[Mesa-dev] [PATCH 08/22] mesa: Add decoding functions for GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC

Brian Paul brianp at vmware.com
Mon Nov 12 07:55:16 PST 2012


On 11/10/2012 12:29 AM, Anuj Phogat wrote:
> v2: Use MESA_FORMAT_SARGB8 to store the decoded texture data
> Signed-off-by: Anuj Phogat<anuj.phogat at gmail.com>
> ---
>   src/mesa/main/texcompress_etc.c |   96 +++++++++++++++++++++++++++++++++++---
>   src/mesa/main/texcompress_etc.h |    9 +++-
>   2 files changed, 96 insertions(+), 9 deletions(-)
>
> diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
> index c04ba8d..9940375 100644
> --- a/src/mesa/main/texcompress_etc.c
> +++ b/src/mesa/main/texcompress_etc.c
> @@ -28,6 +28,7 @@
>    * GL_COMPRESSED_RGB8_ETC2
>    * GL_COMPRESSED_SRGB8_ETC2
>    * GL_COMPRESSED_RGBA8_ETC2_EAC
> + * GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
>    */
>
>   #include<stdbool.h>
> @@ -494,6 +495,14 @@ etc2_alpha8_fetch_texel(const struct etc2_block *block,
>   }
>
>   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);
> +}
> +
> +static void
>   etc2_alpha8_parse_block(struct etc2_block *block, const GLubyte *src)
>   {
>      block->base_codeword = src[0];
> @@ -517,14 +526,6 @@ etc2_rgba8_parse_block(struct etc2_block *block, const GLubyte *src)
>      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].
> @@ -662,6 +663,50 @@ etc2_unpack_rgba8(uint8_t *dst_row,
>       }
>   }
>
> +static void
> +etc2_unpack_srgb8_alpha8(uint8_t *dst_row,
> +                         unsigned dst_stride,
> +                         const uint8_t *src_row,
> +                         unsigned src_stride,
> +                         unsigned width,
> +                         unsigned height)
> +{
> +   /* If internalformat is COMPRESSED_SRGB8_ALPHA8_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.

Missing '*' at start of comment line.


> +   */
> +   const unsigned bw = 4, bh = 4, bs = 16, comps = 4;
> +   struct etc2_block block;
> +   unsigned x, y, i, j;
> +   uint8_t tmp;
> +
> +   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);
> +
> +               /* Convert to MESA_FORMAT_SARGB8 */
> +	       tmp = dst[0];
> +               dst[0] = dst[2];

Indentation is off.


> +               dst[2] = tmp;
> +               dst[3] = dst[3];
> +
> +               dst += comps;
> +            }
> +         }
> +         src += bs;
> +       }
> +
> +      src_row += src_stride;
> +    }
> +}
> +
>   /* ETC2 texture formats are valid in glCompressedTexImage2D and
>    * glCompressedTexSubImage2D functions */
>   GLboolean
> @@ -688,6 +733,14 @@ _mesa_texstore_etc2_rgba8_eac(TEXSTORE_PARAMS)
>      return GL_FALSE;
>   }
>
> +GLboolean
> +_mesa_texstore_etc2_srgb8_alpha8_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)
> @@ -748,11 +801,34 @@ _mesa_fetch_texel_2d_f_etc2_rgba8_eac(const struct swrast_texture_image *texImag
>      texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
>   }
>
> +void
> +_mesa_fetch_texel_2d_f_etc2_srgb8_alpha8_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 +

Again, unneeded cast.


> +      (((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] = nonlinear_to_linear(dst[0]);
> +   texel[GCOMP] = nonlinear_to_linear(dst[1]);
> +   texel[BCOMP] = nonlinear_to_linear(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`
> + * `MESA_FORMAT_ETC2_SRGB8_ALPHA8_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.
> @@ -783,4 +859,8 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
>         etc2_unpack_rgba8(dst_row, dst_stride,
>                           src_row, src_stride,
>                           src_width, src_height);
> +   else if (format == MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC)
> +      etc2_unpack_srgb8_alpha8(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 2191c97..c10414d 100644
> --- a/src/mesa/main/texcompress_etc.h
> +++ b/src/mesa/main/texcompress_etc.h
> @@ -43,6 +43,9 @@ _mesa_texstore_etc2_srgb8(TEXSTORE_PARAMS);
>   GLboolean
>   _mesa_texstore_etc2_rgba8_eac(TEXSTORE_PARAMS);
>
> +GLboolean
> +_mesa_texstore_etc2_srgb8_alpha8_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);
> @@ -55,7 +58,11 @@ _mesa_fetch_texel_2d_f_etc2_srgb8(const struct swrast_texture_image *texImage,
>   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_fetch_texel_2d_f_etc2_srgb8_alpha8_eac(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,



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