Add support for GL_EXT_color_buffer_float.

TRAC #23794

Signed-off-by: Jamie Madill
Signed-off-by: Shannon Woods

1 files changed, 230 insertions, 0 deletions

diff --git a/extensions/EXT_color_buffer_float.txt b/extensions/EXT_color_buffer_float.txt
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+Name
+
+    EXT_color_buffer_float
+
+Name Strings
+
+    GL_EXT_color_buffer_float
+
+Contributors
+
+    OpenGL ES Working Group members
+
+Contact
+
+    Mark Callow, HI Corp. (callow.mark 'at' artspark.co.jp)
+
+Notice
+
+    ©2012 The Khronos Group Inc.
+
+Status
+
+    Complete
+
+IP Status
+
+    Graphics Properties Holdings (GPH, formerly SGI) owns US Patent
+    #6,650,327, issued November 18, 2003. GPH believes this patent
+    contains necessary IP for graphics systems implementing floating
+    point (FP) rasterization and FP framebuffer capabilities.
+
+    GPH will not grant Khronos royalty-free use of this IP for use
+    in OpenGL ES, but will discuss licensing on RAND terms, on an
+    individual basis with companies wishing to use this IP in the
+    context of conformant OpenGL ES implementations. GPH does not
+    plan to make any special exemption for open source
+    implementations.
+
+    See
+    https://www.khronos.org/files/ip-disclosures/opengl/SGI%20IP%20Disclosure%20Mar05_clean.pdf
+    for the full disclosure.
+
+Version
+
+    Date: January 11th, 2013
+    Revision: 5
+
+Number
+
+    OpenGL ES Extension #137
+
+Dependencies
+
+    Requires OpenGL ES 3.0.
+
+    Written based on the wording of the OpenGL ES 3.0.1 Specification
+    (January 10th, 2013).
+
+Overview
+
+    This extension allows a variety of floating point formats to be
+    rendered to via framebuffer objects.
+
+New Procedures and Functions
+
+    None
+
+New Tokens
+
+    None
+
+Additions to Chapter 3 of the OpenGL ES 3.0 Specification
+(Rasterization)
+
+    3.8.3 Texture Image Specification, unnumbered subsection "Required
+    Texture Formats", p. 126
+
+    Change the first two bullet items to the following:
+
+    - Texture and renderbuffer color formats (see section 4.4.2).
+      - RGBA32F, RGBA32I, RGBA32UI, RGBA16F, RGBA16I, RGBA16UI,
+        RGBA8, RGBA8I, RGBA8UI, SRGB8_ALPHA8, RGB10_A2, RGB10_-
+        A2UI, RGBA4, and RGB5_A1.
+      - RGB8 and RGB565.
+      - R11F G11F B10F.
+      - RG32F, RG32I, RG32UI, RG16F, RG16I, RG16UI, RG8, RG8I, and
+        RG8UI.
+      - R32F, R32I, R32UI, R16F, R16I, R16UI, R8, R8I, and R8UI.
+
+    - Texture-only color formats:
+      - RGBA8_SNORM.
+      - RGB32F, RGB32I, and RGB32UI.
+      - RGB16F, RGB16I, and RGB16UI.
+      - RGB8_SNORM, RGB8I, RGB8UI, and SRGB8.
+      - RGB9_E5.
+      - RG8_SNORM.
+      - R8_SNORM.
+
+    Table 3.12, p. 128 & 129
+
+    Convert the dash under 'Color-renderable' to a 'check' for the
+    following internal formats: R16F, RG16F, RGBA16F, R32F, RG32F,
+    RGBA32F and R11F_G11F_B10F.
+    
+Additions to Chapter 4 of the OpenGL ES 3.0 Specification (Per-Fragment
+Operations and the Framebuffer)
+
+    (changed lines marked with *; added lines marked with +)
+
+    Chapter 4 Introduction, p. 167
+
+    Paragraph 5, sentence 3, p 168, insert "floating point" as shown:
+        "R, G, B, and A components may be represented as unsigned
+ *      normalized fixed-point, floating point or signed or unsigned
+        integer values; ..."    ^^^^^^^^^^^^^^
+
+    4.1.7 Blending, p. 174
+
+    Modify paragraphs 3 & 4:
+    
+ *      "If the color buffer is fixed-point, the components of the
+    source and destination values and blend factors are clamped
+ *  to [0; 1] prior to evaluating the blend equation. If the color
+ +  buffer is floating-point, no clamping occurs. The resulting four
+ +  values are sent to the next operation.
+    
+        Blending applies only if the color buffer has a fixed-point or
+ *  or floating-point format. If the color buffer has an integer
+ *  format, proceed to the next operation.  Furthermore, an
+ +  INVALID_OPERATION error is generated by DrawArrays and the other
+ +  drawing commands defined in section 2.8.3 if blending is enabled
+ +  (see below) and any draw buffer has a 32-bit floating-point
+ +  format."
+
+    4.2.3 Clearing the Buffers, p. 183
+
+    Modify second paragraph, inserting "floating point":
+
+    "   void ClearColor(float r, float g, float b, float a);
+
+ *  sets the clear value for fixed- and floating-point color buffers.
+    ..."                            ^^^^^^^^^^^^^^^^^^
+
+    4.3.1 Reading Pixels, p. 186
+
+    In paragraph 4, beginning "Only two combinations of format
+    and type are accepted ...", after the sentence ending "... type
+    UNSIGNED_BYTE is accepted." insert the following sentence:
+        "For floating-point rendering surfaces, the combination
+        format RGBA and type FLOAT is accepted."
+
+    4.3.1 unnumbered subsection "Obtaining Pixels from the Framebuffer",
+    p. 188
+
+    Modify penultimate paragraph, p189, "If format is an integer ..."
+
+    "If format is an integer format and the color buffer is not an
+    integer format; if the color buffer is an integer format and
+ *  format is not an integer format; if format is an integer format
+ *  and type is FLOAT, HALF_FLOAT, or UNSIGNED_INT_10F_11F_11F_REV;
+ +  or if the color buffer is a floating-point format and type is
+ +  not FLOAT, HALF FLOAT, or UNSIGNED_INT_10F_11F_11F_REV, the error
+    INVALID_OPERATION occurs."
+
+    4.3.1 unnumbered subsection "Conversion of RGBA values", p.190
+
+    Sole paragraph, sentence 3, insert "or floating point" as shown:
+ *      "For an integer or floating point color buffer, the elements
+        are unmodified."^^^^^^^^^^^^^^^^^
+
+    4.3.2 Copying Pixels, p192
+
+    Modify first error condition, at bottom of p193, "The read buffer
+    contains ..." to encompass floating-point buffers.
+
+ *  "- The read buffer contains fixed-point or floating-point values
+ *     and any draw buffer contains neither fixed-point nor
+ *     floating-point values."
+
+    4.4.2 Attaching Images to Framebuffer Objects, p. 197, unnumbered
+    subsection "Required Renderbuffer Formats", p. 200
+
+    In the last paragraph beginning "Implementations must support
+    creation ...", modify the final phrase to
+
+ *   "with the exception of signed and unsigned integer, RGBA16F,
+ +   R32F, RG32F and RGBA32F formats.
+
+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)
+
+    6.1.15 Internal Format Queries, p. 237
+
+    P. 238, paragraph 8 after "Since multisampling is not supported
+    for signed and unsigned integer internal formats, the value of
+    NUM_SAMPLE_COUNTS will be zero for such formats.", insert new
+    one-sentence paragraph:
+
+        "If <internalformat> is RGBA16F, R32F, RG32F, or RGBA32F, the
+        value of NUM_SAMPLE_COUNTS may be zero, or else the maximum
+        value in SAMPLES may be less than the value of MAX_SAMPLES."
+
+New Implementation Dependent State
+
+    None
+
+Issues
+
+Revision History
+
+    Rev.  Date     Author     Changes
+    ----  -------- ---------  -----------------------------------------
+      1   10/16/12 markc      Initial version
+      2   10/18/12 markc      Referenced preliminary version of OpenGL
+                              ES 3.0.1 specification and updated page
+                              numbers.
+      3   11/21/12 markc      Corrected IP status.
+      4   01/09/13 markc      Changed date of referenced OpenGL ES
+                              3.0.1 specification. Made minor language
+                              simplification.
+      5   01/11/13 markc      Changed date to release version of
+                              OpenGL ES 3.0.1 specification.
+                              Clarified change to "Required
+                              renderbuffer formats" section.
+
+# vim:ai:ts=4:sts=4:sw=4:expandtab:textwidth=70