Queries

#include <oglplus/query.hpp>

Common query operations

template <>
struct ObjectSubtype<tag::Query>
{
	typedef QueryTarget Type;
};

Operations with direct state access

template <>
class ObjectOps<tag::DirectState, tag::Query>
 : public ObjZeroOps<tag::DirectState, tag::Query>
{
public:
	typedef QueryTarget Target;

	void Begin(QueryTarget target); 
	void End(QueryTarget target); 

#if GL_VERSION_3_0
	void BeginConditionalRender(ConditionalRenderMode mode); 
	static void EndConditionalRender(void); 
#endif

#if GL_VERSION_3_3 || GL_ARB_timer_query
	void Counter(QueryTarget target); 
	void Timestamp(void); 
#endif

	Boolean ResultAvailable(void) const; 

	void Result(GLint& result) const; 
	void Result(GLuint& result) const;

#if GL_VERSION_3_3 || GL_ARB_timer_query
	void Result(GLint64& result) const;
	void Result(GLuint64& result) const;
#endif

	QueryActivator Activate(QueryTarget target); 

	template <typename ResultType>
	QueryExecution<ResultType>
	Execute(QueryTarget target, ResultType& result); 
};

typedef ObjectOps<tag::DirectState, tag::Query>
	QueryOps;

	Begins a query on the specified `target`. See `glBeginQuery`.
	Ends the currently active query on the specified `target`. See `glEndQuery`.
	Begins conditional render on the query in the specified `mode`. See `glBeginConditionalRender`.
	Ends currently active conditional render. See `glEndConditionalRender`.
	Does a counter query on the specified `target`. See `glQueryCounter`.
	Does a timestamp query. See `glQueryCounter`, `GL_TIMESTAMP`.
	Returns true if the query result is available. See `glGetQueryObject`, `GL_QUERY_RESULT_AVAILABLE`.
	Returns the query result. See `glGetQueryObject`, `GL_QUERY_RESULT`.
	This function creates an instance of the `QueryActivator` class which begins a query on the specified `target` when it is constructed and ends this query when it is destroyed.
	This function creates an instance of the `QueryExecution` class which begins a query on the specified `target` when it is constructed and ends this query and gets its `result` when it is destroyed.

Activator

class QueryActivator
{
public:
	QueryActivator(QueryActivator&&);

	QueryActivator(QueryName query, QueryTarget target); 

	~QueryActivator(void) 
	noexcept;

	bool Finish(void); 
};

	Begins a `query` on the specified `target`. See `glBeginQuery`.
	Ends the currently active query. See `glEndQuery`.
	Explicitly ends the query without waiting for the destructor. See `glEndQuery`.

Conditional render

#if GL_VERSION_3_0
class ConditionalRender
{
public:
	ConditionalRender(ConditionalRender&&);

	ConditionalRender(
		QueryName query,
		ConditionalRenderMode mode
	); 

	~ConditionalRender(void) 
	noexcept;

	bool Finish(void); 
};
#endif

	Begins conditional render on a `query` in the specified `mode`. See `glBeginConditionalRender`.
	Ends the currently active conditional render. See `glEndConditionalRender`.
	Explicitly ends the currently active conditional render. See `glEndConditionalRender`.

Execution

template <typename ResultType>
class QueryExecution
 : public QueryActivator
{
public:
	QueryExecution(QueryExecution&&);

	QueryExecution(
		QueryName query,
		QueryTarget target,
		ResultType& result
	); 

	~QueryExecution(void) 
	noexcept;

	void WaitForResult(void);  
};

	Begins a `query` on the specified `target`, taking a `reference` where the result will be stored . See `glBeginQuery`.
	Ends the currently active query and waits for the result. See `glEndQuery`, `glGetQueryObject`, `GL_QUERY_RESULT_AVAILABLE`.
	Explicitly ends the query and waits for the result. See `glEndQuery`.

Target

enum class QueryTarget : GLenum
{
	TimeElapsed                        = GL_TIME_ELAPSED,
	Timestamp                          = GL_TIMESTAMP,
	SamplesPassed                      = GL_SAMPLES_PASSED,
	AnySamplesPassed                   = GL_ANY_SAMPLES_PASSED,
	PrimitivesGenerated                = GL_PRIMITIVES_GENERATED,
	TransformFeedbackPrimitivesWritten = GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN,
	VerticesSubmitted                  = GL_VERTICES_SUBMITTED_ARB,
	PrimitivesSubmitted                = GL_PRIMITIVES_SUBMITTED_ARB,
	VertexShaderInvocations            = GL_VERTEX_SHADER_INVOCATIONS_ARB,
	TessControlShaderPatches           = GL_TESS_CONTROL_SHADER_PATCHES_ARB,
	TessEvaluationShaderInvocations    = GL_TESS_EVALUATION_SHADER_INVOCATIONS_ARB,
	GeometryShaderInvocations          = GL_GEOMETRY_SHADER_INVOCATIONS,
	GeometryShaderPrimitivesEmitted    = GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB,
	FragmentShaderInvocations          = GL_FRAGMENT_SHADER_INVOCATIONS_ARB,
	ComputeShaderInvocations           = GL_COMPUTE_SHADER_INVOCATIONS_ARB,
	ClippingInputPrimitives            = GL_CLIPPING_INPUT_PRIMITIVES_ARB,
	ClippingOutputPrimitives           = GL_CLIPPING_OUTPUT_PRIMITIVES_ARB,
	TransformFeedbackOverflow          = GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB,
	TransformFeedbackStreamOverflow    = GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB
};

template <>
Range<QueryTarget> EnumValueRange<QueryTarget>(void);

StrCRef EnumValueName(QueryTarget);

Conditional render mode

enum class ConditionalRenderMode : GLenum
{
	QueryWait                   = GL_QUERY_WAIT,
	QueryNoWait                 = GL_QUERY_NO_WAIT,
	QueryByRegionWait           = GL_QUERY_BY_REGION_WAIT,
	QueryByRegionNoWait         = GL_QUERY_BY_REGION_NO_WAIT,
	QueryWaitInverted           = GL_QUERY_WAIT_INVERTED,
	QueryNoWaitInverted         = GL_QUERY_NO_WAIT_INVERTED,
	QueryByRegionWaitInverted   = GL_QUERY_BY_REGION_WAIT_INVERTED,
	QueryByRegionNoWaitInverted = GL_QUERY_BY_REGION_NO_WAIT_INVERTED
};

template <>
Range<ConditionalRenderMode> EnumValueRange<ConditionalRenderMode>(void);

StrCRef EnumValueName(ConditionalRenderMode);