qt-everywhere-src-5.15.1/qtbase/examples/opengl/hellogl2/glwidget.cpp - orbit - Git at Google

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** BSD License Usage
 ** Alternatively, you may use this file under the terms of the BSD license
 ** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "glwidget.h"
 #include <QMouseEvent>
 #include <QOpenGLShaderProgram>
 #include <QCoreApplication>
 #include <math.h>

 bool GLWidget::m_transparent = false;

 GLWidget::GLWidget(QWidget *parent)
     : QOpenGLWidget(parent)
 {
     m_core = QSurfaceFormat::defaultFormat().profile() == QSurfaceFormat::CoreProfile;
     // --transparent causes the clear color to be transparent. Therefore, on systems that
     // support it, the widget will become transparent apart from the logo.
     if (m_transparent) {
         QSurfaceFormat fmt = format();
         fmt.setAlphaBufferSize(8);
         setFormat(fmt);
     }
 }

 GLWidget::~GLWidget()
 {
     cleanup();
 }

 QSize GLWidget::minimumSizeHint() const
 {
     return QSize(50, 50);
 }

 QSize GLWidget::sizeHint() const
 {
     return QSize(400, 400);
 }

 static void qNormalizeAngle(int &angle)
 {
     while (angle < 0)
         angle += 360 * 16;
     while (angle > 360 * 16)
         angle -= 360 * 16;
 }

 void GLWidget::setXRotation(int angle)
 {
     qNormalizeAngle(angle);
     if (angle != m_xRot) {
         m_xRot = angle;
         emit xRotationChanged(angle);
         update();
     }
 }

 void GLWidget::setYRotation(int angle)
 {
     qNormalizeAngle(angle);
     if (angle != m_yRot) {
         m_yRot = angle;
         emit yRotationChanged(angle);
         update();
     }
 }

 void GLWidget::setZRotation(int angle)
 {
     qNormalizeAngle(angle);
     if (angle != m_zRot) {
         m_zRot = angle;
         emit zRotationChanged(angle);
         update();
     }
 }

 void GLWidget::cleanup()
 {
     if (m_program == nullptr)
         return;
     makeCurrent();
     m_logoVbo.destroy();
     delete m_program;
     m_program = nullptr;
     doneCurrent();
 }

 static const char *vertexShaderSourceCore =
     "#version 150\n"
     "in vec4 vertex;\n"
     "in vec3 normal;\n"
     "out vec3 vert;\n"
     "out vec3 vertNormal;\n"
     "uniform mat4 projMatrix;\n"
     "uniform mat4 mvMatrix;\n"
     "uniform mat3 normalMatrix;\n"
     "void main() {\n"
     "   vert = vertex.xyz;\n"
     "   vertNormal = normalMatrix * normal;\n"
     "   gl_Position = projMatrix * mvMatrix * vertex;\n"
     "}\n";

 static const char *fragmentShaderSourceCore =
     "#version 150\n"
     "in highp vec3 vert;\n"
     "in highp vec3 vertNormal;\n"
     "out highp vec4 fragColor;\n"
     "uniform highp vec3 lightPos;\n"
     "void main() {\n"
     "   highp vec3 L = normalize(lightPos - vert);\n"
     "   highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
     "   highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
     "   highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
     "   fragColor = vec4(col, 1.0);\n"
     "}\n";

 static const char *vertexShaderSource =
     "attribute vec4 vertex;\n"
     "attribute vec3 normal;\n"
     "varying vec3 vert;\n"
     "varying vec3 vertNormal;\n"
     "uniform mat4 projMatrix;\n"
     "uniform mat4 mvMatrix;\n"
     "uniform mat3 normalMatrix;\n"
     "void main() {\n"
     "   vert = vertex.xyz;\n"
     "   vertNormal = normalMatrix * normal;\n"
     "   gl_Position = projMatrix * mvMatrix * vertex;\n"
     "}\n";

 static const char *fragmentShaderSource =
     "varying highp vec3 vert;\n"
     "varying highp vec3 vertNormal;\n"
     "uniform highp vec3 lightPos;\n"
     "void main() {\n"
     "   highp vec3 L = normalize(lightPos - vert);\n"
     "   highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
     "   highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
     "   highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
     "   gl_FragColor = vec4(col, 1.0);\n"
     "}\n";

