OpenRM - RM Library (rmpipe.c)

## Index of OpenRM - RM Library

     RMenum rmPipeCreateContext (RMpipe *toUse)

     RMpipe *toUse - a handle to an RMpipe (modified).

This routine will create a platform-specific OpenGL context that honors the display format attributes contained in the RMpipe. Use rmPipeSetChannelFormat() to set such parameters prior to creating the context. Changing the channel format parameters after the context has been created with this routine will have no effect.

After the context has been created with this routine, be sure to call rmPipeMakeCurrent() to perform final intialization steps needed to ready the context for use in rendering.

Returns RM_CHILL upon success, or RM_WHACKED upon failure.

librm library source file: rmpipe.c

      RMpipe * rmPipeNew (RMenum targetPlatform)

      RMenum targetPlatform - select the appropriate platform. This parameter
        must be one of RM_PIPE_GLX, RM_PIPE_WGL or RM_PIPE_CR.

Use this routine to create a new RMpipe object for use with a specified display platform. Upon success, a handle to the new RMpipe object is returned to the caller, or NULL is returned upon failure.

The input parameter must be one of RM_PIPE_GLX, RM_PIPE_WGL or RM_PIPE_CR. RM_PIPE_GLX specifies use on any X-based system that has the GLX extension (supports OpenGL through the server). RM_PIPE_WGL specifies use on a Win32 platform. RM_PIPE_CR specifies use only on a Chromium-enabled system.

Note that RM_PIPE_GLX and RM_PIPE_WGL platforms can make use of Chromium as well for doing single application to one or more crservers. However, an RM_PIPE_CR platform is highly Chromium-specific. Refer to the RM Programming Guide for more details.

During rmPipeNew(), the RMpipe object is initialized with the following platform-specific and platform-neutral settings:

1. The "swapbuffers" function is set to a platform-appropriate value. The application may later override this setting using rmPipeSetSwapBuffersFunc(). By assigning a default swapbuffers function, we are assuming that the OpenGL context (created later) will be double buffered.

2. The default channel format is RM_MONO_CHANNEL, which corresponds to an OpenGL visual that has RGBA color buffers, a depth buffer, and which is double-buffered. The channel format can be set using rmPipeSetChannelFormat() after rmPipeNew() returns, and before a window is created (or before drawing occurs in the case of RM_PIPE_CR).

3. The default processing mode is RM_PIPE_MULTISTAGE. This mode corresponds to serial rendering using a two-stage pipeline. You can set the processing mode after rmPipeNew() returns (see rmPipeSetProcessingMode), but before rmPipeMakeCurrent().

4. The "post render barrier function" is set to NULL (see rmPipeSetPostRenderBarrierFunc).

5. The "post render function" is set to NULL (see rmPipeSetPostRenderFunc).

6. Each of the following three passes of the multipass rendering engine is enabled by default: opaque 3D, transparent 3D, opaque 2D. Applications may not change the order of these rendering passes, but may enable or disable a given rendering pass with rmPipeSetRenderPassEnable().

The basic sequence of steps needed to fully initialize RM for rendering are:

1. Use rmPipeNew(yourPlatform) to create the RMpipe object specific for your platform.

2. Set any optional parameters on the RMpipe: processing mode (see rmPipeSetProcessingMode), channel format (see rmPipeSetChannelFormat), XDisplay on X systems (see rmxPipeSetDisplay).

X11 note: if you want to display somewhere other than getenv($DISPLAY), you will need to make an explicit call to rmxPipeSetDisplay() using an appropriate XDisplay structure. By default, rmPipeNew(RM_PIPE_GLX) will perform XOpenDisplay(getenv("$DISPLAY")), and assign the resulting XDisplay structure to the RMpipe.

3. Create a window suitable for display. This can be done with either rmauxCreateXWindow() or rmauxCreateW32Window(), or a suitable drawable can be provided by an external source (for more details, see the RM Programming Guide).

4. Assign the window to the RMpipe (see rmPipeSetWindow)

5. Make the pipe current (rmPipeMakeCurrent).

Note: the routine rmPipeInit() was deprecated after 1.4.3 and is no longer a part of the API. 1. Use rmPipeInit to create and initialize a pipe.

librm library source file: rmpipe.c

     RMenum rmPipeDelete (RMpipe *toDelete)

     RMpipe *toDelete - a handle to an RMpipe to be deleted.

