[Mesa-dev] [PATCH 02/11] i965/blorp: round to nearest when converting float to integer

[Eduardo Lima Mitev]

From: Samuel Iglesias Gonsalvez <siglesias at igalia.com>

Round floating point values to nearest integer to avoid "off by one texel"
kind of errors when blitting.

Fixes:

dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_nearest
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_linear
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_y_nearest
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_y_linear
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_dst_y_nearest
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_dst_y_linear
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_dst_x_nearest
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_dst_x_linear
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_dst_y_nearest
dEQP-GLES3.functional.fbo.blit.rect.out_of_bounds_reverse_src_dst_y_linear

No piglit regressions.

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
---
 src/mesa/drivers/dri/i965/brw_blorp_blit.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index 10a53dc..469baf7 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -1994,10 +1994,13 @@ brw_blorp_blit_params::brw_blorp_blit_params(struct brw_context *brw,
 
    wm_prog_key.src_tiled_w = src.map_stencil_as_y_tiled;
    wm_prog_key.dst_tiled_w = dst.map_stencil_as_y_tiled;
-   x0 = wm_push_consts.dst_x0 = dst_x0;
-   y0 = wm_push_consts.dst_y0 = dst_y0;
-   x1 = wm_push_consts.dst_x1 = dst_x1;
-   y1 = wm_push_consts.dst_y1 = dst_y1;
+   /* Round floating point values to nearest integer to avoid "off by one texel"
+    * kind of errors when blitting.
+    */
+   x0 = wm_push_consts.dst_x0 = dst_x0 + 0.5;
+   y0 = wm_push_consts.dst_y0 = dst_y0 + 0.5;
+   x1 = wm_push_consts.dst_x1 = dst_x1 + 0.5;
+   y1 = wm_push_consts.dst_y1 = dst_y1 + 0.5;
    wm_push_consts.rect_grid_x1 = (minify(src_mt->logical_width0, src_level) *
                                   wm_prog_key.x_scale - 1.0);
    wm_push_consts.rect_grid_y1 = (minify(src_mt->logical_height0, src_level) *
-- 
2.1.3