--- MITgcm_contrib/darwinview/src/darwin.c	2007/07/11 14:34:55	1.1
+++ MITgcm_contrib/darwinview/src/darwin.c	2007/07/12 18:30:19	1.2
@@ -18,146 +18,182 @@
 
 float data[MAX][MAX*MAX], mxval, mnval, jet[MAX][MAX];
 float globalmx=0, globalmn=100;
-int win[MAX], ilev=1, howmany, count=0, glo=0, usr=0, anim=0;
+int win[MAX], ilev=1, howmany, count=0, glo=0, usr=0, anim=0, logscale=0;
 char initfns[MAX][MAX], fns[MAX][MAX][MAX];
 
-void menu(int value){
- int i;
+void menu(int value){           // called when menu is opened on right click
 
  switch( value ){
-  case 1: usr=glo=0;         // unset glo & usr, sets local max/min
-          glutPostRedisplay();
+  case 1: usr=glo=0;            // unset glo & usr, sets local max/min
+          glutPostRedisplay();  // recall display func with new values 
           break;
-  case 2: glo=1;         // enables global max/min  
-          usr=0;         // unsets usr 
-          mxval=globalmx;     // sets max to globalmx
-          mnval=globalmn;     // sets min to globalmn
-          glutPostRedisplay(); // display with new values
+  case 2: glo=1;                // enables global max/min  
+          usr=0;                // unsets usr 
+          mxval=globalmx;       // sets max to globalmx
+          mnval=globalmn;       // sets min to globalmn
+          glutPostRedisplay();  // recall display func with new values
           break;
-  case 3: usr=1;             // switch to user-set max/min 
-          glo=0;             // unset glo
-          printf( "Max=" );  scanf( "%f", &mxval );  // prompt for new max/min
-          printf( "Min=" );  scanf( "%f", &mnval );
-          glutPostRedisplay(); // display with new values
+  case 3: usr=1;                // switch to user-set max/min 
+          glo=0;                // unset glo
+          printf( "Max=" );  scanf( "%f", &mxval );  // prompt user for new max
+          printf( "Min=" );  scanf( "%f", &mnval );  // prompt user for new min
+          glutPostRedisplay();                       // recall display func with new values
+          break;
+  case 4: logscale=(logscale+1)%2;  // switch log scale on/off
+          glutPostRedisplay();
           break;
  }
 }
 
-void display(void){
+void display(void){                 // called on glutPostRedisplay
  int i, j, ioff, q; 
- float r, g, b, num, k, y;
+ float r, g, b, k, y;
+ double num, logmx, logmn;
  char str[MAX]; 
 
