v2: Use MESA_FORMAT_SARGB8 to store the decoded texture data
Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com>
---
src/mesa/main/texcompress_etc.c | 109 +++++++++++++++++++++++++++++++++++++--
src/mesa/main/texcompress_etc.h | 7 +++
2 files changed, 112 insertions(+), 4 deletions(-)
diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
index bf43edb..eacfb0d 100644
--- a/src/mesa/main/texcompress_etc.c
+++ b/src/mesa/main/texcompress_etc.c
@@ -456,6 +456,33 @@ etc2_rgb8_fetch_texel(const struct etc2_block *block,
}
}
+/**
+ * Convert an 8-bit sRGB value from non-linear space to a
+ * linear RGB value in [0, 1].
+ * Implemented with a 256-entry lookup table.
+ */
+static inline GLfloat
+nonlinear_to_linear(GLubyte cs8)
+{
+ static GLfloat table[256];
+ static GLboolean tableReady = GL_FALSE;
+ if (!tableReady) {
+ /* compute lookup table now */
+ GLuint i;
+ for (i = 0; i < 256; i++) {
+ const GLfloat cs = UBYTE_TO_FLOAT(i);
+ if (cs <= 0.04045) {
+ table[i] = cs / 12.92f;
+ }
+ else {
+ table[i] = (GLfloat) pow((cs + 0.055) / 1.055, 2.4);
+ }
+ }
+ tableReady = GL_TRUE;
+ }
+ return table[cs8];
+}
+
static void
etc2_unpack_rgb8(uint8_t *dst_row,
unsigned dst_stride,
@@ -490,6 +517,46 @@ 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;
+ uint8_t tmp;
+
+ 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,
+ false /* punchthrough_alpha */);
+ /* Convert to MESA_FORMAT_SARGB8 */
+ tmp = dst[0];
+ dst[0] = dst[2];
+ dst[2] = tmp;
+ dst[3] = 255;
+
+ dst += comps;
+ }
+ }
+ src += bs;
+ }
+
+ src_row += src_stride;
+ }
+}
+
/* ETC2 texture formats are valid in glCompressedTexImage2D and
* glCompressedTexSubImage2D functions */
GLboolean
@@ -500,6 +567,14 @@ _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)
@@ -520,9 +595,30 @@ _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] = nonlinear_to_linear(dst[0]);
+ texel[GCOMP] = nonlinear_to_linear(dst[1]);
+ texel[BCOMP] = nonlinear_to_linear(dst[2]);
+ texel[ACOMP] = 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.
@@ -541,7 +637,12 @@ _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,
--
1.7.7.6
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