Mesa (master): main: round floating-point value to nearest integer in glGetSamplerParameteriv( )

[Iago Toral Quiroga]

Module: Mesa
Branch: master
Commit: 719e3f016ea69ffddd3bf14ec7a340def62ce464
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=719e3f016ea69ffddd3bf14ec7a340def62ce464

Author: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
Date:   Thu Dec 11 23:34:15 2014 +0100

main: round floating-point value to nearest integer in glGetSamplerParameteriv()

Previously, a cast was done to convert from float to int but there
were rounding errors.

The spec specificies in Data Conversion chapter that Floating-point values are
rounded to the nearest integer.

This patch fixes the following 2 dEQP tests:

dEQP-GLES3.functional.state_query.sampler.sampler_texture_min_lod_getsamplerparameteri
dEQP-GLES3.functional.state_query.sampler.sampler_texture_max_lod_getsamplerparameteri

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 src/mesa/main/samplerobj.c |   20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/mesa/main/samplerobj.c b/src/mesa/main/samplerobj.c
index 18a14d8..cadc9cc 100644
--- a/src/mesa/main/samplerobj.c
+++ b/src/mesa/main/samplerobj.c
@@ -1271,13 +1271,22 @@ _mesa_GetSamplerParameteriv(GLuint sampler, GLenum pname, GLint *params)
       *params = sampObj->MagFilter;
       break;
    case GL_TEXTURE_MIN_LOD:
-      *params = (GLint) sampObj->MinLod;
+      /* GL spec 'Data Conversions' section specifies that floating-point
+       * value in integer Get function is rounded to nearest integer
+       */
+      *params = IROUND(sampObj->MinLod);
       break;
    case GL_TEXTURE_MAX_LOD:
-      *params = (GLint) sampObj->MaxLod;
+      /* GL spec 'Data Conversions' section specifies that floating-point
+       * value in integer Get function is rounded to nearest integer
+       */
+      *params = IROUND(sampObj->MaxLod);
       break;
    case GL_TEXTURE_LOD_BIAS:
-      *params = (GLint) sampObj->LodBias;
+      /* GL spec 'Data Conversions' section specifies that floating-point
+       * value in integer Get function is rounded to nearest integer
+       */
+      *params = IROUND(sampObj->LodBias);
       break;
    case GL_TEXTURE_COMPARE_MODE:
       if (!ctx->Extensions.ARB_shadow)
@@ -1290,7 +1299,10 @@ _mesa_GetSamplerParameteriv(GLuint sampler, GLenum pname, GLint *params)
       *params = sampObj->CompareFunc;
       break;
    case GL_TEXTURE_MAX_ANISOTROPY_EXT:
-      *params = (GLint) sampObj->MaxAnisotropy;
+      /* GL spec 'Data Conversions' section specifies that floating-point
+       * value in integer Get function is rounded to nearest integer
+       */
+      *params = IROUND(sampObj->MaxAnisotropy);
       break;
    case GL_TEXTURE_BORDER_COLOR:
       params[0] = FLOAT_TO_INT(sampObj->BorderColor.f[0]);