ARBOcclusionQuery (LWJGL 3.2.4 SNAPSHOT

java.lang.Object
- org.lwjgl.opengl.ARBOcclusionQuery

```
public class ARBOcclusionQuery
extends java.lang.Object
```
Native bindings to the ARB_occlusion_query extension.
This extension defines a mechanism whereby an application can query the number of pixels (or, more precisely, samples) drawn by a primitive or group of primitives.

The primary purpose of such a query (hereafter referred to as an "occlusion query") is to determine the visibility of an object. Typically, the application will render the major occluders in the scene, then perform an occlusion query for the bounding box of each detail object in the scene. Only if said bounding box is visible, i.e., if at least one sample is drawn, should the corresponding object be drawn.

The earlier HP_occlusion_test extension defined a similar mechanism, but it had two major shortcomings.
- It returned the result as a simple TRUE/FALSE result, when in fact it is often useful to know exactly how many samples were drawn.
- It provided only a simple "stop-and-wait" model for using multiple queries. The application begins an occlusion test and ends it; then, at some later point, it asks for the result, at which point the driver must stop and wait until the result from the previous test is back before the application can even begin the next one. This is a very simple model, but its performance is mediocre when an application wishes to perform many queries, and it eliminates most of the opportunities for parallelism between the CPU and GPU.
This extension solves both of those problems. It returns as its result the number of samples that pass the depth and stencil tests, and it encapsulates occlusion queries in "query objects" that allow applications to issue many queries before asking for the result of any one. As a result, they can overlap the time it takes for the occlusion query results to be returned with other, more useful work, such as rendering other parts of the scene or performing other computations on the CPU.

There are many situations where a pixel/sample count, rather than a boolean result, is useful.
- Objects that are visible but cover only a very small number of pixels can be skipped at a minimal reduction of image quality.
- Knowing exactly how many pixels an object might cover may help the application decide which level-of-detail model should be used. If only a few pixels are visible, a low-detail model may be acceptable.
- "Depth peeling" techniques, such as order-independent transparency, need to know when to stop rendering more layers; it is difficult to determine a priori how many layers are needed. A boolean result allows applications to stop when more layers will not affect the image at all, but this will likely result in unacceptable performance. Instead, it makes more sense to stop rendering when the number of pixels in each layer falls below a given threshold.
- Occlusion queries can replace glReadPixels of the depth buffer to determine whether (for example) a light source is visible for the purposes of a lens flare effect or a halo to simulate glare. Pixel counts allow you to compute the percentage of the light source that is visible, and the brightness of these effects can be modulated accordingly.
Promoted to core in OpenGL 1.5.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`GL_CURRENT_QUERY_ARB` Accepted by the `pname` parameter of GetQueryivARB.
`static int`	`GL_QUERY_COUNTER_BITS_ARB` Accepted by the `pname` parameter of GetQueryivARB.
`static int`	`GL_QUERY_RESULT_ARB` Accepted by the `pname` parameter of GetQueryObjectivARB and GetQueryObjectuivARB.
`static int`	`GL_QUERY_RESULT_AVAILABLE_ARB` Accepted by the `pname` parameter of GetQueryObjectivARB and GetQueryObjectuivARB.
`static int`	`GL_SAMPLES_PASSED_ARB` Accepted by the `target` parameter of BeginQueryARB, EndQueryARB, and GetQueryivARB.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`glBeginQueryARB(int target, int id)` Creates a query object and makes it active.
`static void`	`glDeleteQueriesARB(int id)` Deletes named query objects.
`static void`	`glDeleteQueriesARB(int[] ids)` Array version of: `DeleteQueriesARB`
`static void`	`glDeleteQueriesARB(java.nio.IntBuffer ids)` Deletes named query objects.
`static void`	`glEndQueryARB(int target)` Marks the end of the sequence of commands to be tracked for the active query specified by `target`.
`static int`	`glGenQueriesARB()` Generates query object names.
`static void`	`glGenQueriesARB(int[] ids)` Array version of: `GenQueriesARB`
`static void`	`glGenQueriesARB(java.nio.IntBuffer ids)` Generates query object names.
`static int`	`glGetQueryiARB(int target, int pname)` Returns parameters of a query object target.
`static void`	`glGetQueryivARB(int target, int pname, int[] params)` Array version of: `GetQueryivARB`
`static void`	`glGetQueryivARB(int target, int pname, java.nio.IntBuffer params)` Returns parameters of a query object target.
`static int`	`glGetQueryObjectiARB(int id, int pname)` Returns the integer value of a query object parameter.
`static void`	`glGetQueryObjectivARB(int id, int pname, int[] params)` Array version of: `GetQueryObjectivARB`
`static void`	`glGetQueryObjectivARB(int id, int pname, java.nio.IntBuffer params)` Returns the integer value of a query object parameter.
`static int`	`glGetQueryObjectuiARB(int id, int pname)` Unsigned version of `GetQueryObjectivARB`.
`static void`	`glGetQueryObjectuivARB(int id, int pname, int[] params)` Array version of: `GetQueryObjectuivARB`
`static void`	`glGetQueryObjectuivARB(int id, int pname, java.nio.IntBuffer params)` Unsigned version of `GetQueryObjectivARB`.
`static boolean`	`glIsQueryARB(int id)` Determine if a name corresponds to a query object.
`static void`	`nglDeleteQueriesARB(int n, long ids)` Unsafe version of: `DeleteQueriesARB`
`static void`	`nglGenQueriesARB(int n, long ids)` Unsafe version of: `GenQueriesARB`
`static void`	`nglGetQueryivARB(int target, int pname, long params)` Unsafe version of: `GetQueryivARB`
`static void`	`nglGetQueryObjectivARB(int id, int pname, long params)` Unsafe version of: `GetQueryObjectivARB`
`static void`	`nglGetQueryObjectuivARB(int id, int pname, long params)` Unsafe version of: `GetQueryObjectuivARB`

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - GL_SAMPLES_PASSED_ARB
```
public static final int GL_SAMPLES_PASSED_ARB
```
    Accepted by the target parameter of BeginQueryARB, EndQueryARB, and GetQueryivARB.
    
    See Also:
    
    Constant Field Values
  - GL_QUERY_COUNTER_BITS_ARB
```
public static final int GL_QUERY_COUNTER_BITS_ARB
```
    Accepted by the pname parameter of GetQueryivARB.
    
    See Also:
    
    Constant Field Values
  - GL_CURRENT_QUERY_ARB
```
public static final int GL_CURRENT_QUERY_ARB
```
    Accepted by the pname parameter of GetQueryivARB.
    
    See Also:
    
    Constant Field Values
  - GL_QUERY_RESULT_ARB
```
public static final int GL_QUERY_RESULT_ARB
```
    Accepted by the pname parameter of GetQueryObjectivARB and GetQueryObjectuivARB.
    
    See Also:
    
    Constant Field Values
  - GL_QUERY_RESULT_AVAILABLE_ARB
```
public static final int GL_QUERY_RESULT_AVAILABLE_ARB
```
    Accepted by the pname parameter of GetQueryObjectivARB and GetQueryObjectuivARB.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - nglGenQueriesARB
```
public static void nglGenQueriesARB(int n,
                                    long ids)
```
    Unsafe version of: GenQueriesARB
    
    Parameters:
    
    n - the number of query object names to be generated
  - glGenQueriesARB
```
public static void glGenQueriesARB(java.nio.IntBuffer ids)
```
    Generates query object names.
    
    Parameters:
    
    ids - a buffer in which the generated query object names are stored
  - glGenQueriesARB
```
public static int glGenQueriesARB()
```
    Generates query object names.
  - nglDeleteQueriesARB
```
public static void nglDeleteQueriesARB(int n,
                                       long ids)
```
    Unsafe version of: DeleteQueriesARB
    
    Parameters:
    
    n - the number of query objects to be deleted
  - glDeleteQueriesARB
```
public static void glDeleteQueriesARB(java.nio.IntBuffer ids)
```
    Deletes named query objects.
    
    Parameters:
    
    ids - an array of query objects to be deleted
  - glDeleteQueriesARB
```
public static void glDeleteQueriesARB(int id)
```
    Deletes named query objects.
  - glIsQueryARB
```
public static boolean glIsQueryARB(int id)
```
    Determine if a name corresponds to a query object.
    
    Parameters:
    
    id - a value that may be the name of a query object
  - glBeginQueryARB
```
public static void glBeginQueryARB(int target,
                                   int id)
```
    Creates a query object and makes it active.
    
    Parameters:
    
    target - the target type of query object established. One of:
    SAMPLES_PASSED PRIMITIVES_GENERATED TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN TIME_ELAPSED
    TIMESTAMP ANY_SAMPLES_PASSED ANY_SAMPLES_PASSED_CONSERVATIVE
    
    id - the name of a query object
  - glEndQueryARB
```
public static void glEndQueryARB(int target)
```
    Marks the end of the sequence of commands to be tracked for the active query specified by target.
    
    Parameters:
    
    target - the query object target. One of:
    SAMPLES_PASSED PRIMITIVES_GENERATED TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN TIME_ELAPSED
    TIMESTAMP ANY_SAMPLES_PASSED ANY_SAMPLES_PASSED_CONSERVATIVE
  - nglGetQueryivARB
```
public static void nglGetQueryivARB(int target,
                                    int pname,
                                    long params)
```
    Unsafe version of: GetQueryivARB
  - glGetQueryivARB
```
public static void glGetQueryivARB(int target,
                                   int pname,
                                   java.nio.IntBuffer params)
```
    Returns parameters of a query object target.
    
