From 7d16e2c0cd70dc5a23b746dbc8e44c58366b5353 Mon Sep 17 00:00:00 2001
From: Marek Olšák <maraeo@gmail.com>
Date: Mon, 7 Mar 2011 02:03:52 +0100
Subject: mesa: add EXT_texture_compression_latc

The encoding/decoding algorithms are shared with RGTC.
Thanks to some magic with the base format, the RGTC texstore functions work
for LATC too.

swrast passes the related piglit tests besides two things:
- The alpha channel is wrong (it's always 1), however the incorrect alpha
  channel makes some other tests fail too, so I guess it's unrelated to LATC.
- Signed LATC fetches aren't correct yet (signed values are clamped to [0,1]),
  however RGTC has the same problem.

Further testing (with other of my patches) shows that hardware drivers
and softpipe work.

BTW, ETQW uses this extension.
---
 src/mesa/main/texcompress_rgtc.c | 68 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 64 insertions(+), 4 deletions(-)

(limited to 'src/mesa/main/texcompress_rgtc.c')

diff --git a/src/mesa/main/texcompress_rgtc.c b/src/mesa/main/texcompress_rgtc.c
index 26dca2d760..c50df19c5d 100644
--- a/src/mesa/main/texcompress_rgtc.c
+++ b/src/mesa/main/texcompress_rgtc.c
@@ -98,7 +98,8 @@ _mesa_texstore_red_rgtc1(TEXSTORE_PARAMS)
    GLubyte srcpixels[4][4];
    GLubyte *blkaddr;
    GLint dstRowDiff;
-   ASSERT(dstFormat == MESA_FORMAT_RED_RGTC1);
+   ASSERT(dstFormat == MESA_FORMAT_RED_RGTC1 ||
+          dstFormat == MESA_FORMAT_L_LATC1);
    ASSERT(dstXoffset % 4 == 0);
    ASSERT(dstYoffset % 4 == 0);
    ASSERT(dstZoffset % 4 == 0);
@@ -153,7 +154,8 @@ _mesa_texstore_signed_red_rgtc1(TEXSTORE_PARAMS)
    GLbyte srcpixels[4][4];
    GLbyte *blkaddr;
    GLint dstRowDiff;
-   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RED_RGTC1);
+   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RED_RGTC1 ||
+          dstFormat == MESA_FORMAT_SIGNED_L_LATC1);
    ASSERT(dstXoffset % 4 == 0);
    ASSERT(dstYoffset % 4 == 0);
    ASSERT(dstZoffset % 4 == 0);
@@ -208,7 +210,8 @@ _mesa_texstore_rg_rgtc2(TEXSTORE_PARAMS)
    GLubyte *blkaddr;
    GLint dstRowDiff;
 
-   ASSERT(dstFormat == MESA_FORMAT_RG_RGTC2);
+   ASSERT(dstFormat == MESA_FORMAT_RG_RGTC2 ||
+          dstFormat == MESA_FORMAT_LA_LATC2);
    ASSERT(dstXoffset % 4 == 0);
    ASSERT(dstYoffset % 4 == 0);
    ASSERT(dstZoffset % 4 == 0);
@@ -269,7 +272,8 @@ _mesa_texstore_signed_rg_rgtc2(TEXSTORE_PARAMS)
    GLbyte *blkaddr;
    GLint dstRowDiff;
 
-   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RG_RGTC2);
+   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RG_RGTC2 ||
+          dstFormat == MESA_FORMAT_SIGNED_LA_LATC2);
    ASSERT(dstXoffset % 4 == 0);
    ASSERT(dstYoffset % 4 == 0);
    ASSERT(dstZoffset % 4 == 0);
@@ -374,6 +378,62 @@ _mesa_fetch_texel_2d_f_signed_rg_rgtc2(const struct gl_texture_image *texImage,
    texel[ACOMP] = 1.0;
 }
 
+void
+_mesa_fetch_texel_2d_f_l_latc1(const struct gl_texture_image *texImage,
+                                 GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   GLubyte red;
+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data),
+                       i, j, &red, 1);
+   texel[RCOMP] =
+   texel[GCOMP] =
+   texel[BCOMP] = UBYTE_TO_FLOAT(red);
+   texel[ACOMP] = 1.0;
+}
+
+void
+_mesa_fetch_texel_2d_f_signed_l_latc1(const struct gl_texture_image *texImage,
+                                        GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   GLbyte red;
+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data),
+                       i, j, &red, 1);
+   texel[RCOMP] =
+   texel[GCOMP] =
+   texel[BCOMP] = BYTE_TO_FLOAT_TEX(red);
+   texel[ACOMP] = 1.0;
+}
+
+void
+_mesa_fetch_texel_2d_f_la_latc2(const struct gl_texture_image *texImage,
+                                 GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   GLubyte red, green;
+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data),
+                     i, j, &red, 2);
+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data) + 8,
+                     i, j, &green, 2);
+   texel[RCOMP] =
+   texel[GCOMP] =
+   texel[BCOMP] = UBYTE_TO_FLOAT(red);
+   texel[ACOMP] = UBYTE_TO_FLOAT(green);
+}
+
+void
+_mesa_fetch_texel_2d_f_signed_la_latc2(const struct gl_texture_image *texImage,
+                                       GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   GLbyte red, green;
+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data),
+                     i, j, &red, 2);
+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data) + 8,
+                     i, j, &green, 2);
+   texel[RCOMP] =
+   texel[GCOMP] =
+   texel[BCOMP] = BYTE_TO_FLOAT_TEX(red);
+   texel[ACOMP] = BYTE_TO_FLOAT_TEX(green);
+}
+
 #define TAG(x) unsigned_##x
 
 #define TYPE GLubyte
-- 
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