用OpenGL4.x绘制三角形图元

/* ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ * ┃ ┏━┣━┣┓　　┏┓┏┓┳┓┏━━┓┣┣━┓　┓　┓┣┳━┓ ┃ * ┃ ┏┏┏╯━┓┳┳━┛┏╯┃┃┃　　┃┣┣━┓┃┃　┃┃┃　　 ┃ * ┃ ┃┃┏━╮┃┗┗┏╯┗┃┃╯┃　　┃┏┣━┓┃┃　┃╯┣━┓ ┃ * ┃ ╰┫┏━┻╯┗┳┣┛┏┛┃┃┣━━┫┃┃　┃┃┃┗╯　┃　　 ┃ * ┃ ┏┫━┳━┫┏┃┣┓┗┃┃╯┃　　┃┃┃　┃　┃　┃　┣━┓ ┃ * ┃ ┗┗┗━━╯┗┛┛╯┗╯╰　┗━━╯　┛　┛┗╯　╰┛┗　　 ┃ * ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫ * ┃ 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 jiangcaiyang123@163.com ┃ * ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫ * ┃ file name: GLWindow.cpp ┃ * ┃ create date: 2014年2月19日星期三 18时55分33秒 ┃ * ┃ last modified date: 2014年2月19日星期三 18时55分33秒 ┃ * ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛ */ #include <QApplication> #include <QFile> #include <QSurfaceFormat> #include <QOpenGLContext> #include "GLWindow.h" /*---------------------------------------------------------------------------*/ GLWindow::GLWindow( QWindow* pParent ): QWindow( pParent ), m_pContext( Q_NULLPTR ) { setSurfaceType( OpenGLSurface ); resize( 640, 360 ); setTitle( tr( "OpenGL 4.x Tutorial" ) ); connect( qApp, SIGNAL( lastWindowClosed( ) ), this, SLOT( onClose( ) ) ); } /*---------------------------------------------------------------------------*/ void GLWindow::exposeEvent( QExposeEvent* pEvent ) { Q_UNUSED( pEvent ); if ( m_pContext == Q_NULLPTR ) { QSurfaceFormat format; format.setVersion( 4, 3 ); // 需要OpenGL4.3版本 format.setSamples( 4 ); // 四倍采样 m_pContext = new QOpenGLContext( this ); m_pContext->setFormat( format ); m_pContext->create( ); m_pContext->makeCurrent( this ); initializeOpenGLFunctions( ); InitGL( ); } ResizeGL( width( ), height( ) ); RenderGL( ); m_pContext->swapBuffers( this ); } /*---------------------------------------------------------------------------*/ void GLWindow::onClose( void ) { ReleaseGL( ); } /*---------------------------------------------------------------------------*/ // 这里存放了一些全局变量 GLuint g_VertexShader = 0; GLuint g_FragmentShader = 0; GLuint g_Program = 0; GLuint g_VertexArray = 0; /*---------------------------------------------------------------------------*/ inline QByteArray ShaderData( const QString& fileName ) { QByteArray result; QFile shaderFile( fileName ); if ( shaderFile.open( QIODevice::ReadOnly ) ) { result = shaderFile.readAll( ); shaderFile.close( ); } return result; } /*---------------------------------------------------------------------------*/ void GLWindow::InitGL( void ) { // 初始化顶点着色器 QByteArray vsData = ShaderData( ":/Shader.vert" ); const char* vsPointer = vsData.constData( ); g_VertexShader = glCreateShader( GL_VERTEX_SHADER ); glShaderSource( g_VertexShader, // 着色器标识 1, // 着色器文本数目 &vsPointer, // 着色器字符串指针 Q_NULLPTR ); // 字符串长度 glCompileShader( g_VertexShader ); // 初始化片断着色器 QByteArray fsData = ShaderData( ":/Shader.frag" ); const char* fsPointer = fsData.constData( ); g_FragmentShader = glCreateShader( GL_FRAGMENT_SHADER ); glShaderSource( g_FragmentShader, // 着色器标识 1, // 着色器文本数目 &fsPointer, // 着色器字符串 Q_NULLPTR ); // 字符串长度 glCompileShader( g_FragmentShader ); // 初始化着色器程序 g_Program = glCreateProgram( ); glAttachShader( g_Program, g_VertexShader ); glAttachShader( g_Program, g_FragmentShader ); glLinkProgram( g_Program ); // 删除着色器 glDeleteShader( g_VertexShader ); glDeleteShader( g_FragmentShader ); // 初始化顶点数组对象（VAO） glGenVertexArrays( 1, &g_VertexArray ); glBindVertexArray( g_VertexArray ); } /*---------------------------------------------------------------------------*/ void GLWindow::ResizeGL( int width, int height ) { glViewport( 0, 0, width, height ); } /*---------------------------------------------------------------------------*/ void GLWindow::RenderGL( void ) { static const GLfloat black[] = { 0.0f, 0.0f, 0.0f, 1.0f }; glClearBufferfv( GL_COLOR, 0, black ); glUseProgram( g_Program ); glDrawArrays( GL_TRIANGLES, 0, 3 ); } /*---------------------------------------------------------------------------*/ void GLWindow::ReleaseGL( void ) { glDeleteVertexArrays( 1, &g_VertexArray ); glDeleteProgram( g_Program ); }