swrast: Make the packed depth/stencil read fastpath use MapRenderbuffer.

This also makes it handle 24/8 vs 8/24, fixing piglit
depthstencil-default_fb-readpixels-24_8 on i965.  While here, avoid
incorrectly fast-pathing if packing->SwapBytes is set.

v2: Move the unpack code to format_unpack.c, fix BUFFER_DEPTH typo
v3: Fix signed/unsigned comparison.

Reviewed-by: Brian Paul <[email protected]>

2 files changed, 39 insertions, 0 deletions

diff --git a/src/mesa/main/format_unpack.c b/src/mesa/main/format_unpack.c
index 3d044af0d4d..eaa33dfdb71 100644
--- a/src/mesa/main/format_unpack.c
+++ b/src/mesa/main/format_unpack.c
@@ -1539,3 +1539,38 @@ _mesa_unpack_ubyte_stencil_row(gl_format format, GLuint n,
       return;
    }
 }
+
+static void
+unpack_uint_24_8_depth_stencil_S8_Z24(const GLuint *src, GLuint *dst, GLuint n)
+{
+   GLuint i;
+
+   for (i = 0; i < n; i++) {
+      GLuint val = src[i];
+      dst[i] = val >> 24 | val << 8;
+   }
+}
+
+static void
+unpack_uint_24_8_depth_stencil_Z24_S8(const GLuint *src, GLuint *dst, GLuint n)
+{
+   memcpy(dst, src, n * 4);
+}
+
+void
+_mesa_unpack_uint_24_8_depth_stencil_row(gl_format format, GLuint n,
+					 const void *src, GLuint *dst)
+{
+   switch (format) {
+   case MESA_FORMAT_Z24_S8:
+      unpack_uint_24_8_depth_stencil_Z24_S8(src, dst, n);
+      break;
+   case MESA_FORMAT_S8_Z24:
+      unpack_uint_24_8_depth_stencil_S8_Z24(src, dst, n);
+      break;
+   default:
+      _mesa_problem(NULL, "bad format %s in _mesa_unpack_ubyte_s_row",
+                    _mesa_get_format_name(format));
+      return;
+   }
+}
diff --git a/src/mesa/main/format_unpack.h b/src/mesa/main/format_unpack.h
index 2e00047c201..a8a829c8867 100644
--- a/src/mesa/main/format_unpack.h
+++ b/src/mesa/main/format_unpack.h
@@ -49,5 +49,9 @@ void
 _mesa_unpack_ubyte_stencil_row(gl_format format, GLuint n,
 			       const void *src, GLubyte *dst);
 
+void
+_mesa_unpack_uint_24_8_depth_stencil_row(gl_format format, GLuint n,
+					 const void *src, GLuint *dst);
+
 
 #endif /* FORMAT_UNPACK_H */