r600g: truncate point sampled texture coordinates

By default the hardware rounds texcoords.  However,
for point sampled textures, the expected behavior is
to truncate.  When we have point sampled textures,
set the truncate bit in the sampler.

Should fix:
https://bugs.freedesktop.org/show_bug.cgi?id=25871

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index 3efdbab..a388476 100644 (file)
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -305,11 +305,16 @@ static void *evergreen_create_sampler_state(struct pipe_context *ctx,
 {
        struct r600_pipe_state *rstate = CALLOC_STRUCT(r600_pipe_state);
        union util_color uc;
+       uint32_t coord_trunc = 0;
 
        if (rstate == NULL) {
                return NULL;
        }
 
+       if ((state->mag_img_filter == PIPE_TEX_FILTER_NEAREST) ||
+           (state->min_img_filter == PIPE_TEX_FILTER_NEAREST))
+               coord_trunc = 1;
+
        rstate->id = R600_PIPE_STATE_SAMPLER;
        util_pack_color(state->border_color, PIPE_FORMAT_B8G8R8A8_UNORM, &uc);
        r600_pipe_state_add_reg(rstate, R_03C000_SQ_TEX_SAMPLER_WORD0_0,
@@ -328,6 +333,7 @@ static void *evergreen_create_sampler_state(struct pipe_context *ctx,
                        0xFFFFFFFF, NULL);
        r600_pipe_state_add_reg(rstate, R_03C008_SQ_TEX_SAMPLER_WORD2_0,
                                S_03C008_LOD_BIAS(S_FIXED(CLAMP(state->lod_bias, -16, 16), 8)) |
+                               S_03C008_MC_COORD_TRUNCATE(coord_trunc) |
                                S_03C008_TYPE(1),
                                0xFFFFFFFF, NULL);
 

diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index c365979..3f2af7d 100644 (file)
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -358,11 +358,16 @@ static void *r600_create_sampler_state(struct pipe_context *ctx,
 {
        struct r600_pipe_state *rstate = CALLOC_STRUCT(r600_pipe_state);
        union util_color uc;
+       uint32_t coord_trunc = 0;
 
        if (rstate == NULL) {
                return NULL;
        }
 
+       if ((state->mag_img_filter == PIPE_TEX_FILTER_NEAREST) ||
+           (state->min_img_filter == PIPE_TEX_FILTER_NEAREST))
+               coord_trunc = 1;
+
        rstate->id = R600_PIPE_STATE_SAMPLER;
        util_pack_color(state->border_color, PIPE_FORMAT_B8G8R8A8_UNORM, &uc);
        r600_pipe_state_add_reg(rstate, R_03C000_SQ_TEX_SAMPLER_WORD0_0,
@@ -379,7 +384,9 @@ static void *r600_create_sampler_state(struct pipe_context *ctx,
                        S_03C004_MIN_LOD(S_FIXED(CLAMP(state->min_lod, 0, 15), 6)) |
                        S_03C004_MAX_LOD(S_FIXED(CLAMP(state->max_lod, 0, 15), 6)) |
                        S_03C004_LOD_BIAS(S_FIXED(CLAMP(state->lod_bias, -16, 16), 6)), 0xFFFFFFFF, NULL);
-       r600_pipe_state_add_reg(rstate, R_03C008_SQ_TEX_SAMPLER_WORD2_0, S_03C008_TYPE(1), 0xFFFFFFFF, NULL);
+       r600_pipe_state_add_reg(rstate, R_03C008_SQ_TEX_SAMPLER_WORD2_0,
+                               S_03C008_MC_COORD_TRUNCATE(coord_trunc) |
+                               S_03C008_TYPE(1), 0xFFFFFFFF, NULL);
        if (uc.ui) {
                r600_pipe_state_add_reg(rstate, R_00A400_TD_PS_SAMPLER0_BORDER_RED, fui(state->border_color[0]), 0xFFFFFFFF, NULL);
                r600_pipe_state_add_reg(rstate, R_00A404_TD_PS_SAMPLER0_BORDER_GREEN, fui(state->border_color[1]), 0xFFFFFFFF, NULL);