org.lwjgl.opengles

Class EXTRobustness

java.lang.Object

org.lwjgl.opengles.EXTRobustness

public class EXTRobustness
extends java.lang.Object

Native bindings to the EXT_robustness extension.

Several recent trends in how OpenGL integrates into modern computer systems have created new requirements for robustness and security for OpenGL rendering contexts.

Additionally GPU architectures now support hardware fault detection; for example, video memory supporting ECC (error correcting codes) and error detection. OpenGL contexts should be capable of recovering from hardware faults such as uncorrectable memory errors. Along with recovery from such hardware faults, the recovery mechanism can also allow recovery from video memory access exceptions and system software failures. System software failures can be due to device changes or driver failures.

OpenGL queries that that return (write) some number of bytes to a buffer indicated by a pointer parameter introduce risk of buffer overflows that might be exploitable by malware. To address this, queries with return value sizes that are not expressed directly by the parameters to the query itself are given additional API functions with an additional parameter that specifies the number of bytes in the buffer and never writing bytes beyond that limit. This is particularly useful for multi-threaded usage of OpenGL contexts in a "share group" where one context can change objects in ways that can cause buffer overflows for another context's OpenGL queries.

The original ARB_vertex_buffer_object extension includes an issue that explicitly states program termination is allowed when out-of-bounds vertex buffer object fetches occur. Modern graphics hardware is capable well-defined behavior in the case of out-of- bounds vertex buffer object fetches. Older hardware may require extra checks to enforce well-defined (and termination free) behavior, but this expense is warranted when processing potentially untrusted content.

The intent of this extension is to address some specific robustness goals:

• For all existing OpenGL queries, provide additional "safe" APIs that limit data written to user pointers to a buffer size in bytes that is an explicit additional parameter of the query.
• Provide a mechanism for an OpenGL application to learn about graphics resets that affect the context. When a graphics reset occurs, the OpenGL context becomes unusable and the application must create a new context to continue operation. Detecting a graphics reset happens through an inexpensive query.
• Provide an enable to guarantee that out-of-bounds buffer object accesses by the GPU will have deterministic behavior and preclude application instability or termination due to an incorrect buffer access. Such accesses include vertex buffer fetches of attributes and indices, and indexed reads of uniforms or parameters from buffers.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GL_CONTEXT_ROBUST_ACCESS_EXT Accepted by the value parameter of GetBooleanv, GetIntegerv, and GetFloatv.
static int	GL_GUILTY_CONTEXT_RESET_EXT Returned by GetGraphicsResetStatusEXT.
static int	GL_INNOCENT_CONTEXT_RESET_EXT Returned by GetGraphicsResetStatusEXT.
static int	GL_LOSE_CONTEXT_ON_RESET_EXT Returned by GetIntegerv and related simple queries when value is RESET_NOTIFICATION_STRATEGY_EXT .
static int	GL_NO_RESET_NOTIFICATION_EXT Returned by GetIntegerv and related simple queries when value is RESET_NOTIFICATION_STRATEGY_EXT .
static int	GL_RESET_NOTIFICATION_STRATEGY_EXT Accepted by the value parameter of GetBooleanv, GetIntegerv, and GetFloatv.
static int	GL_UNKNOWN_CONTEXT_RESET_EXT Returned by GetGraphicsResetStatusEXT.

Method Summary

Modifier and Type	Method and Description
static int	glGetGraphicsResetStatusEXT()
static float	glGetnUniformfEXT(int program, int location)
static void	glGetnUniformfvEXT(int program, int location, float[] params) Array version of: GetnUniformfvEXT
static void	glGetnUniformfvEXT(int program, int location, java.nio.FloatBuffer params)
static int	glGetnUniformiEXT(int program, int location)
static void	glGetnUniformivEXT(int program, int location, int[] params) Array version of: GetnUniformivEXT
static void	glGetnUniformivEXT(int program, int location, java.nio.IntBuffer params)
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, java.nio.ByteBuffer data)
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, float[] data) Array version of: ReadnPixelsEXT
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, java.nio.FloatBuffer data)
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, int[] data) Array version of: ReadnPixelsEXT
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, java.nio.IntBuffer data)
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, int bufSize, long data)
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, short[] data) Array version of: ReadnPixelsEXT
static void	glReadnPixelsEXT(int x, int y, int width, int height, int format, int type, java.nio.ShortBuffer data)
static void	nglGetnUniformfvEXT(int program, int location, int bufSize, long params)
static void	nglGetnUniformivEXT(int program, int location, int bufSize, long params)
static void	nglReadnPixelsEXT(int x, int y, int width, int height, int format, int type, int bufSize, long data)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GL_GUILTY_CONTEXT_RESET_EXT

