確定3D立方體的表面

我正在開發一個只繪製3D立方體的iPad應用程序。用戶可以用手指移動它，並可以通過捏住它來放大/縮小。確定3D立方體的表面

現在我在同一時間着色整個立方體（每個表面）。現在，如果我想要用戶分別對立方體的每個表面着色，意味着用戶將點擊一個表面，並且它只會着色該表面，但我不知道如何識別該表面用戶已經挖掘了哪些表面。

我正在繪製整個立方體簡單的openGL基礎如下。

static const GLfloat cubeVertices[] = { 

     -1.0, -1.0, 1.0, 
     1.0, -1.0, 1.0, 
     1.0, 1.0, 1.0, 
     -1.0, 1.0, 1.0, 

     -1.0, -1.0, -1.0, 
     1.0, -1.0, -1.0, 
     1.0, 1.0, -1.0, 
     -1.0, 1.0, -1.0, 
    }; 


    static const GLushort cubeIndicesFaceFront[] = { 
     0, 1, 2, 3, 0 
    }; 

    static const GLushort cubeIndicesFaceBack[] = { 
     4, 5, 6, 7, 4 
    }; 

    static const GLushort cubeIndicesFaceLeft[] = { 
     0, 4, 7, 3, 0 
    }; 

    static const GLushort cubeIndicesFaceRight[] = { 
     1, 5, 6, 2, 1 
    }; 

    static const GLushort cubeIndicesFaceTop[] = { 
     3, 2, 6, 7, 3 
    }; 

    static const GLushort cubeIndicesFaceBottom[] = { 
     0, 1, 5, 4, 0 
    }; 

static const GLubyte cubeColors[] = { 
    0, 255, 255, 255, 
    0, 255, 255, 255, 
    0, 255, 255, 255, 
    0, 255, 255, 255, 
    0, 255, 255, 255, 
};  


    glVertexPointer(3, GL_FLOAT, 0, cubeVertices); 
    glEnableClientState(GL_VERTEX_ARRAY); 


    glColorPointer(4, GL_UNSIGNED_BYTE, 0, cubeColors); 
    glEnableClientState(GL_COLOR_ARRAY); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceFront); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceBack); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceLeft); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceRight); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceTop); 
    glDrawElements(GL_TRIANGLE_FAN, 5, GL_UNSIGNED_SHORT, cubeIndicesFaceBottom); 


    glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer); 
    [context presentRenderbuffer:GL_RENDERBUFFER_OES];

在此先感謝....讚賞您的支持。

來源

2010-07-21 rohanparekh