1 /*-------------------------------------------------------------------------
2  * drawElements Quality Program Tester Core
3  * ----------------------------------------
4  *
5  * Copyright 2014 The Android Open Source Project
6  *
7  * Licensed under the Apache License, Version 2.0 (the "License");
8  * you may not use this file except in compliance with the License.
9  * You may obtain a copy of the License at
10  *
11  *      http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS,
15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  * See the License for the specific language governing permissions and
17  * limitations under the License.
18  *
19  *//*!
20  * \file
21  * \brief Internal utilities shared between TexLookup and TexCompare verifiers.
22  *//*--------------------------------------------------------------------*/
23 
24 #include "tcuTexVerifierUtil.hpp"
25 #include "tcuFloat.hpp"
26 
27 namespace tcu
28 {
29 namespace TexVerifierUtil
30 {
31 
computeFloatingPointError(const float value,const int numAccurateBits)32 float computeFloatingPointError (const float value, const int numAccurateBits)
33 {
34 	const int		numGarbageBits	= 23-numAccurateBits;
35 	const deUint32	mask			= (1u<<numGarbageBits)-1u;
36 	const int		exp				= tcu::Float32(value).exponent();
37 
38 	return Float32::construct(+1, exp, (1u<<23) | mask).asFloat() - Float32::construct(+1, exp, 1u<<23).asFloat();
39 }
40 
computeFixedPointError(const int numAccurateBits)41 float computeFixedPointError (const int numAccurateBits)
42 {
43 	return computeFloatingPointError(1.0f, numAccurateBits);
44 }
45 
computeNonNormalizedCoordBounds(const bool normalizedCoords,const int dim,const float coord,const int coordBits,const int uvBits)46 Vec2 computeNonNormalizedCoordBounds (const bool normalizedCoords, const int dim, const float coord, const int coordBits, const int uvBits)
47 {
48 	const float		coordErr		= computeFloatingPointError(coord, coordBits);
49 	const float		minN			= coord - coordErr;
50 	const float		maxN			= coord + coordErr;
51 	const float		minA			= normalizedCoords ? minN*float(dim) : minN;
52 	const float		maxA			= normalizedCoords ? maxN*float(dim) : maxN;
53 	const float		minC			= minA - computeFixedPointError(uvBits);
54 	const float		maxC			= maxA + computeFixedPointError(uvBits);
55 
56 	DE_ASSERT(minC <= maxC);
57 
58 	return Vec2(minC, maxC);
59 }
60 
getPossibleCubeFaces(const Vec3 & coord,const IVec3 & bits,CubeFace * faces,int & numFaces)61 void getPossibleCubeFaces (const Vec3& coord, const IVec3& bits, CubeFace* faces, int& numFaces)
62 {
63 	const float	x	= coord.x();
64 	const float	y	= coord.y();
65 	const float	z	= coord.z();
66 	const float ax	= de::abs(x);
67 	const float ay	= de::abs(y);
68 	const float az	= de::abs(z);
69 	const float ex	= computeFloatingPointError(x, bits.x());
70 	const float	ey	= computeFloatingPointError(y, bits.y());
71 	const float ez	= computeFloatingPointError(z, bits.z());
72 
73 	numFaces = 0;
74 
75 	if (ay+ey < ax-ex && az+ez < ax-ex)
76 	{
77 		if (x >= ex) faces[numFaces++] = CUBEFACE_POSITIVE_X;
78 		if (x <= ex) faces[numFaces++] = CUBEFACE_NEGATIVE_X;
79 	}
80 	else if (ax+ex < ay-ey && az+ez < ay-ey)
81 	{
82 		if (y >= ey) faces[numFaces++] = CUBEFACE_POSITIVE_Y;
83 		if (y <= ey) faces[numFaces++] = CUBEFACE_NEGATIVE_Y;
84 	}
85 	else if (ax+ex < az-ez && ay+ey < az-ez)
86 	{
87 		if (z >= ez) faces[numFaces++] = CUBEFACE_POSITIVE_Z;
88 		if (z <= ez) faces[numFaces++] = CUBEFACE_NEGATIVE_Z;
89 	}
90 	else
91 	{
92 		// One or more components are equal (or within error bounds). Allow all faces where major axis is not zero.
93 		if (ax > ex)
94 		{
95 			faces[numFaces++] = CUBEFACE_NEGATIVE_X;
96 			faces[numFaces++] = CUBEFACE_POSITIVE_X;
97 		}
98 
99 		if (ay > ey)
100 		{
101 			faces[numFaces++] = CUBEFACE_NEGATIVE_Y;
102 			faces[numFaces++] = CUBEFACE_POSITIVE_Y;
103 		}
104 
105 		if (az > ez)
106 		{
107 			faces[numFaces++] = CUBEFACE_NEGATIVE_Z;
108 			faces[numFaces++] = CUBEFACE_POSITIVE_Z;
109 		}
110 	}
111 }
112 
getUnnormalizedCoordSampler(const Sampler & sampler)113 Sampler getUnnormalizedCoordSampler (const Sampler& sampler)
114 {
115 	Sampler copy = sampler;
116 	copy.normalizedCoords = false;
117 	return copy;
118 }
119 
imod(int a,int b)120 static inline int imod (int a, int b)
121 {
122 	int m = a % b;
123 	return m < 0 ? m + b : m;
124 }
125 
mirror(int a)126 static inline int mirror (int a)
127 {
128 	return a >= 0.0f ? a : -(1 + a);
129 }
130 
wrap(Sampler::WrapMode mode,int c,int size)131 int wrap (Sampler::WrapMode mode, int c, int size)
132 {
133 	switch (mode)
134 	{
135 		// \note CL and GL modes are handled identically here, as verification process accounts for
136 		//		 accuracy differences caused by different methods (wrapping vs. denormalizing first).
137 		case tcu::Sampler::CLAMP_TO_BORDER:
138 			return deClamp32(c, -1, size);
139 
140 		case tcu::Sampler::CLAMP_TO_EDGE:
141 			return deClamp32(c, 0, size-1);
142 
143 		case tcu::Sampler::REPEAT_GL:
144 		case tcu::Sampler::REPEAT_CL:
145 			return imod(c, size);
146 
147 		case tcu::Sampler::MIRRORED_REPEAT_GL:
148 		case tcu::Sampler::MIRRORED_REPEAT_CL:
149 			return (size - 1) - mirror(imod(c, 2*size) - size);
150 
151 		default:
152 			DE_ASSERT(DE_FALSE);
153 			return 0;
154 	}
155 }
156 
157 } // TexVerifierUtil
158 } // tcu
159