Releases resources associated with an RMpipe object. This is the opposite of rmPipeNew(). Returns RM_WHACKED if the input RMpipe is NULL.

librm library source file: rmpipe.c

     RMenum rmPipeMakeCurrent (RMpipe *toUse)

     RMpipe *toUse - a handle to an RMpipe object (input).

Use this routine to make a named RMpipe "active." Inside this routine, the OpenGL rendering context associated with the input RMpipe is made current, and all subsequent OpenGL commands are executed to that context.

All applications will use this routine to make an RMpipe "active."

During the process of making an RMpipe active, this routine will check for the existance of a "context cache," and will create a new one, if one does not exist. If a context cache exists, it will be replaced with a new one.

The context cache is used internally by RM to store retained mode, OpenGL context-specific data, such as display list indices, texture object identifiers, and so forth. The reason for creating/replacing/activating the context cache in this routine, rather than earlier (when the OpenGL context is created) is due to the inconsistencies between X11 and Win32 in how OpenGL is initialized. In X11, the GLX context must be created prior to creating an X11 window (XCreateWindow needs an XVisualInfo structure, which reflects the pixel format chosen with glXChooseVisual). In Win32, the equivalent of an XVisualInfo structure is created using a window handle.

In nearly all applications, this routine will be called only once. It is not an error call it multiple times, but developers must be aware that any existing retained mode structures will be flushed by rmPipeMakeCurrent, and rebuilt during subsequent renderings.

This routine *must* be called by all applications between rmPipeInit() (RMpipe initialization) and rmFrame() (rendering). Note that some applications (CAVELib apps, for example) will *not* call rmPipeInit, but will instead call rmPipeNew, followed by some number of steps to fully specify the rendering context, window parameters, and so forth into the RMpipe. Those apps must call rmPipeMakeCurrent between the time the GLXcontext is assigned to the RMpipe and the first time rendering is performed to the RMpipe.

librm library source file: rmpipe.c

     RMenum rmPipeClose(RMpipe *toClose)

     RMpipe *toClose - a handle to an RMpipe (modified).

This routine will destroy the OpenGL rendering context associated with the input RMpipe object, and delete all resources associated with the RMpipe's context cache, including all OpenGL display lists and texture object id's.

On X11, this routine will also close the X Display associated with the RMpipe.

Returns RM_CHILL upon success, or RM_WHACKED upon failure.

librm library source file: rmpipe.c

     RMenum rmPipeSwapBuffers (RMpipe *p)

     RMpipe *p - a handle to an RMpipe (input).

This routine will cause a buffer-swap on the display and window specified by the input RMpipe.

In the interest of speed, no error checking is performed inside this routine.

This routine is most typically called from within a rendering manager routine, and not directly from the application. There is nothing that precludes it's use directly by applications, if so desired.

librm library source file: rmpipe.c

     RMenum rmPipeSetChannelFormat (RMpipe *toModify,
    		                RMenum channelFormat)

     RMpipe *toModify - a handle to an RMpipe object (modified).

     RMenum channelFormat - an RMenum value specifying a display
        format. May be one of RM_MONO_CHANNEL, RM_REDBLUE_STEREO_CHANNEL,

Use this routine to set the "channel format" of an RMpipe object. Returns RM_CHILL upon success, or RM_WHACKED upon failure.

The RMpipe channel format serves two purposes. First, when multibuffered stereo is requested, this information must be known prior to creating an OpenGL rendering context. So, the channel format provides hints about the type of OpenGL capabilities that are needed by the application. As such, it is likely that the channel format interface will evolve over time to include more access to additional OpenGL capabilities.

Second, when a channel format is specified, internal to rmPipeSetChannelFormat(), an RM rendering callback is assigned to the pipe. The rendering callback knows about multipass rendering as well as how to instruct the underlying rendering engine in the details of managing stereo rendering.

This routine must be called between the time you create the RMpipe with rmPipeNew(), and before an OpenGL rendering context is created with rmPipeCreateContext(). It is a logic error to change an RMpipe's channel format after the OpenGL context has been created.

librm library source file: rmpipe.c

     RMenum rmPipeGetChannelFormat (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

Returns to the caller the current channel format of an RMpipe object. A successful return value will be one of RM_MONO_CHANNEL, RM_REDBLUE_STEREO_CHANNEL, RM_BLUERED_STEREO_CHANNEL or RM_MBUF_STEREO_CHANNEL. A return value of RM_WHACKED indicates an error of some type.

librm library source file: rmpipe.c

     RMenum rmPipeSetInitMatrixStackMode(RMpipe *toModify,
    			             RMenum newMode)

     RMpipe *toModify - a handle to an RMpipe object (modified).
     RMenum newMode - an RMenum value, either RM_TRUE or RM_FALSE, that
        controls how matrix transformations are applied to the OpenGL
        matrix stack.

