OpenGl 4.x for Mac开发环境配置

概述

不同平台OpenGL开发环境的配置大同小异，我认为可以分为4部分：
1. OpenGL库：Mac OS X、Windows已经预安装，可以直接使用，linux和unix则需要自己安装，安装方法自行Google，在此不做详解。
2. OpenGL扩展库：GLEW提供了高效的运行机制,来决定哪个OpenGL扩展在目标平台上是否支持。它将OpenGL核心和扩展功能暴露在一个头文件，以供使用。安装方法自行Google，在此不做详解。
3. 应用程序框架：OpenGL是一种应用程序编程接口，本身不具有创建窗口、接收外设事件等功能，所以需要第三方软件库。目前应用较广泛的有GLUT和GLFW等，安装方法自行Google，在此不做详解。
4. 其他实用工具库：

Mac OS X平台通用步骤：

1. 链接GLUT.framwork和OpenGL.framwork库。
2. 导入GLEW扩展库。

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基于xcode7的示例：

1. 链接GLUT.framwork和OpenGL.framwork库。
   
2. 导入GLEW扩展库。
   
   
3. 基本配置已经完成，引用OpenGL编程指南（第8版）的triangles实例，来展示一个OpenGL应用的基本结构。

triangles.cpp

#include <stdio.h>#include <iostream>#include <gl/glew.h>#include <GLUT/GLUT.h>#include "LoadShaders.h"#define BUFFER_OFFSET(x)  ((const void*) (x))enum VAO_IDs { Triangles, NumVAOs };enum Buffer_IDs { ArrayBuffer, NumBuffers };enum Attrib_IDs { vPosition = 0 };GLuint VAOs[NumVAOs];GLuint Buffers[NumBuffers];const GLuint NumVertices = 6;void init(void){    glGenVertexArrays(NumVAOs, VAOs);    glBindVertexArray(VAOs[Triangles]);    GLfloat vertices[NumVertices][2] = {        { -0.90, -0.90 },        {  0.85, -0.90 },        { -0.90,  0.85 },        {  0.90, -0.85 },        {  0.90,  0.90 },        { -0.85,  0.90 }    };    glGenBuffers(NumBuffers, Buffers);    glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);    ShaderInfo shaders[] = {        { GL_VERTEX_SHADER, "/Users/LXY/Desktop/test_opengl/triangles.vert" },        { GL_FRAGMENT_SHADER, "/Users/LXY/Desktop/test_opengl/triangles.frag" },        { GL_NONE, NULL }    };    GLuint program = LoadShaders(shaders);    glUseProgram(program);    glVertexAttribPointer(vPosition, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));    glEnableVertexAttribArray(vPosition);}void display(void){    glClear(GL_COLOR_BUFFER_BIT);    glBindVertexArray(VAOs[Triangles]);    glDrawArrays(GL_TRIANGLES, 0, NumVertices);    glFlush();}int main(int argc, const char * argv[]){    glutInit(&argc, (char**)argv);    glutInitDisplayMode(GLUT_3_2_CORE_PROFILE | GLUT_RGBA);    glutInitWindowSize(512, 512);    glutCreateWindow(argv[0]);    glewExperimental = GL_TRUE;    GLenum err = glewInit();    if (GLEW_OK != err) {        fprintf(stderr, "Error: %s\n", glewGetErrorString(err));    }    fprintf(stdout, "Status: Using GLEW %s\n", glewGetString(GLEW_VERSION));    if (GLEW_VERSION_4_1) {        std::cout << "Yay! OpenGL 4.1 is supported!" << std::endl;    }    init();    glutDisplayFunc(display);    glutMainLoop();}}