 void GLWidget::initializeGL()
 {
     // In this example the widget's corresponding top-level window can change
     // several times during the widget's lifetime. Whenever this happens, the
     // QOpenGLWidget's associated context is destroyed and a new one is created.
     // Therefore we have to be prepared to clean up the resources on the
     // aboutToBeDestroyed() signal, instead of the destructor. The emission of
     // the signal will be followed by an invocation of initializeGL() where we
     // can recreate all resources.
     connect(context(), &QOpenGLContext::aboutToBeDestroyed, this, &GLWidget::cleanup);

     initializeOpenGLFunctions();
     glClearColor(0, 0, 0, m_transparent ? 0 : 1);

     m_program = new QOpenGLShaderProgram;
     m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, m_core ? vertexShaderSourceCore : vertexShaderSource);
     m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, m_core ? fragmentShaderSourceCore : fragmentShaderSource);
     m_program->bindAttributeLocation("vertex", 0);
     m_program->bindAttributeLocation("normal", 1);
     m_program->link();

     m_program->bind();
     m_projMatrixLoc = m_program->uniformLocation("projMatrix");
     m_mvMatrixLoc = m_program->uniformLocation("mvMatrix");
     m_normalMatrixLoc = m_program->uniformLocation("normalMatrix");
     m_lightPosLoc = m_program->uniformLocation("lightPos");

     // Create a vertex array object. In OpenGL ES 2.0 and OpenGL 2.x
     // implementations this is optional and support may not be present
     // at all. Nonetheless the below code works in all cases and makes
     // sure there is a VAO when one is needed.
     m_vao.create();
     QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);

     // Setup our vertex buffer object.
     m_logoVbo.create();
     m_logoVbo.bind();
     m_logoVbo.allocate(m_logo.constData(), m_logo.count() * sizeof(GLfloat));

     // Store the vertex attribute bindings for the program.
     setupVertexAttribs();

     // Our camera never changes in this example.
     m_camera.setToIdentity();
     m_camera.translate(0, 0, -1);

     // Light position is fixed.
     m_program->setUniformValue(m_lightPosLoc, QVector3D(0, 0, 70));

     m_program->release();
 }

 void GLWidget::setupVertexAttribs()
 {
     m_logoVbo.bind();
     QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
     f->glEnableVertexAttribArray(0);
     f->glEnableVertexAttribArray(1);
     f->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
                              nullptr);
     f->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
                              reinterpret_cast<void *>(3 * sizeof(GLfloat)));
     m_logoVbo.release();
 }

 void GLWidget::paintGL()
 {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     glEnable(GL_DEPTH_TEST);
     glEnable(GL_CULL_FACE);

     m_world.setToIdentity();
     m_world.rotate(180.0f - (m_xRot / 16.0f), 1, 0, 0);
     m_world.rotate(m_yRot / 16.0f, 0, 1, 0);
     m_world.rotate(m_zRot / 16.0f, 0, 0, 1);

     QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
     m_program->bind();
     m_program->setUniformValue(m_projMatrixLoc, m_proj);
     m_program->setUniformValue(m_mvMatrixLoc, m_camera * m_world);
     QMatrix3x3 normalMatrix = m_world.normalMatrix();
     m_program->setUniformValue(m_normalMatrixLoc, normalMatrix);

     glDrawArrays(GL_TRIANGLES, 0, m_logo.vertexCount());

     m_program->release();
 }

 void GLWidget::resizeGL(int w, int h)
 {
     m_proj.setToIdentity();
     m_proj.perspective(45.0f, GLfloat(w) / h, 0.01f, 100.0f);
 }

 void GLWidget::mousePressEvent(QMouseEvent *event)
 {
     m_lastPos = event->pos();
 }

 void GLWidget::mouseMoveEvent(QMouseEvent *event)
 {
     int dx = event->x() - m_lastPos.x();
     int dy = event->y() - m_lastPos.y();

     if (event->buttons() & Qt::LeftButton) {
         setXRotation(m_xRot + 8 * dy);
         setYRotation(m_yRot + 8 * dx);
     } else if (event->buttons() & Qt::RightButton) {
         setXRotation(m_xRot + 8 * dy);
         setZRotation(m_zRot + 8 * dx);
     }
     m_lastPos = event->pos();
 }
	/****************************************************************************
	**
	** Copyright (C) 2016 The Qt Company Ltd.
	** Contact: https://www.qt.io/licensing/
	**
	** This file is part of the examples of the Qt Toolkit.
	**
	** $QT_BEGIN_LICENSE:BSD$
	** Commercial License Usage
	** Licensees holding valid commercial Qt licenses may use this file in
	** accordance with the commercial license agreement provided with the
	** Software or, alternatively, in accordance with the terms contained in
	** a written agreement between you and The Qt Company. For licensing terms
	** and conditions see https://www.qt.io/terms-conditions. For further
	** information use the contact form at https://www.qt.io/contact-us.
	**
	** BSD License Usage
	** Alternatively, you may use this file under the terms of the BSD license
	** as follows:
	**
	** "Redistribution and use in source and binary forms, with or without
	** modification, are permitted provided that the following conditions are
	** met:
	** * Redistributions of source code must retain the above copyright
	** notice, this list of conditions and the following disclaimer.
	** * Redistributions in binary form must reproduce the above copyright
	** notice, this list of conditions and the following disclaimer in
	** the documentation and/or other materials provided with the
	** distribution.
	** * Neither the name of The Qt Company Ltd nor the names of its
	** contributors may be used to endorse or promote products derived
	** from this software without specific prior written permission.
	**
	**
	** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
	**
	** $QT_END_LICENSE$
	**
	****************************************************************************/