By default, OpenRM will initialize the OpenGL matrix stack during a frame rendering operation by setting GL_MODELVIEW, GL_PROJECTION and GL_TEXTURE matrices to the Identity matrix. This behavior may be overridden, so that OpenRM will honor any existing matrices in the matrix stacks while accumulating nested transformations. This is helpful in some deployment environments, such as combining OpenRM with CAVElib (www.vrco.com).

When the input enumerator is set to RM_TRUE (the default), OpenRM will initialize the OpenGL matrix stack to the identity matrix prior to accumulating transformations during rendering. When the input enum is set to RM_FALSE, OpenRM will NOT initialize the matrix stack, and any existing transformations within the scene graph will be accumulated with the contents of the matrix stack at render time.

More precisely, if the GL_MODELVIEW matrix stack has the matrix M, and the scene graph defines a matrix transformation S, the combined transformation will be S*M (left multiplication), so that the scene graph transformation S is effectively applied prior to the outer transformation M when vertex data moves down the OpenGL transformation pipeline.

Returns RM_CHILL upon success, or RM_WHACKED upon failure.

librm library source file: rmpipe.c

     RMenum rmPipeGetInitMatrixStackMode(const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (queried).

This routine will return the "init matrix stack" attribute of an RMpipe object. A return value of RM_TRUE means the OpenGL matrix stack will be initialized by OpenRM during frame rendering, while a value of RM_FALSE means that any existing values in the OpenGL matrix stack will be honored during rendering.

A return value of RM_WHACKED indicates an error condition.

librm library source file: rmpipe.c

     RMenum rmPipeSetRenderPassEnable(RMpipe *toModify,
    			          RMenum opaque3DEnable,
    				  RMenum transparent3DEnable,
    				  RMenum opaque2DEnable)

     RMpipe *toModify - a handle to an RMpipe (modified).

     RMenum opaque3DEnable,transparent3DEnable, opaque2DEnable - RMenum
        values, may be either RM_TRUE or RM_FALSE.

This routine is used to selectely enable or disable one of the rendering passes of the RM multipass rendering engine. Applications may not change the order of the rendering passes, but may selectively enable or disable a given pass. The order of the passes is:

1. 3D Opaque

2. 3D Transparent

3. 2D Opaque

(There may be a 2D transparent pass in a later release.)

During each of these passes, traversal filters are applied at each node of the RM scene graph. If, at any stage during the traversal, the scene graph node does not pass the traversal filter test, that node, and any descendents, are not processed.

For this reason, developers should carefully consider scene graph design such that 3D opaque, 3D transparent and 2D objects are appropriately partitioned within the scene graph itself.

Background scene operations (background clear color, background image tile, background depth value, background depth image) are performed during rendering passes 1 and 3. A common RM error is to place a background scene operation at a node that is processed during multiple rendering passes.

Returns RM_CHILL upon success, or RM_WHACKED upon failure.

librm library source file: rmpipe.c

     RMenum rmPipeGetRenderPassEnable(const RMpipe *t,
    			          RMenum *opaque3DEnableReturn,
    				  RMenum *transparent3DEnableReturn,
    				  RMenum *opaque2DEnableReturn)

     const RMpipe *t - a handle to an RMpipe (input).

     RMenum *opaque3DEnableReturn, *transparent3DEnableReturn,
        *opaque2DEnableReturn - handles to RMenum values (result).

This routine is used to obtain the boolean values that indicate if a particular rendering pass is enabled in the RMpipe.

Each of the return parameters is optional - a value of NULL will skip reporting of that particular rendering pass.

Upon success, RM_CHILL is returned, and RM_TRUE or RM_FALSE is copied into non-NULL caller-supplied memory for each of the RMpipe rendering passes. Otherwise, RM_WHACKED is returned, and caller-supplied memory remains unmodified.

librm library source file: rmpipe.c

     RMenum rmPipeSetWindowSize (RMpipe *toModify,
    		             int newWidth,
    			     int newHeight)

     RMpipe *toModify - a handle to an RMpipe (modified).

     int newWidth, newHeight - integer values specifing the pixel width
        and height of the window associated with an RMpipe (input).

