gallium: add initial pure integer support (v2)

This add support for unsigned/signed integer types via adding a 'pure' bit
in the format description table. It adds 4 new u_format get/put hooks,
for get/put uint and get/put sint so that accessors can get native access
to the integer bits. This is used to avoid precision loss via float converting
paths.

It doesn't add any float fetchers for these types at the moment, GL doesn't
require float fetching from these types and I expect we'll introduce a lot
of hidden bugs if we start allowing such conversions without an API mandating
it.

It adds all formats from EXT_texture_integer and EXT_texture_rg.

0 regressions on llvmpipe here with this.

(there is some more follow on code in my gallium-int-work branch, bringing
 softpipe and mesa to a pretty integer clean state)

v2: fixup python generator to get signed->unsigned and unsigned->signed
fetches working.

Signed-off-by: Dave Airlie <[email protected]>

1 files changed, 122 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.c b/src/gallium/auxiliary/util/u_format.c
index 129b8e93ed3..730dc31ac03 100644
--- a/src/gallium/auxiliary/util/u_format.c
+++ b/src/gallium/auxiliary/util/u_format.c
@@ -118,6 +118,45 @@ util_format_is_luminance(enum pipe_format format)
    return FALSE;
 }
 
+boolean
+util_format_is_pure_integer(enum pipe_format format)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   int i;
+
+   /* Find the first non-void channel. */
+   i = util_format_get_first_non_void_channel(format);
+   if (i == -1)
+      return FALSE;
+
+   return desc->channel[i].pure_integer ? TRUE : FALSE;
+}
+
+boolean
+util_format_is_pure_sint(enum pipe_format format)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   int i;
+
+   i = util_format_get_first_non_void_channel(format);
+   if (i == -1)
+      return FALSE;
+
+   return (desc->channel[i].type == UTIL_FORMAT_TYPE_SIGNED && desc->channel[i].pure_integer) ? TRUE : FALSE;
+}
+
+boolean
+util_format_is_pure_uint(enum pipe_format format)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   int i;
+
+   i = util_format_get_first_non_void_channel(format);
+   if (i == -1)
+      return FALSE;
+
+   return (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED && desc->channel[i].pure_integer) ? TRUE : FALSE;
+}
 
 boolean
 util_format_is_luminance_alpha(enum pipe_format format)
@@ -256,6 +295,89 @@ util_format_write_4ub(enum pipe_format format, const uint8_t *src, unsigned src_
    format_desc->pack_rgba_8unorm(dst_row, dst_stride, src_row, src_stride, w, h);
 }
 
+void
+util_format_read_4ui(enum pipe_format format,
+                     unsigned *dst, unsigned dst_stride,
+                     const void *src, unsigned src_stride,
+                     unsigned x, unsigned y, unsigned w, unsigned h)
+{
+   const struct util_format_description *format_desc;
+   const uint8_t *src_row;
+   unsigned *dst_row;
+
+   format_desc = util_format_description(format);
+
+   assert(x % format_desc->block.width == 0);
+   assert(y % format_desc->block.height == 0);
+
+   src_row = (const uint8_t *)src + y*src_stride + x*(format_desc->block.bits/8);
+   dst_row = dst;
+
+   format_desc->unpack_rgba_uint(dst_row, dst_stride, src_row, src_stride, w, h);
+}
+
+void
+util_format_write_4ui(enum pipe_format format,
+                      const unsigned int *src, unsigned src_stride,
+                      void *dst, unsigned dst_stride,
+                      unsigned x, unsigned y, unsigned w, unsigned h)
+{
+   const struct util_format_description *format_desc;
+   uint8_t *dst_row;
+   const unsigned *src_row;
+
+   format_desc = util_format_description(format);
+
+   assert(x % format_desc->block.width == 0);
+   assert(y % format_desc->block.height == 0);
+
+   dst_row = (uint8_t *)dst + y*dst_stride + x*(format_desc->block.bits/8);
+   src_row = src;
+
+   format_desc->pack_rgba_uint(dst_row, dst_stride, src_row, src_stride, w, h);
+}
+
+void
+util_format_read_4i(enum pipe_format format,
+                    int *dst, unsigned dst_stride,
+                    const void *src, unsigned src_stride,
+                    unsigned x, unsigned y, unsigned w, unsigned h)
+{
+   const struct util_format_description *format_desc;
+   const uint8_t *src_row;
+   int *dst_row;
+
+   format_desc = util_format_description(format);
+
+   assert(x % format_desc->block.width == 0);
+   assert(y % format_desc->block.height == 0);
+
+   src_row = (const uint8_t *)src + y*src_stride + x*(format_desc->block.bits/8);
+   dst_row = dst;
+
+   format_desc->unpack_rgba_sint(dst_row, dst_stride, src_row, src_stride, w, h);
+}
+
+void
+util_format_write_4i(enum pipe_format format,
+                      const int *src, unsigned src_stride,
+                      void *dst, unsigned dst_stride,
+                      unsigned x, unsigned y, unsigned w, unsigned h)
+{
+   const struct util_format_description *format_desc;
+   uint8_t *dst_row;
+   const int *src_row;
+
+   format_desc = util_format_description(format);
+
+   assert(x % format_desc->block.width == 0);
+   assert(y % format_desc->block.height == 0);
+
+   dst_row = (uint8_t *)dst + y*dst_stride + x*(format_desc->block.bits/8);
+   src_row = src;
+
+   format_desc->pack_rgba_sint(dst_row, dst_stride, src_row, src_stride, w, h);
+}
 
 boolean
 util_is_format_compatible(const struct util_format_description *src_desc,