Relax LOD computation bounds

This change updates LOD approximation rules to match proposed spec
language in Vulkan texture filtering and mipmap tests.

This is partial cherry-pick of 9f0ff9f49ae3359d9b2e50f5d720fc77460d0f4f.
Mustpass changes are not included.

Affects: dEQP-VK.texture.*

Change-Id: Ic786bc733913a76d27f0cba31f3a61a10f8144fc
diff --git a/external/vulkancts/modules/vulkan/texture/vktTextureFilteringTests.cpp b/external/vulkancts/modules/vulkan/texture/vktTextureFilteringTests.cpp
index 7d1e94f..2393c5f 100644
--- a/external/vulkancts/modules/vulkan/texture/vktTextureFilteringTests.cpp
+++ b/external/vulkancts/modules/vulkan/texture/vktTextureFilteringTests.cpp
@@ -217,7 +217,7 @@
 		const tcu::IVec4		formatBitDepth	= getTextureFormatBitDepth(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
 		const tcu::PixelFormat	pixelFormat		(formatBitDepth[0], formatBitDepth[1], formatBitDepth[2], formatBitDepth[3]);
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_VULKAN);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
@@ -434,7 +434,7 @@
 			const tcu::IVec4		formatBitDepth	= getTextureFormatBitDepth(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
 			const tcu::PixelFormat	pixelFormat		(formatBitDepth[0], formatBitDepth[1], formatBitDepth[2], formatBitDepth[3]);
 			const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-			tcu::LodPrecision		lodPrecision;
+			tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_VULKAN);
 			tcu::LookupPrecision	lookupPrecision;
 
 			lodPrecision.derivateBits		= 10;
@@ -635,7 +635,7 @@
 		const tcu::IVec4		formatBitDepth	= getTextureFormatBitDepth(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
 		const tcu::PixelFormat	pixelFormat		(formatBitDepth[0], formatBitDepth[1], formatBitDepth[2], formatBitDepth[3]);
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_VULKAN);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
@@ -813,7 +813,7 @@
 		const tcu::IVec4		formatBitDepth	= getTextureFormatBitDepth(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
 		const tcu::PixelFormat	pixelFormat		(formatBitDepth[0], formatBitDepth[1], formatBitDepth[2], formatBitDepth[3]);
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_VULKAN);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
diff --git a/external/vulkancts/modules/vulkan/texture/vktTextureMipmapTests.cpp b/external/vulkancts/modules/vulkan/texture/vktTextureMipmapTests.cpp
index bb5558e..9bc4c4a 100644
--- a/external/vulkancts/modules/vulkan/texture/vktTextureMipmapTests.cpp
+++ b/external/vulkancts/modules/vulkan/texture/vktTextureMipmapTests.cpp
@@ -335,7 +335,7 @@
 		tcu::Surface			referenceFrame	(viewportWidth, viewportHeight);
 		tcu::Surface			errorMask		(viewportWidth, viewportHeight);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_VULKAN);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 0);
@@ -569,7 +569,7 @@
 		tcu::Surface			errorMask			(viewportWidth, viewportHeight);
 		int						numFailedPixels		= 0;
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec				(tcu::LodPrecision::RULE_VULKAN);
 
 		// Params for rendering reference
 		refParams.sampler					= util::createSampler(m_testParameters.wrapS, m_testParameters.wrapT, m_testParameters.minFilter, m_testParameters.magFilter);
@@ -849,7 +849,7 @@
 		tcu::Surface			referenceFrame	(viewportWidth, viewportHeight);
 		tcu::Surface			errorMask		(viewportWidth, viewportHeight);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_VULKAN);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 20);
@@ -1032,7 +1032,7 @@
 		tcu::Surface			referenceFrame	(viewportWidth, viewportHeight);
 		tcu::Surface			errorMask		(viewportWidth, viewportHeight);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_VULKAN);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 0);
@@ -1289,7 +1289,7 @@
 		tcu::Surface			errorMask			(viewportWidth, viewportHeight);
 		int						numFailedPixels		= 0;
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec				(tcu::LodPrecision::RULE_VULKAN);
 
