[Mesa-dev] [PATCH] mesa: Add unpack_uint_z_row support for floating-point depth buffers

[Brian Paul]

On 02/01/2012 02:38 PM, Ian Romanick wrote:
> From: Ian Romanick<ian.d.romanick at intel.com>
>
> This is a hack, and it will result in incorrect rendering.  However,
> it does eliminate spurious warnings in several piglit CopyPixels tests
> that involve floating-point depth buffers.
>
> The real solution is to add a zf field to SWspan to store float Z
> values.  When a float depth buffer is involved, swrast should also
> populate the zf field.  I'll consider this post-8.0 work.
>
> Signed-off-by: Ian Romanick<ian.d.romanick at intel.com>
> ---
>   src/mesa/main/format_unpack.c |   32 ++++++++++++++++++++++++++++++++
>   1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/src/mesa/main/format_unpack.c b/src/mesa/main/format_unpack.c
> index cd16a9e..b45dde2 100644
> --- a/src/mesa/main/format_unpack.c
> +++ b/src/mesa/main/format_unpack.c
> @@ -2916,6 +2916,32 @@ unpack_uint_z_Z32(const void *src, GLuint *dst, GLuint n)
>      memcpy(dst, src, n * sizeof(GLuint));
>   }
>
> +static void
> +unpack_uint_z_Z32_FLOAT(const void *src, GLuint *dst, GLuint n)
> +{
> +   const float *s = ((const float *)src);

More parens than necessary there.


> +   GLuint i;
> +   for (i = 0; i<  n; i++) {
> +      dst[i] = FLOAT_TO_UINT(IROUND(CLAMP((s[i]), 0.0F, 1.0F)));
> +   }
> +}
> +
> +static void
> +unpack_uint_z_Z32_FLOAT_X24S8(const void *src, GLuint *dst, GLuint n)
> +{
> +   struct z32f_x24s8 {
> +      float z;
> +      uint32_t x24s8;
> +   };
> +
> +   const struct z32f_x24s8 *s = (const struct z32f_x24s8 *) src;
> +   GLuint i;
> +
> +   for (i = 0; i<  n; i++) {
> +      dst[i] = FLOAT_TO_UINT(IROUND(CLAMP((s[i].z), 0.0F, 1.0F)));
> +   }
> +}
> +
>
>   /**
>    * Unpack Z values.
> @@ -2943,6 +2969,12 @@ _mesa_unpack_uint_z_row(gl_format format, GLuint n,
>      case MESA_FORMAT_Z32:
>         unpack = unpack_uint_z_Z32;
>         break;
> +   case MESA_FORMAT_Z32_FLOAT:
> +      unpack = unpack_uint_z_Z32_FLOAT;
> +      break;
> +   case MESA_FORMAT_Z32_FLOAT_X24S8:
> +      unpack = unpack_uint_z_Z32_FLOAT_X24S8;
> +      break;
>      default:
>         _mesa_problem(NULL, "bad format %s in _mesa_unpack_uint_z_row",
>                       _mesa_get_format_name(format));


Reviewed-by: Brian Paul <brianp at vmware.com>