diff -r 000000000000 -r 6474c204b198 gfx/angle/extensions/ANGLE_texture_usage.txt
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+++ b/gfx/angle/extensions/ANGLE_texture_usage.txt	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,202 @@
+Name
+
+    ANGLE_texture_usage
+
+Name Strings
+
+    GL_ANGLE_texture_usage
+
+Contributors
+
+    Nicolas Capens, TransGaming
+    Daniel Koch, TransGaming
+
+Contact
+
+    Daniel Koch, TransGaming (daniel 'at' transgaming.com)
+
+Status
+
+    Complete
+
+Version
+
+    Last Modified Date:  November 10, 2011
+    Version:             2
+
+Number
+
+    OpenGL ES Extension #112 
+
+Dependencies
+
+    This extension is written against the OpenGL ES 2.0 Specification.
+
+Overview
+
+    In some implementations it is advantageous to know the expected
+    usage of a texture before the backing storage for it is allocated.  
+    This can help to inform the implementation's choice of format
+    and type of memory used for the allocation. If the usage is not
+    known in advance, the implementation essentially has to make a 
+    guess as to how it will be used.  If it is later proven wrong,
+    it may need to perform costly re-allocations and/or reformatting 
+    of the texture data, resulting in reduced performance.
+
+    This extension adds a texture usage flag that is specified via
+    the TEXTURE_USAGE_ANGLE TexParameter.  This can be used to 
+    indicate that the application knows that this texture will be 
+    used for rendering.
+
+IP Status
+
+    No known IP claims.
+
+New Procedures and Functions
+
+    None
+
+New Tokens
+
+    Accepted as a value for <pname> for the TexParameter{if} and 
+    TexParameter{if}v commands and for the <value> parameter of
+    GetTexParameter{if}v: 
+
+        TEXTURE_USAGE_ANGLE                     0x93A2
+
+    Accepted as a value to <param> for the TexParameter{if} and 
+    to <params> for the TexParameter{if}v commands with a <pname> of 
+    TEXTURE_USAGE_ANGLE; returned as possible values for <data> when 
+    GetTexParameter{if}v is queried with a <value> of TEXTURE_USAGE_ANGLE:
+
+        NONE                                    0x0000
+        FRAMEBUFFER_ATTACHMENT_ANGLE            0x93A3
+
+Additions to Chapter 2 of the OpenGL ES 2.0 Specification (OpenGL ES Operation)
+
+    None
+
+Additions to Chapter 3 of the OpenGL ES 2.0 Specification (Rasterization)
+
+    Add a new row to Table 3.10 (Texture parameters and their values):
+
+    Name                | Type | Legal Values 
+    ------------------------------------------------------------
+    TEXTURE_USAGE_ANGLE | enum | NONE, FRAMEBUFFER_ATTACHMENT_ANGLE
+
+    Add a new section 3.7.x (Texture Usage) before section 3.7.12 and 
+    renumber the subsequent sections: 
+
+    "3.7.x Texture Usage
+
+    Texture usage can be specified via the TEXTURE_USAGE_ANGLE value
+    for the <pname> argument to TexParameter{if}[v]. In order to take effect,
+    the texture usage must be specified before the texture contents are
+    defined either via TexImage2D or TexStorage2DEXT.
+
+    The usage values can impact the layout and type of memory used for the 
+    texture data. Specifying incorrect usage values may result in reduced
+    functionality and/or significantly degraded performance.
+
+    Possible values for <params> when <pname> is TEXTURE_USAGE_ANGLE are:
+
+    NONE - the default. No particular usage has been specified and it is
+        up to the implementation to determine the usage of the texture.
+        Leaving the usage unspecified means that the implementation may 
+        have to reallocate the texture data as the texture is used in 
+        various ways.
+
+    FRAMEBUFFER_ATTACHMENT_ANGLE - this texture will be attached to a 
+        framebuffer object and used as a desination for rendering or blits."
+
+    Modify section 3.7.12 (Texture State) and place the last 3 sentences
+    with the following:
+
+    "Next, there are the three sets of texture properties; each consists of
+    the selected minification and magnification filters, the wrap modes for
+    <s> and <t>, and the usage flags. In the initial state, the value assigned
+    to TEXTURE_MIN_FILTER is NEAREST_MIPMAP_LINEAR, and the value for 
+    TEXTURE_MAG_FILTER is LINEAR. <s> and <t> wrap modes are both set to
+    REPEAT. The initial value for TEXTURE_USAGE_ANGLE is NONE."
+
+
+Additions to Chapter 4 of the OpenGL ES 2.0 Specification (Per-Fragment
+Operations and the Framebuffer)
+
+    None
+
+Additions to Chapter 5 of the OpenGL ES 2.0 Specification (Special
+Functions):
+
+    None
+
+Additions to Chapter 6 of the OpenGL ES 2.0 Specification (State and
+State Requests)
+
+    None
+
+Dependencies on EXT_texture_storage
+
+    If EXT_texture_storage is not supported, omit any references to 
+    TexStorage2DEXT.
+
+Errors
+
+    If TexParameter{if} or TexParamter{if}v is called with a <pname>
+    of TEXTURE_USAGE_ANGLE and the value of <param> or <params> is not
+    NONE or FRAMEBUFFER_ATTACHMENT_ANGLE the error INVALID_VALUE is
+    generated.
+
+Usage Example
+
+    /* create and bind texture */
+    glGenTextures(1, &texture);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, texture);
+
+    /* specify texture parameters */
+    glTexParameteri(GL_TEXTURE_2D, GL_*, ...);  /* as before */
+    
+    /* specify that we'll be rendering to the texture */
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_USAGE_ANGLE, GL_FRAMEBUFFER_ATTACHMENT_ANGLE);
+
+    glTexStorage2DEXT(GL_TEXTURE_2D, levels, ...); // Allocation
+    for(int level = 0; level < levels; ++level)
+        glTexSubImage2D(GL_TEXTURE_2D, level, ...); // Initialisation
+
+Issues
+
+    1. Should there be a dynamic usage value?
+   
+       DISCUSSION: We could accept a dynamic flag to indicate that a texture will
+       be updated frequently. We could map this to D3D9 dynamic textures. This would
+       allow us to avoid creating temporary surfaces when updating the texture.
+       However renderable textures cannot be dynamic in D3D9, which eliminates the 
+       primary use case for this.  Furthermore, the memory usage of dynamic textures
+       typically increases threefold when you lock it.
+
+    2. Should the texture usage be an enum or a bitfield?
+
+       UNRESOLVED.  Using a bitfield would allow combination of values to be specified.
+       On the other hand, if combinations are really required, additional <pnames>
+       could be added as necessary.  Querying a bitfield via the GetTexParameter command
+       feels a bit odd.
+
+    3. What should happen if TEXTURE_USAGE_ANGLE is set/changed after the texture
+       contents have been specified?
+
+       RESOLVED: It will have no effect. However, if the texture is redefined (for 
+       example by TexImage2D) the new allocation will use the updated usage.
+       GetTexParameter is used to query the value of the TEXTURE_USAGE_ANGLE
+       state that was last set by TexParameter for the currently bound texture, or
+       the default value if it has never been set. There is no way to determine the 
+       usage that was in effect at the time the texture was defined.
+
+Revision History
+
+    Rev.    Date      Author     Changes
+    ----  ----------- ---------  ----------------------------------------
+      1   10 Nov 2011 dgkoch     Initial revision
+      2   10 Nov 2011 dgkoch     Add overview
+   
+