/* Last edited on 2007-01-08 03:28:07 by stolfi
 * Mased on {wplot.cpp} by Margarete Domingues, date: 1/Aug/2006
 * Converted to C by J. Stolfi and A. Gomide, 07/jan/2007
 */

/* We need to define _GNU_SOURCE to get {asprintf} and {NAN}. */
#define _GNU_SOURCE
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <math.h>

#include "mwplot.h"

struct mwplot_t 
  {
    FILE *pp;  /* Pipe to {stdin} of the {gnuplot} process. */

    /* These {gnuplot} options apply to subsequent plot commands: */
    char *setTerminalCmds;
    char *fileExtension;   /* If not NULL, the current terminal type needs "set output". */
    char *setPaletteCmds;  
    char *setPlotStyleCmds;
    char *splotCommand;     /* The {splot} command of {gnuplot}, with some options. */
    int splotNeedsXY;       /* TRUE iff the current plot style needs X and Y data besides Z */
    char *xLabel;   /* Label for the X axis. */
    char *yLabel;   /* Label for the Y axis. */
    char *zLabel;   /* Label for the Z axis. */

    /* Ranges for {plot} or {splot} (NaN if autoscale): */
    double xMin, xMax; 
    double yMin, yMax;
    double zMin, zMax;
  };

/* INTERNAL PROTOTYPES */

void mwplot_write_set_range_cmd(FILE *pp, char *axis, double vMin, double vMax);
  /* Sends to {gnuplot} the command "set {axis}range [{vMin}:{vMax}]".
    If {vMin} or {vMax} is NAN, omits it from the "set range" command. */

void mwplot_write_set_axis_label_cmd(FILE *pp, char *axis, char *txt);
  /* Sends to {gnuplot} the command "set {axis}label \"{txt}\"",
    or "unset {axis}label" if {txt} is NULL. */

/* EXTERNAL IMPLEMENTATIONS */

mwplot_t *mwplot_start_gnuplot(int debug)
  { 
    /* Create the plotter object {wp}: */
    mwplot_t *wp = malloc(sizeof(mwplot_t));
    assert(wp != NULL);
    
    /* Initialize fields of {wp} with sensible defaults: */
    mwplot_set_terminal(wp, /*x11*/ 0);
    mwplot_set_palette(wp, /*blue--red*/ 20);
    mwplot_set_bivariate_plot_style(wp, /*surface*/ 0);
    mwplot_set_axis_labels(wp, "X", "Y", "Z");
    mwplot_set_ranges(wp, NAN, NAN, NAN, NAN, NAN, NAN);
    
    /* Start {gnuplot} and set up a pipe {wp->pp} to it: */
    char *execCommand;
    if (debug)
      { execCommand = "cat > mwplot.plt"; }
    else
      { execCommand = "gnuplot -geometry '800x600' -persist >& /dev/null"; }
    wp->pp = popen(execCommand, "w");
    if (wp->pp == NULL)
      { fprintf(stderr, "failed starting gnuplot"); 
        exit(-1);
      }
      
    return wp;
  }

void mwplot_stop_gnuplot(mwplot_t *wp)
  {
    if (wp->pp != NULL) { pclose(wp->pp); wp->pp = NULL; }
    free(wp);
  }

void mwplot_set_terminal(mwplot_t *wp, int terminalKind)
  {
    wp->setTerminalCmds = NULL;
    wp->fileExtension = NULL;
    switch(terminalKind)
      {
        case 0:
          wp->setTerminalCmds = 
            "set terminal x11 0\n";
          break;

        case 10: /*eps */
          wp->setTerminalCmds = 
            "set terminal postscript eps enhanced  \"Times-Roman\" 12\n";
          wp->fileExtension = "eps";
          break;

        case 11: /*eps */
          wp->setTerminalCmds = 
            "set terminal postscript eps color enhanced  \"Times-Roman\" 12\n";
          wp->fileExtension = "eps";
          break;

