Merge pull request #105 from anholt/mesa-tile-raster-order
Add a new MESA_tile_raster_order extension.
diff --git a/api/GL/glext.h b/api/GL/glext.h
index b61a145..96e3daf 100644
--- a/api/GL/glext.h
+++ b/api/GL/glext.h
@@ -9219,6 +9219,13 @@
#define GL_MESA_shader_integer_functions 1
#endif /* GL_MESA_shader_integer_functions */
+#ifndef GL_MESA_tile_raster_order
+#define GL_MESA_tile_raster_order 1
+#define GL_TILE_RASTER_ORDER_FIXED_MESA 0x8BB8
+#define GL_TILE_RASTER_ORDER_INCREASING_X_MESA 0x8BB9
+#define GL_TILE_RASTER_ORDER_INCREASING_Y_MESA 0x8BBA
+#endif /* GL_MESA_tile_raster_order */
+
#ifndef GL_MESA_window_pos
#define GL_MESA_window_pos 1
typedef void (APIENTRYP PFNGLWINDOWPOS2DMESAPROC) (GLdouble x, GLdouble y);
diff --git a/extensions/MESA/MESA_tile_raster_order.txt b/extensions/MESA/MESA_tile_raster_order.txt
new file mode 100644
index 0000000..24c46aa
--- /dev/null
+++ b/extensions/MESA/MESA_tile_raster_order.txt
@@ -0,0 +1,127 @@
+Name
+
+ MESA_tile_raster_order
+
+Name Strings
+
+ GL_MESA_tile_raster_order
+
+Contact
+
+ Eric Anholt, Broadcom (eric@anholt.net)
+
+Status
+
+ Proposal
+
+Version
+
+ Last modified date: 24 September 2017
+
+Number
+
+ OpenGL Extension #515
+ OpenGL ES Extension #292
+
+Dependencies
+
+ GL_ARB_texture_barrier or GL_NV_texture_barrier is required.
+
+ This extension is written against the OpenGL 4.4 (Compatibility
+ Profile) specification, as modified by the GL_ARB_texture_barrier
+ extension.
+
+Overview
+
+ This extension extends the sampling-from-the-framebuffer behavior provided
+ by GL_ARB_texture_barrier to allow setting the rasterization order of the
+ scene, so that overlapping blits can be implemented. This can be used for
+ scrolling or window movement within in 2D scenes, without first copying to
+ a temporary.
+
+IP Status
+
+ None
+
+Issues
+
+ 1. Should this extension also affect BlitFramebuffer?
+
+ NOT RESOLVED: BlitFramebuffer could use the same underlying
+ functionality to provide defined results for 1:1 overlapping blits,
+ but one could use the coordinates being copied to just produce the
+ right result automatically, rather than requiring the state flags to
+ be adjusted.
+
+New Procedures and Functions
+
+ None
+
+New Tokens
+
+ None
+
+Additions to Chapter 9 of the OpenGL 4.4 Specification (Per-Fragment
+Operations and the Frame Buffer)
+
+ Modify Section 9.3.1 Rendering Feedback Loops, p. 289
+
+ Replace the bullet point "If a texel has been written..." with:
+
+ - A texel has been written, but it has been separated from this
+ Draw call by the command:
+
+ void TextureBarrier(void);
+
+ TextureBarrier() will guarantee that writes have completed and
+ caches have been invalidated before subsequent Draws are
+ executed."
+
+ - TILE_RASTER_ORDER_FIXED_MESA is enabled, and there is only a
+ single write of each texel, and primitives are emitted in the
+ order of TILE_RASTER_ORDER_INCREASING_X/Y_MESA (where those
+ being disabled mean negative texel offsets), and reads are
+ only performed from texels offset from the current fragment
+ shader invocation in the direction specified by
+ TILE_RASTER_ORDER_INCREASING_X/Y_MESA, e.g. using
+ "texelFetch2D(sampler, ivec2(gl_FragCoord.xy + vec2(dx, dy)),
+ 0);".
+
+Additions to the AGL/GLX/WGL Specifications
+
+ None
+
+GLX Protocol
+
+ None
+
+Errors
+
+ None
+
+New State
+
+ Get Value Type Get Command Initial Value Description Section Attribute
+ ----------------------------------- ------ ------------- ------------- --------------------------- -------- ------------
+ TILE_RASTER_ORDER_FIXED_MESA B IsEnabled True Tile rasterization order is 9.3.1 enable
+ defined by
+ TILE_RASTER_ORDER_INCREASING_*_MESA.
