[Mesa-stable] [PATCH V2] mesa: Don't use memcpy() in _mesa_texstore() for float depth texture data

[Anuj Phogat]

because float depth texture data needs clamping to [0.0, 1.0]. Let the
_mesa_texstore() fallback to slower path.

Fixes Khronos GLES3 CTS tests:
shadow_execution_vert
shadow_execution_frag

V2: Move the check to _mesa_texstore_can_use_memcpy() function.
    Add check for floating point data types.

Cc: <mesa-stable at lists.freedesktop.org>
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 src/mesa/main/texstore.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/mesa/main/texstore.c b/src/mesa/main/texstore.c
index d363f9f..c87e407 100644
--- a/src/mesa/main/texstore.c
+++ b/src/mesa/main/texstore.c
@@ -3830,6 +3830,21 @@ _mesa_texstore_can_use_memcpy(struct gl_context *ctx,
       return GL_FALSE;
    }
 
+   /* Depth texture data needs clamping in following cases:
+    * - Floating point dstFormat with signed srcType: clamp to [0.0, 1.0].
+    * - Fixed point dstFormat with signed srcType: clamp to [0, 2^n -1].
+    *
+    * All the cases except one (float dstFormat with float srcType) are ruled
+    * out by _mesa_format_matches_format_and_type() check above. Handle the
+    * remaining case here.
+    */
+   if ((baseInternalFormat == GL_DEPTH_COMPONENT ||
+        baseInternalFormat == GL_DEPTH_STENCIL) &&
+       (srcType == GL_FLOAT ||
+        srcType == GL_FLOAT_32_UNSIGNED_INT_24_8_REV)) {
+      return GL_FALSE;
+   }
+
    return GL_TRUE;
 }
 
-- 
1.9.3