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50
51#include "hellowindow.h"
52
53#include <QOpenGLContext>
54#include <QOpenGLFunctions>
55#include <QRandomGenerator>
56#include <qmath.h>
57
58Renderer::Renderer(const QSurfaceFormat &format, Renderer *share, QScreen *screen)
59 : m_initialized(false)
60 , m_format(format)
61 , m_currentWindow(0)
62{
63 m_context = new QOpenGLContext(this);
64 if (screen)
65 m_context->setScreen(screen);
66 m_context->setFormat(format);
67 if (share)
68 m_context->setShareContext(share->m_context);
69 m_context->create();
70
71 m_backgroundColor = QColor::fromRgbF(r: 0.1f, g: 0.1f, b: 0.2f, a: 1.0f);
72 m_backgroundColor.setRed(QRandomGenerator::global()->bounded(highest: 64));
73 m_backgroundColor.setGreen(QRandomGenerator::global()->bounded(highest: 128));
74 m_backgroundColor.setBlue(QRandomGenerator::global()->bounded(highest: 256));
75}
76
77HelloWindow::HelloWindow(const QSharedPointer<Renderer> &renderer, QScreen *screen)
78 : m_colorIndex(0), m_renderer(renderer)
79{
80 setSurfaceType(QWindow::OpenGLSurface);
81 setFlags(Qt::Window | Qt::WindowSystemMenuHint | Qt::WindowTitleHint | Qt::WindowMinMaxButtonsHint | Qt::WindowCloseButtonHint);
82
83 setGeometry(QRect(10, 10, 640, 480));
84
85 setFormat(renderer->format());
86 if (screen)
87 setScreen(screen);
88
89 create();
90
91 updateColor();
92}
93
94void HelloWindow::exposeEvent(QExposeEvent *)
95{
96 m_renderer->setAnimating(window: this, animating: isExposed());
97 if (isExposed())
98 m_renderer->render();
99}
100
101bool HelloWindow::event(QEvent *ev)
102{
103 if (ev->type() == QEvent::UpdateRequest) {
104 m_renderer->render();
105 requestUpdate();
106 }
107 return QWindow::event(ev);
108}
109
110void HelloWindow::mousePressEvent(QMouseEvent *)
111{
112 updateColor();
113}
114
115QColor HelloWindow::color() const
116{
117 QMutexLocker locker(&m_colorLock);
118 return m_color;
119}
120
121void HelloWindow::updateColor()
122{
123 QMutexLocker locker(&m_colorLock);
124
125 QColor colors[] =
126 {
127 QColor(100, 255, 0),
128 QColor(0, 100, 255)
129 };
130
131 m_color = colors[m_colorIndex];
132 m_colorIndex = 1 - m_colorIndex;
133}
134
135void Renderer::setAnimating(HelloWindow *window, bool animating)
136{
137 QMutexLocker locker(&m_windowLock);
138 if (m_windows.contains(t: window) == animating)
139 return;
140
141 if (animating) {
142 m_windows << window;
143 if (m_windows.size() == 1)
144 window->requestUpdate();
145 } else {
146 m_currentWindow = 0;
147 m_windows.removeOne(t: window);
148 }
149}
150
151void Renderer::render()
152{
153 QMutexLocker locker(&m_windowLock);
154
155 if (m_windows.isEmpty())
156 return;
157
158 HelloWindow *surface = m_windows.at(i: m_currentWindow);
159 QColor color = surface->color();
160
161 m_currentWindow = (m_currentWindow + 1) % m_windows.size();
162
163 if (!m_context->makeCurrent(surface))
164 return;
165
166 QSize viewSize = surface->size();
167
168 locker.unlock();
169
170 if (!m_initialized) {
171 initialize();
172 m_initialized = true;
173 }
174
175 QOpenGLFunctions *f = m_context->functions();
176 f->glViewport(x: 0, y: 0, width: viewSize.width() * surface->devicePixelRatio(), height: viewSize.height() * surface->devicePixelRatio());
