1// Copyright (C) 2019 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
3
4#ifndef QSSGSHADERRESOURCEMERGECONTEXT_P_H
5#define QSSGSHADERRESOURCEMERGECONTEXT_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists purely as an
12// implementation detail. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include "qssgrendershadercodegenerator_p.h"
19#include "qssgrendershadermetadata_p.h"
20
21QT_BEGIN_NAMESPACE
22
23class QSSGShaderResourceMergeContext
24{
25public:
26 // Resource bindings 0..2 are reserved for uniform buffers.
27 // (0 is cbMain, 1 is cbLights)
28 static const int FIRST_CUSTOM_RESOURCE_BINDING_POINT = 3;
29
30 struct InOutVar {
31 QSSGShaderGeneratorStageFlags stageOutputFrom;
32 QSSGShaderGeneratorStageFlags stagesInputIn;
33 QByteArray type;
34 QByteArray name;
35 int location;
36 bool output;
37 bool flat;
38 };
39
40 struct Sampler {
41 QByteArray type;
42 QByteArray name;
43 QSSGRenderShaderMetadata::Uniform::Condition conditionType;
44 QByteArray conditionName;
45 int binding;
46 };
47
48 struct BlockMember {
49 QByteArray type;
50 QByteArray name;
51 QSSGRenderShaderMetadata::Uniform::Condition conditionType;
52 QByteArray conditionName;
53 };
54
55 // Using QMap intentionally - while it is not strictly required to use an
56 // ordered map, being sorted by key when iterating is helpful to get the
57 // same ordered list of vertex inputs, uniforms, etc. on every run, which
58 // in turn helps shader (disk) cache efficiency due to not generating a
59 // different shader string just because QHash decided to iterate entries in
60 // a different order.
61 QMap<QByteArray, InOutVar> m_inOutVars;
62 QMap<QByteArray, Sampler> m_samplers;
63 QMap<QByteArray, BlockMember> m_uniformMembers;
64
65 int m_nextFreeResourceBinding = FIRST_CUSTOM_RESOURCE_BINDING_POINT;
66 QHash<int, int> m_nextFreeInLocation;
67 QHash<int, int> m_nextFreeOutLocation;
68
69 int viewCount = 1;
70
71 void registerInput(QSSGShaderGeneratorStage stage, const QByteArray &type, const QByteArray &name, bool flat = false)
72 {
73 auto it = m_inOutVars.find(key: name);
74 if (it != m_inOutVars.end()) {
75 it->stagesInputIn |= stage;
76 return;
77 }
78 InOutVar var { .stageOutputFrom: {}, .stagesInputIn: stage, .type: type, .name: name, .location: m_nextFreeInLocation[int(stage)]++, .output: false, .flat: flat };
79 m_inOutVars.insert(key: name, value: var);
80 }
81
82 void registerOutput(QSSGShaderGeneratorStage stage, const QByteArray &type, const QByteArray &name, bool flat = false)
83 {
84 auto it = m_inOutVars.find(key: name);
85 if (it != m_inOutVars.end()) {
86 it->stageOutputFrom |= stage;
87 return;
88 }
89 InOutVar var { .stageOutputFrom: stage, .stagesInputIn: {}, .type: type, .name: name, .location: m_nextFreeOutLocation[int(stage)]++, .output: true, .flat: flat };
90 m_inOutVars.insert(key: name, value: var);
91 }
92
93 void registerSampler(const QByteArray &type,
94 const QByteArray &name,
95 QSSGRenderShaderMetadata::Uniform::Condition conditionType = QSSGRenderShaderMetadata::Uniform::None,
96 const QByteArray &conditionName = QByteArray())
97 {
98 if (m_samplers.contains(key: name))
99 return;
100 Sampler var { .type: type, .name: name, .conditionType: conditionType, .conditionName: conditionName, .binding: m_nextFreeResourceBinding++ };
101 m_samplers.insert(key: name, value: var);
102 }
103
104 void registerUniformMember(const QByteArray &type,
105 const QByteArray &name,
106 QSSGRenderShaderMetadata::Uniform::Condition conditionType = QSSGRenderShaderMetadata::Uniform::None,
107 const QByteArray &conditionName = QByteArray())
108 {
109 auto it = m_uniformMembers.constFind(key: name);
110 if (it != m_uniformMembers.constEnd()) {
111 if (it->conditionType != conditionType) {
112 qWarning(msg: "Encountered uniform %s with different conditions, this is not supported.",
113 name.constData());
114 }
115 return;
116 }
117 BlockMember var { .type: type, .name: name, .conditionType: conditionType, .conditionName: conditionName };
118 m_uniformMembers.insert(key: name, value: var);
119 }
120};
121
122QT_END_NAMESPACE
123
124#endif
125

source code of qtquick3d/src/runtimerender/qssgshaderresourcemergecontext_p.h