[Mesa-dev] [PATCH 5/6] mesa: Add decoding functions for GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2

[Anuj Phogat]

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 src/mesa/main/texcompress_etc.c |   77 +++++++++++++++++++++++++++++++++++++++
 src/mesa/main/texcompress_etc.h |    8 ++++
 2 files changed, 85 insertions(+), 0 deletions(-)

diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
index eb2ce1a..6281aae 100644
--- a/src/mesa/main/texcompress_etc.c
+++ b/src/mesa/main/texcompress_etc.c
@@ -1052,6 +1052,47 @@ etc2_unpack_rgb8_punchthrough_alpha1(uint8_t *dst_row,
    }
 }
 
+static void
+etc2_unpack_srgb8_punchthrough_alpha1(uint8_t *dst_row,
+                                     unsigned dst_stride,
+                                     const uint8_t *src_row,
+                                     unsigned src_stride,
+                                     unsigned width,
+                                     unsigned height)
+{
+   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
+   struct etc2_block block;
+   unsigned x, y, i, j;
+
+   for (y = 0; y < height; y += bh) {
+      const uint8_t *src = src_row;
+
+      for (x = 0; x < width; x+= bw) {
+         etc2_rgb8_parse_block(&block, src,
+                               true /* punchthrough_alpha */);
+         for (j = 0; j < bh; j++) {
+            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
+            for (i = 0; i < bw; i++) {
+               etc2_rgb8_fetch_texel(&block, i, j, dst,
+	                             true /* punchthrough_alpha */);
+
+               /* sRGB color space to linear color space conversion */
+               dst[0] = FLOAT_TO_UBYTE(decode_srgb(UBYTE_TO_FLOAT(dst[0])));
+               dst[1] = FLOAT_TO_UBYTE(decode_srgb(UBYTE_TO_FLOAT(dst[1])));
+               dst[2] = FLOAT_TO_UBYTE(decode_srgb(UBYTE_TO_FLOAT(dst[2])));
+               dst[3] = dst[3];
+
+               dst += comps;
+            }
+         }
+
+         src += bs;
+      }
+
+      src_row += src_stride;
+   }
+}
+
 /* ETC2 texture formats are valid in glCompressedTexImage2D and
  * glCompressedTexSubImage2D functions */
 GLboolean
@@ -1126,6 +1167,14 @@ _mesa_texstore_etc2_rgb8_punchthrough_alpha1(TEXSTORE_PARAMS)
    return GL_FALSE;
 }
 
+GLboolean
+_mesa_texstore_etc2_srgb8_punchthrough_alpha1(TEXSTORE_PARAMS)
+{
+   ASSERT(0);
+
+   return GL_FALSE;
+}
+
 void
 _mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
                                  GLint i, GLint j, GLint k, GLfloat *texel)
@@ -1317,6 +1366,29 @@ _mesa_fetch_texel_2d_f_etc2_rgb8_punchthrough_alpha1(
    texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
 }
 
+void
+_mesa_fetch_texel_2d_f_etc2_srgb8_punchthrough_alpha1(
+   const struct swrast_texture_image *texImage,
+   GLint i, GLint j,
+   GLint k, GLfloat *texel)
+{
+   struct etc2_block block;
+   GLubyte dst[4];
+   const GLubyte *src;
+
+   src = (const GLubyte *) texImage->Map +
+      (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
+
+   etc2_rgb8_parse_block(&block, src,
+                         true /* punchthrough alpha */);
+   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
+                         true /* punchthrough alpha */);
+   texel[RCOMP] = decode_srgb(UBYTE_TO_FLOAT(dst[0]));
+   texel[GCOMP] = decode_srgb(UBYTE_TO_FLOAT(dst[1]));
+   texel[BCOMP] = decode_srgb(UBYTE_TO_FLOAT(dst[2]));
+   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
+}
+
 /**
  * Decode texture data in any one of following formats:
  * `MESA_FORMAT_ETC2_RGB8`
@@ -1328,6 +1400,7 @@ _mesa_fetch_texel_2d_f_etc2_rgb8_punchthrough_alpha1(
  * `MESA_FORMAT_ETC2_SIGNED_R11_EAC`
  * `MESA_FORMAT_ETC2_SIGNED_RG11_EAC`
  * `MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1`
+ * `MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1`
  *
  * The size of the source data must be a multiple of the ETC2 block size
  * even if the texture image's dimensions are not aligned to 4.
@@ -1382,4 +1455,8 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
       etc2_unpack_rgb8_punchthrough_alpha1(dst_row, dst_stride,
                                            src_row, src_stride,
                                            src_width, src_height);
+   else if (format == MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1)
+      etc2_unpack_srgb8_punchthrough_alpha1(dst_row, dst_stride,
+                                            src_row, src_stride,
+                                            src_width, src_height);
 }
diff --git a/src/mesa/main/texcompress_etc.h b/src/mesa/main/texcompress_etc.h
index b9e4d85..18951b8 100644
--- a/src/mesa/main/texcompress_etc.h
+++ b/src/mesa/main/texcompress_etc.h
@@ -61,6 +61,9 @@ _mesa_texstore_etc2_signed_rg11_eac(TEXSTORE_PARAMS);
 GLboolean
 _mesa_texstore_etc2_rgb8_punchthrough_alpha1(TEXSTORE_PARAMS);
 
+GLboolean
+_mesa_texstore_etc2_srgb8_punchthrough_alpha1(TEXSTORE_PARAMS);
+
 void
 _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
                                  GLint i, GLint j, GLint k, GLfloat *texel);
@@ -100,6 +103,11 @@ _mesa_fetch_texel_2d_f_etc2_rgb8_punchthrough_alpha1(
                                  GLint i, GLint j,
                                  GLint k, GLfloat *texel);
 void
+_mesa_fetch_texel_2d_f_etc2_srgb8_punchthrough_alpha1(
+                                 const struct swrast_texture_image *texImage,
+                                 GLint i, GLint j,
+                                 GLint k, GLfloat *texel);
+void
 _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
                            unsigned dst_stride,
                            const uint8_t *src_row,
-- 
1.7.7.6