[Mesa-dev] [PATCH 08/27] mesa: Add decoding functions for GL_COMPRESSED_SRGB8_ETC2
Anuj Phogat
anuj.phogat at gmail.com
Fri Nov 9 21:19:42 PST 2012
On Tue, Nov 6, 2012 at 3:23 PM, Ian Romanick <idr at freedesktop.org> wrote:
>
> On 10/19/2012 04:28 PM, Anuj Phogat wrote:
>>
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>> src/mesa/main/texcompress_etc.c | 96 +++++++++++++++++++++++++++++++++++++--
>> src/mesa/main/texcompress_etc.h | 7 +++
>> 2 files changed, 99 insertions(+), 4 deletions(-)
>>
>> diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
>> index 8294144..6589c8d 100644
>> --- a/src/mesa/main/texcompress_etc.c
>> +++ b/src/mesa/main/texcompress_etc.c
>> @@ -459,6 +459,20 @@ etc2_rgb8_fetch_texel(const struct etc2_block *block,
>> }
>> }
>>
>> +/**
>> + * Convert from sRGB color space to linear color space, using the
>> + * formula from the GL 3.0 spec, section 4.1.8 (sRGB Texture Color
>> + * Conversion).
>> + */
>> +static float
>> +decode_srgb(float cs)
>> +{
>> + if (cs <= 0.0405)
>> + return cs / 12.92;
>> + else
>> + return pow((cs + 0.055) / 1.055, 2.4);
>> +}
>> +
>
>
> Isn't there already some code for sRGB conversion? It seems like there should be to support GL_SRGB8 textures.
>
yeah. duplicate static inline functions exist in format_unpack.c and
texcompress_s3tc.c.
I'll fix it in a separate patch to make the function available to other files.
>
>> static void
>> etc2_unpack_rgb8(uint8_t *dst_row,
>> unsigned dst_stride,
>> @@ -493,6 +507,46 @@ etc2_unpack_rgb8(uint8_t *dst_row,
>> }
>> }
>>
>> +static void
>> +etc2_unpack_srgb8(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);
>> +
>> + 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);
>> + dst[3] = 255;
>> +
>> + /* 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] = FLOAT_TO_UBYTE(decode_srgb(1.0f));
>> +
>> + dst += comps;
>> + }
>> + }
>> + src += bs;
>> + }
>> +
>> + src_row += src_stride;
>> + }
>> +}
>> +
>> /* ETC2 texture formats are valid in glCompressedTexImage2D and
>> * glCompressedTexSubImage2D functions */
>> GLboolean
>> @@ -503,6 +557,14 @@ _mesa_texstore_etc2_rgb8(TEXSTORE_PARAMS)
>> return GL_FALSE;
>> }
>>
>> +GLboolean
>> +_mesa_texstore_etc2_srgb8(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)
>> @@ -523,9 +585,30 @@ _mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
>> texel[ACOMP] = 1.0f;
>> }
>>
>> +void
>> +_mesa_fetch_texel_2d_f_etc2_srgb8(const struct swrast_texture_image *texImage,
>> + GLint i, GLint j, GLint k, GLfloat *texel)
>> +{
>> + struct etc2_block block;
>> + GLubyte dst[3];
>> + const GLubyte *src;
>> +
>> + src = (const GLubyte *) texImage->Map +
>> + (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
>> +
>> + etc2_rgb8_parse_block(&block, src);
>> + etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst);
>> +
>> + 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] = decode_srgb(1.0f);
>> +}
>>
>> /**
>> - * Decode texture data in format `MESA_FORMAT_ETC2_RGB8`
>> + * Decode texture data in any one of following formats:
>> + * `MESA_FORMAT_ETC2_RGB8`
>> + * `MESA_FORMAT_ETC2_SRGB8`
>> *
>> * 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.
>> @@ -544,7 +627,12 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
>> unsigned src_height,
>> gl_format format)
>> {
>> - etc2_unpack_rgb8(dst_row, dst_stride,
>> - src_row, src_stride,
>> - src_width, src_height);
>> + if (format == MESA_FORMAT_ETC2_RGB8)
>> + etc2_unpack_rgb8(dst_row, dst_stride,
>> + src_row, src_stride,
>> + src_width, src_height);
>> + else if (format == MESA_FORMAT_ETC2_SRGB8)
>> + etc2_unpack_srgb8(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 2508f5f..1dc1d5a 100644
>> --- a/src/mesa/main/texcompress_etc.h
>> +++ b/src/mesa/main/texcompress_etc.h
>> @@ -37,6 +37,9 @@ _mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS);
>> GLboolean
>> _mesa_texstore_etc2_rgb8(TEXSTORE_PARAMS);
>>
>> +GLboolean
>> +_mesa_texstore_etc2_srgb8(TEXSTORE_PARAMS);
>> +
>> void
>> _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
>> GLint i, GLint j, GLint k, GLfloat *texel);
>> @@ -44,6 +47,10 @@ void
>> _mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
>> GLint i, GLint j, GLint k, GLfloat *texel);
>> void
>> +_mesa_fetch_texel_2d_f_etc2_srgb8(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,
>>
>
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