        case 101:
          wp->setTerminalCmds = 
            "set terminal png medium "
            "size 600,600 "
            "xffffff x000000 "
            "x202020 x404040 x606060 "
            "x808080 xA0A0A0 xC0C0C0 xE0E0E0\n";
          wp->fileExtension = "png";
          break;

        case 111:
          wp->setTerminalCmds = 
            "set terminal png "
            "font arial 14 "
            "size 600,600\n";
          wp->fileExtension = "png";
          break;

        case 200:
          wp->setTerminalCmds = 
            "set terminal png medium"
            " size 600 , 600\n";
          wp->fileExtension = "png";
          break;
          
        default:
          fprintf(stderr, "invalid terminal kind = %d\n", terminalKind); 
          exit(-1);
      }
  }

void mwplot_set_palette(mwplot_t *wp, int paletteCode)
  {
    wp->setPaletteCmds = NULL;
    switch(paletteCode)
      {
        case 10: /*  Field palette: dark-red to yellow: */
          wp->setPaletteCmds = 
            "set palette defined("
            " 0.000 \"yellow\","
            " 0.500 \"dark-red\","
            " 1.000 \"red\")\n";
          break;

        case 15: /* Field palette: dark-red to yellow: */
          wp->setPaletteCmds = 
            "set palette defined ("
            " 0.000 \"dark-red\","
            " 0.300 \"red\","
            " 0.600 \"orange\","
            " 1.000 \"yellow\")\n";
          break;

        case 20: /* Field palette: dark-blue, blue, yellow, dark red, red: */
          wp->setPaletteCmds = 
            "set palette defined ("
            "-1.000 \"dark-blue\","
            "-0.500 \"blue\","
            " 0.000 \"yellow\","
            " 0.500 \"dark-red\","
            " 1.000 \"red\")\n";
          break;

        case 30: /* Field palette: dark-blue, blue, grey, yellow, grey dark red, red: */
          wp->setPaletteCmds = 
            "set palette defined ("
            "-1.000 \"dark-blue\","
            "-0.500 \"blue\","
            "-0.001 \"light-grey\","
            " 0.000 \"yellow\","
            " 0.001 \"light-grey\","
            " 0.500 \"dark-red\","
            " 1.000 \"red\")\n";
          break;

        case 100:  /* Palette for the grid points: */
          wp->setPaletteCmds = 
            "set palette defined ("
            "-1 'light-grey',"
            " 0 'light-grey',"
            " 0 'blue',"
            " 1 'blue',"
            " 2 'magenta',"
            " 3 'light-green',"
            " 4 'dark-green',"
            " 5 'yellow',"
            " 6 'orange',"
            " 7 'light-red',"
            " 8 'dark-red') \n";
          break;

        default:
          fprintf(stderr, "invalid palette kind = %d\n", paletteCode);
          break;
      }
  }

void mwplot_set_bivariate_plot_style(mwplot_t *wp, int splotStyle)
  {
    /* Set {wp->splotCommand} and {wp->splotNeedsXY}: */
    switch(splotStyle)
      {
        case 0:  /* 3D graph, painted surface, hidden parts removed. */
          wp->splotCommand = "splot '-'\n";
          wp->splotNeedsXY = 1;
          wp->setPlotStyleCmds = 
            "set size square\n"
            "unset key\n"
            "set pm3d\n"
            "set grid\n"
            "set border\n"
            "set hidden3d\n"
            "unset surface\n";
          break;

        case 10: /* 3D graph, painted surface, hidden parts visible. */
          wp->splotCommand = "splot '-'\n";
          wp->splotNeedsXY = 1;
          wp->setPlotStyleCmds = 
            "set size square\n"
            "unset key\n"
            "set pm3d\n"
            "set grid\n"
            "set border\n"
            "unset hidden3d\n"
            "unset surface\n";
          break;

        case 20: /* 3D graph, wire mesh. */
          wp->splotCommand = "splot '-' w line\n";
          wp->splotNeedsXY = 1;
          wp->setPlotStyleCmds = 
            "set size square\n"
            "unset key\n"
            "unset pm3d\n"
            "unset grid\n"
            "set border\n"
            "unset hidden3d\n"
            "set surface\n";
          break;