This routine sets the RMpipe's notion of pixel width and height of it's associated display window. RM_CHILL is returned upon success, or RM_WHACKED upon failure.

The most typical use of this routine will be when an application detects, through an event loop, that the window geometry has changed. The application is reponsible for notifying RM of such changes; RM doesn't manage events and doesn't keep track of the size of the display window.

This routine is called by rmPipeSetWindow().

librm library source file: rmpipe.c

     RMenum rmPipeGetWindowSize (const RMpipe *toQuery,
    		             int *widthReturn,
    			     int *heightReturn)

     const RMpipe *toQuery - a handle to an RMpipe (input).

     int *widthReturn, *heightReturn - pointers to integers (return).
        Values of NULL are acceptable.

This routine returns via caller-supplied memory the named RMpipe's notion of the current window width and height. RM_CHILL is returned upon success, or RM_WHACKED upon failure.

Callers interested in only width or height may specify NULL for the parameter for which information is not requested.

librm library source file: rmpipe.c

     RMenum rmPipeSetSwapBuffersFunc (RMpipe *toModify,
    			          void (newFunc)(RMpipe *))

     RMpipe *toModify - a handle to an RMpipe (modified).

     void (newFunc)(RMpipe *) - a handle to an application callback
        (input).

Use this routine to set the "swapbuffers" callback function associated with an RMpipe object. Returns RM_CHILL upon success, or RM_WHACKED upon failure.

The swapbuffers function is invoked after rendering has completed, and after the post-render barrier function, and the post-render framebuffer and depthbuffer grab callbacks, if any. By default, rmSwapBuffers() is assigned to all RMpipe objects' swapbuffers callback functions at the time the RMpipe is created with RMpipe new. The function rmSwapBuffers() calls the native window-system procedure that causes front and back buffers to be swapped.

If the application overrides the default swapbuffers function, the application callback will be provided a single input parameter: a handle to an RMpipe object. The RMpipe object contains enough information to enable application code to do the swapbuffers call.

librm library source file: rmpipe.c

     RMenum rmPipeSetPostRenderFunc (RMpipe *toModify,
    			         void (*postRenderFunc)(const RMimage *, RMenum))

     RMpipe *toModify - a handle to an RMpipe (modified).

     void (*postRenderFunc)(RMimage *, RMenum) - a handle to an
        application callback.

This routine assigns a "post render" application callback to the RMpipe. The post render callback is invoked after rendering has occured, and after the "post render barrier function" has been called (if any), but before the "post render depthbuffer function" (if any) and before the swapbuffers function. RM_CHILL is returned upon success, or RM_WHACKED upon failure.

Use a value of NULL for the postRenderFunc to effectively disable post rendering callbacks.

The purpose of the post render function is to allow applications to grab a copy of the color planes of the framebuffer after rendering has occured. If you want the raw image data produced by the rendering, this is the path to use.

When the application callback is invoked, the callback is invoked with two parameters. The first is a handle to an RMimage object. Use rmImageGetPixelData() to obtain the raw pixel data from this image. At this time (Jan 2000) the image provided to the app callback is in GL_RGBA, GL_UNSIGNED_BYTE format. Applications are advised to use the rmImageGet*() series of routines to obtain RMimage configuration information. In particular, pay close attention to scanline-padding issues.

The second parameter provided to the application callback is an RMenum value that is one of RM_ALL_CHANNELS, RM_LEFT_CHANNEL or RM_RIGHT_CHANNEL. Multibuffered stereo channels will invoke the application callback twice, once for each channel. Anaglyph stereo formats (RM_REDBLUE_STEREO_CHANNEL and RM_BLUERED_STEREO_CHANNEL) will trigger the callback just once. This may change in the future (Jan 2000).

The RMimage object provided to applications is managed by RM.

librm library source file: rmpipe.c

     RMenum rmPipeSetPostRenderDepthFunc (RMpipe *toModify,
    			              void (*postRenderDepthFunc)(const RMimage *, RMenum))

     RMpipe *toModify - a handle to an RMimage object (modified).

     void (*postRenderDepthFunc)(RMimage *, RMenum) - a handle to an
        application callback (input).