 		// Params for rendering reference
 		refParams.sampler					= util::createSampler(wrapS, wrapT, m_testParameters.minFilter, magFilter);
@@ -1557,7 +1557,7 @@
 		tcu::Surface			referenceFrame	(viewportWidth, viewportHeight);
 		tcu::Surface			errorMask		(viewportWidth, viewportHeight);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_VULKAN);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 20);
diff --git a/external/vulkancts/modules/vulkan/texture/vktTextureShadowTests.cpp b/external/vulkancts/modules/vulkan/texture/vktTextureShadowTests.cpp
index 62874a5..ab294d8 100644
--- a/external/vulkancts/modules/vulkan/texture/vktTextureShadowTests.cpp
+++ b/external/vulkancts/modules/vulkan/texture/vktTextureShadowTests.cpp
@@ -346,7 +346,7 @@
 
 	{
 		const tcu::PixelFormat		pixelFormat			= getPixelFormat(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
-		tcu::LodPrecision			lodPrecision;
+		tcu::LodPrecision			lodPrecision		(tcu::LodPrecision::RULE_VULKAN);
 		tcu::TexComparePrecision	texComparePrecision;
 
 		lodPrecision.derivateBits			= 18;
@@ -562,7 +562,7 @@
 
 		{
 			const tcu::PixelFormat		pixelFormat			= getPixelFormat(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
-			tcu::LodPrecision			lodPrecision;
+			tcu::LodPrecision			lodPrecision		(tcu::LodPrecision::RULE_VULKAN);
 			tcu::TexComparePrecision	texComparePrecision;
 
 			lodPrecision.derivateBits			= 10;
@@ -774,7 +774,7 @@
 
 	{
 		const tcu::PixelFormat		pixelFormat			= getPixelFormat(vk::mapVkFormat(VK_FORMAT_R8G8B8A8_UNORM));
-		tcu::LodPrecision			lodPrecision;
+		tcu::LodPrecision			lodPrecision		(tcu::LodPrecision::RULE_VULKAN);
 		tcu::TexComparePrecision	texComparePrecision;
 
 		lodPrecision.derivateBits			= 18;
diff --git a/framework/common/tcuTexLookupVerifier.cpp b/framework/common/tcuTexLookupVerifier.cpp
index 7f3e277..5b4ac5e 100644
--- a/framework/common/tcuTexLookupVerifier.cpp
+++ b/framework/common/tcuTexLookupVerifier.cpp
@@ -2117,7 +2117,7 @@
 	return computeFloatingPointError(value, bits);
 }
 
-Vec2 computeLodBoundsFromDerivates (const float dudx, const float dvdx, const float dwdx, const float dudy, const float dvdy, const float dwdy, const LodPrecision& prec)
+Vec2 computeOpenGLLodBoundsFromDerivates (const float dudx, const float dvdx, const float dwdx, const float dudy, const float dvdy, const float dwdy, const LodPrecision& prec)
 {
 	const float		mu			= de::max(deFloatAbs(dudx), deFloatAbs(dudy));
 	const float		mv			= de::max(deFloatAbs(dvdx), deFloatAbs(dvdy));
@@ -2134,6 +2134,52 @@
 	return Vec2(minLod-lodErr, maxLod+lodErr);
 }
 
