gallium/format: Add a helper to combine separate Z24 and S8 stencil.

This new function takes separate Z24 depth and S8 stencil sources,
and packs them into a single combined Z24S8 buffer.

Reviewed-by: Eric Anholt <[email protected]>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format_zs.c b/src/gallium/auxiliary/util/u_format_zs.c
index 4ad3a0c6477..4b801d2dcf7 100644
--- a/src/gallium/auxiliary/util/u_format_zs.c
+++ b/src/gallium/auxiliary/util/u_format_zs.c
@@ -449,6 +449,26 @@ util_format_z24_unorm_s8_uint_pack_s_8uint(uint8_t *dst_row, unsigned dst_stride
 }
 
 void
+util_format_z24_unorm_s8_uint_pack_separate(uint8_t *dst_row, unsigned dst_stride,
+                                            const uint32_t *z_src_row, unsigned z_src_stride,
+                                            const uint8_t *s_src_row, unsigned s_src_stride,
+                                            unsigned width, unsigned height)
+{
+   unsigned x, y;
+   for (y = 0; y < height; ++y) {
+      const uint32_t *z_src = z_src_row;
+      const uint8_t *s_src = s_src_row;
+      uint32_t *dst = (uint32_t *)dst_row;
+      for (x = 0; x < width; ++x) {
+         *dst++ = (*z_src++ & 0x00ffffff) | (*s_src++ << 24);
+      }
+      dst_row += dst_stride / sizeof(*dst_row);
+      z_src_row += z_src_stride / sizeof(*z_src_row);
+      s_src_row += s_src_stride / sizeof(*s_src_row);
+   }
+}
+
+void
 util_format_s8_uint_z24_unorm_unpack_z_float(float *dst_row, unsigned dst_stride,
                                                 const uint8_t *src_row, unsigned src_stride,
                                                 unsigned width, unsigned height)
diff --git a/src/gallium/auxiliary/util/u_format_zs.h b/src/gallium/auxiliary/util/u_format_zs.h
index adddfaf3a74..160919dde73 100644
--- a/src/gallium/auxiliary/util/u_format_zs.h
+++ b/src/gallium/auxiliary/util/u_format_zs.h
@@ -112,6 +112,8 @@ util_format_z24_unorm_s8_uint_unpack_s_8uint(uint8_t *dst_row, unsigned dst_stri
 void
 util_format_z24_unorm_s8_uint_pack_s_8uint(uint8_t *dst_row, unsigned dst_stride, const uint8_t *src_row, unsigned src_stride, unsigned width, unsigned height);
 
+void
+util_format_z24_unorm_s8_uint_pack_separate(uint8_t *dst_row, unsigned dst_stride, const uint32_t *z_src_row, unsigned z_src_stride, const uint8_t *s_src_row, unsigned s_src_stride, const unsigned width, unsigned height);
 
 void
 util_format_s8_uint_z24_unorm_unpack_z_float(float *dst_row, unsigned dst_stride, const uint8_t *src_row, unsigned src_stride, unsigned width, unsigned height);