- for( q=0; q<setsx*setsy; q++ ){    //runs display func for each window
-  glutSetWindow( win[q] ); 
-  glClear( GL_COLOR_BUFFER_BIT );  // background to black
-  if( glo || usr )
-   readarray( data[q], fns[q][count], ilev ); 
-  else                           
-   local( q, count, ilev );        
-
-  ioff=0;                    // ioff will count thru both i&j b/c data is 1D
-  for( j=0; j<NY; j++ ){
-   for( i=0; i<NX; i++ ){
-    r=g=b=0;                 // set color values to black
-    if( data[q][ioff]==0 );     // if data=0, values stay black
+ for( q=0; q<setsx*setsy; q++ ){    // runs display func for each subwindow
+  glutSetWindow( win[q] );          // sets which subwindow to display to
+  glClear( GL_COLOR_BUFFER_BIT );   // background to black
+  if( glo || usr )                  // if global or user-set max/min 
+   readarray( data[q], fns[q][count], ilev );  // read new array w/o calculating local max/min
+  else                              // if local max/min is set 
+   local( q, count, ilev );         // read new array and calculate local max/min
+
+  if( logscale ){
+   if( usr ){
+    logmx=(double)mxval;
+    logmn=(double)mnval;
+   }
+   else{
+    logmx=log10( mxval );
+    logmn=log10( mnval );
+   }
+  }
+
+  ioff=0;                           // ioff will count both i&j b/c data is 1D
+  for( j=0; j<NY; j++ ){            // cycles through y values
+   for( i=0; i<NX; i++ ){           // cycles through x values
+    r=g=b=0;                        // set color values to black
+    if( data[q][ioff]==0 );           // if data=0, values stay black
     else{
-     if( data[q][ioff]<mnval )  num=0;  // if data is less than min, =min
+     if( logscale ){
+      num=(double)data[q][ioff];
+      num=log10( num );
+      if( num<logmn ) num=0;
+      if( num>logmx ) num=63;
+      else
+       num=63*( num-logmn )/( logmx-logmn );
+     }
      else{
-      if( data[q][ioff]>mxval )  num=63; // if data is more than max, =max
-      else 
-       num=63*( data[q][ioff]-mnval )/( mxval-mnval );  //scale num from 0-63
+      if( data[q][ioff]<mnval )  num=0;   // if data is less than min, =min
+      else
+       if( data[q][ioff]>mxval )  num=63; // if data is more than max, =max
+       else
+        num=63*( data[q][ioff]-mnval )/( mxval-mnval );  // scale num from 0-63 (not defined for 64)
      }
-     r=jet[(int)num][0];  // set red val
-     g=jet[(int)num][1];  // set green val
-     b=jet[(int)num][2];  // set blue val  
+     r=jet[(int)num][0];            // set red val
+     g=jet[(int)num][1];            // set green val
+     b=jet[(int)num][2];            // set blue val  
     }
- 
-    glColor3f( r, g, b );      // put r, g, b into effect
-    glRectf( i, j, i+1, j+1 ); // draws a square for data value 
+
+    glColor3f( r, g, b );           // put r, g, b into effect
+    glRectf( i, j, i+1, j+1 );      // draws a square for data value 
     ioff++;                    
    } 
   } 
-  glColor3f( 1, 1, 1 );       // set color to white
-  glRectf( NX, 0, NX+1, NY+1 );    // draws a border
-  glRectf( 0, NY, NX, NY+1 );        // draws a border  
-  for( i=0; i<64; i++ ){       //draws color bar    
-   glColor3f( jet[i][0], jet[i][1], jet[i][2]);         //sets color
-   k=(float)i;                // turns i into a float
-   y=(float)NY/64;            // sets height of rectangles
-   glRectf( NX+10, y*k, NX+20, (k+1)*y );    // draws rectangle 
+  glColor3f( 1, 1, 1 );             // set color to white
+  glRectf( NX, 0, NX+1, NY+1 );     // draws a border
+  glRectf( 0, NY, NX, NY+1 );       // draws a border  
+  for( i=0; i<64; i++ ){            // draws color bar    
+   glColor3f( jet[i][0], jet[i][1], jet[i][2]);         // sets color
+   k=(float)i;                      // turns i into a float
+   y=(float)NY/64;                  // sets height of rectangles
+   glRectf( NX+10, y*k, NX+20, (k+1)*y );               // draws rectangle 
   } 
-  glColor3f( 1, 1, 1 );     // color to white
+  glColor3f( 1, 1, 1 );             // color to white
 
-  sprintf( str, "%.2e", mxval );      // labels color bar with max val
+  if( logscale )
+   sprintf( str, "%.2f", logmx );
+  else
+   sprintf( str, "%.2e", mxval );    // labels color bar with max val
   bitmap( str, NX+2, NY-1 );
   
-  sprintf( str, "%.2e", mnval );      // labels color bar with min val
+  if( logscale )
+   sprintf( str, "%.2f", logmn );
+  else
+   sprintf( str, "%.2e", mnval );    // labels color bar with min val
   bitmap( str, NX+2, 1 );
 
-  sprintf( str, "Level %d", ilev );   // labels current level 
-  bitmap( str, 1, NY+3);
+  sprintf( str, "Level %d", ilev ); // labels current level 
+  bitmap( str, 1, NY+3 );
 
-  if( glo )                   // labels how max/min have been set
-   sprintf( str, "Global" );  // if glo is set, display Global
+  sprintf( str, "Time %d", count+1 ); // labels current time 
+  bitmap( str, 50, NY+3 );
+
+  if( glo )                         // labels how max/min have been set
+   sprintf( str, "Global" );        // if glo is set, display Global
   if( usr ) 
-   sprintf( str, "User-set" );  // if usr is set, display User-set
+   sprintf( str, "User-set" );      // if usr is set, display User-set
   if( !usr && !glo ) 
-   sprintf( str, "Local" );    // else display Local 
-  bitmap( str, NX+12, NY+3);
+   sprintf( str, "Local" );         // else display Local 
+  bitmap( str, NX+12, NY+3 );
   