+Vec2 computeVulkanLodBoundsFromDerivates (const float dudx, const float dvdx, const float dwdx, const float dudy, const float dvdy, const float dwdy, const LodPrecision& prec)
+{
+	const float		mux			= deFloatAbs(dudx);
+	const float		mvx			= deFloatAbs(dvdx);
+	const float		mwx			= deFloatAbs(dwdx);
+	const float		muy			= deFloatAbs(dudy);
+	const float		mvy			= deFloatAbs(dvdy);
+	const float		mwy			= deFloatAbs(dwdy);
+
+	// Ideal:
+	// px = deFloatSqrt2(mux*mux + mvx*mvx + mwx*mwx);
+	// py = deFloatSqrt2(muy*muy + mvy*mvy + mwy*mwy);
+
+	// fx, fy estimate lower bounds
+	const float		fxMin		= de::max(de::max(mux, mvx), mwx);
+	const float		fyMin		= de::max(de::max(muy, mvy), mwy);
+
+	// fx, fy estimate upper bounds
+	const float		sqrt2		= deFloatSqrt(2.0f);
+	const float		fxMax		= sqrt2 * (mux + mvx + mwx);
+	const float		fyMax		= sqrt2 * (muy + mvy + mwy);
+
+	// p = max(px, py) (isotropic filtering)
+	const float		pMin		= de::max(fxMin, fyMin);
+	const float		pMax		= de::max(fxMax, fyMax);
+
+	// error terms
+	const float		pMinErr		= computeFloatingPointError(pMin, prec.derivateBits);
+	const float		pMaxErr		= computeFloatingPointError(pMax, prec.derivateBits);
+
+	const float		minLod		= deFloatLog2(pMin-pMinErr);
+	const float		maxLod		= deFloatLog2(pMax+pMaxErr);
+	const float		lodErr		= computeFixedPointError(prec.lodBits);
+
+	DE_ASSERT(minLod <= maxLod);
+	return Vec2(minLod-lodErr, maxLod+lodErr);
+}
+
+Vec2 computeLodBoundsFromDerivates (const float dudx, const float dvdx, const float dwdx, const float dudy, const float dvdy, const float dwdy, const LodPrecision& prec)
+{
+	if (prec.rule == LodPrecision::RULE_VULKAN)
+		return computeVulkanLodBoundsFromDerivates(dudx, dvdx, dwdx, dudy, dvdy, dwdy, prec);
+	else
+		return computeOpenGLLodBoundsFromDerivates(dudx, dvdx, dwdx, dudy, dvdy, dwdy, prec);
+}
+
 Vec2 computeLodBoundsFromDerivates (const float dudx, const float dvdx, const float dudy, const float dvdy, const LodPrecision& prec)
 {
 	return computeLodBoundsFromDerivates(dudx, dvdx, 0.0f, dudy, dvdy, 0.0f, prec);
diff --git a/framework/common/tcuTexLookupVerifier.hpp b/framework/common/tcuTexLookupVerifier.hpp
index 6f6aaec..192986e 100644
--- a/framework/common/tcuTexLookupVerifier.hpp
+++ b/framework/common/tcuTexLookupVerifier.hpp
@@ -77,11 +77,21 @@
  *//*--------------------------------------------------------------------*/
 struct LodPrecision
 {
+	enum Rule
+	{
+		RULE_OPENGL		= 0,	//!< OpenGL LOD
+		RULE_VULKAN,			//!< Vulkan LOD
+
+		RULE_LAST
+	};
+
+	Rule		rule;			//!< LOD computation rule (Vulkan or OpenGL)
 	int			derivateBits;	//!< Number of bits in derivates. (Floating-point)
 	int			lodBits;		//!< Number of bits in final lod (accuracy of log2()). (Fixed-point)
 
-	LodPrecision (void)
-		: derivateBits	(22)
+	LodPrecision (Rule rule_)
+		: rule			(rule_)
+		, derivateBits	(22)
 		, lodBits		(16)
 	{
 	}
diff --git a/modules/gles2/functional/es2fTextureFilteringTests.cpp b/modules/gles2/functional/es2fTextureFilteringTests.cpp
index 2e38f7e..0a412a0 100644
--- a/modules/gles2/functional/es2fTextureFilteringTests.cpp
+++ b/modules/gles2/functional/es2fTextureFilteringTests.cpp
@@ -299,7 +299,7 @@
 		const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 		const tcu::PixelFormat	pixelFormat		= m_renderCtx.getRenderTarget().getPixelFormat();
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 7;
@@ -585,7 +585,7 @@
 			const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 			const tcu::PixelFormat	pixelFormat		= m_renderCtx.getRenderTarget().getPixelFormat();
 			const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-			tcu::LodPrecision		lodPrecision;
+			tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 			tcu::LookupPrecision	lookupPrecision;
 
 			lodPrecision.derivateBits		= 5;
diff --git a/modules/gles2/functional/es2fTextureMipmapTests.cpp b/modules/gles2/functional/es2fTextureMipmapTests.cpp
index cc65e5d..af7f9e8 100644
--- a/modules/gles2/functional/es2fTextureMipmapTests.cpp
+++ b/modules/gles2/functional/es2fTextureMipmapTests.cpp
@@ -350,7 +350,7 @@
 		tcu::Surface			referenceFrame	(viewport.width, viewport.height);
 		tcu::Surface			errorMask		(viewport.width, viewport.height);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 0);
@@ -670,7 +670,7 @@
 		int						numFailedPixels		= 0;
 		ReferenceParams			params				(TEXTURETYPE_CUBE);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec				(tcu::LodPrecision::RULE_OPENGL);
 
 		// Params for rendering reference
 		params.sampler					= glu::mapGLSampler(m_wrapS, m_wrapT, m_minFilter, magFilter);
diff --git a/modules/gles3/functional/es3fTextureFilteringTests.cpp b/modules/gles3/functional/es3fTextureFilteringTests.cpp
index 929eb43..3c62936 100644
--- a/modules/gles3/functional/es3fTextureFilteringTests.cpp
+++ b/modules/gles3/functional/es3fTextureFilteringTests.cpp
@@ -299,7 +299,7 @@
 		const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 		const tcu::PixelFormat	pixelFormat		= m_renderCtx.getRenderTarget().getPixelFormat();
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
@@ -612,7 +612,7 @@
 			const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 			const tcu::PixelFormat	pixelFormat		= m_renderCtx.getRenderTarget().getPixelFormat();
 			const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-			tcu::LodPrecision		lodPrecision;
+			tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 			tcu::LookupPrecision	lookupPrecision;
 
 			lodPrecision.derivateBits		= 10;
@@ -878,7 +878,7 @@
 		const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 		const tcu::PixelFormat	pixelFormat		= m_context.getRenderTarget().getPixelFormat();
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
@@ -1120,7 +1120,7 @@
 		const bool				isNearestOnly	= m_minFilter == GL_NEAREST && m_magFilter == GL_NEAREST;
 		const tcu::PixelFormat	pixelFormat		= m_context.getRenderTarget().getPixelFormat();
 		const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-		tcu::LodPrecision		lodPrecision;
+		tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::LookupPrecision	lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
diff --git a/modules/gles3/functional/es3fTextureMipmapTests.cpp b/modules/gles3/functional/es3fTextureMipmapTests.cpp
index bbb581f..4409631 100644
--- a/modules/gles3/functional/es3fTextureMipmapTests.cpp
+++ b/modules/gles3/functional/es3fTextureMipmapTests.cpp
@@ -394,7 +394,7 @@
 		tcu::Surface			referenceFrame	(viewport.width, viewport.height);
 		tcu::Surface			errorMask		(viewport.width, viewport.height);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 0);
@@ -709,7 +709,7 @@
 		int						numFailedPixels		= 0;
 		ReferenceParams			params				(TEXTURETYPE_CUBE);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec				(tcu::LodPrecision::RULE_OPENGL);
 
 		// Params for rendering reference
 		params.sampler					= glu::mapGLSampler(m_wrapS, m_wrapT, m_minFilter, magFilter);
@@ -1341,7 +1341,7 @@
 		tcu::Surface			referenceFrame	(viewport.width, viewport.height);
 		tcu::Surface			errorMask		(viewport.width, viewport.height);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 20);
@@ -1555,7 +1555,7 @@
 		tcu::Surface			referenceFrame	(viewport.width, viewport.height);
 		tcu::Surface			errorMask		(viewport.width, viewport.height);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 0);
@@ -1866,7 +1866,7 @@
 		int						numFailedPixels		= 0;
 		ReferenceParams			params				(TEXTURETYPE_CUBE);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec				(tcu::LodPrecision::RULE_OPENGL);
 
 		// Params for rendering reference
 		params.sampler					= glu::mapGLSampler(wrapS, wrapT, m_minFilter, magFilter);
@@ -2187,7 +2187,7 @@
 		tcu::Surface			referenceFrame	(viewport.width, viewport.height);
 		tcu::Surface			errorMask		(viewport.width, viewport.height);
 		tcu::LookupPrecision	lookupPrec;
-		tcu::LodPrecision		lodPrec;
+		tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 		int						numFailedPixels	= 0;
 
 		lookupPrec.coordBits		= tcu::IVec3(20, 20, 20);
diff --git a/modules/gles3/functional/es3fTextureShadowTests.cpp b/modules/gles3/functional/es3fTextureShadowTests.cpp
index 6eb9985..8383ece 100644
--- a/modules/gles3/functional/es3fTextureShadowTests.cpp
+++ b/modules/gles3/functional/es3fTextureShadowTests.cpp
@@ -362,7 +362,7 @@
 
 	{
 		const tcu::PixelFormat		pixelFormat		= m_context.getRenderTarget().getPixelFormat();
-		tcu::LodPrecision			lodPrecision;
+		tcu::LodPrecision			lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::TexComparePrecision	texComparePrecision;
 
 		lodPrecision.derivateBits			= 18;
@@ -652,7 +652,7 @@
 
 		{
 			const tcu::PixelFormat		pixelFormat		= m_context.getRenderTarget().getPixelFormat();
-			tcu::LodPrecision			lodPrecision;
+			tcu::LodPrecision			lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 			tcu::TexComparePrecision	texComparePrecision;
 
