【OpenGL】GLES20.glClear

【OpenGL】glClear

The function prototype

void glClear(GLbitfield mask);

Parameter description

GLbitfield： have access to | Operator combines different buffer flag bits , Indicates the buffer that needs to be cleared , for example glClear（GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT） Indicates to clear the color buffer and depth buffer , The following flag bits can be used

GL_COLOR_BUFFER_BIT:     Currently writable color buffer 
GL_DEPTH_BUFFER_BIT:     Deep buffer 
GL_ACCUM_BUFFER_BIT:    Cumulative buffer 
GL_STENCIL_BUFFER_BIT:  Template buffer 

Function description

glClear（） The function clears the value with the current buffer , That is to say glClearColor perhaps glClearDepth、glClearIndex、glClearStencil、glClearAccum Wait for the value specified by the function to clear the specified buffer , You can also use glDrawBuffer Clear multiple color caches at a time . such as ：

glClearColor(0.0,0.0,0.0,0.0);

Indicates that the clear color is set to black

glClear(GL_COLOR_BUFFER_BIT);

Indicates that the task of clearing the whole window to black has been actually completed ,glClear（） The only parameter of indicates the buffer that needs to be cleared .

Pixel check 、 Cutting inspection 、 Jitter and cache write masking will affect glClear The operation of , among , The clipping range limits the area to be cleared , and glClear The command also ignores alpha function 、 Fusion function 、 Logical operation 、 Templates 、 Texture mapping and z cache ;