1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "squircle.h"
#include <QtQuick/qquickwindow.h>
#include <QOpenGLShaderProgram>
#include <QOpenGLContext>
#include <QtCore/QRunnable>
//! [7]
Squircle::Squircle()
: m_t(0)
, m_renderer(nullptr)
{
connect(this, &QQuickItem::windowChanged, this, &Squircle::handleWindowChanged);
}
//! [7]
//! [8]
void Squircle::setT(qreal t)
{
if (t == m_t)
return;
m_t = t;
emit tChanged();
if (window())
window()->update();
}
//! [8]
//! [1]
void Squircle::handleWindowChanged(QQuickWindow *win)
{
if (win) {
connect(win, &QQuickWindow::beforeSynchronizing, this, &Squircle::sync, Qt::DirectConnection);
connect(win, &QQuickWindow::sceneGraphInvalidated, this, &Squircle::cleanup, Qt::DirectConnection);
//! [1]
//! [3]
// Ensure we start with cleared to black. The squircle's blend mode relies on this.
win->setColor(Qt::black);
}
}
//! [3]
//! [6]
void Squircle::cleanup()
{
delete m_renderer;
m_renderer = nullptr;
}
class CleanupJob : public QRunnable
{
public:
CleanupJob(SquircleRenderer *renderer) : m_renderer(renderer) { }
void run() override { delete m_renderer; }
private:
SquircleRenderer *m_renderer;
};
void Squircle::releaseResources()
{
window()->scheduleRenderJob(new CleanupJob(m_renderer), QQuickWindow::BeforeSynchronizingStage);
m_renderer = nullptr;
}
SquircleRenderer::~SquircleRenderer()
{
delete m_program;
}
//! [6]
//! [9]
void Squircle::sync()
{
if (!m_renderer) {
m_renderer = new SquircleRenderer();
connect(window(), &QQuickWindow::beforeRendering, m_renderer, &SquircleRenderer::init, Qt::DirectConnection);
connect(window(), &QQuickWindow::beforeRenderPassRecording, m_renderer, &SquircleRenderer::paint, Qt::DirectConnection);
}
m_renderer->setViewportSize(window()->size() * window()->devicePixelRatio());
m_renderer->setT(m_t);
m_renderer->setWindow(window());
}
//! [9]
//! [4]
void SquircleRenderer::init()
{
if (!m_program) {
QSGRendererInterface *rif = m_window->rendererInterface();
Q_ASSERT(rif->graphicsApi() == QSGRendererInterface::OpenGL);
initializeOpenGLFunctions();
m_program = new QOpenGLShaderProgram();
m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex,
"attribute highp vec4 vertices;"
"varying highp vec2 coords;"
"void main() {"
" gl_Position = vertices;"
" coords = vertices.xy;"
"}");
m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment,
"uniform lowp float t;"
"varying highp vec2 coords;"
"void main() {"
" lowp float i = 1. - (pow(abs(coords.x), 4.) + pow(abs(coords.y), 4.));"
" i = smoothstep(t - 0.8, t + 0.8, i);"
" i = floor(i * 20.) / 20.;"
" gl_FragColor = vec4(coords * .5 + .5, i, i);"
"}");
m_program->bindAttributeLocation("vertices", 0);
m_program->link();
}
}
//! [4] //! [5]
void SquircleRenderer::paint()
{
// Play nice with the RHI. Not strictly needed when the scenegraph uses
// OpenGL directly.
m_window->beginExternalCommands();
m_program->bind();
m_program->enableAttributeArray(0);
float values[] = {
-1, -1,
1, -1,
-1, 1,
1, 1
};
// This example relies on (deprecated) client-side pointers for the vertex
// input. Therefore, we have to make sure no vertex buffer is bound.
glBindBuffer(GL_ARRAY_BUFFER, 0);
m_program->setAttributeArray(0, GL_FLOAT, values, 2);
m_program->setUniformValue("t", (float) m_t);
glViewport(0, 0, m_viewportSize.width(), m_viewportSize.height());
glDisable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
m_program->disableAttributeArray(0);
m_program->release();
m_window->endExternalCommands();
}
//! [5]
|