Use this routine to assign a "post render depth buffer" callback to an RMpipe object. RM_CHILL is returned upon success, or RM_WHACKED upon failure.

Use a value of NULL for the postRenderDepthFunc to effectively disable this post rendering callback.

Whereas the "post render callback" gives applications access to the color planes of the framebuffer after rendering, the purpose of this callback is to give applications access to the depth buffer after rendering has completed. Assigning a "post render depth buffer callback" will cause the application callback to be invoked after rendering, and after the post-render barrier function, after the post render callback (the color planes) but before the swapbuffers function.

The pixel data of the RMimage object provided to the application, the first application callback parameter, contains the contents of the depth buffer of the scene just rendered. The pixel data in the RMimage object is in RM_FLOAT format. Applications should use the rmImageGet*() series of routines to query specific RMimage attributes.

The second parameter provided to the application callback is an RMenum value that is one of RM_ALL_CHANNELS, RM_LEFT_CHANNEL or RM_RIGHT_CHANNEL. Multibuffered stereo channels will invoke the application callback twice, once for each channel. Anaglyph stereo formats (RM_REDBLUE_STEREO_CHANNEL and RM_BLUERED_STEREO_CHANNEL) will trigger the callback just once. This may change in the future (Jan 2000).

The RMimage object provided to applications is managed by RM.

librm library source file: rmpipe.c

     RMenum rmPipeSetPostRenderBarrierFunc (RMpipe *toModify,
    			                void (*barrierFunc)(RMpipe *))

     RMpipe *toModify - a handle to an RMpipe object (modified).

     void (*barrierFunc)(RMpipe *) - a handle to an application callback
        (input).

Use this routine to set the "post render barrier function" on an RMpipe object. Use a value of NULL for barrierFunc to disable this callback, or remove a previously installed callback. Returns RM_CHILL upon success, or RM_WHACKED upon failure.

The "post render barrier" callback, if present, will be invoked immediately after rendering, but prior to any other callbacks (post render color planes callback, post render depth buffer callback or swapbuffers). This routine is intended for use by parallel rendering applications.

The application callback will be provided a single parameter, an RMpipe.

librm library source file: rmpipe.c

     RMenum rmPipeProcessingModeIsMultithreaded (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe (input).

This routine can be used to determine if the processing mode of the RMpipe toQuery is a multithreaded format. If toQuery's processing mode is either RM_PIPE_MULTISTAGE_VIEW_PARALLEL or RM_PIPE_MULTISTAGE_PARALLEL, this routine will return RM_TRUE. Otherwise, RM_FALSE is returned.

See also rmPipeGetProcessingMode().

librm library source file: rmpipe.c

     RMenum rmPipeGetProcessingMode (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

This routine will return the processing mode of the RMpipe toQuery. Upon success, one of the following is returned to the caller: RM_PIPE_SERIAL, RM_PIPE_MULTISTAGE, RM_PIPE_MULTISTAGE_PARALLEL or RM_PIPE_MULTISTAGE_VIEW_PARALLEL.

Upon failure, RM_WHACKED is returned to the caller.

librm library source file: rmpipe.c

     RMenum rmPipeSetProcessingMode (RMpipe *toModify,
    			         RMenum newMode)

     RMpipe *toModify - a handle to an RMpipe (modified).
     RMenum newMode - a RMenum specifying a processing mode. This value must
     be one of:  RM_PIPE_SERIAL, RM_PIPE_MULTISTAGE, RM_PIPE_MULTISTAGE_PARALLEL
     or RM_PIPE_MULTISTAGE_VIEW_PARALLEL.

This routine will select the "processing mode" for an RMpipe object. The processing mode assigns a rendering engine to the RMpipe for use in subsequent rendering operations. Upon success, RM_CHILL is returned to the caller; upon failure, RM_WHACKED is returned.

Applications may set the processing mode on an RMpipe any time between when it is created (using either rmPipeNew or rmPipeInit) and the first time a frame is rendered. As of this time (June 2001), it is not possible to change the processing mode of an RMpipe, and this routine will not detect this error condition. Your application will likely crash if you attempt to alter the processing mode of an RMpipe after the first frame has been drawn.

OpenRM uses a two-stage rendering pipeline: a view traversal of the scene graph prepares a list of things to be drawn during a rendering traversal.