 			lodPrecision.derivateBits			= 10;
@@ -928,7 +928,7 @@
 
 	{
 		const tcu::PixelFormat		pixelFormat		= m_context.getRenderTarget().getPixelFormat();
-		tcu::LodPrecision			lodPrecision;
+		tcu::LodPrecision			lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::TexComparePrecision	texComparePrecision;
 
 		lodPrecision.derivateBits			= 18;
diff --git a/modules/gles3/functional/es3fTextureWrapTests.cpp b/modules/gles3/functional/es3fTextureWrapTests.cpp
index d4edcdd..da12488 100644
--- a/modules/gles3/functional/es3fTextureWrapTests.cpp
+++ b/modules/gles3/functional/es3fTextureWrapTests.cpp
@@ -334,7 +334,7 @@
 		const bool						isSRGB			= tcu::isSRGB(texFormat);
 		const tcu::PixelFormat			pixelFormat		= m_renderCtx.getRenderTarget().getPixelFormat();
 		const tcu::IVec4				colorBits		= tcu::max(getBitsVec(pixelFormat) - (isNearestOnly && !isSRGB ? 1 : 2), tcu::IVec4(0));
-		tcu::LodPrecision				lodPrecision;
+		tcu::LodPrecision				lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 		tcu::LookupPrecision			lookupPrecision;
 
 		lodPrecision.derivateBits		= 18;
diff --git a/modules/gles31/functional/es31fStencilTexturingTests.cpp b/modules/gles31/functional/es31fStencilTexturingTests.cpp
index c592288..92bb9a1 100644
--- a/modules/gles31/functional/es31fStencilTexturingTests.cpp
+++ b/modules/gles31/functional/es31fStencilTexturingTests.cpp
@@ -716,7 +716,7 @@
 																					tcu::Sampler::NEAREST,
 																					tcu::Sampler::NEAREST));
 			tcu::LookupPrecision	lookupPrec;
-			tcu::LodPrecision		lodPrec;
+			tcu::LodPrecision		lodPrec			(tcu::LodPrecision::RULE_OPENGL);
 			bool					compareOk;
 
 			lookupPrec.colorMask		= tcu::BVec4(true, true, true, true);
diff --git a/modules/gles31/functional/es31fTextureBorderClampTests.cpp b/modules/gles31/functional/es31fTextureBorderClampTests.cpp
index 0587f5a..05f383e 100644
--- a/modules/gles31/functional/es31fTextureBorderClampTests.cpp
+++ b/modules/gles31/functional/es31fTextureBorderClampTests.cpp
@@ -912,7 +912,7 @@
 {
 	const tcu::PixelFormat	pixelFormat		= m_context.getRenderTarget().getPixelFormat();
 
-	tcu::LodPrecision		lodPrecision;
+	tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 	std::vector<float>		texCoord;
 	bool					verificationOk;
 
@@ -2211,7 +2211,7 @@
 	const tcu::IVec4				colorBits			= tcu::max(glu::TextureTestUtil::getBitsVec(pixelFormat) - tcu::IVec4(colorErrorBits), tcu::IVec4(0));
 	tcu::Surface					reference			(renderedFrame.getWidth(), renderedFrame.getHeight());
 	tcu::Surface					errorMask			(renderedFrame.getWidth(), renderedFrame.getHeight());
-	tcu::LodPrecision				lodPrecision;
+	tcu::LodPrecision				lodPrecision		(tcu::LodPrecision::RULE_OPENGL);
 	tcu::LookupPrecision			lookupPrecision;
 	int								numFailedPixels;
 
diff --git a/modules/gles31/functional/es31fTextureFilteringTests.cpp b/modules/gles31/functional/es31fTextureFilteringTests.cpp
index bc26811..5784c37 100644
--- a/modules/gles31/functional/es31fTextureFilteringTests.cpp
+++ b/modules/gles31/functional/es31fTextureFilteringTests.cpp
@@ -376,7 +376,7 @@
 			const tcu::PixelFormat	pixelFormat		= renderCtx.getRenderTarget().getPixelFormat();
 			const tcu::IVec4		coordBits		= tcu::IVec4(10);
 			const tcu::IVec4		colorBits		= max(getBitsVec(pixelFormat) - (isNearestOnly ? 1 : 2), tcu::IVec4(0)); // 1 inaccurate bit if nearest only, 2 otherwise
-			tcu::LodPrecision		lodPrecision;
+			tcu::LodPrecision		lodPrecision	(tcu::LodPrecision::RULE_OPENGL);
 			tcu::LookupPrecision	lookupPrecision;
 
 			lodPrecision.derivateBits		= 10;