-  if( anim ){                  // tell user if autoplay is on
+  if( anim ){                       // tell user if autoplay is on
    sprintf( str, "Autoplay" );
-   bitmap( str, NX-15, NY+3 );
+   bitmap( str, NX-25, NY+3 );
+  }
+
+  if( logscale ){
+   sprintf( str, "Log Scale" );     // tell user if log scale is on
+   bitmap( str, NX-25, NY+10 ); 
   }
 
-  bitmap( fns[q][count], 1, NY+6 );  // labels current file
+  bitmap( fns[q][count], 1, NY+10 ); // labels current file
  
-  glutSwapBuffers();  
+  glutSwapBuffers();                // double buffering set to animate smoothly
   glFlush(); 
  }
 }
 
-void bitmap( char str[], int x, int y ){
+void bitmap( char str[], int x, int y ){  // called to display text onscreen
  int i;
 
- glRasterPos2f( x, y );
- for( i=0; i<strlen( str ); i++) 
+ glRasterPos2f( x, y );             // set position of text
+ for( i=0; i<strlen( str ); i++)    // display each character of str
   glutBitmapCharacter( GLUT_BITMAP_HELVETICA_12, str[i] );
 }
 
-void key( unsigned char key, int x, int y ){   //called on key press
+void key( unsigned char key, int x, int y ){   // called on key press
  int i;
  
  switch(key){
-  case 'q':   exit(0);     //quits on 'q'
+  case 'q':   exit(0);              // quits on 'q'
               break;
-  case 'r':   count=0; 
-              ilev=1;
+  case 'r':   count=0;              // resets back to first time    
+              ilev=1;               // and first level
               glutPostRedisplay();            
               break;
-  case 'a':   anim++;            // switches autoplay off/on  
-              anim=anim%2;       // when a is pressed repeatedly 
+  case 'a':   anim=(anim+1)%2;      // turns anim on/off
               glutPostRedisplay();            
               break;
  } 
 }
 
-void TimerFunction( int value ){
+void TimerFunction( int value ){    // called when anim is set and arrow key is pressed
  int i;
 
- switch(value){          // increments in the correct direction
+ switch(value){                     // increments in the correct direction
   case DOWN : if( ilev<MAXNZ ) 
-               ilev++;    // if down arrow pressed, moves down levels       
+               ilev++;              // if down arrow pressed, move down a level      
               break;
   case UP   : if( ilev>1 )    
-               ilev--;    // if up arrow is pressed, moves up levels
+               ilev--;              // if up arrow is pressed, move up a level
               break;
   case LEFT : if( count>0 )      
-               count--;   // if left arrow is pressed, moves back in time
+               count--;             // if left arrow is pressed, move back one time step 
               break;
   case RIGHT: if( count<howmany-1 )
-               count++;   // if right arrow is pressed, moves forward in time
+               count++;             // if right arrow is pressed, moves forward one time step 
               break;
  }
  
@@ -165,16 +201,16 @@
 
  if (anim )
   switch( value ){    
-   case DOWN : if( ilev==MAXNZ ) ilev=1;   // sets limit that you can go down
+   case DOWN : if( ilev==MAXNZ ) ilev=1;                   // if end reached, restart 
                glutTimerFunc( 100, TimerFunction, value ); // recalls itself
                break;
-   case UP   : if( ilev==1 ) ilev=MAXNZ;   // sets limit that you can go up
+   case UP   : if( ilev==1 ) ilev=MAXNZ;                   // if end reached, restart 
                glutTimerFunc( 100, TimerFunction, value ); // recalls itself 
                break;
-   case LEFT : if( count==0 ) count=howmany-1;// sets limit that you can go left
+   case LEFT : if( count==0 ) count=howmany-1;             // if end reached, restart 
                glutTimerFunc( 100, TimerFunction, value ); // recalls itself
                break;
-   case RIGHT: if( count==howmany-1 ) count=0; //sets limit that you can go right
+   case RIGHT: if( count==howmany-1 ) count=0;             // if end reached, restart                 
                glutTimerFunc( 100, TimerFunction, value ); // recalls itself
                break;
   } 
@@ -183,15 +219,15 @@
 void specialkey( int key, int x, int y ){
  int i;
 
