/* * SUNBUFF   A SIMULINK unbuffer block with overlap * *           Syntax:  [sys, x0] = sunbuff(t,x,u,flag,BufferOverlap,OutputIndex,sampleTime) * * Rick Spada  Jan 28, 1994 * Gary Levenson July 24, 1994 - modified to include overlap * * Copyright (c) 1994-96 by The MathWorks, Inc. * All Rights Reserved * $Revision: 1.1 $  $Date: 1996/04/01 19:05:53 $ */#define S_FUNCTION_NAME sunbuff#ifdef MATLAB_MEX_FILE#include <stdio.h>    /* needed for declaration of sprintf */#include "mex.h"      /* needed for declaration of mexErrMsgTxt */#endif/* * need to include simstruc.h for the definition of the SimStruct and * its associated macro definitions. */#include "simstruc.h"/* * Defines for easy access of the input parameters */#define NUM_ARGS        3#define BUFFER_OVERLAP  ssGetArg(S,0)#define OUTPUT_INDEX    ssGetArg(S,1)#define SAMPLE_TIME     ssGetArg(S,2)/* * mdlInitializeSizes - called to initialize the sizes array stored in *                      the SimStruct.  The sizes array defines the *                      characteristics (number of inputs, outputs, *                      states, etc.) of the S-Function. */static void mdlInitializeSizes(S)    SimStruct *S;{    /*     * Set-up size information.     */         if (ssGetNumArgs(S) == NUM_ARGS) {            if ((mxGetN(SAMPLE_TIME)*mxGetM(SAMPLE_TIME) != 1) &&              (mxGetN(SAMPLE_TIME)*mxGetM(SAMPLE_TIME) != 2)) {#ifdef MATLAB_MEX_FILE            mexErrMsgTxt("The sample time must be a scalar or a vector of length 2");#endif        }        if ((mxGetN(BUFFER_OVERLAP) != 1) || (mxGetM(BUFFER_OVERLAP) != 1)) {#ifdef MATLAB_MEX_FILE            mexErrMsgTxt("The buffer overlap must be a scalar");#endif        }                ssSetNumContStates(    S, 0);        ssSetNumDiscStates(    S, 0);        ssSetNumInputs(        S, -1);        ssSetNumOutputs(       S, 1);        ssSetDirectFeedThrough(S, 0);        ssSetNumInputArgs(     S, 3);        ssSetNumSampleTimes(   S, 1);        ssSetNumRWork(         S, -1);        ssSetNumIWork(         S, 2);        ssSetNumPWork(         S, 0);  }  else {#ifdef MATLAB_MEX_FILE        char err_msg[256];        sprintf(err_msg, "Wrong number of input arguments passed to S-function MEX-file.\n"                "%d input arguments were passed in when expecting %d input arguments.\n", ssGetNumArgs(S) + 4, NUM_ARGS + 4);        mexErrMsgTxt(err_msg);#endif   }}    /* * mdlInitializeSampleTimes - initializes the array of sample times stored in *                            the SimStruct associated with this S-Function. */static void mdlInitializeSampleTimes(S)    SimStruct *S;{    double sampleTime, offsetTime;     /*     * Note, blocks that are continuous in nature should have a single     * sample time of 0.0.     */    sampleTime = mxGetPr(SAMPLE_TIME)[0];    if ((mxGetN(SAMPLE_TIME) * mxGetM(SAMPLE_TIME)) == 2)        offsetTime = mxGetPr(SAMPLE_TIME)[1];    else        offsetTime = 0.;        ssSetSampleTimeEvent(S, 0, sampleTime);    ssSetOffsetTimeEvent(S, 0, offsetTime);}/* * mdlInitializeConditions - initializes the states for the S-Function */static void mdlInitializeConditions(x0, S)    double *x0;    SimStruct *S;{    double *buffer      = ssGetRWork(S);    int  *bufIndex      = ssGetIWork(S);     int *bufOutputIndex = ssGetIWork(S)+ 1;    int i, bufSize, bufOverlap;        /*      * Initialize the buffer to all zeros, we could allow this to     * be an additional paramter.     */        bufSize = ssGetNumInputs(S);    for (i = 0; i < bufSize; i++)        *buffer++ = 0.;    /*     * Initialize the current buffer position, buffer start, and output index     */        bufOverlap          = mxGetPr(BUFFER_OVERLAP)[0];        *bufOutputIndex     = mxGetPr(OUTPUT_INDEX)[0];    *bufIndex           = 0;        /*      * Some defensive programing     */         if (ssGetNumInputs(S) != -1) {        if ((*bufOutputIndex) < 0) {#ifdef MATLAB_MEX_FILE             char err_msg[256];             sprintf(err_msg,"Invalid Output Index specfied.\n"                    "Output Index must be a positive integer\n");             mexErrMsgTxt(err_msg);#endif    }       else if ( bufOverlap < 0 ) {#ifdef MATLAB_MEX_FILE            mexErrMsgTxt("Invalid Overlap specfied - Overlap should be a positive integer\n");#endif    }      else if ((*bufOutputIndex) > (bufSize - bufOverlap) ) { #ifdef MATLAB_MEX_FILE        mexErrMsgTxt("Error: Output Index exceeds buffer frame \n");      #endif      }     }}/* * mdlOutputs - computes the outputs of the S-Function */static void mdlOutputs(y, x, u, S, tid)    double *y, *x, *u;    SimStruct *S;    int tid;{    if (ssIsSampleHitEvent(S, 0, 0)) {        double *buffer          = ssGetRWork(S);        int *bufIndex           = ssGetIWork(S);        int *bufOutputIndex     = ssGetIWork(S) + 1;        int bufSize             = ssGetNumInputs(S);        int bufOverlap = mxGetPr(BUFFER_OVERLAP)[0];    /*       * bufIndex being zero is our queue to reload the buffer         */     if ((*bufIndex) == 0) {     int i;                  /*       * acquire the buffer data       */     buffer = ssGetRWork(S);         for (i = 0; i < bufSize; i++) {             *buffer++  = *u++;              *bufIndex %= bufSize;       }   }               /*       * now output the overlap frame when the buffer is full                  */     buffer = ssGetRWork(S) + (*bufOutputIndex)++;   *y = *buffer;           if (++(*bufIndex) == bufSize - bufOverlap) {        *bufIndex = 0;          *bufOutputIndex = mxGetPr(OUTPUT_INDEX)[0]; }                           }}/* * mdlUpdate - computes the discrete states of the S-Function */static void mdlUpdate(x, u, S, tid)    double *x, *u;    SimStruct *S;    int tid;{}/* * mdlDerivatives - computes the derivatives of the S-Function */static void mdlDerivatives(dx, x, u, S, tid)    double *dx, *x, *u;    SimStruct *S;    int tid;{}/* * mdlTerminate - called at termination of model execution. */static void mdlTerminate(S)    SimStruct *S;{}#ifdef  MATLAB_MEX_FILE    /* Is this file being compiled as a MEX-file? */#include "simulink.c"   /* MEX-File interface mechanism */#else#include "cg_sfun.h"    /* Code generation registration function */#endif