[Mesa-dev] [PATCH 14/22] mesa: Add decoding functions for GL_COMPRESSED_SIGNED_R11_EAC
Anuj Phogat
anuj.phogat at gmail.com
Fri Nov 9 23:30:01 PST 2012
v2: Fixed an issue with signed-r11 decoding. 16 bit signed data is
now converted to 16 bit unsigned data by adding 2 ^ 15 and stored
in an unsigned texture format.
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
src/mesa/main/texcompress_etc.c | 113 +++++++++++++++++++++++++++++++++++++++
src/mesa/main/texcompress_etc.h | 8 +++
2 files changed, 121 insertions(+), 0 deletions(-)
diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
index 4cf7d57..f7d0c43 100644
--- a/src/mesa/main/texcompress_etc.c
+++ b/src/mesa/main/texcompress_etc.c
@@ -31,6 +31,7 @@
* GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
* GL_COMPRESSED_R11_EAC
* GL_COMPRESSED_RG11_EAC
+ * GL_COMPRESSED_SIGNED_R11_EAC
*/
#include <stdbool.h>
@@ -327,6 +328,13 @@ etc2_clamp2(int color)
return (GLushort) CLAMP(color, 0, 2047);
}
+static GLshort
+etc2_clamp3(int color)
+{
+ /* CLAMP(color, -1023, 1023) */
+ return (GLshort) CLAMP(color, -1023, 1023);
+}
+
static void
etc2_rgb8_parse_block(struct etc2_block *block, const GLubyte *src)
{
@@ -545,6 +553,42 @@ etc2_r11_fetch_texel(const struct etc2_block *block,
}
static void
+etc2_signed_r11_fetch_texel(const struct etc2_block *block,
+ int x, int y, GLubyte *dst)
+{
+ GLint modifier, idx;
+ GLshort color;
+ GLbyte base_codeword = (GLbyte) block->base_codeword;
+ /* Get pixel index */
+ idx = etc2_get_pixel_index(block, x, y);
+ modifier = etc2_modifier_tables[block->table_index][idx];
+
+ if (block->multiplier != 0)
+ /* clamp3(base codeword × 8 + modifier × multiplier × 8) */
+ color = etc2_clamp3((base_codeword << 3) +
+ ((modifier * block->multiplier) << 3));
+ else
+ color = etc2_clamp3((base_codeword << 3) + modifier);
+
+ /* Extend 11 bits color value to 16 bits. OpenGL ES 3.0 specification
+ * allows extending the color value to any number of bits. But, an
+ * implementation is not allowed to truncate the 11-bit value to less than
+ * 11 bits. A negative 11-bit value must first be made positive before bit
+ * replication, and then made negative again
+ */
+ if (color >= 0)
+ color = (color << 5) | (color >> 5);
+ else {
+ color = -color;
+ color = (color << 5) | (color >> 5);
+ color = -color;
+ }
+ /* Add 2^15 to get a 16-bit unsigned value */
+ color = color + (1 << 15);
+ ((GLushort *)dst)[0] = color;
+}
+
+static void
etc2_alpha8_parse_block(struct etc2_block *block, const GLubyte *src)
{
block->base_codeword = src[0];
@@ -839,6 +883,42 @@ etc2_unpack_rg11(uint8_t *dst_row,
}
}
+static void
+etc2_unpack_signed_r11(uint8_t *dst_row,
+ unsigned dst_stride,
+ const uint8_t *src_row,
+ unsigned src_stride,
+ unsigned width,
+ unsigned height)
+{
+ /* If internalformat is COMPRESSED_SIGNED_R11_EAC, each 4 × 4 block of
+ red color information is compressed to 64 bits.
+ */
+ const unsigned bw = 4, bh = 4, bs = 8, comps = 1, comp_size = 2;
+ 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_r11_parse_block(&block, src);
+
+ for (j = 0; j < bh; j++) {
+ uint8_t *dst = dst_row + (y + j) * dst_stride +
+ x * comps * comp_size;
+ for (i = 0; i < bw; i++) {
+ etc2_signed_r11_fetch_texel(&block, i, j, dst);
+ dst += comps * comp_size;
+ }
+ }
+ src += bs;
+ }
+
+ src_row += src_stride;
+ }
+}
+
/* ETC2 texture formats are valid in glCompressedTexImage2D and
* glCompressedTexSubImage2D functions */
GLboolean
@@ -882,6 +962,14 @@ _mesa_texstore_etc2_r11_eac(TEXSTORE_PARAMS)
}
GLboolean
+_mesa_texstore_etc2_signed_r11_eac(TEXSTORE_PARAMS)
+{
+ ASSERT(0);
+
+ return GL_FALSE;
+}
+
+GLboolean
_mesa_texstore_etc2_rg11_eac(TEXSTORE_PARAMS)
{
ASSERT(0);
@@ -1018,6 +1106,26 @@ _mesa_fetch_texel_2d_f_etc2_rg11_eac(const struct
texel[ACOMP] = 1.0f;
}
+void
+_mesa_fetch_texel_2d_f_etc2_signed_r11_eac(const struct swrast_texture_image *texImage,
+ GLint i, GLint j, GLint k, GLfloat *texel)
+{
+ struct etc2_block block;
+ GLushort dst;
+ const GLubyte *src;
+
+ src = (const GLubyte *) texImage->Map +
+ (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
+
+ etc2_r11_parse_block(&block, src);
+ etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (GLubyte *)&dst);
+
+ texel[RCOMP] = SHORT_TO_FLOAT(dst);
+ texel[GCOMP] = 0.0f;
+ texel[BCOMP] = 0.0f;
+ texel[ACOMP] = 1.0f;
+}
+
/**
* Decode texture data in any one of following formats:
* `MESA_FORMAT_ETC2_RGB8`
@@ -1026,6 +1134,7 @@ _mesa_fetch_texel_2d_f_etc2_rg11_eac(const struct
* `MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC`
* `MESA_FORMAT_ETC2_R11_EAC`
* `MESA_FORMAT_ETC2_RG11_EAC`
+ * `MESA_FORMAT_ETC2_SIGNED_R11_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.
@@ -1068,4 +1177,8 @@ _mesa_unpack_etc2_format(uint8_t *dst_row,
etc2_unpack_rg11(dst_row, dst_stride,
src_row, src_stride,
src_width, src_height);
+ else if (format == MESA_FORMAT_ETC2_SIGNED_R11_EAC)
+ etc2_unpack_signed_r11(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 358163d..362fa78 100644
--- a/src/mesa/main/texcompress_etc.h
+++ b/src/mesa/main/texcompress_etc.h
@@ -52,6 +52,9 @@ _mesa_texstore_etc2_r11_eac(TEXSTORE_PARAMS);
GLboolean
_mesa_texstore_etc2_rg11_eac(TEXSTORE_PARAMS);
+GLboolean
+_mesa_texstore_etc2_signed_r11_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);
@@ -76,6 +79,11 @@ void
_mesa_fetch_texel_2d_f_etc2_rg11_eac(const struct swrast_texture_image *texImage,
GLint i, GLint j, GLint k, GLfloat *texel);
void
+_mesa_fetch_texel_2d_f_etc2_signed_r11_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,
const uint8_t *src_row,
--
1.7.7.6
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