	#include "glwidget.h"
	#include <QMouseEvent>
	#include <QOpenGLShaderProgram>
	#include <QCoreApplication>
	#include <math.h>

	bool GLWidget::m_transparent = false;

	GLWidget::GLWidget(QWidget *parent)
	: QOpenGLWidget(parent)
	{
	m_core = QSurfaceFormat::defaultFormat().profile() == QSurfaceFormat::CoreProfile;
	// --transparent causes the clear color to be transparent. Therefore, on systems that
	// support it, the widget will become transparent apart from the logo.
	if (m_transparent) {
	QSurfaceFormat fmt = format();
	fmt.setAlphaBufferSize(8);
	setFormat(fmt);
	}
	}

	GLWidget::~GLWidget()
	{
	cleanup();
	}

	QSize GLWidget::minimumSizeHint() const
	{
	return QSize(50, 50);
	}

	QSize GLWidget::sizeHint() const
	{
	return QSize(400, 400);
	}

	static void qNormalizeAngle(int &angle)
	{
	while (angle < 0)
	angle += 360 * 16;
	while (angle > 360 * 16)
	angle -= 360 * 16;
	}

	void GLWidget::setXRotation(int angle)
	{
	qNormalizeAngle(angle);
	if (angle != m_xRot) {
	m_xRot = angle;
	emit xRotationChanged(angle);
	update();
	}
	}

	void GLWidget::setYRotation(int angle)
	{
	qNormalizeAngle(angle);
	if (angle != m_yRot) {
	m_yRot = angle;
	emit yRotationChanged(angle);
	update();
	}
	}

	void GLWidget::setZRotation(int angle)
	{
	qNormalizeAngle(angle);
	if (angle != m_zRot) {
	m_zRot = angle;
	emit zRotationChanged(angle);
	update();
	}
	}

	void GLWidget::cleanup()
	{
	if (m_program == nullptr)
	return;
	makeCurrent();
	m_logoVbo.destroy();
	delete m_program;
	m_program = nullptr;
	doneCurrent();
	}

	static const char *vertexShaderSourceCore =
	"#version 150\n"
	"in vec4 vertex;\n"
	"in vec3 normal;\n"
	"out vec3 vert;\n"
	"out vec3 vertNormal;\n"
	"uniform mat4 projMatrix;\n"
	"uniform mat4 mvMatrix;\n"
	"uniform mat3 normalMatrix;\n"
	"void main() {\n"
	" vert = vertex.xyz;\n"
	" vertNormal = normalMatrix * normal;\n"
	" gl_Position = projMatrix * mvMatrix * vertex;\n"
	"}\n";

	static const char *fragmentShaderSourceCore =
	"#version 150\n"
	"in highp vec3 vert;\n"
	"in highp vec3 vertNormal;\n"
	"out highp vec4 fragColor;\n"
	"uniform highp vec3 lightPos;\n"
	"void main() {\n"
	" highp vec3 L = normalize(lightPos - vert);\n"
	" highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
	" highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
	" highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
	" fragColor = vec4(col, 1.0);\n"
	"}\n";

	static const char *vertexShaderSource =
	"attribute vec4 vertex;\n"
	"attribute vec3 normal;\n"
	"varying vec3 vert;\n"
	"varying vec3 vertNormal;\n"
	"uniform mat4 projMatrix;\n"
	"uniform mat4 mvMatrix;\n"
	"uniform mat3 normalMatrix;\n"
	"void main() {\n"
	" vert = vertex.xyz;\n"
	" vertNormal = normalMatrix * normal;\n"
	" gl_Position = projMatrix * mvMatrix * vertex;\n"
	"}\n";

