[Mesa-stable] [PATCH v3 13/51] st/nine: NineBaseTexture9: update sampler view creation

[Axel Davy]

While previous code was having the correct behaviour in general,
this new code is more readable (without checking all gallium formats
manually) and has a more defined behaviour for depth stencil resources.

Reviewed-by: Tiziano Bacocco <tizbac2 at gmail.com>
Reviewed-by: David Heidelberg <david at ixit.cz>
Signed-off-by: Axel Davy <axel.davy at ens.fr>
Cc: "10.4" <mesa-stable at lists.freedesktop.org>
---
Since last version, we have tested precisely Win behaviour for depth buffer formats

 src/gallium/state_trackers/nine/basetexture9.c | 45 ++++++++++++++++++--------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/src/gallium/state_trackers/nine/basetexture9.c b/src/gallium/state_trackers/nine/basetexture9.c
index af4778b..efa884f 100644
--- a/src/gallium/state_trackers/nine/basetexture9.c
+++ b/src/gallium/state_trackers/nine/basetexture9.c
@@ -436,6 +436,10 @@ NineBaseTexture9_CreatePipeResource( struct NineBaseTexture9 *This,
     return D3D_OK;
 }
 
+#define SWIZZLE_TO_REPLACE(s) (s == UTIL_FORMAT_SWIZZLE_0 || \
+                               s == UTIL_FORMAT_SWIZZLE_1 || \
+                               s == UTIL_FORMAT_SWIZZLE_NONE)
+
 HRESULT
 NineBaseTexture9_UpdateSamplerView( struct NineBaseTexture9 *This,
                                     const int sRGB )
@@ -444,6 +448,7 @@ NineBaseTexture9_UpdateSamplerView( struct NineBaseTexture9 *This,
     struct pipe_context *pipe = This->pipe;
     struct pipe_resource *resource = This->base.resource;
     struct pipe_sampler_view templ;
+    unsigned i;
     uint8_t swizzle[4];
 
     DBG("This=%p sRGB=%d\n", This, sRGB);
@@ -463,20 +468,34 @@ NineBaseTexture9_UpdateSamplerView( struct NineBaseTexture9 *This,
     swizzle[3] = PIPE_SWIZZLE_ALPHA;
     desc = util_format_description(resource->format);
     if (desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS) {
-        /* ZZZ1 -> 0Z01 (see end of docs/source/tgsi.rst)
-         * XXX: but it's wrong
-        swizzle[0] = PIPE_SWIZZLE_ZERO;
-        swizzle[2] = PIPE_SWIZZLE_ZERO; */
-    } else
-    if (desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_X &&
-        desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_1) {
-        /* R001/RG01 -> R111/RG11 */
-        if (desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_0)
-            swizzle[1] = PIPE_SWIZZLE_ONE;
-        if (desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_0)
-            swizzle[2] = PIPE_SWIZZLE_ONE;
+        /* msdn doc is incomplete here and wrong.
+         * The only formats that can be read directly here
+         * are DF16, DF24 and INTZ.
+         * Tested on win the swizzle is
+         * R = depth, G = B = 0, A = 1 for DF16 and DF24
+         * R = G = B = A = depth for INTZ
+         * For the other ZS formats that can't be read directly
+         * but can be used as shadow map, the result is duplicated on
+         * all channel */
+        if (This->format == D3DFMT_DF16 ||
+            This->format == D3DFMT_DF24) {
+            swizzle[1] = PIPE_SWIZZLE_ZERO;
+            swizzle[2] = PIPE_SWIZZLE_ZERO;
+            swizzle[3] = PIPE_SWIZZLE_ONE;
+        } else {
+            swizzle[1] = PIPE_SWIZZLE_RED;
+            swizzle[2] = PIPE_SWIZZLE_RED;
+            swizzle[3] = PIPE_SWIZZLE_RED;
+        }
+    } else if (resource->format != PIPE_FORMAT_A8_UNORM) {
+        /* A8 is the only exception that should have 0.0 as default values
+         * for RGB. It is already what gallium does. All the other ones
+         * should have 1.0 for non-defined values */
+        for (i = 0; i < 4; i++) {
+            if (SWIZZLE_TO_REPLACE(desc->swizzle[i]))
+                swizzle[i] = PIPE_SWIZZLE_ONE;
+        }
     }
-    /* but 000A remains unchanged */
 
     templ.format = sRGB ? util_format_srgb(resource->format) : resource->format;
     templ.u.tex.first_layer = 0;
-- 
2.1.0