Gallium: Add format PIPE_FORMAT_R8_SRGB

This format is needed to support EXT_texture_sRGB_R8. THe patch adds a new
format enum, the format entries in Gallium and and svga, the mapping between
sRGB and linear formats, and tests.

  v2: - add mapping to linear format for PIPE_FORMATR_R8_SRGB
  v3: - Add texture format to svga format table since otherwise building
        mesa will fail when this driver is enabled. It was not tested
        whether the extension actually works.
  v4: - svga: remove the SVGA specific format definitions and table entries
        and only add correct the location of PIPE_FORMAT_R8_SRGB in the
        format_conversion_table (Ilia Mirkin)
      - Split patch (1/2) to separate Gallium part and mesa/st part.
        (Roland Scheidegger)
      - Trim the commit message to only contain the relevant parts from the
        split.
  v5: - svga: correct location of PIPE_FORMAT_SRGB_R8 (Ilia Mirkin)

Signed-off-by: Gert Wollny <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>
Reviewed-by: Ilia Mirkin <[email protected]>

3 files changed, 9 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.csv b/src/gallium/auxiliary/util/u_format.csv
index f9e4925f27c..911ac07d32a 100644
--- a/src/gallium/auxiliary/util/u_format.csv
+++ b/src/gallium/auxiliary/util/u_format.csv
@@ -114,6 +114,7 @@ PIPE_FORMAT_I32_FLOAT             , plain, 1, 1, f32 ,     ,     ,     , xxxx, r
 
 # SRGB formats
 PIPE_FORMAT_L8_SRGB               , plain, 1, 1, un8 ,     ,     ,     , xxx1, srgb 
+PIPE_FORMAT_R8_SRGB               , plain, 1, 1, un8 ,     ,     ,     , x001, srgb
 PIPE_FORMAT_L8A8_SRGB             , plain, 1, 1, un8 , un8 ,     ,     , xxxy, srgb 
 PIPE_FORMAT_R8G8B8_SRGB           , plain, 1, 1, un8 , un8 , un8 ,     , xyz1, srgb 
 PIPE_FORMAT_R8G8B8A8_SRGB         , plain, 1, 1, un8 , un8 , un8 , un8 , xyzw, srgb 
diff --git a/src/gallium/auxiliary/util/u_format.h b/src/gallium/auxiliary/util/u_format.h
index e66849c16b1..5bcfc1f1154 100644
--- a/src/gallium/auxiliary/util/u_format.h
+++ b/src/gallium/auxiliary/util/u_format.h
@@ -925,6 +925,8 @@ util_format_srgb(enum pipe_format format)
    switch (format) {
    case PIPE_FORMAT_L8_UNORM:
       return PIPE_FORMAT_L8_SRGB;
+   case PIPE_FORMAT_R8_UNORM:
+      return PIPE_FORMAT_R8_SRGB;
    case PIPE_FORMAT_L8A8_UNORM:
       return PIPE_FORMAT_L8A8_SRGB;
    case PIPE_FORMAT_R8G8B8_UNORM:
@@ -1001,6 +1003,8 @@ util_format_linear(enum pipe_format format)
    switch (format) {
    case PIPE_FORMAT_L8_SRGB:
       return PIPE_FORMAT_L8_UNORM;
+   case PIPE_FORMAT_R8_SRGB:
+      return PIPE_FORMAT_R8_UNORM;
    case PIPE_FORMAT_L8A8_SRGB:
       return PIPE_FORMAT_L8A8_UNORM;
    case PIPE_FORMAT_R8G8B8_SRGB:
diff --git a/src/gallium/auxiliary/util/u_format_tests.c b/src/gallium/auxiliary/util/u_format_tests.c
index 9c9a5838d17..dee52533c15 100644
--- a/src/gallium/auxiliary/util/u_format_tests.c
+++ b/src/gallium/auxiliary/util/u_format_tests.c
@@ -236,6 +236,10 @@ util_format_test_cases[] =
    {PIPE_FORMAT_L8_SRGB, PACKED_1x8(0xff), PACKED_1x8(0xbc), UNPACKED_1x1(0.502886458033, 0.502886458033, 0.502886458033, 1.0)},
    {PIPE_FORMAT_L8_SRGB, PACKED_1x8(0xff), PACKED_1x8(0xff), UNPACKED_1x1(1.0, 1.0, 1.0, 1.0)},
 
+   {PIPE_FORMAT_R8_SRGB, PACKED_1x8(0xff), PACKED_1x8(0x00), UNPACKED_1x1(0.0, 0.0, 0.0, 1.0)},
+   {PIPE_FORMAT_R8_SRGB, PACKED_1x8(0xff), PACKED_1x8(0xbc), UNPACKED_1x1(0.502886458033, 0.0, 0.0, 1.0)},
+   {PIPE_FORMAT_R8_SRGB, PACKED_1x8(0xff), PACKED_1x8(0xff), UNPACKED_1x1(1.0, 0.0, 0.0, 1.0)},
+
    {PIPE_FORMAT_L8A8_SRGB, PACKED_1x16(0xffff), PACKED_1x16(0x0000), UNPACKED_1x1(0.0, 0.0, 0.0, 0.0)},
    {PIPE_FORMAT_L8A8_SRGB, PACKED_1x16(0xffff), PACKED_1x16(0x00bc), UNPACKED_1x1(0.502886458033, 0.502886458033, 0.502886458033, 0.0)},
    {PIPE_FORMAT_L8A8_SRGB, PACKED_1x16(0xffff), PACKED_1x16(0x00ff), UNPACKED_1x1(1.0, 1.0, 1.0, 0.0)},