	static const char *fragmentShaderSource =
	"varying highp vec3 vert;\n"
	"varying highp vec3 vertNormal;\n"
	"uniform highp vec3 lightPos;\n"
	"void main() {\n"
	" highp vec3 L = normalize(lightPos - vert);\n"
	" highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
	" highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
	" highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
	" gl_FragColor = vec4(col, 1.0);\n"
	"}\n";

	void GLWidget::initializeGL()
	{
	// In this example the widget's corresponding top-level window can change
	// several times during the widget's lifetime. Whenever this happens, the
	// QOpenGLWidget's associated context is destroyed and a new one is created.
	// Therefore we have to be prepared to clean up the resources on the
	// aboutToBeDestroyed() signal, instead of the destructor. The emission of
	// the signal will be followed by an invocation of initializeGL() where we
	// can recreate all resources.
	connect(context(), &QOpenGLContext::aboutToBeDestroyed, this, &GLWidget::cleanup);

	initializeOpenGLFunctions();
	glClearColor(0, 0, 0, m_transparent ? 0 : 1);

	m_program = new QOpenGLShaderProgram;
	m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, m_core ? vertexShaderSourceCore : vertexShaderSource);
	m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, m_core ? fragmentShaderSourceCore : fragmentShaderSource);
	m_program->bindAttributeLocation("vertex", 0);
	m_program->bindAttributeLocation("normal", 1);
	m_program->link();

	m_program->bind();
	m_projMatrixLoc = m_program->uniformLocation("projMatrix");
	m_mvMatrixLoc = m_program->uniformLocation("mvMatrix");
	m_normalMatrixLoc = m_program->uniformLocation("normalMatrix");
	m_lightPosLoc = m_program->uniformLocation("lightPos");

	// Create a vertex array object. In OpenGL ES 2.0 and OpenGL 2.x
	// implementations this is optional and support may not be present
	// at all. Nonetheless the below code works in all cases and makes
	// sure there is a VAO when one is needed.
	m_vao.create();
	QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);

	// Setup our vertex buffer object.
	m_logoVbo.create();
	m_logoVbo.bind();
	m_logoVbo.allocate(m_logo.constData(), m_logo.count() * sizeof(GLfloat));

	// Store the vertex attribute bindings for the program.
	setupVertexAttribs();

	// Our camera never changes in this example.
	m_camera.setToIdentity();
	m_camera.translate(0, 0, -1);

	// Light position is fixed.
	m_program->setUniformValue(m_lightPosLoc, QVector3D(0, 0, 70));

	m_program->release();
	}

	void GLWidget::setupVertexAttribs()
	{
	m_logoVbo.bind();
	QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
	f->glEnableVertexAttribArray(0);
	f->glEnableVertexAttribArray(1);
	f->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
	nullptr);
	f->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
	reinterpret_cast<void >(3 sizeof(GLfloat)));
	m_logoVbo.release();
	}

	void GLWidget::paintGL()
	{
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_CULL_FACE);

	m_world.setToIdentity();
	m_world.rotate(180.0f - (m_xRot / 16.0f), 1, 0, 0);
	m_world.rotate(m_yRot / 16.0f, 0, 1, 0);
	m_world.rotate(m_zRot / 16.0f, 0, 0, 1);

	QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
	m_program->bind();
	m_program->setUniformValue(m_projMatrixLoc, m_proj);
	m_program->setUniformValue(m_mvMatrixLoc, m_camera * m_world);
	QMatrix3x3 normalMatrix = m_world.normalMatrix();
	m_program->setUniformValue(m_normalMatrixLoc, normalMatrix);

	glDrawArrays(GL_TRIANGLES, 0, m_logo.vertexCount());

	m_program->release();
	}

	void GLWidget::resizeGL(int w, int h)
	{
	m_proj.setToIdentity();
	m_proj.perspective(45.0f, GLfloat(w) / h, 0.01f, 100.0f);
	}

	void GLWidget::mousePressEvent(QMouseEvent *event)
	{
	m_lastPos = event->pos();
	}

	void GLWidget::mouseMoveEvent(QMouseEvent *event)
	{
	int dx = event->x() - m_lastPos.x();
	int dy = event->y() - m_lastPos.y();

	if (event->buttons() & Qt::LeftButton) {
	setXRotation(m_xRot + 8 * dy);
	setYRotation(m_yRot + 8 * dx);
	} else if (event->buttons() & Qt::RightButton) {
	setXRotation(m_xRot + 8 * dy);
	setZRotation(m_zRot + 8 * dx);
	}
	m_lastPos = event->pos();
	}