swrast: add 0.5 bias in tex_array_slice() per the spec

diff --git a/src/mesa/swrast/s_texfilter.c b/src/mesa/swrast/s_texfilter.c
index 478fb1557f61d231acc457748fd6d38a326fb90e..997c2f4bb79c5c443ed008be194f640c056a1414 100644 (file)
--- a/src/mesa/swrast/s_texfilter.c
+++ b/src/mesa/swrast/s_texfilter.c
@@ -480,7 +480,7 @@ clamp_rect_coord_linear(GLenum wrapMode, GLfloat coord, GLint max,
 static INLINE GLint
 tex_array_slice(GLfloat coord, GLsizei size)
 {
-   GLint slice = IFLOOR(coord);
+   GLint slice = IFLOOR(coord + 0.5f);
    slice = CLAMP(slice, 0, size - 1);
    return slice;
 }