OpenGL framebuffer attributes. 
| Enumerator | 
|---|
| VISUAL_GL_ATTRIBUTE_NONE  | 
 Special flag to indicate no attributes.  
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| VISUAL_GL_ATTRIBUTE_BUFFER_SIZE  | 
 Depth of the color buffer.  
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| VISUAL_GL_ATTRIBUTE_LEVEL  | 
 Level in plane stacking.  
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| VISUAL_GL_ATTRIBUTE_RGBA  | 
 True if RGBA mode.  
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| VISUAL_GL_ATTRIBUTE_DOUBLEBUFFER  | 
 Double buffering supported.  
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| VISUAL_GL_ATTRIBUTE_STEREO  | 
 Stereo buffering supported.  
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| VISUAL_GL_ATTRIBUTE_AUX_BUFFERS  | 
 Number of aux buffers.  
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| VISUAL_GL_ATTRIBUTE_RED_SIZE  | 
 Number of red component bits.  
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| VISUAL_GL_ATTRIBUTE_GREEN_SIZE  | 
 Number of green component bits.  
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| VISUAL_GL_ATTRIBUTE_BLUE_SIZE  | 
 Number of blue component bits.  
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| VISUAL_GL_ATTRIBUTE_ALPHA_SIZE  | 
 Number of alpha component bits.  
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| VISUAL_GL_ATTRIBUTE_DEPTH_SIZE  | 
 Number of depth bits.  
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| VISUAL_GL_ATTRIBUTE_STENCIL_SIZE  | 
 Number of stencil bits.  
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| VISUAL_GL_ATTRIBUTE_ACCUM_RED_SIZE  | 
 Number of red accum bits.  
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| VISUAL_GL_ATTRIBUTE_ACCUM_GREEN_SIZE  | 
 Number of green accum bits.  
 | 
| VISUAL_GL_ATTRIBUTE_ACCUM_BLUE_SIZE  | 
 Number of blue accum bits.  
 | 
| VISUAL_GL_ATTRIBUTE_ACCUM_ALPHA_SIZE  | 
 Number of alpha accum bits.  
 |