Struct glium::draw_parameters::AnySamplesPassedQuery
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[src]
pub struct AnySamplesPassedQuery {
// some fields omitted
}A query type that allows you to know whether any sample has been written to the output during the operations executed with this query.
OpenGL
This is usually a query of type GL_ANY_SAMPLES_PASSED or
GL_ANY_SAMPLES_PASSED_CONSERVATIVE.
However if the backend doesn't support conservative queries, glium will automatically fall
back to a non-conservative query. If the backend doesn't support either types but supports
GL_SAMPLES_PASSED, then glium will automatically use a GL_SAMPLES_PASSED query instead.
Methods
impl AnySamplesPassedQuery[src]
fn new<F>(facade: &F, conservative: bool) -> Result<AnySamplesPassedQuery, QueryCreationError> where F: Facade
Builds a new query.
If you pass true for conservative, then OpenGL may use a less accurate algorithm,
leading to a faster result but with more false positives.
impl AnySamplesPassedQuery[src]
fn is_ready(&self) -> bool
Queries the counter to see if the result is already available.
fn get(self) -> bool
Returns the value of the query. Blocks until it is available.
This function doesn't block if is_ready would return true.
Note that you are strongly discouraged from calling this in the middle of the rendering process, as it may block for a long time.
Queries should either have their result written into a buffer, be used for conditional rendering, or stored and checked during the next frame.
fn to_buffer_u32(&self, target: BufferSlice<u32>) -> Result<(), ToBufferError>
Writes the result of the query to a buffer when it is available.
This function doesn't block. Instead it submits a commands to the GPU's commands queue and orders the GPU to write the result of the query to a buffer.
This operation is not necessarly supported everywhere.