LoadShaders.h

//////////////////////////////////////////////////////////////////////////////////  --- LoadShaders.h ---////////////////////////////////////////////////////////////////////////////////#ifndef __LOAD_SHADERS_H__#define __LOAD_SHADERS_H__#include <OpenGL/OpenGL.h>#ifdef __cplusplusextern "C" {#endif  // __cplusplus//----------------------------------------------------------------------------////  LoadShaders() takes an array of ShaderFile structures, each of which//    contains the type of the shader, and a pointer a C-style character//    string (i.e., a NULL-terminated array of characters) containing the//    entire shader source.////  The array of structures is terminated by a final Shader with the//    "type" field set to GL_NONE.////  LoadShaders() returns the shader program value (as returned by//    glCreateProgram()) on success, or zero on failure. //typedef struct {    GLenum       type;    const char*  filename;    GLuint       shader;} ShaderInfo;GLuint LoadShaders( ShaderInfo* );//----------------------------------------------------------------------------#ifdef __cplusplus};#endif // __cplusplus#endif // __LOAD_SHADERS_H__

LoadShaders.cpp

//////////////////////////////////////////////////////////////////////////////////  --- LoadShaders.cxx ---////////////////////////////////////////////////////////////////////////////////#include <cstdlib>#include <iostream>#define GLEW_STATIC#include <GL/glew.h>#include "LoadShaders.h"#ifdef __cplusplusextern "C" {#endif // __cplusplus//----------------------------------------------------------------------------static const GLchar*ReadShader( const char* filename ){#ifdef WIN32    FILE* infile;    fopen_s( &infile, filename, "rb" );#else    FILE* infile = fopen( filename, "rb" );#endif // WIN32    if ( !infile ) {#ifdef _DEBUG        std::cerr << "Unable to open file '" << filename << "'" << std::endl;#endif /* DEBUG */        return NULL;    }    fseek( infile, 0, SEEK_END );    int len = ftell( infile );    fseek( infile, 0, SEEK_SET );    GLchar* source = new GLchar[len+1];    fread( source, 1, len, infile );    fclose( infile );    source[len] = 0;    return const_cast<const GLchar*>(source);}//----------------------------------------------------------------------------GLuintLoadShaders( ShaderInfo* shaders ){    if ( shaders == NULL ) { return 0; }    GLuint program = glCreateProgram();    ShaderInfo* entry = shaders;    while ( entry->type != GL_NONE ) {        GLuint shader = glCreateShader( entry->type );        entry->shader = shader;        const GLchar* source = ReadShader( entry->filename );        if ( source == NULL ) {            for ( entry = shaders; entry->type != GL_NONE; ++entry ) {                glDeleteShader( entry->shader );                entry->shader = 0;            }            return 0;        }        glShaderSource( shader, 1, &source, NULL );        delete [] source;        glCompileShader( shader );        GLint compiled;        glGetShaderiv( shader, GL_COMPILE_STATUS, &compiled );        if ( !compiled ) {#ifdef _DEBUG            GLsizei len;            glGetShaderiv( shader, GL_INFO_LOG_LENGTH, &len );            GLchar* log = new GLchar[len+1];            glGetShaderInfoLog( shader, len, &len, log );            std::cerr << "Shader compilation failed: " << log << std::endl;            delete [] log;#endif /* DEBUG */            return 0;        }        glAttachShader( program, shader );        ++entry;    }#ifdef GL_VERSION_4_1    if ( GLEW_VERSION_4_1 ) {        // glProgramParameteri( program, GL_PROGRAM_SEPARABLE, GL_TRUE );    }#endif /* GL_VERSION_4_1 */    glLinkProgram( program );    GLint linked;    glGetProgramiv( program, GL_LINK_STATUS, &linked );    if ( !linked ) {#ifdef _DEBUG        GLsizei len;        glGetProgramiv( program, GL_INFO_LOG_LENGTH, &len );        GLchar* log = new GLchar[len+1];        glGetProgramInfoLog( program, len, &len, log );        std::cerr << "Shader linking failed: " << log << std::endl;        delete [] log;#endif /* DEBUG */        for ( entry = shaders; entry->type != GL_NONE; ++entry ) {            glDeleteShader( entry->shader );            entry->shader = 0;        }        return 0;    }    return program;}//----------------------------------------------------------------------------#ifdef __cplusplus}#endif // __cplusplus

result: