Mesa (master): r600g: document why texture offset emulation is needed

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 9c2a3934c5e039d996c721478eeb1fa3f956904e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9c2a3934c5e039d996c721478eeb1fa3f956904e

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Mon Mar 10 00:19:21 2014 +0100

r600g: document why texture offset emulation is needed

---

 src/gallium/drivers/r600/r600_shader.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 0016d29..ddf79ee 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -4800,8 +4800,9 @@ static int tgsi_tex(struct r600_shader_ctx *ctx)
 	if (inst->Texture.NumOffsets) {
 		assert(inst->Texture.NumOffsets == 1);
 
+		/* The texture offset feature doesn't work with the TXF instruction
+		 * and must be emulated by adding the offset to the texture coordinates. */
 		if (txf_add_offsets) {
-			/* Add the offsets for texelFetch manually. */
 			const struct tgsi_texture_offset *off = inst->TexOffsets;
 
 			switch (inst->Texture.Texture) {