Beginning OpenGL on Mac OS X

since: 2012/04/23
update: 2012/04/27

reference:
1. Beginning OpenGL on OS X
2. OpenGL: A Primer, 3/e

A. 說明:
      在繼續學習 OpenGL ES 前, 想先對 OpenGL 多瞭解一些, 這裡的學習記錄,
      可能會多次的更新與修正, 僅供參考.

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B. 環境:
     1. MacBook Pro (13-inch, Mid 2009)
     2. Mac OS X 10.7.3
     3. Xcode 4.3.2
     4. 檢測目前的環境:
          OpenGL Extensions Viewer

     說明: 可以看到目前這台電腦支援的 OpenGL 版本為:
               完全支援: 1.1 ~ 2.1
               部分支援: 3.0 ~ 3.3
               全不支援: 4.0 ~ 4.2

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C. 新增專案:
     1. Xcode > File > New > Project... > Mac OS X > Application >
         Command Line Tool > Next

       Product Name: OpenGLStart

       Company Identifier: com.blogspot
       Type: C++
       Use Automatic Reference Counting: checked
       > Next > Create

     2. 新增 Framework:

       OpenGL
        - OpenGL is the premier environment for developing portable,
           interactive 2D and 3D graphics applications.

       GLUT

        - OpenGL Utility Toolkit

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D. 開啓 main.cpp 檔案, 修改如下:
//This is just for basic io, you really DON'T need it
//#include <iostream>

//@add
#include <OpenGL/OpenGL.h> // OpenGL Library
#include <GLUT/GLUT.h> // GLUT Library, will make you life easier

//@add
void display()
{
    // Clear the buffer
    glClear(GL_COLOR_BUFFER_BIT);
   
    // Let us begin drawing some points
    glBegin(GL_POLYGON);
   
    // Specify the points
    glVertex2f(-0.5, -0.5);
    glVertex2f(-0.5, 0.5);
    glVertex2f(0.5, 0.5);
    glVertex2f(0.5, -0.5);
   
    // Ok we are done specifying points
    glEnd();
   
    // Write this out to the screen
    glFlush();
}

//int main(int argc, const char * argv[])
//@update: just remove "const"
int main(int argc, char * argv[])
{
    // insert code here...
    //std::cout << "Hello, World!\n";
   
    //@add for OpenGL
    //
    // Init glut
    glutInit(&argc, argv);
   
    // Name the window and create it
    //
    // default position: upper-left corner
    // default size: 300 x 300 pixels
    glutCreateWindow("Hello OpenGL");
   
    // Set the callback function, will be called as needed
    glutDisplayFunc(display);
   
    // Start the main loop running,
    // nothing after this will execute for all eternity (right now)
    glutMainLoop();
   
    //@ will not be executed (update: 2012/04/26)
    //return 0;
}

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E. 編譯並執行:

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F. 備註:
     1. MeshLab 軟體.
         可用來讀取與編輯鬆散的 3D 三角形面的網狀模型.
         (unstructured 3D triangular meshes)
         p.s. 可以從 The Stanford 3D Scanning Repository 下載 3D 模型檔.

      (bunny\reconstruction\bun_zipper.ply)
      看看可愛的 Bunny ~

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     2. Nate Robins - OpenGL - Tutors
         a. 下載:
              Tutors source code package (tutors-src.zip 920KB)

         b. 解壓縮後, 開啓 tutors.xcodeproj 
              將右上方的 "active scheme" 選為 shapes 或 lightmaterial, 然後執行. 

         c. 執行結果
             shapes:

             lightmaterial: