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, FaceType visibleFace_);
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	FaceType					visibleFace;		//!< Which face (front or back) is visible
49};
50
51// Write output
52
53template <typename T>
54void writeFragmentOutput (const FragmentShadingContext& context, int packetNdx, int fragNdx, int outputNdx, const T& value)
55{
56	DE_ASSERT(packetNdx >= 0);
57	DE_ASSERT(fragNdx >= 0 && fragNdx < 4);
58	DE_ASSERT(outputNdx >= 0 && outputNdx < context.numFragmentOutputs);
59
60	context.outputArray[outputNdx + context.numFragmentOutputs*(fragNdx + packetNdx*4)] = value;
61}
62
63// Read Varying
64
65template <typename T>
66tcu::Vector<T, 4> readPointVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
67{
68	DE_UNREF(fragNdx);
69	DE_UNREF(packet);
70
71	return context.varyings[0][varyingLoc].get<T>();
72}
73
74template <typename T>
75tcu::Vector<T, 4> readLineVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
76{
77	return   packet.barycentric[0][fragNdx] * context.varyings[0][varyingLoc].get<T>()
78		   + packet.barycentric[1][fragNdx] * context.varyings[1][varyingLoc].get<T>();
79}
80
81template <typename T>
82tcu::Vector<T, 4> readTriangleVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
83{
84	return   packet.barycentric[0][fragNdx] * context.varyings[0][varyingLoc].get<T>()
85		   + packet.barycentric[1][fragNdx] * context.varyings[1][varyingLoc].get<T>()
86		   + packet.barycentric[2][fragNdx] * context.varyings[2][varyingLoc].get<T>();
87}
88
89template <typename T>
90tcu::Vector<T, 4> readVarying (const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc, int fragNdx)
91{
92	if (context.varyings[1] == DE_NULL)	return readPointVarying<T>		(packet, context, varyingLoc, fragNdx);
93	if (context.varyings[2] == DE_NULL)	return readLineVarying<T>		(packet, context, varyingLoc, fragNdx);
94										return readTriangleVarying<T>	(packet, context, varyingLoc, fragNdx);
95}
96
97// Derivative
98
99template <typename T, int Size>
100void dFdxLocal (tcu::Vector<T, Size> outFragmentdFdx[4], const tcu::Vector<T, Size> func[4])
101{
102	const tcu::Vector<T, Size> dFdx[2] =
103	{
104		func[1] - func[0],
105		func[3] - func[2]
106	};
107
108	outFragmentdFdx[0] = dFdx[0];
109	outFragmentdFdx[1] = dFdx[0];
110	outFragmentdFdx[2] = dFdx[1];
111	outFragmentdFdx[3] = dFdx[1];
112}
113
114template <typename T, int Size>
115void dFdyLocal (tcu::Vector<T, Size> outFragmentdFdy[4], const tcu::Vector<T, Size> func[4])
116{
117	const tcu::Vector<T, Size> dFdy[2] =
118	{
119		func[2] - func[0],
120		func[3] - func[1]
121	};
122
123	outFragmentdFdy[0] = dFdy[0];
124	outFragmentdFdy[1] = dFdy[1];
125	outFragmentdFdy[2] = dFdy[0];
126	outFragmentdFdy[3] = dFdy[1];
127}
128
129template <typename T>
130inline void dFdxVarying (tcu::Vector<T, 4> outFragmentdFdx[4], const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc)
131{
132	const tcu::Vector<T, 4> func[4] =
133	{
134		readVarying<T>(packet, context, varyingLoc, 0),
135		readVarying<T>(packet, context, varyingLoc, 1),
136		readVarying<T>(packet, context, varyingLoc, 2),
137		readVarying<T>(packet, context, varyingLoc, 3),
138	};
139
140	dFdxLocal(outFragmentdFdx, func);
141}
142
143template <typename T>
144inline void dFdyVarying (tcu::Vector<T, 4> outFragmentdFdy[4], const FragmentPacket& packet, const FragmentShadingContext& context, int varyingLoc)
145{
146	const tcu::Vector<T, 4> func[4] =
147	{
148		readVarying<T>(packet, context, varyingLoc, 0),
149		readVarying<T>(packet, context, varyingLoc, 1),
150		readVarying<T>(packet, context, varyingLoc, 2),
151		readVarying<T>(packet, context, varyingLoc, 3),
152	};
153
154	dFdyLocal(outFragmentdFdy, func);
155}
156
157// Fragent depth
158
159inline float readFragmentDepth (const FragmentShadingContext& context, int packetNdx, int fragNdx, int sampleNdx)
160{
161	// Reading or writing to fragment depth values while there is no depth buffer is legal but not supported by rr
162	DE_ASSERT(context.fragmentDepths);
163	return context.fragmentDepths[(packetNdx * 4 + fragNdx) * context.numSamples + sampleNdx];
164}
165
166inline void writeFragmentDepth (const FragmentShadingContext& context, int packetNdx, int fragNdx, int sampleNdx, float depthValue)
167{
168	// Reading or writing to fragment depth values while there is no depth buffer is legal but not supported by rr
169	DE_ASSERT(context.fragmentDepths);
170	context.fragmentDepths[(packetNdx * 4 + fragNdx) * context.numSamples + sampleNdx] = depthValue;
171}
172
173} // rr
174
175#endif // _RRSHADINGCONTEXT_HPP
176