Merge pull request #18 from courtney-g/170614-scrgb-nonlinear
Add non-linear scRGB extension
diff --git a/api/EGL/egl.h b/api/EGL/egl.h
index 5d122f7..42db1b6 100644
--- a/api/EGL/egl.h
+++ b/api/EGL/egl.h
@@ -38,7 +38,7 @@
#include <EGL/eglplatform.h>
-/* Generated on date 20170406 */
+/* Generated on date 20170621 */
/* Generated C header for:
* API: egl
diff --git a/api/EGL/eglext.h b/api/EGL/eglext.h
index 5f914f4..c2a76a2 100644
--- a/api/EGL/eglext.h
+++ b/api/EGL/eglext.h
@@ -38,7 +38,7 @@
#include <EGL/eglplatform.h>
-#define EGL_EGLEXT_VERSION 20170406
+#define EGL_EGLEXT_VERSION 20170621
/* Generated C header for:
* API: egl
@@ -661,6 +661,11 @@
#define EGL_GL_COLORSPACE_DISPLAY_P3_LINEAR_EXT 0x3362
#endif /* EGL_EXT_gl_colorspace_display_p3_linear */
+#ifndef EGL_EXT_gl_colorspace_scrgb
+#define EGL_EXT_gl_colorspace_scrgb 1
+#define EGL_GL_COLORSPACE_SCRGB_EXT 0x3351
+#endif /* EGL_EXT_gl_colorspace_scrgb */
+
#ifndef EGL_EXT_gl_colorspace_scrgb_linear
#define EGL_EXT_gl_colorspace_scrgb_linear 1
#define EGL_GL_COLORSPACE_SCRGB_LINEAR_EXT 0x3350
diff --git a/api/egl.xml b/api/egl.xml
index 7e831fc..9c3445b 100644
--- a/api/egl.xml
+++ b/api/egl.xml
@@ -788,7 +788,7 @@
<enum value="0x334E" name="EGL_STREAM_CROSS_DISPLAY_NV"/>
<enum value="0x334F" name="EGL_STREAM_CROSS_SYSTEM_NV"/>
<enum value="0x3350" name="EGL_GL_COLORSPACE_SCRGB_LINEAR_EXT"/>
- <unused start="0x3351"/>
+ <enum value="0x3351" name="EGL_GL_COLORSPACE_SCRGB_EXT"/>
<enum value="0x3352" name="EGL_TRACK_REFERENCES_KHR"/>
<unused start="0x3353" end="0x335F"/>
<enum value="0x3360" name="EGL_CTA861_3_MAX_CONTENT_LIGHT_LEVEL_EXT"/>
@@ -2104,6 +2104,11 @@
<enum name="EGL_GL_COLORSPACE_BT2020_PQ_EXT"/>
</require>
</extension>
+ <extension name="EGL_EXT_gl_colorspace_scrgb" supported="egl">
+ <require>
+ <enum name="EGL_GL_COLORSPACE_SCRGB_EXT"/>
+ </require>
+ </extension>
<extension name="EGL_EXT_gl_colorspace_scrgb_linear" supported="egl">
<require>
<enum name="EGL_GL_COLORSPACE_SCRGB_LINEAR_EXT"/>
diff --git a/extensions/EXT/EGL_EXT_gl_colorspace_scrgb.txt b/extensions/EXT/EGL_EXT_gl_colorspace_scrgb.txt
new file mode 100644
index 0000000..f16ca96
--- /dev/null
+++ b/extensions/EXT/EGL_EXT_gl_colorspace_scrgb.txt
@@ -0,0 +1,127 @@
+Name
+
+ EXT_gl_colorspace_scrgb
+
+Name Strings
+
+ EGL_EXT_gl_colorspace_scrgb
+
+Contributors
+
+ Courtney Goeltzenleuchter
+ Lauri Hyvarinen
+ Weiwan Liu
+ Arun Swain
+
+Contact
+
+ Courtney Goeltzenleuchter (courtneygo 'at' google.com)
+
+IP Status
+
+ No known IP claims.
+
+Status
+
+ Draft
+
+Version
+
+ Version 1 - June 21, 2017
+
+Number
+
+ EGL Extension #119
+
+Dependencies
+
+ This extension is written against the wording of the EGL 1.5 specification
+ (August 27, 2014).
+
+ This extension requires EGL_KHR_gl_colorspace and EGL_EXT_pixel_format_-
+ float, and interacts with EGL_EXT_surface_SMPTE2086_metadata. This extension
+ is closely related to EGL_EXT_gl_colorspace_scrgb_linear.
+
+Overview
+
+ This extension provides a new color space option, scRGB, for applications to
+ choose from when creating an EGLSurface. The scRGB color space defines a
+ non-linear display referred space. It has the same white point and color
+ primaries as sRGB, and thus is backward-compatible with sRGB. Refer to
+ the IEC 61966-2-2:2003 standard for details on scRGB color space.