177 f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
178
179 f->glClearColor(red: m_backgroundColor.redF(), green: m_backgroundColor.greenF(), blue: m_backgroundColor.blueF(), alpha: m_backgroundColor.alphaF());
180 f->glFrontFace(GL_CW);
181 f->glCullFace(GL_FRONT);
182 f->glEnable(GL_CULL_FACE);
183 f->glEnable(GL_DEPTH_TEST);
184
185 m_program->bind();
186 m_vbo.bind();
187
188 m_program->enableAttributeArray(location: vertexAttr);
189 m_program->enableAttributeArray(location: normalAttr);
190 m_program->setAttributeBuffer(location: vertexAttr, GL_FLOAT, offset: 0, tupleSize: 3);
191 const int verticesSize = vertices.count() * 3 * sizeof(GLfloat);
192 m_program->setAttributeBuffer(location: normalAttr, GL_FLOAT, offset: verticesSize, tupleSize: 3);
193
194 QMatrix4x4 modelview;
195 modelview.rotate(angle: m_fAngle, x: 0.0f, y: 1.0f, z: 0.0f);
196 modelview.rotate(angle: m_fAngle, x: 1.0f, y: 0.0f, z: 0.0f);
197 modelview.rotate(angle: m_fAngle, x: 0.0f, y: 0.0f, z: 1.0f);
198 modelview.translate(x: 0.0f, y: -0.2f, z: 0.0f);
199
200 m_program->setUniformValue(location: matrixUniform, value: modelview);
201 m_program->setUniformValue(location: colorUniform, color);
202
203 m_context->functions()->glDrawArrays(GL_TRIANGLES, first: 0, count: vertices.size());
204
205 m_context->swapBuffers(surface);
206
207 m_fAngle += 1.0f;
208}
209
210Q_GLOBAL_STATIC(QMutex, initMutex)
211
212void Renderer::initialize()
213{
214 // Threaded shader compilation can confuse some drivers. Avoid it.
215 QMutexLocker lock(initMutex());
216
217 QOpenGLShader *vshader = new QOpenGLShader(QOpenGLShader::Vertex, this);
218 vshader->compileSourceCode(
219 source: "attribute highp vec4 vertex;"
220 "attribute mediump vec3 normal;"
221 "uniform mediump mat4 matrix;"
222 "uniform lowp vec4 sourceColor;"
223 "varying mediump vec4 color;"
224 "void main(void)"
225 "{"
226 " vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));"
227 " float angle = max(dot(normal, toLight), 0.0);"
228 " vec3 col = sourceColor.rgb;"
229 " color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);"
230 " color = clamp(color, 0.0, 1.0);"
231 " gl_Position = matrix * vertex;"
232 "}");
233
234 QOpenGLShader *fshader = new QOpenGLShader(QOpenGLShader::Fragment, this);
235 fshader->compileSourceCode(
236 source: "varying mediump vec4 color;"
237 "void main(void)"
238 "{"
239 " gl_FragColor = color;"
240 "}");
241
242 m_program = new QOpenGLShaderProgram(this);
243 m_program->addShader(shader: vshader);
244 m_program->addShader(shader: fshader);
245 m_program->link();
246 m_program->bind();
247
248 vertexAttr = m_program->attributeLocation(name: "vertex");
249 normalAttr = m_program->attributeLocation(name: "normal");
250 matrixUniform = m_program->uniformLocation(name: "matrix");
251 colorUniform = m_program->uniformLocation(name: "sourceColor");
252
253 m_fAngle = 0;
254 createGeometry();
255
256 m_vbo.create();
257 m_vbo.bind();
258 const int verticesSize = vertices.count() * 3 * sizeof(GLfloat);
259 m_vbo.allocate(count: verticesSize * 2);
260 m_vbo.write(offset: 0, data: vertices.constData(), count: verticesSize);
261 m_vbo.write(offset: verticesSize, data: normals.constData(), count: verticesSize);