The following processing modes are supported:

RM_PIPE_MULTISTAGE - uses a two-stage rendering traversal (view, render), and both stages are called sequentially within the same process/thread as the caller. There is no parallelization in this processing mode.

RM_PIPE_MULTISTAGE_PARALLEL - each of the two rendering stages are called from detached Posix threads. The render thread will assume ownership of the OpenGL context (applications should NOT make any OpenGL calls except from within node callbacks invoked by the OpenRM renderer). This mode is fully parallelized.

RM_PIPE_MULTISTAGE_VIEW_PARALLEL - the view traversal is assigned to a detached thread, while the render traversal remains in the same execution process/thread as the caller (and does not attempt to exert ownership of the OpenGL rendering context). This mode is also fully parallelized, and is quite useful when combining OpenRM with other toolkits that provide device and event management and which make assumptions about ownership of the OpenGL rendering context (e.g., CAVELibrary, VRJuggler, FLTK, etc.).

librm library source file: rmpipe.c

     RMenum rmPipeGetDisplayListEnable (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

This routine will return the RMpipe's notion of whether or not it will use OpenGL display lists when rendering primitives. The returned value will be either RM_TRUE, which indicates that display lists will be used when rendering primitives on the RMpipe, or RM_FALSE, which indicates that no RMprimitives will be drawn using display lists.

See also: rmPipeSetDisplayListEnable, rmPrimitiveSetDisplayListEnable.

librm library source file: rmpipe.c

     RMenum rmPipeSetDisplayListEnable (RMpipe *toModify,
    			            RMenum newMode)

     RMpipe *toModify - a handle to an RMpipe (modified).
     RMenum newMode - a RMenum specifying whether or not RMprimitives rendered on
       the RMpipe toModify will use display lists. The input value should be
       either RM_TRUE or RM_FALSE.

Set's the RMpipe's policy on the use of display lists. When the value of newMode is set to RM_TRUE, use of display lists on the RMpipe toModify is enabled. When set to RM_FALSE, use of display lists on the RMpipe is disabled. The default policy for use of display lists is RM_TRUE, and this value is set at the time the RMpipe is created. You can override the default behavior by calling rmPipeSetDisplayListEnable() with a value of RM_FALSE.

Use of display lists can greatly accelerate rendering performance on many platforms. By default, RM will attempt to create display lists for RMprimitives during rendering, and reuse them in subsequent renderings.

Applications can control use of display lists in two ways: at the RMpipe level, and at the RMprimitive level. At the RMpipe level, you can enable or disable use of display lists for all RMprimitives drawn on RMpipe using the routine rmPipeSetDisplayListEnable. At the RMprimitive level, you can enable or disable the use of display lists for a single primitive using rmPrimitiveSetDisplayListEnable().

The RMprimitive display list policy does not override the display list policy set at the RMpipe level. In other words, if the policy at the RMpipe level is set to RM_FALSE, then no display lists will be used, even if the policy at the RMprimitive level is set to RM_TRUE. On the other hand, if the policy at the RMpipe level is set to RM_TRUE, a policy at the RMprimitive level of RM_FALSE will result on no display lists being used for the one RMprimitive. In order for display lists to be used at any given RMprimitive, the logical AND of RMpipe and RMprimitive display list policies must be RM_TRUE.

To obtain the current display list use policy at an RMpipe, use the routine rmPipeGetDisplayListEnable().

See also rmPrimitiveSetDisplayListEnable().

librm library source file: rmpipe.c

     RMenum rmPipeSetCommSize (RMpipe *toModify)

     RMpipe *toModify - a handle to an RMpipe object (modified).

Sets the global number of PEs in an MPI-parallel application. Docs need to be better written.

librm library source file: rmpipe.c

     int rmPipeSetCommSize (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

Returns the global number of PEs in an MPI-parallel application. Docs need to be better written.

librm library source file: rmpipe.c

     RMenum rmPipeSetRank (RMpipe *toModify)

     RMpipe *toModify - a handle to an RMpipe object (modified).

Sets the rank value of one RMpipe in an MPI-parallel application. Docs need to be better written.

librm library source file: rmpipe.c

     int rmPipeGetRank (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

Obtains the rank value of one RMpipe in an MPI-parallel application. Docs need to be better written.

librm library source file: rmpipe.c

     const char * rmPipeGetDisplayName (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object (input).

