Class KHRDebug


  • public class KHRDebug
    extends java.lang.Object
    Native bindings to the KHR_debug extension.

    This extension allows the GL to notify applications when various events occur that may be useful during application development, debugging and profiling.

    These events are represented in the form of enumerable messages with a human-readable string representation. Examples of debug events include incorrect use of the GL, warnings of undefined behavior, and performance warnings.

    A message is uniquely identified by a source, a type and an implementation-dependent ID within the source and type pair.

    A message's source identifies the origin of the message and can either describe components of the GL, the window system, third-party external sources such as external debuggers, or even the application itself.

    The type of the message roughly identifies the nature of the event that caused the message. Examples include errors, performance warnings, warnings about undefined behavior or notifications identifying that the application is within a specific section of the application code.

    A message's ID for a given source and type further distinguishes messages within namespaces. For example, an error caused by a negative parameter value or an invalid internal texture format are both errors generated by the API, but would likely have different message IDs.

    Each message is also assigned to a severity level that denotes roughly how "important" that message is in comparison to other messages across all sources and types. For example, notification of a GL error would likely have a higher severity than a performance warning due to redundant state changes.

    Furthermore, every message contains an implementation-dependent string representation that provides a useful description of the event.

    Messages are communicated to the application through an application-defined callback function that is called by the GL implementation on each debug message. The motivation for the callback routine is to free application developers from actively having to query whether a GL error, or any other debuggable event has happened after each call to a GL function. With a callback, developers can keep their code free of debug checks, set breakpoints in the callback function, and only have to react to messages as they occur. In situations where using a callback is not possible, a message log is also provided that stores only copies of recent messages until they are actively queried.

    To control the volume of debug output, messages can be disabled either individually by ID, or entire sets of messages can be turned off based on combination of source and type, through the entire application code or only section of the code encapsulated in debug groups. A debug group may also be used to annotate the command stream using descriptive texts.

    This extension also defines debug markers, a mechanism for the OpenGL application to annotate the command stream with markers for discrete events.

    When profiling or debugging an OpenGL application with a built-in or an external debugger or profiler, it is difficult to relate the commands within the command stream to the elements of the scene or parts of the program code to which they correspond. Debug markers and debug groups help obviate this by allowing applications to specify this link. For example, a debug marker can be used to identify the beginning of a frame in the command stream and a debug group can encapsulate a specific command stream to identify a rendering pass. Debug groups also allow control of the debug outputs volume per section of an application code providing an effective way to handle the massive amount of debug outputs that drivers can generate.

    Some existing implementations of ARB_debug_output only expose the ARB_debug_output extension string if the context was created with the debug flag {GLX|WGL}_CONTEXT_DEBUG_BIT_ARB as specified in {GLX|WGL}_ARB_create_context. The behavior is not obvious when the functionality is brought into the OpenGL core specification because the extension string and function entry points must always exist.

    This extension modifies the existing ARB_debug_output extension to allow implementations to always have an empty message log. The specific messages written to the message log or callback routines are already implementation defined, so this specification simply makes it explicit that it's fine for there to be zero messages generated, even when a GL error occurs, which is useful if the context is non-debug.

    Debug output can be enabled and disabled by changing the DEBUG_OUTPUT state. It is implementation defined how much debug output is generated if the context was created without the CONTEXT_FLAG_DEBUG_BIT set. This is a new query bit added to the existing CONTEXT_FLAGS state to specify whether the context was created with debug enabled.

    Finally, this extension defines a mechanism for OpenGL applications to label their objects (textures, buffers, shaders, etc.) with a descriptive string.

    When profiling or debugging an OpenGL application within an external or built-in (debut output API) debugger or profiler it is difficult to identify objects from their object names (integers).

    Even when the object itself is viewed it can be problematic to differentiate between similar objects. Attaching a descriptive string, a label, to an object obviates this difficulty.

    The intended purpose of this extension is purely to improve the user experience within OpenGL development tools and application built-in profilers and debuggers. This extension typically improves OpenGL programmers efficiency by allowing them to instantly detect issues and the reason for these issues giving him more time to focus on adding new features to an OpenGL application.

    Promoted to core in OpenGL 4.3.

    • Method Detail

      • nglDebugMessageControl

        public static void nglDebugMessageControl​(int source,
                                                  int type,
                                                  int severity,
                                                  int count,
                                                  long ids,
                                                  boolean enabled)
        Unsafe version of: DebugMessageControl
        Parameters:
        count - the length of the array ids
      • glDebugMessageControl

        public static void glDebugMessageControl​(int source,
                                                 int type,
                                                 int severity,
                                                 @Nullable
                                                 java.nio.IntBuffer ids,
                                                 boolean enabled)
        Controls the volume of debug output in the active debug group, by disabling specific or groups of messages.

        If enabled is TRUE, the referenced subset of messages will be enabled. If FALSE, then those messages will be disabled.

        This command can reference different subsets of messages by first considering the set of all messages, and filtering out messages based on the following ways:

        • If source, type, or severity is DONT_CARE, the messages from all sources, of all types, or of all severities are referenced respectively.
        • When values other than DONT_CARE are specified, all messages whose source, type, or severity match the specified source, type, or severity respectively will be referenced.
        • If count is greater than zero, then ids is an array of count message IDs for the specified combination of source and type. In this case, if source or type is DONT_CARE, or severity is not DONT_CARE, the error INVALID_OPERATION is generated.

        Unrecognized message IDs in ids are ignored. If count is zero, the value if ids is ignored.

        Although messages are grouped into an implicit hierarchy by their sources and types, there is no explicit per-source, per-type or per-severity enabled state. Instead, the enabled state is stored individually for each message. There is no difference between disabling all messages from one source in a single call, and individually disabling all messages from that source using their types and IDs.

        If the DEBUG_OUTPUT state is disabled the GL operates the same as if messages of every source, type or severity are disabled.

        Parameters:
        source - the source of debug messages to enable or disable. One of:
        DEBUG_SOURCE_APIDEBUG_SOURCE_WINDOW_SYSTEMDEBUG_SOURCE_SHADER_COMPILER
        DEBUG_SOURCE_THIRD_PARTYDEBUG_SOURCE_APPLICATIONDEBUG_SOURCE_OTHER
        type - the type of debug messages to enable or disable. One of:
        DEBUG_TYPE_ERRORDEBUG_TYPE_DEPRECATED_BEHAVIORDEBUG_TYPE_UNDEFINED_BEHAVIOR
        DEBUG_TYPE_PORTABILITYDEBUG_TYPE_PERFORMANCEDEBUG_TYPE_OTHER
        DEBUG_TYPE_MARKER
        severity - the severity of debug messages to enable or disable. One of:
        DEBUG_SEVERITY_HIGHDEBUG_SEVERITY_MEDIUMDEBUG_SEVERITY_LOW
        DEBUG_SEVERITY_NOTIFICATION
        ids - an array of unsigned integers containing the ids of the messages to enable or disable
        enabled - whether the selected messages should be enabled or disabled
      • glDebugMessageControl

        public static void glDebugMessageControl​(int source,
                                                 int type,
                                                 int severity,
                                                 @Nullable
                                                 int id,
                                                 boolean enabled)
        Controls the volume of debug output in the active debug group, by disabling specific or groups of messages.

        If enabled is TRUE, the referenced subset of messages will be enabled. If FALSE, then those messages will be disabled.

        This command can reference different subsets of messages by first considering the set of all messages, and filtering out messages based on the following ways:

        • If source, type, or severity is DONT_CARE, the messages from all sources, of all types, or of all severities are referenced respectively.
        • When values other than DONT_CARE are specified, all messages whose source, type, or severity match the specified source, type, or severity respectively will be referenced.
        • If count is greater than zero, then ids is an array of count message IDs for the specified combination of source and type. In this case, if source or type is DONT_CARE, or severity is not DONT_CARE, the error INVALID_OPERATION is generated.

        Unrecognized message IDs in ids are ignored. If count is zero, the value if ids is ignored.

        Although messages are grouped into an implicit hierarchy by their sources and types, there is no explicit per-source, per-type or per-severity enabled state. Instead, the enabled state is stored individually for each message. There is no difference between disabling all messages from one source in a single call, and individually disabling all messages from that source using their types and IDs.

        If the DEBUG_OUTPUT state is disabled the GL operates the same as if messages of every source, type or severity are disabled.

        Parameters:
        source - the source of debug messages to enable or disable. One of:
        DEBUG_SOURCE_APIDEBUG_SOURCE_WINDOW_SYSTEMDEBUG_SOURCE_SHADER_COMPILER
        DEBUG_SOURCE_THIRD_PARTYDEBUG_SOURCE_APPLICATIONDEBUG_SOURCE_OTHER
        type - the type of debug messages to enable or disable. One of:
        DEBUG_TYPE_ERRORDEBUG_TYPE_DEPRECATED_BEHAVIORDEBUG_TYPE_UNDEFINED_BEHAVIOR
        DEBUG_TYPE_PORTABILITYDEBUG_TYPE_PERFORMANCEDEBUG_TYPE_OTHER
        DEBUG_TYPE_MARKER
        severity - the severity of debug messages to enable or disable. One of:
        DEBUG_SEVERITY_HIGHDEBUG_SEVERITY_MEDIUMDEBUG_SEVERITY_LOW
        DEBUG_SEVERITY_NOTIFICATION
        enabled - whether the selected messages should be enabled or disabled
      • nglDebugMessageInsert

        public static void nglDebugMessageInsert​(int source,
                                                 int type,
                                                 int id,
                                                 int severity,
                                                 int length,
                                                 long message)
        Unsafe version of: DebugMessageInsert
        Parameters:
        length - the length of the string contained in the character array whose address is given by message
      • nglDebugMessageCallback

        public static void nglDebugMessageCallback​(long callback,
                                                   long userParam)
        Unsafe version of: DebugMessageCallback
      • glDebugMessageCallback

        public static void glDebugMessageCallback​(@Nullable
                                                  GLDebugMessageCallbackI callback,
                                                  long userParam)
        Specifies a callback to receive debugging messages from the GL.

        The function's prototype must follow the type definition of DEBUGPROC including its platform-dependent calling convention. Anything else will result in undefined behavior. Only one debug callback can be specified for the current context, and further calls overwrite the previous callback. Specifying NULL as the value of callback clears the current callback and disables message output through callbacks. Applications can provide user-specified data through the pointer userParam. The context will store this pointer and will include it as one of the parameters in each call to the callback function.

        If the application has specified a callback function for receiving debug output, the implementation will call that function whenever any enabled message is generated. The source, type, ID, and severity of the message are specified by the DEBUGPROC parameters source, type, id, and severity, respectively. The string representation of the message is stored in message and its length (excluding the null-terminator) is stored in length. The parameter userParam is the user-specified parameter that was given when calling DebugMessageCallback.

        Applications can query the current callback function and the current user-specified parameter by obtaining the values of DEBUG_CALLBACK_FUNCTION and DEBUG_CALLBACK_USER_PARAM, respectively.

        Applications that specify a callback function must be aware of certain special conditions when executing code inside a callback when it is called by the GL, regardless of the debug source.

        The memory for message is owned and managed by the GL, and should only be considered valid for the duration of the function call.

        The behavior of calling any GL or window system function from within the callback function is undefined and may lead to program termination.

        Care must also be taken in securing debug callbacks for use with asynchronous debug output by multi-threaded GL implementations.

        If the DEBUG_OUTPUT state is disabled then the GL will not call the callback function.

        Parameters:
        callback - a callback function that will be called when a debug message is generated
        userParam - a user supplied pointer that will be passed on each invocation of callback
      • nglGetDebugMessageLog

        public static int nglGetDebugMessageLog​(int count,
                                                int bufsize,
                                                long sources,
                                                long types,
                                                long ids,
                                                long severities,
                                                long lengths,
                                                long messageLog)
        Unsafe version of: GetDebugMessageLog
        Parameters:
        bufsize - the size of the buffer whose address is given by messageLog
      • glGetDebugMessageLog

        public static int glGetDebugMessageLog​(int count,
                                               @Nullable
                                               java.nio.IntBuffer sources,
                                               @Nullable
                                               java.nio.IntBuffer types,
                                               @Nullable
                                               java.nio.IntBuffer ids,
                                               @Nullable
                                               java.nio.IntBuffer severities,
                                               @Nullable
                                               java.nio.IntBuffer lengths,
                                               @Nullable
                                               java.nio.ByteBuffer messageLog)
        Retrieves messages from the debug message log.

        This function fetches a maximum of count messages from the message log, and will return the number of messages successfully fetched.

        Messages will be fetched from the log in order of oldest to newest. Those messages that were fetched will be removed from the log.

        The sources, types, severities, IDs, and string lengths of fetched messages will be stored in the application-provided arrays sources, types, severities, ids, and lengths, respectively. The application is responsible for allocating enough space for each array to hold up to count elements. The string representations of all fetched messages are stored in the messageLog array. If multiple messages are fetched, their strings are concatenated into the same messageLog array and will be separated by single null terminators. The last string in the array will also be null-terminated. The maximum size of messageLog, including the space used by all null terminators, is given by bufSize. If bufSize is less than zero and messageLog is not NULL, an INVALID_VALUE error will be generated. If a message's string, including its null terminator, can not fully fit within the messageLog array's remaining space, then that message and any subsequent messages will not be fetched and will remain in the log. The string lengths stored in the array lengths include the space for the null terminator of each string.

        Any or all of the arrays sources, types, ids, severities, lengths and messageLog can also be null pointers, which causes the attributes for such arrays to be discarded when messages are fetched, however those messages will still be removed from the log. Thus to simply delete up to count messages from the message log while ignoring their attributes, the application can call the function with null pointers for all attribute arrays.

        If the context was created without the CONTEXT_FLAG_DEBUG_BIT in the CONTEXT_FLAGS state, then the GL can opt to never add messages to the message log so GetDebugMessageLog will always return zero.

        Parameters:
        count - the number of debug messages to retrieve from the log
        sources - an array of variables to receive the sources of the retrieved messages
        types - an array of variables to receive the types of the retrieved messages
        ids - an array of unsigned integers to receive the ids of the retrieved messages
        severities - an array of variables to receive the severites of the retrieved messages
        lengths - an array of variables to receive the lengths of the received messages
        messageLog - an array of characters that will receive the messages
      • nglPushDebugGroup

        public static void nglPushDebugGroup​(int source,
                                             int id,
                                             int length,
                                             long message)
        Unsafe version of: PushDebugGroup
        Parameters:
        length - the length of the message to be sent to the debug output stream
      • glPushDebugGroup

        public static void glPushDebugGroup​(int source,
                                            int id,
                                            java.nio.ByteBuffer message)
        
        public static void glPushDebugGroup​(int source,
                                            int id,
                                            java.lang.CharSequence message)
        
        Pushes a debug group described by the string message into the command stream. The value of id specifies the ID of messages generated. The parameter length contains the number of characters in message. If length is negative, it is implied that message contains a null terminated string. The message has the specified source and id, type DEBUG_TYPE_PUSH_GROUP, and severity DEBUG_SEVERITY_NOTIFICATION. The GL will put a new debug group on top of the debug group stack which inherits the control of the volume of debug output of the debug group previously residing on the top of the debug group stack. Because debug groups are strictly hierarchical, any additional control of the debug output volume will only apply within the active debug group and the debug groups pushed on top of the active debug group.

        An INVALID_ENUM error is generated if the value of source is neither DEBUG_SOURCE_APPLICATION nor DEBUG_SOURCE_THIRD_PARTY. An INVALID_VALUE error is generated if length is negative and the number of characters in message, excluding the null-terminator, is not less than the value of MAX_DEBUG_MESSAGE_LENGTH.

        Parameters:
        source - the source of the debug message. One of:
        DEBUG_SOURCE_APPLICATIONDEBUG_SOURCE_THIRD_PARTY
        id - the identifier of the message
        message - a string containing the message to be sent to the debug output stream
      • glPopDebugGroup

        public static void glPopDebugGroup()
        Pops the active debug group. When a debug group is popped, the GL will also generate a debug output message describing its cause based on the message string, the source source, and an ID id submitted to the associated PushDebugGroup command. DEBUG_TYPE_PUSH_GROUP and DEBUG_TYPE_POP_GROUP share a single namespace for message id. severity has the value DEBUG_SEVERITY_NOTIFICATION. The type has the value DEBUG_TYPE_POP_GROUP. Popping a debug group restores the debug output volume control of the parent debug group.

        Attempting to pop the default debug group off the stack generates a STACK_UNDERFLOW error; pushing a debug group onto a stack containing MAX_DEBUG_GROUP_STACK_DEPTH minus one elements will generate a STACK_OVERFLOW error.

