Struct glium::draw_parameters::AnySamplesPassedQuery

pub struct AnySamplesPassedQuery { /* 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

pub fn new<F: ?Sized>(
    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

pub fn is_ready(&self) -> bool

Queries the counter to see if the result is already available.

pub 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.

pub 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.

Trait Implementations

impl Debug for AnySamplesPassedQuery

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl GlObject for AnySamplesPassedQuery

type Id = c_uint

The type of identifier for this object.

fn get_id(&self) -> c_uint

Returns the id of the object.

impl<'a> From<&'a AnySamplesPassedQuery> for SamplesQueryParam<'a>

fn from(r: &'a AnySamplesPassedQuery) -> SamplesQueryParam<'a>

Performs the conversion.