Returns to the caller a character string defining $DISPLAY, the display name. $DISPLAY has an effect only on GL_PIPE_GLX platforms.

librm library source file: rmpipe.c

     RMenum rmPipeSetDisplayName (RMpipe *toModify, const char *displayName)

     RMpipe *toModify - a handle to an RMpipe object (modified).
     const char *displayName - character string defining name of the $DISPLAY
       to use in subsequent window system operations.

Use this routine to set the $DISPLAY variable in an RMpipe. This variable is used only on RM_PIPE_GLX platforms, and only when a Returns to the caller a character string defining $DISPLAY, the display name. $DISPLAY has an effect only on GL_PIPE_GLX platforms.

librm library source file: rmpipe.c

     void * rmPipeGetDisplay (const RMpipe *toQuery)

     const RMpipe *toQuery - a handle to an RMpipe object that will be
        queried (input).

Returns to the caller the X Display handle, cast to void *, associated with an RMpipe.

librm library source file: rmpipe.c

     RMenum rmPipeSetFrameRate (RMpipe *toModify, int newFPS)

     RMpipe *toModify - a handle to an RMpipe (modified).
     int newFPS - an integer value indicating the target frames-per-second
         renderering rate when rendering on the RMpipe toModify.

This routine is used to specify the desired frame rate when rendering on the RMpipe toModify. The caller provides an integer value, newFPS, that indicates the desired number of frames per second. A value of 30 will result in 30 frames per second being rendered, etc. A value of -1 will disable constant-rate rendering: OpenRM will not "watch the clock" if you specify a value of -1 frames per second as the desired target rate. The value for newFPS should be a positive integer. Note that not all values of newFPS make sense on all platforms for reasons related to how OpenGL is implemented on your machine.

Constant-rate rendering is really a misnomer : what the contstant-rate rendering capability in OpenRM really does is to use a high precision timer and sleep function to ensure that *no more than a given number of frames per second are rendered*. In this way, you can be assured that your application will not be rendering more than newFPS per second. If your application produces a heavy graphics load, the actual rendering rate may fall well short of newFPS frames per second. Rather than calling this capability "constant frame rate" rendering, it is more accurately called "bounded frame rate" rendering.

Future work in this area will result in the ability for the application to query the rendering "load" or "stress" values. This way, you'll be able to obtain a quantitative value that indicates how far "over budget" your rendering is, and take action accordingly. One remedial action will be for the application to use switch nodes and render lower-resolution models as a way to reduce graphics rendering load.

From the newFPS parameter, a value of milliseconds-per-frame is computed. When your application calls rmFrame() for the first time, OpenRM makes note of the current time. It then proceeds with rendering without delay, and then returns control to the application after rendering is complete. The second time your application calls rmFrame(), OpenRM will delay rendering so that the time taken by rendering during the previous frame along with the time taken by the application for processing inbetween frames does not exceed the occur before the milliseconds-per-frame amount of time has passed. In other words, the period of timing is from the start of rendering to the start of rendering.

The bounded-frame-rendering capability works on both Unix/Linux and Win32 platforms subject to caveats that are described in the OpenRM Programming Guide. Additional caveats not specific to a platform are also discussed in the OpenRM Progamming Guide.

Use the routine rmPipeGetFrameRate() to query the frames-per-second parameter of an RMpipe.

Returns RM_CHILL upon success, or RM_WHACKED upon failure.

librm library source file: rmpipe.c

     int rmPipeGetFrameRate (constRMpipe *toQuery)

     RMpipe *toQuery - a handle to an RMpipe (queried).

Use this routine to obtain the RMpipe's notion of how many frames per second it is supposed to render. For a more meaningful discussion of what the frames-per-second RMpipe attribute means, refer to the discussion for rmPipeSetFrameRate() as well as the OpenRM Programming Guide.

Returns either -1 or a positive integer on success, or zero on failure.

librm library source file: rmpipe.c

     int rmPipeGetFrameNumber (const RMpipe *toQuery)

     const RMpipe *toQuery - (input) a handle to an RMpipe.

Use this routine to obtain the RMpipe's notion of the current frame number. Upon success, a non-negative integer is returned. Upon failure, a value of -1 is returned.

The RMpipe's frame number is initialized to zero when the RMpipe is created with rmPipeNew(). Upon each call to rmFrame(), the the frame number is incremented by one. There is no mechanism for applications to set the frame number, or for applications to reset the frame number to zero.

librm library source file: rmpipe.c