[Mesa-dev] [PATCH 06/22] mesa: Add decoding functions for GL_COMPRESSED_RGBA8_ETC2_EAC

Brian Paul brianp at vmware.com
Mon Nov 12 07:53:42 PST 2012


On 11/10/2012 12:29 AM, Anuj Phogat wrote:
> Signed-off-by: Anuj Phogat<anuj.phogat at gmail.com>
> ---
>   src/mesa/main/texcompress_etc.c |  146 +++++++++++++++++++++++++++++++++++++-
>   src/mesa/main/texcompress_etc.h |    7 ++
>   2 files changed, 149 insertions(+), 4 deletions(-)
>
> diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
> index eacfb0d..c04ba8d 100644
> --- a/src/mesa/main/texcompress_etc.c
> +++ b/src/mesa/main/texcompress_etc.c
> @@ -26,6 +26,8 @@
>    * GL_OES_compressed_ETC1_RGB8_texture support.
>    * Supported ETC2 texture formats are:
>    * GL_COMPRESSED_RGB8_ETC2
> + * GL_COMPRESSED_SRGB8_ETC2
> + * GL_COMPRESSED_RGBA8_ETC2_EAC
>    */
>
>   #include<stdbool.h>
> @@ -39,7 +41,7 @@
>   struct etc2_block {
>      int flipped;
>      int distance;
> -   uint32_t pixel_indices;
> +   uint64_t pixel_indices[2];
>      const int *modifier_tables[2];
>      GLboolean is_ind_mode;
>      GLboolean is_diff_mode;
> @@ -48,11 +50,33 @@ struct etc2_block {
>      GLboolean is_planar_mode;
>      GLubyte base_colors[3][3];
>      GLubyte paint_colors[4][3];
> +   GLubyte base_codeword;
> +   GLubyte multiplier;
> +   GLubyte table_index;
>   };
>
>   static const int etc2_distance_table[8] = {
>      3, 6, 11, 16, 23, 32, 41, 64 };
>
> +static const int etc2_modifier_tables[16][8] = {
> +   {  -3,   -6,   -9,  -15,   2,   5,   8,   14},
> +   {  -3,   -7,  -10,  -13,   2,   6,   9,   12},
> +   {  -2,   -5,   -8,  -13,   1,   4,   7,   12},
> +   {  -2,   -4,   -6,  -13,   1,   3,   5,   12},
> +   {  -3,   -6,   -8,  -12,   2,   5,   7,   11},
> +   {  -3,   -7,   -9,  -11,   2,   6,   8,   10},
> +   {  -4,   -7,   -8,  -11,   3,   6,   7,   10},
> +   {  -3,   -5,   -8,  -11,   2,   4,   7,   10},
> +   {  -2,   -6,   -8,  -10,   1,   5,   7,    9},
> +   {  -2,   -5,   -8,  -10,   1,   4,   7,    9},
> +   {  -2,   -4,   -8,  -10,   1,   3,   7,    9},
> +   {  -2,   -5,   -7,  -10,   1,   4,   6,    9},
> +   {  -3,   -4,   -7,  -10,   2,   3,   6,    9},
> +   {  -1,   -2,   -3,  -10,   0,   1,   2,    9},
> +   {  -4,   -6,   -8,   -9,   3,   5,   7,    8},
> +   {  -3,   -5,   -7,   -9,   2,   4,   6,    8},
> +};
> +
>   /* define etc1_parse_block and etc. */
>   #define UINT8_TYPE GLubyte
>   #define TAG(x) x
> @@ -400,7 +424,7 @@ etc2_rgb8_parse_block(struct etc2_block *block, const GLubyte *src)
>         block->flipped = (src[3]&  0x1);
>      }
>
> -   block->pixel_indices =
> +   block->pixel_indices[0] =
>         (src[4]<<  24) | (src[5]<<  16) | (src[6]<<  8) | src[7];
>   }
>
> @@ -413,8 +437,8 @@ etc2_rgb8_fetch_texel(const struct etc2_block *block,
>
>      /* get pixel index */
>      bit = y + x * 4;
> -   idx = ((block->pixel_indices>>  (15 + bit))&  0x2) |
> -         ((block->pixel_indices>>       (bit))&  0x1);
> +   idx = ((block->pixel_indices[0]>>  (15 + bit))&  0x2) |
> +         ((block->pixel_indices[0]>>       (bit))&  0x1);
>
>      if (block->is_ind_mode || block->is_diff_mode) {
>         /* Use pixel index and subblock to get the modifier */
> @@ -456,6 +480,51 @@ etc2_rgb8_fetch_texel(const struct etc2_block *block,
>     }
>   }
>
> +static void
> +etc2_alpha8_fetch_texel(const struct etc2_block *block,
> +      int x, int y, GLubyte *dst)

Further indent the second line of parameters as for other functions.