+ in increasing X direction
+ TILE_RASTER_ORDER_INCREASING_X_MESA B IsEnabled True Tiles are rasterized 9.3.1 enable
+ in increasing X direction
+ TILE_RASTER_ORDER_INCREASING_Y_MESA B IsEnabled True Tiles are rasterized 9.3.1 enable
+ in increasing Y direction
+
+Revision History
+
+ 26 July 2017 - Initial draft
+
+ 24 September 2017 - Improved wording of the new specification
+ paragraph. Adjust the ARB_texture_barrier
+ paragraph, to make it clear that it's not
+ required when in tile raster order mode.
+
+ 2 October 2017 - Give it an ES extension number, mention
+ NV_texture_barrier for ES.
+
+ 5 October 2017 - Mention what spec it's written against.
diff --git a/extensions/esext.php b/extensions/esext.php
index 631c401..90a77b4 100644
--- a/extensions/esext.php
+++ b/extensions/esext.php
@@ -605,4 +605,6 @@
</li>
<li value=291><a href="extensions/EXT/EXT_texture_mirror_clamp_to_edge.txt">GL_EXT_texture_mirror_clamp_to_edge</a>
</li>
+<li value=292><a href="extensions/MESA/MESA_tile_raster_order.txt">GL_MESA_tile_raster_order</a>
+</li>
</ol>
diff --git a/extensions/glext.php b/extensions/glext.php
index 62344a6..3c7657b 100644
--- a/extensions/glext.php
+++ b/extensions/glext.php
@@ -965,4 +965,6 @@
</li>
<li value=514><a href="extensions/MESA/GLX_MESA_swap_control.txt">GLX_MESA_swap_control</a>
</li>
+<li value=515><a href="extensions/MESA/MESA_tile_raster_order.txt">GL_MESA_tile_raster_order</a>
+</li>
</ol>
diff --git a/extensions/registry.py b/extensions/registry.py
index 2452e7b..4604628 100644
--- a/extensions/registry.py
+++ b/extensions/registry.py
@@ -2926,6 +2926,13 @@
'supporters' : { 'MESA' },
'url' : 'extensions/MESA/GLX_MESA_swap_control.txt',
},
+ 'GL_MESA_tile_raster_order' : {
+ 'number' : 515,
+ 'esnumber' : 292,
+ 'flags' : { 'public' },
+ 'supporters' : { 'MESA' },
+ 'url' : 'extensions/MESA/MESA_tile_raster_order.txt',
+ },
'GL_MESA_window_pos' : {
'number' : 197,
'flags' : { 'public' },
diff --git a/xml/gl.xml b/xml/gl.xml
index 639f15a..e2d42c6 100644
--- a/xml/gl.xml
+++ b/xml/gl.xml
@@ -7741,6 +7741,9 @@
<enum value="0x8BB5" name="GL_VERTEX_PROGRAM_CALLBACK_MESA"/>
<enum value="0x8BB6" name="GL_VERTEX_PROGRAM_CALLBACK_FUNC_MESA"/>
<enum value="0x8BB7" name="GL_VERTEX_PROGRAM_CALLBACK_DATA_MESA"/>
+ <enum value="0x8BB8" name="GL_TILE_RASTER_ORDER_FIXED_MESA"/>
+ <enum value="0x8BB9" name="GL_TILE_RASTER_ORDER_INCREASING_X_MESA"/>
+ <enum value="0x8BBA" name="GL_TILE_RASTER_ORDER_INCREASING_Y_MESA"/>
</enums>
<enums namespace="GL" start="0x8BC0" end="0x8BFF" vendor="QCOM" comment="Reassigned from AMD to QCOM">
@@ -45627,6 +45630,13 @@
</require>
</extension>
<extension name="GL_MESA_shader_integer_functions" supported="gl|gles2"/>
+ <extension name="GL_MESA_tile_raster_order" supported="gl">
+ <require>
+ <enum name="GL_TILE_RASTER_ORDER_FIXED_MESA"/>
+ <enum name="GL_TILE_RASTER_ORDER_INCREASING_X_MESA"/>
+ <enum name="GL_TILE_RASTER_ORDER_INCREASING_Y_MESA"/>
+ </require>
+ </extension>
<extension name="GL_MESA_window_pos" supported="gl">
<require>
<command name="glWindowPos2dMESA"/>
