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50 | |
51 | #include "linenode.h" |
52 | |
53 | #include <QtGui/QColor> |
54 | |
55 | #include <QtQuick/QSGSimpleMaterial> |
56 | |
57 | struct LineMaterial |
58 | { |
59 | QColor color; |
60 | float spread; |
61 | float size; |
62 | }; |
63 | |
64 | class LineShader : public QSGSimpleMaterialShader<LineMaterial> |
65 | { |
66 | QSG_DECLARE_SIMPLE_SHADER(LineShader, LineMaterial) |
67 | |
68 | public: |
69 | LineShader() { |
70 | setShaderSourceFile(type: QOpenGLShader::Vertex, sourceFile: ":/scenegraph/graph/shaders/line.vsh" ); |
71 | setShaderSourceFile(type: QOpenGLShader::Fragment, sourceFile: ":/scenegraph/graph/shaders/line.fsh" ); |
72 | } |
73 | |
74 | QList<QByteArray> attributes() const override { return QList<QByteArray>() << "pos" << "t" ; } |
75 | |
76 | void updateState(const LineMaterial *m, const LineMaterial *) override { |
77 | program()->setUniformValue(location: id_color, color: m->color); |
78 | program()->setUniformValue(location: id_spread, value: m->spread); |
79 | program()->setUniformValue(location: id_size, value: m->size); |
80 | } |
81 | |
82 | void resolveUniforms() override { |
83 | id_spread = program()->uniformLocation(name: "spread" ); |
84 | id_size = program()->uniformLocation(name: "size" ); |
85 | id_color = program()->uniformLocation(name: "color" ); |
86 | } |
87 | |
88 | private: |
89 | int id_color = -1; |
90 | int id_spread = -1; |
91 | int id_size = -1; |
92 | }; |
93 | |
94 | struct LineVertex { |
95 | float x; |
96 | float y; |
97 | float t; |
98 | inline void set(float xx, float yy, float tt) { x = xx; y = yy; t = tt; } |
99 | }; |
100 | |
101 | static const QSGGeometry::AttributeSet &attributes() |
102 | { |
103 | static QSGGeometry::Attribute attr[] = { |
104 | QSGGeometry::Attribute::create(pos: 0, tupleSize: 2, GL_FLOAT, isPosition: true), |
105 | QSGGeometry::Attribute::create(pos: 1, tupleSize: 1, GL_FLOAT) |
106 | }; |
107 | static QSGGeometry::AttributeSet set = { .count: 2, .stride: 3 * sizeof(float), .attributes: attr }; |
108 | return set; |
109 | } |
110 | |
111 | LineNode::LineNode(float size, float spread, const QColor &color) |
112 | : m_geometry(attributes(), 0) |
113 | { |
114 | setGeometry(&m_geometry); |
115 | m_geometry.setDrawingMode(GL_TRIANGLE_STRIP); |
116 | |
117 | QSGSimpleMaterial<LineMaterial> *m = LineShader::createMaterial(); |
118 | m->state()->color = color; |
119 | m->state()->size = size; |
120 | m->state()->spread = spread; |
121 | m->setFlag(flags: QSGMaterial::Blending); |
122 | setMaterial(m); |
123 | setFlag(OwnsMaterial); |
124 | } |
125 | |
126 | /* |
127 | * Assumes that samples have values in the range of 0 to 1 and scales them to |
128 | * the height of bounds. The samples are stretched out horizontally along the |
129 | * width of the bounds. |
130 | * |
131 | * The position of each pair of points is identical, but we use the third value |
132 | * "t" to shift the point up or down and to add antialiasing. |
133 | */ |
134 | void LineNode::updateGeometry(const QRectF &bounds, const QList<qreal> &samples) |
135 | { |
136 | m_geometry.allocate(vertexCount: samples.size() * 2); |
137 | |
138 | float x = bounds.x(); |
139 | float y = bounds.y(); |
140 | float w = bounds.width(); |
141 | float h = bounds.height(); |
142 | |
143 | float dx = w / (samples.size() - 1); |
144 | |
145 | LineVertex *v = (LineVertex *) m_geometry.vertexData(); |
146 | for (int i=0; i<samples.size(); ++i) { |
147 | v[i*2+0].set(xx: x + dx * i, yy: y + samples.at(i) * h, tt: 0); |
148 | v[i*2+1].set(xx: x + dx * i, yy: y + samples.at(i) * h, tt: 1); |
149 | } |
150 | |
151 | markDirty(bits: QSGNode::DirtyGeometry); |
152 | } |
153 | |