> +{
> +   int modifier, alpha, bit, idx;
> +   /* get pixel index */
> +   bit = ((3 - y) + (3 - x) * 4) * 3;
> +   idx = (block->pixel_indices[1]>>  bit)&  0x7;
> +   modifier = etc2_modifier_tables[block->table_index][idx];
> +   alpha = block->base_codeword + modifier * block->multiplier;
> +   dst[3] = etc2_clamp(alpha);
> +}
> +
> +static void
> +etc2_alpha8_parse_block(struct etc2_block *block, const GLubyte *src)
> +{
> +   block->base_codeword = src[0];
> +   block->multiplier = 	(src[1]>>  4)&  0xf;
> +   block->table_index = src[1]&  0xf;
> +   block->pixel_indices[1] = (((uint64_t)src[2]<<  40) |
> +                              ((uint64_t)src[3]<<  32) |
> +                              ((uint64_t)src[4]<<  24) |
> +                              ((uint64_t)src[5]<<  16) |
> +                              ((uint64_t)src[6]<<  8)  |
> +                              ((uint64_t)src[7]));
> +}
> +
> +static void
> +etc2_rgba8_parse_block(struct etc2_block *block, const GLubyte *src)
> +{
> +   /* RGB component is parsed the same way as for MESA_FORMAT_ETC2_RGB8 */
> +   etc2_rgb8_parse_block(block, src + 8);
> +
> +   /* Parse Alpha component */
> +   etc2_alpha8_parse_block(block, src);
> +}
> +
> +static void
> +etc2_rgba8_fetch_texel(const struct etc2_block *block,
> +      int x, int y, GLubyte *dst)
> +{
> +   etc2_rgb8_fetch_texel(block, x, y, dst);
> +   etc2_alpha8_fetch_texel(block, x, y, dst);
> +}
> +
>   /**
>    * Convert an 8-bit sRGB value from non-linear space to a
>    * linear RGB value in [0, 1].
> @@ -557,6 +626,42 @@ etc2_unpack_srgb8(uint8_t *dst_row,
>       }
>   }
>
> +static void
> +etc2_unpack_rgba8(uint8_t *dst_row,
> +                  unsigned dst_stride,
> +                  const uint8_t *src_row,
> +                  unsigned src_stride,
> +                  unsigned width,
> +                  unsigned height)
> +{
> +   /* If internalformat is COMPRESSED_RGBA8_ETC2_EAC, each 4 × 4 block of
> +      RGBA8888 information is compressed to 128 bits. To decode a block, the
> +      two 64-bit integers int64bitAlpha and int64bitColor are calculated.
> +   */

For block comments like that we usually prefix each line with '*'.


> +   const unsigned bw = 4, bh = 4, bs = 16, 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_rgba8_parse_block(&block, src);
> +
> +         for (j = 0; j<  bh; j++) {
> +            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
> +            for (i = 0; i<  bw; i++) {
> +               etc2_rgba8_fetch_texel(&block, i, j, dst);
> +               dst += comps;
> +            }
> +         }
> +         src += bs;
> +       }
> +
> +      src_row += src_stride;
> +    }
> +}
> +
>   /* ETC2 texture formats are valid in glCompressedTexImage2D and
>    * glCompressedTexSubImage2D functions */
>   GLboolean
> @@ -575,6 +680,14 @@ _mesa_texstore_etc2_srgb8(TEXSTORE_PARAMS)
>      return GL_FALSE;
>   }
>
> +GLboolean
> +_mesa_texstore_etc2_rgba8_eac(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)
> @@ -615,10 +728,31 @@ _mesa_fetch_texel_2d_f_etc2_srgb8(const struct swrast_texture_image *texImage,
>      texel[ACOMP] = 1.0f;
>   }
>
> +void
> +_mesa_fetch_texel_2d_f_etc2_rgba8_eac(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 +

The texImage->Map field is already a GLubyte so I don't think you need 
that cast.  I think there's quite a few innstances of this.


> +      (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
> +
> +   etc2_rgba8_parse_block(&block, src);
> +   etc2_rgba8_fetch_texel(&block, i % 4, j % 4, dst);
> +
> +   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
> +   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
> +   texel[BCOMP] = 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`
>    * `MESA_FORMAT_ETC2_SRGB8`
> + * `MESA_FORMAT_ETC2_RGBA8_EAC`
>    *
>    * 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.
> @@ -645,4 +779,8 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
>         etc2_unpack_srgb8(dst_row, dst_stride,
>                           src_row, src_stride,
>                           src_width, src_height);
> +   else if (format == MESA_FORMAT_ETC2_RGBA8_EAC)
> +      etc2_unpack_rgba8(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 1dc1d5a..2191c97 100644
> --- a/src/mesa/main/texcompress_etc.h
> +++ b/src/mesa/main/texcompress_etc.h
> @@ -40,6 +40,9 @@ _mesa_texstore_etc2_rgb8(TEXSTORE_PARAMS);
>   GLboolean
>   _mesa_texstore_etc2_srgb8(TEXSTORE_PARAMS);
>
> +GLboolean
> +_mesa_texstore_etc2_rgba8_eac(TEXSTORE_PARAMS);
> +
>   void
>   _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
>                                    GLint i, GLint j, GLint k, GLfloat *texel);
> @@ -49,6 +52,9 @@ _mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
>   void
>   _mesa_fetch_texel_2d_f_etc2_srgb8(const struct swrast_texture_image *texImage,
>                                     GLint i, GLint j, GLint k, GLfloat *texel);
> +void
> +_mesa_fetch_texel_2d_f_etc2_rgba8_eac(const struct swrast_texture_image *texImage,
> +                                      GLint i, GLint j, GLint k, GLfloat *texel);
>
>   void
>   _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
> @@ -65,4 +71,5 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
>                            unsigned src_width,
>                            unsigned src_height,
>                            gl_format format);
> +
>   #endif



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