glDrawBuffers — Specifies a list of color buffers to be drawn into
|const GLenum *||bufs|
Specifies the number of buffers in
Points to an array of symbolic constants specifying the buffers into which fragment colors or data values will be written.
glDrawBuffers defines an array of buffers into which outputs from the fragment shader data will be written. If a fragment shader writes a value to one or more user defined output variables, then the value of each variable will be written into the buffer specified at a location within
bufs corresponding to the location assigned to that user defined output. The draw buffer used for user defined outputs assigned to locations greater than or equal to
n is implicitly set to
GL_NONE and any data written to such an output is discarded.
The symbolic constants contained in
bufs may be any of the following:
The fragment shader output value is not written into any color buffer.
The fragment shader output value is written into the front left color buffer.
The fragment shader output value is written into the front right color buffer.
The fragment shader output value is written into the back left color buffer.
The fragment shader output value is written into the back right color buffer.
The fragment shader output value is written into the nth color attachment of the current framebuffer. n may range from 0 to the value of
GL_NONE, the preceding symbolic constants may not appear more than once in
bufs. The maximum number of draw buffers supported is implementation dependent and can be queried by calling glGet with the argument
The symbolic constants
GL_FRONT_AND_BACK are not allowed in the
bufs array since they may refer to multiple buffers.
If a fragment shader does not write to a user defined output variable, the values of the fragment colors following shader execution are undefined. For each fragment generated in this situation, a different value may be written into each of the buffers specified by
GL_INVALID_ENUM is generated if one of the values in
bufs is not an accepted value.
GL_INVALID_ENUM is generated if the GL is bound to the default framebuffer and one or more of the values in
bufs is one of the
GL_INVALID_ENUM is generated if the GL is bound to a framebuffer object and one or more of the values in
bufs is anything other than
GL_NONE or one of the
GL_INVALID_ENUM is generated if
n is less than 0.
GL_INVALID_OPERATION is generated if a symbolic constant other than
GL_NONE appears more than once in
GL_INVALID_OPERATION is generated if any of the entries in
bufs (other than
GL_NONE ) indicates a color buffer that does not exist in the current GL context.
GL_INVALID_VALUE is generated if
n is greater than
glGet with argument
glGet with argument
i indicates the number of the draw buffer whose value is to be queried
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