+
+ This extension chooses to use floating-point formats for scRGB color space.
+ For each color channel, the floating-point values of 0.0 and 1.0 still
+ correspond to sRGB chromaticities and luminance levels. However, scRGB
+ space allows for color values beyond the range of [0.0, 1.0], and can thus
+ achieve a larger color volume than that of sRGB. As it is display referred,
+ scRGB space makes assumptions of how the floating-point color values should
+ map to luminance levels by the underlying display pipeline. The expected
+ mapping is such that a color value of (1.0, 1.0, 1.0) corresponds to a
+ luminance level of 80 nits on a standardized studio monitor. As the color
+ value per channel goes beyond 1.0 and up to 125.0, the corresponding
+ luminance levels also increase linearly to a maximum of 10000 nits.
+
+ The application is responsible for applying the sRGB transfer function to
+ color values written to or read from a surface with a colorspace of
+ EGL_EXT_gl_colorspace_scrgb.
+
+New Procedures and Functions
+
+ None.
+
+New Tokens
+
+ Accepted as attribute values for EGL_GL_COLORSPACE by
+ eglCreateWindowSurface, eglCreatePbufferSurface and eglCreatePixmapSurface:
+
+ EGL_GL_COLORSPACE_SCRGB_EXT 0x3351
+
+Modifications to the EGL 1.5 Specification
+
+ Insert below text in the 3rd paragraph on page 33 in 3.5.1 "Creating On-
+ Screen Rendering Surfaces", before "The default value of EGL_GL_COLORSPACE
+ is EGL_GL_COLORSPACE_LINEAR.":
+
+ [[ If EGL_EXT_gl_colorspace_scrgb is supported ]]
+
+ If its value is EGL_GL_COLORSPACE_SCRGB_EXT, then a non-linear scRGB
+ color space is assumed. with a corresponding GL_FRAMEBUFFER_ATTACHMENT_-
+ COLOR_ENCODING value of GL_SRGB. As defined in IEC 61966-2-2:2003, scRGB
+ is a non-linear color space and has the same white point and color primaries as
+ those of sRGB. The application is responsible for applying the appropriate
+ sRGB transfer function when reading or writing to this surface.
+
+
+ Add two paragraphs after the 4th paragraph above:
+
+ When using a floating-point EGL surface with EGL_GL_COLORSPACE_SCRGB_EXT,
+ the display-referred values in the range of (0.0, 0.0, 0.0) to
+ (1.0, 1.0, 1.0) correspond to a luminance range of 0 to 80 nits, which is
+ the same luminance range for sRGB. To achieve a larger dynamic range of up
+ to 10000 nits, the output values can go beyond 1.0 and to a range of
+ [0.0, 125.0] (approximately 7.83 after sRGB transfer function applied) for
+ each channel.
+
+ The effective color gamut and luminance range of the content that extend
+ beyond those of sRGB may be described via EGL_EXT_surface_SMPTE2086_metadata.
+ It is highly recommended to supply such metadata, so the display pipeline
+ may use this information to transform the the colors in a manner that
+ attempts to preserve the creative intent of the color data.
+
+ In the "Errors" section on page 34 in 3.5.1 "Creating On Screen Rendering
+ Surfaces", change the 3rd error definition to:
+
+ * If config does not support the OpenGL colorspace, the OpenVG colorspace or
+ alpha format attributes specified in attrib list (as defined for
+ eglCreatePlatformWindowSurface), an EGL_BAD_MATCH error is generated.
+
+Issues
+
+ No issues so far.
+
+Revision History
+
+ Version 1, 2017/06/21
+ - Initial draft
+
diff --git a/index.php b/index.php
index 23b935b..830614b 100644
--- a/index.php
+++ b/index.php
@@ -314,6 +314,8 @@
</li>
<li value=118> <a href="extensions/EXT/EGL_EXT_gl_colorspace_display_p3.txt">EGL_EXT_gl_colorspace_display_p3_linear</a>
</li>
+<li value=119> <a href="extensions/EXT/EGL_EXT_gl_colorspace_scrgb.txt">EGL_EXT_gl_colorspace_scrgb (non-linear)</a>
+</li>
</ol>
<h6> Providing Feedback on the Registry </h6>
diff --git a/registry.tcl b/registry.tcl
index 97d85ca..e56894d 100644
--- a/registry.tcl
+++ b/registry.tcl
@@ -619,4 +619,9 @@
flags public
filename extensions/EXT/EGL_EXT_colorspace_display_p3.txt
}
+extension EGL_EXT_gl_colorspace_scrgb {
+ number 119
+ flags public
+ filename extensions/EXT/EGL_EXT_gl_colorspace_scrgb.txt
+}
# Next free extension number: 119
