From: Pyry Haulos <phaulos@google.com>
Date: Fri, 13 Feb 2015 18:58:03 +0000 (-0800)
Subject: Relax mediump interpolation accuracy requirements and clarify thresholds
X-Git-Tag: upstream/0.1.0~1788^2^2^2~6^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2cd1e178d456ed3fe617603abffebda7bb18075d;p=platform%2Fupstream%2FVK-GL-CTS.git

Relax mediump interpolation accuracy requirements and clarify thresholds

This change relaxes mediump interpolation accuracy in
dEQP-GLES3.functional.fragment_out.* to 4 ULP from 1 ULP.

Threshold computation is also fixed/clarified by moving interpolation
threshold to be dependent on precision qualifier, and allowing only
rounding difference in format-dependent threshold. The original error
was likely due to incorrectly accomodating for interpolation in format
threshold.

Bug: 19380820
Change-Id: I457a9b7e07bad94399d07f37caa29d65ad95a5c8
---

diff --git a/modules/gles3/functional/es3fFragmentOutputTests.cpp b/modules/gles3/functional/es3fFragmentOutputTests.cpp
index 319dcc9..f7fb0ad 100644
--- a/modules/gles3/functional/es3fFragmentOutputTests.cpp
+++ b/modules/gles3/functional/es3fFragmentOutputTests.cpp
@@ -825,21 +825,23 @@ FragmentOutputCase::IterateResult FragmentOutputCase::iterate (void)
 				deUint32	precThreshold	= 0;	//!< Threshold computed based on output type precision
 				UVec4		finalThreshold;
 
+				// 1 ULP rounding error is allowed for smaller floating-point formats
 				switch (format.type)
 				{
-					case tcu::TextureFormat::FLOAT:							formatThreshold = UVec4(4);										break;
-					case tcu::TextureFormat::HALF_FLOAT:					formatThreshold = UVec4((1<<13) + 4);							break;
-					case tcu::TextureFormat::UNSIGNED_INT_11F_11F_10F_REV:	formatThreshold = UVec4((1<<17) + 4, (1<<17)+4, (1<<18)+4, 4);	break;
+					case tcu::TextureFormat::FLOAT:							formatThreshold = UVec4(0);											break;
+					case tcu::TextureFormat::HALF_FLOAT:					formatThreshold = UVec4((1<<(23-10)));								break;
+					case tcu::TextureFormat::UNSIGNED_INT_11F_11F_10F_REV:	formatThreshold = UVec4((1<<(23-6)), (1<<(23-6)), (1<<(23-5)), 0);	break;
 					default:
 						DE_ASSERT(false);
 						break;
 				}
 
+				// 4 ULP interpolation
 				switch (outPrecision)
 				{
-					case glu::PRECISION_LOWP:		precThreshold	= (1<<21);	break;
-					case glu::PRECISION_MEDIUMP:	precThreshold	= (1<<13);	break;
-					case glu::PRECISION_HIGHP:		precThreshold	= 0;		break;
+					case glu::PRECISION_LOWP:		precThreshold	= (4<<(23-8));	break;
+					case glu::PRECISION_MEDIUMP:	precThreshold	= (4<<(23-10));	break;
+					case glu::PRECISION_HIGHP:		precThreshold	= 4;			break;
 					default:
 						DE_ASSERT(false);
 				}