用Qt和OpenGL制作的颜色立方体例子（演示程序+源代码）

/* ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ * ┃ ┏━┣━┣┓　　┏┓┏┓┳┓┏━━┓┣┣━┓　┓　┓┣┳━┓ ┃ * ┃ ┏┏┏╯━┓┳┳━┛┏╯┃┃┃　　┃┣┣━┓┃┃　┃┃┃　　 ┃ * ┃ ┃┃┏━╮┃┗┗┏╯┗┃┃╯┃　　┃┏┣━┓┃┃　┃╯┣━┓ ┃ * ┃ ╰┫┏━┻╯┗┳┣┛┏┛┃┃┣━━┫┃┃　┃┃┃┗╯　┃　　 ┃ * ┃ ┏┫━┳━┫┏┃┣┓┗┃┃╯┃　　┃┃┃　┃　┃　┃　┣━┓ ┃ * ┃ ┗┗┗━━╯┗┛┛╯┗╯╰　┗━━╯　┛　┛┗╯　╰┛┗　　 ┃ * ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫ * ┃ Copyright (c) 2013 jiangcaiyang ┃ * ┃ This software is provided 'as-is', without any express or implied ┃ * ┃ warranty. In no event will the authors be held liable for any damages ┃ * ┃ arising from the use of this software. ┃ * ┃ ┃ * ┃ Permission is granted to anyone to use this software for any purpose, ┃ * ┃ including commercial applications, and to alter it and redistribute it ┃ * ┃ freely, subject to the following restrictions: ┃ * ┃ ┃ * ┃ 1. The origin of this software must not be misrepresented; you must ┃ * ┃ not claim that you wrote the original software. If you use this ┃ * ┃ software in a product, an acknowledgment in the product ┃ * ┃ documentation would be appreciated but is not required. ┃ * ┃ 2. Altered source versions must be plainly marked as such, and must ┃ * ┃ not be misrepresented as being the original software. ┃ * ┃ 3. This notice may not be removed or altered from any source ┃ * ┃ distribution. ┃ * ┃ ┃ * ┃ jiangcaiyang [email protected] ┃ * ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫ * ┃ file name: GLWidget.cpp ┃ * ┃ create date: 2013年7月16日星期二 19时45分31秒 ┃ * ┃ last modified date: 2013年7月12日星期五 17时46分9秒 ┃ * ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛ */ #include <cmath> #include <QKeyEvent> #include <QWheelEvent> #include <QKeySequence> #include "GLWidget.h" /*---------------------------------------------------------------------------*/ void MyPerspective( GLdouble fov, GLdouble aspectRatio, GLdouble zNear, GLdouble zFar ) { using namespace std; // 使用OpenGL函数，但是需要添加math.h头文件 GLdouble rFov = fov * 3.14159265 / 180.0; GLdouble up = -zNear * tan( rFov / 2.0 ); GLdouble down = -up; GLdouble left = up * aspectRatio; GLdouble right = -left; glFrustum( left, right, up, down, zNear, zFar ); } /*---------------------------------------------------------------------------*/ GLWidget::GLWidget( QWidget* pParent ): QGLWidget( pParent ) { // 设置窗口 resize( 640, 360 ); // 初始大小为640×360（小宽屏） m_AspectRatio = qreal( width( ) ) / qreal( height( ) ); // 初始的宽高比 } void GLWidget::initializeGL( void ) { initializeOpenGLFunctions( ); // 打开开关 qglClearColor( QColor( 0, 0, 0, 255 ) ); qglColor( QColor( 255, 0, 0 ) ); glEnableClientState( GL_VERTEX_ARRAY ); glEnableClientState( GL_COLOR_ARRAY ); // 创建顶点缓存并且设置顶点 glGenBuffers( 1, &m_VertexBuffer ); glBindBuffer( GL_ARRAY_BUFFER, m_VertexBuffer ); CubeVertices( 20.0f ); // 创建索引缓存以及设置索引 glGenBuffers( 1, &m_ColorBuffer ); glBindBuffer( GL_ARRAY_BUFFER, m_ColorBuffer ); CubeColors( ); glEnable( GL_DEPTH_TEST ); glFrontFace( GL_CW ); glEnable( GL_CULL_FACE ); glHint( GL_POINT_SMOOTH_HINT, GL_NICEST ); glHint( GL_LINE_SMOOTH_HINT, GL_NICEST ); glShadeModel( GL_SMOOTH ); // 设置摄像机 m_Camera.SetPos( QVector3D( 0.0, 0.0, 50.0 ) );// 设置摄像机坐标 } /*---------------------------------------------------------------------------*/ void GLWidget::resizeGL( int width, int height ) { // 改变大小时程序如何应对？ GLdouble aspectRatio = GLdouble( width ) / GLdouble( height ); // 设置视口 if ( aspectRatio < m_AspectRatio ) { GLint smallHeight = GLint( GLdouble( width ) / m_AspectRatio ); GLint heightBlank = ( GLint( height ) - smallHeight ) / 2; glViewport( 0, heightBlank, GLint( width ), smallHeight ); } else { GLint smallWidth = GLint( GLdouble( height ) * m_AspectRatio ); GLint widthBlank = ( GLint( width ) - smallWidth ) / 2; glViewport( widthBlank, 0, smallWidth, GLint( height ) ); } glMatrixMode( GL_PROJECTION ); glLoadIdentity( ); // 设置裁剪区域 MyPerspective( 45.0, m_AspectRatio, 0.5, 1000.0 ); // 为模型视图载入标准矩阵 glMatrixMode( GL_MODELVIEW ); glLoadIdentity( ); } /*---------------------------------------------------------------------------*/ void GLWidget::CubeVertices( GLfloat length ) { // 设置立方体的顶点 GLfloat semiLength = length / 2.0f; GLfloat cubeVertices[] = { -semiLength, -semiLength, semiLength, // 0 semiLength, -semiLength, semiLength, // 1 semiLength, -semiLength, -semiLength, // 2 -semiLength, -semiLength, -semiLength, // 3 -semiLength, semiLength, semiLength, // 4 semiLength, semiLength, semiLength, // 5 semiLength, semiLength, -semiLength, // 6 -semiLength, semiLength, -semiLength, // 7 }; glBufferData( GL_ARRAY_BUFFER, sizeof( cubeVertices ), cubeVertices, GL_STATIC_DRAW ); glVertexPointer( 3, GL_FLOAT, 0, 0 ); } /*---------------------------------------------------------------------------*/ void GLWidget::CubeColors( void ) { GLubyte cubeColors[] = { 255, 0, 0, 255, 255, 255, 0, 255, 0, 255, 0, 255, 0, 0, 0, 255, 255, 0, 255, 255, 255, 255, 255, 255, 0, 255, 255, 255, 0, 0, 255, 255, }; glBufferData( GL_ARRAY_BUFFER, sizeof( cubeColors ), cubeColors, GL_STATIC_DRAW ); glColorPointer( 4, GL_UNSIGNED_BYTE, 0, 0 ); } /*---------------------------------------------------------------------------*/ void GLWidget::paintGL( void ) { GLubyte cubeIndices[] = { 0, 1, 2, 0, 2, 3,// 下面 7, 6, 4, 6, 5, 4,// 上面 7, 4, 3, 4, 0, 3,// 左面 5, 6, 1, 6, 2, 1,// 右面 4, 5, 0, 5, 1, 0,// 前面 3, 2, 6, 3, 6, 7,// 背面 }; glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); glPushMatrix( ); m_Camera.Apply( ); glBindBuffer( GL_ARRAY_BUFFER, m_VertexBuffer ); glBindBuffer( GL_ARRAY_BUFFER, m_ColorBuffer ); glDrawElements( GL_TRIANGLES, 36, GL_UNSIGNED_BYTE, cubeIndices ); glPopMatrix( ); } /*-------------------------------