1#ifndef _RRSHADINGCONTEXT_HPP
2#define _RRSHADINGCONTEXT_HPP
3/*-------------------------------------------------------------------------
4 * drawElements Quality Program Reference Renderer
5 * -----------------------------------------------
6 *
7 * Copyright 2014 The Android Open Source Project
8 *
9 * Licensed under the Apache License, Version 2.0 (the "License");
10 * you may not use this file except in compliance with the License.
11 * You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 *
21 *//*!
22 * \file
23 * \brief Shading context
24 *//*--------------------------------------------------------------------*/
25
26#include "rrDefs.hpp"
27#include "rrGenericVector.hpp"
28#include "rrFragmentPacket.hpp"
29
30namespace rr
31{
32
33/*--------------------------------------------------------------------*//*!
34 * \brief Fragment shading context
35 *
36 * Contains per-primitive information used in fragment shading
37 *//*--------------------------------------------------------------------*/
38struct FragmentShadingContext
39{
40								FragmentShadingContext (const GenericVec4* varying0, const GenericVec4* varying1, const GenericVec4* varying2, GenericVec4* outputArray, float* fragmentDepths, int primitiveID, int numFragmentOutputs, int numSamples);
41
42	const GenericVec4*			varyings[3];		//!< Vertex shader outputs. Pointer will be NULL if there is no such vertex.
43	GenericVec4* const			outputArray;		//!< Fragment output array
44	const int					primitiveID;		//!< Geometry shader output
45	const int					numFragmentOutputs;	//!< Fragment output count
46	const int					numSamples;			//!< Number of samples
47	float*						fragmentDepths;		//!< Fragment packet depths. Pointer will be NULL if there is no depth buffer. Each sample has per-sample depth values
48};
49
50// Write output
51
52template <typename T>
53void writeFragmentOutput (const FragmentShadingContext& context, int packetNdx, int fragNdx, int outputNdx, const T& value)
54{
55	DE_ASSERT(packetNdx >= 0);
56	DE_ASSERT(fragNdx >= 0 && fragNdx < 4);
57	DE_ASSERT(outputNdx >= 0 && outputNdx < context.numFragmentOutputs);
58
59	context.outputArray[outputNdx + context.numFragmentOutputs*(fragNdx + packetNdx*4)] = value;
60}
61
62// Read Varying
63
64template <typename T>
65tcu::Vector<T, 4> readPointVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
66{
67	DE_UNREF(fragNdx);
68	DE_UNREF(packet);
69
70	return context.varyings[0][varyingLoc].get<T>();
71}
72
73template <typename T>
74tcu::Vector<T, 4> readLineVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
75{
76	return   packet.barycentric[0][fragNdx] * context.varyings[0][varyingLoc].get<T>()
77		   + packet.barycentric[1][fragNdx] * context.varyings[1][varyingLoc].get<T>();
78}
79
80template <typename T>
81tcu::Vector<T, 4> readTriangleVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
82{
83	return   packet.barycentric[0][fragNdx] * context.varyings[0][varyingLoc].get<T>()
84		   + packet.barycentric[1][fragNdx] * context.varyings[1][varyingLoc].get<T>()
85		   + packet.barycentric[2][fragNdx] * context.varyings[2][varyingLoc].get<T>();
86}
87
88template <typename T>
89tcu::Vector<T, 4> readVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
90{
91	if (context.varyings[1] == DE_NULL)	return readPointVarying<T>		(packet, context, varyingLoc, fragNdx);
92	if (context.varyings[2] == DE_NULL)	return readLineVarying<T>		(packet, context, varyingLoc, fragNdx);
93										return readTriangleVarying<T>	(packet, context, varyingLoc, fragNdx);
94}
95
96// Derivative
97
98template <typename T, int Size>
99void dFdxLocal (tcu::Vector<T, Size> outFragmentdFdx[4], const tcu::Vector<T, Size> func[4])
100{
101	const tcu::Vector<T, Size> dFdx[2] =
102	{
103		func[1] - func[0],
104		func[3] - func[2]
105	};
106
107	outFragmentdFdx[0] = dFdx[0];
108	outFragmentdFdx[1] = dFdx[0];
109	outFragmentdFdx[2] = dFdx[1];
110	outFragmentdFdx[3] = dFdx[1];
111}
112
113template <typename T, int Size>
114void dFdyLocal (tcu::Vector<T, Size> outFragmentdFdy[4], const tcu::Vector<T, Size> func[4])
115{
116	const tcu::Vector<T, Size> dFdy[2] =
117	{
118		func[2] - func[0],
119		func[3] - func[1]
120	};
121
122	outFragmentdFdy[0] = dFdy[0];
123	outFragmentdFdy[1] = dFdy[1];
124	outFragmentdFdy[2] = dFdy[0];
125	outFragmentdFdy[3] = dFdy[1];
126}
127
128template <typename T>
129inline void dFdxVarying (tcu::Vector<T, 4> outFragmentdFdx[4], const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc)
130{
131	const tcu::Vector<T, 4> func[4] =
132	{
133		readVarying<T>(packet, context, varyingLoc, 0),
134		readVarying<T>(packet, context, varyingLoc, 1),
135		readVarying<T>(packet, context, varyingLoc, 2),
136		readVarying<T>(packet, context, varyingLoc, 3),
137	};
138
139	dFdxLocal(outFragmentdFdx, func);
140}
141
142template <typename T>
143inline void dFdyVarying (tcu::Vector<T, 4> outFragmentdFdy[4], const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc)
144{
145	const tcu::Vector<T, 4> func[4] =
146	{
147		readVarying<T>(packet, context, varyingLoc, 0),
148		readVarying<T>(packet, context, varyingLoc, 1),
149		readVarying<T>(packet, context, varyingLoc, 2),
150		readVarying<T>(packet, context, varyingLoc, 3),
151	};
152
153	dFdyLocal(outFragmentdFdy, func);
154}
155
156// Fragent depth
157
158inline float readFragmentDepth (const FragmentShadingContext& context, int packetNdx, int fragNdx, int sampleNdx)
159{
160	// Reading or writing to fragment depth values while there is no depth buffer is legal but not supported by rr
161	DE_ASSERT(context.fragmentDepths);
162	return context.fragmentDepths[(packetNdx * 4 + fragNdx) * context.numSamples + sampleNdx];
163}
164
165inline void writeFragmentDepth (const FragmentShadingContext& context, int packetNdx, int fragNdx, int sampleNdx, float depthValue)
166{
167	// Reading or writing to fragment depth values while there is no depth buffer is legal but not supported by rr
168	DE_ASSERT(context.fragmentDepths);
169	context.fragmentDepths[(packetNdx * 4 + fragNdx) * context.numSamples + sampleNdx] = depthValue;
170}
171
172} // rr
173
174#endif // _RRSHADINGCONTEXT_HPP
175