r300g: implement D24X8 texture sampling for r3xx-r4xx

Because the hw can't sample it, I reinterpret the format as G16R16 and
sample the G component. This gives 16 bits of precision, which should be
enough for depth texturing (surprisingly, the sampled values are exactly
the same as in D16 textures).

This also enables EXT_packed_depth_stencil on those old chipsets, finally.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/gallium/drivers/r300/r300_texture.h b/src/gallium/drivers/r300/r300_texture.h
index 585036ab3b..a4524320fd 100644
--- a/src/gallium/drivers/r300/r300_texture.h
+++ b/src/gallium/drivers/r300/r300_texture.h
@@ -35,7 +35,8 @@ unsigned r300_get_swizzle_combined(const unsigned char *swizzle_format,
                                    const unsigned char *swizzle_view);
 
 uint32_t r300_translate_texformat(enum pipe_format format,
-                                  const unsigned char *swizzle_view);
+                                  const unsigned char *swizzle_view,
+                                  boolean is_r500);
 
 uint32_t r500_tx_format_msb_bit(enum pipe_format format);