Add drawingBufferColorSpace/unpackColorSpace attributes to WebGLRenderingContextBase.

specs/latest/1.0/index.html

@@ -1721,6 +1721,8 @@ <h3><a name="WEBGLRENDERINGCONTEXT">The WebGL context</a></h3>
     [Exposed=Worker] readonly attribute OffscreenCanvas canvas;
     readonly attribute GLsizei drawingBufferWidth;
     readonly attribute GLsizei drawingBufferHeight;
+    attribute PredefinedColorSpace drawingBufferColorSpace = "srgb";
+    attribute PredefinedColorSpace unpackColorSpace = "srgb";
 
     [WebGLHandlesContextLoss] WebGLContextAttributes? getContextAttributes();
     [WebGLHandlesContextLoss] boolean isContextLost();
@@ -1979,6 +1981,33 @@ <h4>Attributes</h4>
             The actual height of the drawing buffer. May be different from the
             <code>height</code> attribute of the <code>HTMLCanvasElement</code> if
             the implementation is unable to satisfy the requested width or height.
+        <dt>
+            <code class=attribute-name>
+                <a id="DOM-WebGLRenderingContext-drawingBufferColorSpace">
+                    drawingBufferColorSpace
+                </a>
+            </code>
+            of type <code><a href="https://html.spec.whatwg.org/multipage/canvas.html#predefinedcolorspace">PredefinedColorSpace</a></code>
+            <a href="#refsPREDEFINEDCOLORSPACE">(specification)</a>
+        <dd>
+            The color space used to interpret the drawing buffer's content values.
+            Changing this attribute causes the drawing buffer to be reallocated; its
+            current contents are lost. This attribute affects the on-screen display
+            of the rendering context, and the interpretation of this context's
+            drawing buffer when it is drawn to a 2D canvas context, or uploaded to
+            textures in another WebGL or <a href="#refsWEBGPU">WebGPU</a> rendering
+            context.
+        <dt>
+            <code class=attribute-name>
+                <a id="DOM-WebGLRenderingContext-unpackColorSpace">
+                    unpackColorSpace
+                </a>
+            </code>
+            of type <code><a href="https://html.spec.whatwg.org/multipage/canvas.html#predefinedcolorspace">PredefinedColorSpace</a></code>
+            <a href="#refsPREDEFINEDCOLORSPACE">(specification)</a>
+        <dd>
+            The color space into which <code>TexImageSource</code> sources are
+            converted when uploading them to textures in this context.
     </dl>
 
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@@ -2653,10 +2682,27 @@ <h4>Texture objects</h4>
             The width and height of the texture are set as specified in section
             <a href="#TEXTURE_UPLOAD_SIZE">Texture Upload Width and Height</a>.<br><br>
 
-            The source image data is conceptually first converted to the data type and format
-            specified by the <em>format</em> and <em>type</em> arguments, and then transferred to
-            the WebGL implementation. Format conversion is performed according to the following table.
-            If a packed pixel format is specified which would imply loss of bits of precision from the
+            First, the source image data is conceptually converted to the color space specified by
+            the <a href="#DOM-WebGLRenderingContext-unpackColorSpace">unpackColorSpace</a>
+            attribute, except if the source image data is an <code>HTMLImageElement</code>, and
+            the <code>UNPACK_COLORSPACE_CONVERSION_WEBGL</code> pixel storage parameter is set
+            to <code>NONE</code>. <br><br>
+
+            <div class="note rationale">
+
+            This color space conversion applies to <code>ImageBitmap</code> objects as well, though
+            other texture unpack parameters do not apply to <code>ImageBitmap</code>s because they
+            are expected to be specified during <code>ImageBitmap</code> construction.
+            Implementation experience revealed that it was beneficial to
+            perform <code>ImageBitmap</code>s' color space conversion as late as possible when
+            uploading to WebGL textures.
+
+            </div>
+
+            Next, the source image data is converted to the data type and format specified by
+            the <em>format</em> and <em>type</em> arguments, and then transferred to the WebGL
+            implementation. Format conversion is performed according to the following table.  If a
+            packed pixel format is specified which would imply loss of bits of precision from the
             image data, this loss of precision must occur. <br><br>
 
             <table class="foo">
@@ -2799,12 +2845,8 @@ <h4>Texture objects</h4>
             <a href="#TEXTURE_UPLOAD_SIZE">Texture Upload Width and Height</a>.<br><br>
 
             See <a href="#TEXIMAGE2D_HTML">texImage2D</a> for the interpretation of
-            the <em>format</em> and <em>type</em> arguments, and notes on
-            the <code>UNPACK_PREMULTIPLY_ALPHA_WEBGL</code> pixel storage parameter. <br><br>
-
-            See <a href="#PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a> for WebGL-specific
-            pixel storage parameters that affect the behavior of this function when it is called
-            with any argument type other than <code>ImageBitmap</code>. <br><br>
+            the <em>format</em> and <em>type</em> arguments, handling of WebGL-specific pixel
+            storage parameters, and potential color space transformations of the input. <br><br>
 
             The first pixel transferred from the source to the WebGL implementation corresponds
             to the upper left corner of the source. This behavior is modified by the
@@ -4555,6 +4597,16 @@ <h2>References</h2>
         <dd>(Non-normative) <cite><a href="https://w3c.github.io/webcodecs/">WebCodecs API</a></cite>,
             C. Cunningham, P. Adenot, B. Aboba. W3C.
         </dd>
+        <dt id="refsPREDEFINEDCOLORSPACE">[PREDEFINEDCOLORSPACE]</dt>
+        <dd><cite><a href="https://html.spec.whatwg.org/multipage/canvas.html#predefinedcolorspace">
+            HTML Living Standard - The PredefinedColorSpace enum</a></cite>,
+            WHATWG.
+        </dd>
+        <dt id="refsWEBGPU">[WEBGPU]</dt>
+        <dd><cite><a href="https://gpuweb.github.io/gpuweb/">
+            WebGPU Editor's Draft</a></cite>,
+            WebGPU Community Group.
+        </dd>
     </dl>
 
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