        case 100: /* 2D image of grid. */
          wp->splotCommand = "splot '-' matrix with points ps 1 pt 5 palette\n";
          wp->splotNeedsXY = 0;
          wp->setPlotStyleCmds = 
            "set size square\n"
            "unset key\n"
            "unset pm3d\n"
            "unset grid\n"
            "unset border\n"
            "set ticscale 0 0\n"
            "set pm3d map\n";
          break;

        default:
          fprintf(stderr, "invalid splot style = %d\n", splotStyle);
          break;
      }
  }

void mwplot_set_axis_labels(mwplot_t *wp, char *xLabel, char *yLabel, char *zLabel)
  { 
    wp->xLabel = xLabel;
    wp->yLabel = yLabel;
    wp->zLabel = zLabel;
  }

void mwplot_set_ranges
  ( mwplot_t *wp, 
    double xMin, double xMax, 
    double yMin, double yMax,
    double zMin, double zMax
  )
  {
    wp->xMin = xMin;
    wp->xMax = xMax;
    wp->yMin = yMin;
    wp->yMax = yMax;
    wp->zMin = zMin;
    wp->zMax = zMax;
  }

void mwplot_plot_array
  ( mwplot_t *wp,
    char *fileName,
    int nx, 
    int ny, 
    double dx, 
    double dy,
    double **A, 
    char *title
  )
  {
    fputs(wp->setTerminalCmds, wp->pp);

    if (wp->fileExtension != NULL)
      { if (fileName == NULL)
          { fprintf(stderr, "current terminal type requires a file name\n");
            exit(-1);
          }
        fprintf(wp->pp, "set output \"%s.%s\"\n", fileName, wp->fileExtension);
      }

    fprintf(wp->pp, "set title \"%s\"\n", title);

    fputs(wp->setPaletteCmds, wp->pp);
    fputs(wp->setPlotStyleCmds,wp->pp);

    mwplot_write_set_axis_label_cmd(wp->pp, "x", wp->xLabel);
    mwplot_write_set_axis_label_cmd(wp->pp, "y", wp->yLabel);
    mwplot_write_set_axis_label_cmd(wp->pp, "z", wp->zLabel);

    mwplot_write_set_range_cmd(wp->pp, "x",  wp->xMin, wp->xMax);
    mwplot_write_set_range_cmd(wp->pp, "y",  wp->yMin, wp->yMax);
    mwplot_write_set_range_cmd(wp->pp, "z",  wp->zMin, wp->zMax);
    mwplot_write_set_range_cmd(wp->pp, "cb", wp->zMin, wp->zMax);

    fputs(wp->splotCommand, wp->pp);

    /* Output the data to be visualized: */
    int i, j;
    for (i = 0; i < nx; i++)
      { for (j = 0; j < ny; j++)
          { if (wp->splotNeedsXY) 
              { fprintf(wp->pp, "%f\t%f\t%g\n", i*dx, j*dy, A[i][j]); }
            else
              { fprintf(wp->pp, "%3.0f ", A[i][j]); } /*for the grid */
          }
        fputc('\n', wp->pp);
      }
    fputs("e\n", wp->pp);
    fflush(wp->pp);
  }

/* INTERNAL IMPLEMENTATIONS */

void mwplot_write_set_range_cmd(FILE *pp, char *axis, double vMin, double vMax)
  {
    fprintf(pp, "set %srange [", axis);
    if (! isnan(vMin)) { fprintf(pp, "%g", vMin); }
    fprintf(pp, ":");
    if (! isnan(vMax)) { fprintf(pp, "%g", vMax); }
    fprintf(pp, "]\n");
  }

void mwplot_write_set_axis_label_cmd(FILE *pp, char *axis, char *txt)
  {
    if (txt == NULL)
      { fprintf(pp, "unset %slabel\n", axis); }
    else
      { fprintf(pp, "set %slabel \"%s\"\n", axis, txt); }
  }