[Mesa-dev] [PATCH] mesa: Add linear ETC2/EAC to the compressed format list with ES3 compat.

[Kenneth Graunke]

GL_ARB_ES3_compatibility brings ETC2/EAC formats to desktop GL.

The meaning of the GL compressed format list is pretty vague - it's
supposed to return formats for "general-purpose usage".  (GL 4.2
deprecates the list because of this.)  Basically everyone interprets
this as "linear RGB/RGBA".

ETC2/EAC meets that criteria, so while we shouldn't be required to add
it to the list, there's also little harm in doing so, at least on
platforms with native support.  I doubt anyone is using this list for
much anyway, so even on platforms without native support, it's probably
not a big deal.

Makes the following GL45-CTS.gtf43 tests pass:

* GL3Tests.eac_compression_r11.gl_compressed_r11_eac
* GL3Tests.eac_compression_rg11.gl_compressed_rg11_eac
* GL3Tests.eac_compression_signed_r11.gl_compressed_signed_r11_eac
* GL3Tests.eac_compression_signed_rg11.gl_compressed_signed_rg11_eac
* GL3Tests.etc2_compression_rgb8.gl_compressed_rgb8_etc2
* GL3Tests.etc2_compression_rgb8_pt_alpha1.gl_compressed_rgb8_pt_alpha1_etc2
* GL3Tests.etc2_compression_rgba8.gl_compressed_rgba8_etc2

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/main/texcompress.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/mesa/main/texcompress.c b/src/mesa/main/texcompress.c
index 9567c5d..15970a7 100644
--- a/src/mesa/main/texcompress.c
+++ b/src/mesa/main/texcompress.c
@@ -358,21 +358,27 @@ _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats)
       }
    }
 
-   if (_mesa_is_gles3(ctx)) {
+   if (_mesa_is_gles3(ctx) || ctx->Extensions.ARB_ES3_compatibility) {
       if (formats) {
          formats[n++] = GL_COMPRESSED_RGB8_ETC2;
-         formats[n++] = GL_COMPRESSED_SRGB8_ETC2;
          formats[n++] = GL_COMPRESSED_RGBA8_ETC2_EAC;
-         formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
          formats[n++] = GL_COMPRESSED_R11_EAC;
          formats[n++] = GL_COMPRESSED_RG11_EAC;
          formats[n++] = GL_COMPRESSED_SIGNED_R11_EAC;
          formats[n++] = GL_COMPRESSED_SIGNED_RG11_EAC;
          formats[n++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2;
-         formats[n++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
+      } else {
+         n += 7;
       }
-      else {
-         n += 10;
+   }
+
+   if (_mesa_is_gles3(ctx)) {
+      if (formats) {
+         formats[n++] = GL_COMPRESSED_SRGB8_ETC2;
+         formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
+         formats[n++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
+      } else {
+         n += 3;
       }
    }
 
-- 
2.10.1