    Parameters:
    
    target - the query object target. One of:
    SAMPLES_PASSED PRIMITIVES_GENERATED TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN TIME_ELAPSED
    TIMESTAMP ANY_SAMPLES_PASSED ANY_SAMPLES_PASSED_CONSERVATIVE
    
    pname - the symbolic name of a query object target parameter. One of:
    QUERY_COUNTER_BITS_ARB CURRENT_QUERY_ARB
    
    params - the requested data
  - glGetQueryiARB
```
public static int glGetQueryiARB(int target,
                                 int pname)
```
    Returns parameters of a query object target.
    
    Parameters:
    
    target - the query object target. One of:
    SAMPLES_PASSED PRIMITIVES_GENERATED TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN TIME_ELAPSED
    TIMESTAMP ANY_SAMPLES_PASSED ANY_SAMPLES_PASSED_CONSERVATIVE
    
    pname - the symbolic name of a query object target parameter. One of:
    QUERY_COUNTER_BITS_ARB CURRENT_QUERY_ARB
  - nglGetQueryObjectivARB
```
public static void nglGetQueryObjectivARB(int id,
                                          int pname,
                                          long params)
```
    Unsafe version of: GetQueryObjectivARB
  - glGetQueryObjectivARB
```
public static void glGetQueryObjectivARB(int id,
                                         int pname,
                                         java.nio.IntBuffer params)
```
    Returns the integer value of a query object parameter.
    
    Parameters:
    
    id - the name of a query object
    
    pname - the symbolic name of a query object parameter. One of:
    QUERY_RESULT_ARB QUERY_RESULT_AVAILABLE_ARB
    
    params - the requested data
  - glGetQueryObjectiARB
```
public static int glGetQueryObjectiARB(int id,
                                       int pname)
```
    Returns the integer value of a query object parameter.
    
    Parameters:
    
    id - the name of a query object
    
    pname - the symbolic name of a query object parameter. One of:
    QUERY_RESULT_ARB QUERY_RESULT_AVAILABLE_ARB
  - nglGetQueryObjectuivARB
```
public static void nglGetQueryObjectuivARB(int id,
                                           int pname,
                                           long params)
```
    Unsafe version of: GetQueryObjectuivARB
  - glGetQueryObjectuivARB
```
public static void glGetQueryObjectuivARB(int id,
                                          int pname,
                                          java.nio.IntBuffer params)
```
    Unsigned version of GetQueryObjectivARB.
    
    Parameters:
    
    id - the name of a query object
    
    pname - the symbolic name of a query object parameter. One of:
    QUERY_RESULT_ARB QUERY_RESULT_AVAILABLE_ARB
    
    params - the requested data
  - glGetQueryObjectuiARB
```
public static int glGetQueryObjectuiARB(int id,
                                        int pname)
```
    Unsigned version of GetQueryObjectivARB.
    
    Parameters:
    
    id - the name of a query object
    
    pname - the symbolic name of a query object parameter. One of:
    QUERY_RESULT_ARB QUERY_RESULT_AVAILABLE_ARB
  - glGenQueriesARB
```
public static void glGenQueriesARB(int[] ids)
```
    Array version of: GenQueriesARB
  - glDeleteQueriesARB
```
public static void glDeleteQueriesARB(int[] ids)
```
    Array version of: DeleteQueriesARB
  - glGetQueryivARB
```
public static void glGetQueryivARB(int target,
                                   int pname,
                                   int[] params)
```
    Array version of: GetQueryivARB
  - glGetQueryObjectivARB
```
public static void glGetQueryObjectivARB(int id,
                                         int pname,
                                         int[] params)
```
    Array version of: GetQueryObjectivARB
  - glGetQueryObjectuivARB
```
public static void glGetQueryObjectuivARB(int id,
                                          int pname,
                                          int[] params)
```
    Array version of: GetQueryObjectuivARB

`SAMPLES_PASSED`	`PRIMITIVES_GENERATED`	`TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN`	`TIME_ELAPSED`
`TIMESTAMP`	`ANY_SAMPLES_PASSED`	`ANY_SAMPLES_PASSED_CONSERVATIVE`

Class ARBOcclusionQuery

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

GL_SAMPLES_PASSED_ARB

GL_QUERY_COUNTER_BITS_ARB

GL_CURRENT_QUERY_ARB

GL_QUERY_RESULT_ARB

GL_QUERY_RESULT_AVAILABLE_ARB

Method Detail

nglGenQueriesARB

glGenQueriesARB

glGenQueriesARB

nglDeleteQueriesARB

glDeleteQueriesARB

glDeleteQueriesARB

glIsQueryARB

glBeginQueryARB

glEndQueryARB

nglGetQueryivARB

glGetQueryivARB

glGetQueryiARB

nglGetQueryObjectivARB

glGetQueryObjectivARB

glGetQueryObjectiARB

nglGetQueryObjectuivARB

glGetQueryObjectuivARB

glGetQueryObjectuiARB

glGenQueriesARB

glDeleteQueriesARB

glGetQueryivARB

glGetQueryObjectivARB

glGetQueryObjectuivARB