162,6 +164,10 @@
only if <target> is TEXTURE_2D. Using these formats in conjunction with
any other <target> will result in an INVALID_OPERATION error.
+ Textures with a base internal format of DEPTH_COMPONENT or
+ DEPTH_STENCIL_OES only support one level of image data. Specifying a
+ non-zero value for <level> will result in an INVALID_OPERATION error.
+
Textures with a base internal format of DEPTH_COMPONENT or DEPTH_STENCIL_OES
require either depth component data or depth/stencil component data.
Textures with other base internal formats require RGBA component data. The
@@ -289,49 +295,55 @@
DEPTH_COMPONENT32_OES DEPTH_COMPONENT UNSIGNED_INT
DEPTH24_STENCIL8_OES DEPTH_STENCIL_OES UNSIGNED_INT
+ Textures with the above <internalformats> only support one level of
+ image data. Specifying a value other than one for the <levels> parameter
+ to TexStorage2DEXT will result in an INVALID_OPERATION error.
+
If EXT_texture_storage is not supported, ignore any references
to TexStorage2DEXT.
Errors
- The error INVALID_ENUM is generated by TexImage2D if <format> and
+ The error INVALID_OPERATION is generated by TexImage2D if <format> and
<internalformat> are DEPTH_COMPONENT and <type> is not UNSIGNED_SHORT,
or UNSIGNED_INT.
- The error INVALID_ENUM is generated by TexSubImage2D if <format> is
+ The error INVALID_OPERATION is generated by TexSubImage2D if <format> is
DEPTH_COMPONENT and <type> is not UNSIGNED_SHORT, or UNSIGNED_INT.
- The error INVALID_ENUM is generated by TexImage2D if <format> and
+ The error INVALID_OPERATION is generated by TexImage2D if <format> and
<internalformat> are not DEPTH_COMPONENT and <type> is UNSIGNED_SHORT,
or UNSIGNED_INT.
- The error INVALID_ENUM is generated by TexSubImage2D if <format> is
+ The error INVALID_OPERATION is generated by TexSubImage2D if <format> is
not DEPTH_COMPONENT and <type> is UNSIGNED_SHORT, or UNSIGNED_INT.
- The error INVALID_ENUM is generated by TexImage2D if <format> and
+ The error INVALID_OPERATION is generated by TexImage2D if <format> and
<internalformat> are DEPTH_STENCIL_OES and <type> is not
UNSIGNED_INT_24_8_OES.
- The error INVALID_ENUM is generated by TexSubImage2D if <format>
+ The error INVALID_OPERATION is generated by TexSubImage2D if <format>
is DEPTH_STENCIL_OES and <type> is not UNSIGNED_INT_24_8_OES.
- The error INVALID_ENUM is generated by TexImage2D if <format> and
+ The error INVALID_OPERATION is generated by TexImage2D if <format> and
<internalformat> is not DEPTH_STENCIL_OES and <type> is
UNSIGNED_INT_24_8_OES.
- The error INVALID_ENUM is generated by TexSubImage2D if <format>
+ The error INVALID_OPERATION is generated by TexSubImage2D if <format>
is not DEPTH_STENCIL_OES and <type> is UNSIGNED_INT_24_8_OES.
The error INVALID_OPERATION is generated in the following situations:
- TexImage2D is called with <format> and <internalformat> of
DEPTH_COMPONENT or DEPTH_STENCIL_OES and
- - <target> is not TEXTURE_2D, or
- - <data> is not NULL
+ - <target> is not TEXTURE_2D,
+ - <data> is not NULL, or
+ - <level> is not zero.
- TexSubImage2D is called with <format> of DEPTH_COMPONENT or
DEPTH_STENCIL_OES.
- TexStorage2DEXT is called with <internalformat> of DEPTH_COMPONENT16,
- DEPTH_COMPONENT32_OES, DEPTH24_STENCIL8_OES, and
- - <target> is not TEXTURE_2D
+ DEPTH_COMPONENT32_OES, or DEPTH24_STENCIL8_OES, and
+ - <target> is not TEXTURE_2D, or
+ - <levels> is not one.
- CopyTexImage2D is called with an <internalformat> that has a base
internal format of DEPTH_COMPONENT or DEPTH_STENCIL_OES.
- CopyTexSubImage2D is called with a target texture that has a base
@@ -348,27 +360,39 @@
1) What are the differences between this extension and OES_depth_texture
and OES_packed_depth_stencil?
- RESOLVED: This extension does not support loading pre-baked depth
- or stencil data via TexImage2D or TexSubImage2D. This extension
- also allows variability in w-component of the sample results from
- depth textures. This version also explicitly lists the errors for
- unsupported functionality. Since this was not clearly specified in
- the OES_depth_texture extension there may be differences in error
- values between implementations of OES_depth_texture and
- ANGLE_depth_texture. This specification was also rebased to apply
- against the OpenGL ES 2.0 specification instead of the OpenGL
- specification, making it more obvious what all the functionality
- changes are.
+ RESOLVED: This extension:
+ - does not support loading pre-baked depth stencil data via
+ TexImage2D or TexSubImage2D.
+ - allows variability in w-component of the sample results from
+ depth textures.
+ - only supports one level textures.
+ - explicitly lists the errors for unsupported functionality.
+ Since these were not clearly specified in the OES_depth_texture
+ extension there may be differences in error values between
+ implementations of OES_depth_texture and ANGLE_depth_texture.
+ This specification was also rebased to apply against the OpenGL ES 2.0
+ specification instead of the OpenGL specification, making it more
+ obvious what all the functionality changes are.
2) Why does TexSubImage2D accept the new format/type combinations even
though it does not actually support loading data?
- RESOLVE: This was done to be more consistent with the OES_depth_texture
+ RESOLVED: This was done to be more consistent with the OES_depth_texture
extension and to make it easier to add support for loading texture
data if it is possible to support in the future.
+ 3) Why are only 1-level depth textures supported?
+
+ RESOLVED: The only use for multiple levels of depth textures would
+ be for fitlered texturing. However since it is not possible to
+ render to non-zero-level texture levels in OpenGL ES 2.0, and since
+ this extension forbids loading existing data and GenerateMipmap on
+ depth textures, it is impossible to initialize or specify contents
+ for non-zero levels of depth textures.
+
Revision History
+ 06/04/2012 dgkoch fix errors, disallow multi-level depth textures.
05/30/2012 dgkoch minor updates and add issues.
05/23/2012 dgkoch intial revision based on OES_depth_texture and
OES_packed_depth_stencil and rebased against the ES 2.0 spec