262}
263
264void Renderer::createGeometry()
265{
266 vertices.clear();
267 normals.clear();
268
269 qreal x1 = +0.06f;
270 qreal y1 = -0.14f;
271 qreal x2 = +0.14f;
272 qreal y2 = -0.06f;
273 qreal x3 = +0.08f;
274 qreal y3 = +0.00f;
275 qreal x4 = +0.30f;
276 qreal y4 = +0.22f;
277
278 quad(x1, y1, x2, y2, x3: y2, y3: x2, x4: y1, y4: x1);
279 quad(x1: x3, y1: y3, x2: x4, y2: y4, x3: y4, y3: x4, x4: y3, y4: x3);
280
281 extrude(x1, y1, x2, y2);
282 extrude(x1: x2, y1: y2, x2: y2, y2: x2);
283 extrude(x1: y2, y1: x2, x2: y1, y2: x1);
284 extrude(x1: y1, y1: x1, x2: x1, y2: y1);
285 extrude(x1: x3, y1: y3, x2: x4, y2: y4);
286 extrude(x1: x4, y1: y4, x2: y4, y2: x4);
287 extrude(x1: y4, y1: x4, x2: y3, y2: x3);
288
289 const int NumSectors = 100;
290 const qreal sectorAngle = 2 * qreal(M_PI) / NumSectors;
291 for (int i = 0; i < NumSectors; ++i) {
292 qreal angle = i * sectorAngle;
293 qreal x5 = 0.30 * qSin(v: angle);
294 qreal y5 = 0.30 * qCos(v: angle);
295 qreal x6 = 0.20 * qSin(v: angle);
296 qreal y6 = 0.20 * qCos(v: angle);
297
298 angle += sectorAngle;
299 qreal x7 = 0.20 * qSin(v: angle);
300 qreal y7 = 0.20 * qCos(v: angle);
301 qreal x8 = 0.30 * qSin(v: angle);
302 qreal y8 = 0.30 * qCos(v: angle);
303
304 quad(x1: x5, y1: y5, x2: x6, y2: y6, x3: x7, y3: y7, x4: x8, y4: y8);
305
306 extrude(x1: x6, y1: y6, x2: x7, y2: y7);
307 extrude(x1: x8, y1: y8, x2: x5, y2: y5);
308 }
309
310 for (int i = 0;i < vertices.size();i++)
311 vertices[i] *= 2.0f;
312}
313
314void Renderer::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
315{
316 vertices << QVector3D(x1, y1, -0.05f);
317 vertices << QVector3D(x2, y2, -0.05f);
318 vertices << QVector3D(x4, y4, -0.05f);
319
320 vertices << QVector3D(x3, y3, -0.05f);
321 vertices << QVector3D(x4, y4, -0.05f);
322 vertices << QVector3D(x2, y2, -0.05f);
323
324 QVector3D n = QVector3D::normal
325 (v1: QVector3D(x2 - x1, y2 - y1, 0.0f), v2: QVector3D(x4 - x1, y4 - y1, 0.0f));
326
327 normals << n;
328 normals << n;
329 normals << n;
330
331 normals << n;
332 normals << n;
333 normals << n;
334
335 vertices << QVector3D(x4, y4, 0.05f);
336 vertices << QVector3D(x2, y2, 0.05f);
337 vertices << QVector3D(x1, y1, 0.05f);
338
339 vertices << QVector3D(x2, y2, 0.05f);
340 vertices << QVector3D(x4, y4, 0.05f);
341 vertices << QVector3D(x3, y3, 0.05f);
342
343 n = QVector3D::normal
344 (v1: QVector3D(x2 - x4, y2 - y4, 0.0f), v2: QVector3D(x1 - x4, y1 - y4, 0.0f));
345
346 normals << n;
347 normals << n;
348 normals << n;
349
350 normals << n;
351 normals << n;
352 normals << n;
353}
354
355void Renderer::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
356{
357 vertices << QVector3D(x1, y1, +0.05f);
358 vertices << QVector3D(x2, y2, +0.05f);
359 vertices << QVector3D(x1, y1, -0.05f);
360
361 vertices << QVector3D(x2, y2, -0.05f);
362 vertices << QVector3D(x1, y1, -0.05f);
363 vertices << QVector3D(x2, y2, +0.05f);
364
365 QVector3D n = QVector3D::normal
366 (v1: QVector3D(x2 - x1, y2 - y1, 0.0f), v2: QVector3D(0.0f, 0.0f, -0.1f));
367
368 normals << n;
369 normals << n;
370 normals << n;
371
372 normals << n;
373 normals << n;
374 normals << n;
375}
376

source code of qtbase/examples/opengl/hellowindow/hellowindow.cpp