[Mesa-dev] [PATCH 08/16] main: round floating-point value to nearest integer in glGetTexParameteriv()

[Eduardo Lima Mitev]

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

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 8 dEQP tests:

dEQP-GLES3.functional.state_query.texture.texture_2d_texture_min_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_2d_texture_max_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_3d_texture_min_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_3d_texture_max_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_2d_array_texture_min_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_2d_array_texture_max_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_cube_map_texture_min_lod_gettexparameteri
dEQP-GLES3.functional.state_query.texture.texture_cube_map_texture_max_lod_gettexparameteri

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
---
 src/mesa/main/texparam.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/mesa/main/texparam.c b/src/mesa/main/texparam.c
index e40fb24..2d5a9b7 100644
--- a/src/mesa/main/texparam.c
+++ b/src/mesa/main/texparam.c
@@ -1658,14 +1658,18 @@ _mesa_GetTexParameteriv( GLenum target, GLenum pname, GLint *params )
       case GL_TEXTURE_MIN_LOD:
          if (!_mesa_is_desktop_gl(ctx) && !_mesa_is_gles3(ctx))
             goto invalid_pname;
-
-         *params = (GLint) obj->Sampler.MinLod;
+         /* GL spec 'Data Conversions' section specifies that floating-point
+          * value in integer Get function is rounded to nearest integer
+          */
+         *params = IROUND(obj->Sampler.MinLod);
          break;
       case GL_TEXTURE_MAX_LOD:
          if (!_mesa_is_desktop_gl(ctx) && !_mesa_is_gles3(ctx))
             goto invalid_pname;
-
-         *params = (GLint) obj->Sampler.MaxLod;
+         /* GL spec 'Data Conversions' section specifies that floating-point
+          * value in integer Get function is rounded to nearest integer
+          */
+         *params = IROUND(obj->Sampler.MaxLod);
          break;
       case GL_TEXTURE_BASE_LEVEL:
          if (!_mesa_is_desktop_gl(ctx) && !_mesa_is_gles3(ctx))
@@ -1679,7 +1683,10 @@ _mesa_GetTexParameteriv( GLenum target, GLenum pname, GLint *params )
       case GL_TEXTURE_MAX_ANISOTROPY_EXT:
          if (!ctx->Extensions.EXT_texture_filter_anisotropic)
             goto invalid_pname;
-         *params = (GLint) obj->Sampler.MaxAnisotropy;
+         /* GL spec 'Data Conversions' section specifies that floating-point
+          * value in integer Get function is rounded to nearest integer
+          */
+         *params = IROUND(obj->Sampler.MaxAnisotropy);
          break;
       case GL_GENERATE_MIPMAP_SGIS:
          if (ctx->API != API_OPENGL_COMPAT && ctx->API != API_OPENGLES)
-- 
2.1.3