      • nglObjectLabel

        public static void nglObjectLabel​(int identifier,
                                          int name,
                                          int length,
                                          long label)
        Unsafe version of: ObjectLabel
        Parameters:
        length - the length of the label to be used for the object
      • glObjectLabel

        public static void glObjectLabel​(int identifier,
                                         int name,
                                         java.nio.ByteBuffer label)
        
        public static void glObjectLabel​(int identifier,
                                         int name,
                                         java.lang.CharSequence label)
        
        Labels a named object identified within a namespace.
        Parameters:
        identifier - the namespace from which the name of the object is allocated. One of:
        BUFFERSHADERPROGRAMQUERYPROGRAM_PIPELINESAMPLERVERTEX_ARRAYTEXTURE
        RENDERBUFFERFRAMEBUFFERTRANSFORM_FEEDBACK
        name - the name of the object to label
        label - a string containing the label to assign to the object
      • nglGetObjectLabel

        public static void nglGetObjectLabel​(int identifier,
                                             int name,
                                             int bufSize,
                                             long length,
                                             long label)
        Unsafe version of: GetObjectLabel
        Parameters:
        bufSize - the length of the buffer whose address is in label
      • glGetObjectLabel

        public static void glGetObjectLabel​(int identifier,
                                            int name,
                                            @Nullable
                                            java.nio.IntBuffer length,
                                            java.nio.ByteBuffer label)
        Retrieves the label of a named object identified within a namespace.
        Parameters:
        identifier - the namespace from which the name of the object is allocated. One of:
        BUFFERSHADERPROGRAMQUERYPROGRAM_PIPELINESAMPLERVERTEX_ARRAYTEXTURE
        RENDERBUFFERFRAMEBUFFERTRANSFORM_FEEDBACK
        name - the name of the object whose label to retrieve
        length - the address of a variable to receive the length of the object label
        label - a string that will receive the object label
      • nglObjectPtrLabel

        public static void nglObjectPtrLabel​(long ptr,
                                             int length,
                                             long label)
        Unsafe version of: ObjectPtrLabel
        Parameters:
        length - the length of the label to be used for the object
      • glObjectPtrLabel

        public static void glObjectPtrLabel​(long ptr,
                                            java.nio.ByteBuffer label)
        
        public static void glObjectPtrLabel​(long ptr,
                                            java.lang.CharSequence label)
        
        Labels a sync object identified by a pointer.
        Parameters:
        ptr - a pointer identifying a sync object
        label - a string containing the label to assign to the object
      • nglGetObjectPtrLabel

        public static void nglGetObjectPtrLabel​(long ptr,
                                                int bufSize,
                                                long length,
                                                long label)
        Unsafe version of: GetObjectPtrLabel
        Parameters:
        bufSize - the length of the buffer whose address is in label
      • glGetObjectPtrLabel

        public static void glGetObjectPtrLabel​(long ptr,
                                               @Nullable
                                               java.nio.IntBuffer length,
                                               java.nio.ByteBuffer label)
        Retrieves the label of a sync object identified by a pointer.
        Parameters:
        ptr - the name of the sync object whose label to retrieve
        length - a variable to receive the length of the object label
        label - a string that will receive the object label
      • glGetObjectPtrLabel

        public static java.lang.String glGetObjectPtrLabel​(long ptr,
                                                           int bufSize)
        Retrieves the label of a sync object identified by a pointer.
        Parameters:
        ptr - the name of the sync object whose label to retrieve
        bufSize - the length of the buffer whose address is in label
      • glGetObjectPtrLabel

        public static java.lang.String glGetObjectPtrLabel​(long ptr)
        Retrieves the label of a sync object identified by a pointer.
        Parameters:
        ptr - the name of the sync object whose label to retrieve
      • glDebugMessageControl

        public static void glDebugMessageControl​(int source,
                                                 int type,
                                                 int severity,
                                                 @Nullable
                                                 int[] ids,
                                                 boolean enabled)
        Array version of: DebugMessageControl
      • glGetDebugMessageLog

        public static int glGetDebugMessageLog​(int count,
                                               @Nullable
                                               int[] sources,
                                               @Nullable
                                               int[] types,
                                               @Nullable
                                               int[] ids,
                                               @Nullable
                                               int[] severities,
                                               @Nullable
                                               int[] lengths,
                                               @Nullable
                                               java.nio.ByteBuffer messageLog)
        Array version of: GetDebugMessageLog
      • glGetObjectLabel

        public static void glGetObjectLabel​(int identifier,
                                            int name,
                                            @Nullable
                                            int[] length,
                                            java.nio.ByteBuffer label)
        Array version of: GetObjectLabel
      • glGetObjectPtrLabel

        public static void glGetObjectPtrLabel​(long ptr,
                                               @Nullable
                                               int[] length,
                                               java.nio.ByteBuffer label)
        Array version of: GetObjectPtrLabel