public static final int GL_GUILTY_CONTEXT_RESET_EXT

Returned by GetGraphicsResetStatusEXT.

See Also:

Constant Field Values

GL_INNOCENT_CONTEXT_RESET_EXT

public static final int GL_INNOCENT_CONTEXT_RESET_EXT

Returned by GetGraphicsResetStatusEXT.

See Also:

Constant Field Values

GL_UNKNOWN_CONTEXT_RESET_EXT

public static final int GL_UNKNOWN_CONTEXT_RESET_EXT

Returned by GetGraphicsResetStatusEXT.

See Also:

Constant Field Values

GL_CONTEXT_ROBUST_ACCESS_EXT

public static final int GL_CONTEXT_ROBUST_ACCESS_EXT

Accepted by the value parameter of GetBooleanv, GetIntegerv, and GetFloatv.

See Also:

Constant Field Values

GL_RESET_NOTIFICATION_STRATEGY_EXT

public static final int GL_RESET_NOTIFICATION_STRATEGY_EXT

Accepted by the value parameter of GetBooleanv, GetIntegerv, and GetFloatv.

See Also:

Constant Field Values

GL_LOSE_CONTEXT_ON_RESET_EXT

public static final int GL_LOSE_CONTEXT_ON_RESET_EXT

Returned by GetIntegerv and related simple queries when value is RESET_NOTIFICATION_STRATEGY_EXT .

See Also:

Constant Field Values

GL_NO_RESET_NOTIFICATION_EXT

public static final int GL_NO_RESET_NOTIFICATION_EXT

Returned by GetIntegerv and related simple queries when value is RESET_NOTIFICATION_STRATEGY_EXT .

See Also:

Constant Field Values

Method Detail

glGetGraphicsResetStatusEXT

public static int glGetGraphicsResetStatusEXT()

nglReadnPixelsEXT

public static void nglReadnPixelsEXT(int x,
                                     int y,
                                     int width,
                                     int height,
                                     int format,
                                     int type,
                                     int bufSize,
                                     long data)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    int bufSize,
                                    long data)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    java.nio.ByteBuffer data)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    java.nio.ShortBuffer data)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    java.nio.IntBuffer data)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    java.nio.FloatBuffer data)

nglGetnUniformfvEXT

public static void nglGetnUniformfvEXT(int program,
                                       int location,
                                       int bufSize,
                                       long params)

glGetnUniformfvEXT

public static void glGetnUniformfvEXT(int program,
                                      int location,
                                      java.nio.FloatBuffer params)

glGetnUniformfEXT

public static float glGetnUniformfEXT(int program,
                                      int location)

nglGetnUniformivEXT

public static void nglGetnUniformivEXT(int program,
                                       int location,
                                       int bufSize,
                                       long params)

glGetnUniformivEXT

public static void glGetnUniformivEXT(int program,
                                      int location,
                                      java.nio.IntBuffer params)

glGetnUniformiEXT

public static int glGetnUniformiEXT(int program,
                                    int location)

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    short[] data)

Array version of: ReadnPixelsEXT

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    int[] data)

Array version of: ReadnPixelsEXT

glReadnPixelsEXT

public static void glReadnPixelsEXT(int x,
                                    int y,
                                    int width,
                                    int height,
                                    int format,
                                    int type,
                                    float[] data)

Array version of: ReadnPixelsEXT

glGetnUniformfvEXT

public static void glGetnUniformfvEXT(int program,
                                      int location,
                                      float[] params)

Array version of: GetnUniformfvEXT

glGetnUniformivEXT

public static void glGetnUniformivEXT(int program,
                                      int location,
                                      int[] params)

Array version of: GetnUniformivEXT