- if( anim )     // if animation is set, call the timer function
-  glutTimerFunc( 100, TimerFunction, key);
+ if( anim )                       // if animation is set, call the timer function
+  glutTimerFunc( 100, TimerFunction, key);             // to scroll automatically
 
  switch(key){
-  case DOWN   :  if( ilev<MAXNZ ) // if you haven't reached the bottom
-                  ilev++;         // keep going down
+  case DOWN   :  if( ilev<MAXNZ )      // if you haven't reached the bottom
+                  ilev++;              // keep going down
                  break;
-  case UP     :  if( ilev>1 )     // if you haven't reached the top
-                  ilev--;         // keep going up
+  case UP     :  if( ilev>1 )          // if you haven't reached the top
+                  ilev--;              // keep going up
                  break;
   case RIGHT  :  if( count<howmany-1 ) // if you haven't reached the last file
                   count++;             // keep going right
@@ -203,64 +239,66 @@
  glutPostRedisplay();            
 }
 
-void global(){  // calculates the max/min for the total data set
+void global(){                         // calculates the max/min for the total data set
  FILE* fp;
  int h, i, j;
- for( h=0; h<setsx*setsy; h++) // cycles through each data set
-  for( i=0; i<howmany; i++ )   // cycles through each time 
-   for( j=0; j<MAXNZ; j++ ){   // cycles through each level for each file
-    local( h, i, j );         // calculates local/max/min for specific data set 
+ for( h=0; h<setsx*setsy; h++)         // cycles through each window 
+  for( i=0; i<howmany; i++ )           // cycles through each time 
+   for( j=0; j<MAXNZ; j++ ){           // cycles through each level for each file
+    local( h, i, j );                  // calculates local max/min for specific data set 
     if( mxval > globalmx ) globalmx = mxval;   // sets highest value to globalmx
     if( mnval < globalmn ) globalmn = mnval;   // sets lowest value to globalmn
    }
 }
 
-void local( int i, int time, int lev ){  // calculates local max/min
+void local( int i, int time, int lev ){        // calculates local max/min
  int j;
  
  mxval=0;  
  mnval=100;
- readarray( data[i], fns[i][time], lev ); // read new array of data
+ readarray( data[i], fns[i][time], lev );      // read new array of data
  for( j=0; j<NX*NY; j++ ){
-  if( data[i][j] > mxval )  mxval=data[i][j]; // set largest val to mxval 
-  if( data[i][j] < mnval )  mnval=data[i][j]; // set smallest val to mnval 
+  if( data[i][j] > mxval ) 
+   mxval=data[i][j];                           // set largest val to mxval 
+  if( data[i][j] < mnval && data[i][j] > 0 ) 
+   mnval=data[i][j];                           // set smallest positive val to mnval 
  }
 }
 
-void readnames( char filename[] ){  // reads in list of filenames 
+void readnames( char filename[] ){             // reads in list of filenames 
  FILE* fp;
  int i=0, j=0;
  
- fp=fopen( filename, "r" );    // opens list
- while( !feof(fp) ){           // reads until the end of the file 
-  fscanf( fp, "%s", initfns[i] );   // places filename into an array of strings 
-  i++;                         // counts how many filenames there are  
+ fp=fopen( filename, "r" );                    // opens list of filenames
+ while( !feof(fp) ){                           // reads until the end of the file 
+  fscanf( fp, "%s", initfns[i] );              // places filename into an array of strings 
+  i++;                                         // counts how many filenames there are  
  } 
- fclose( fp );                 // close file
- howmany=i-1;                 
+ fclose( fp );                                 // close file
+ howmany=i-1;                                  // saves number of initial filenames 
  
- for(i=0; i<howmany; i++){
-  fp=fopen( initfns[i], "r" );
+ for(i=0; i<howmany; i++){                     // goes through each read-in filename 
+  fp=fopen( initfns[i], "r" );                 // opens each filename  
   j=0;
-  while( !feof(fp) ){
-   fscanf( fp, "%s", fns[i][j]);
+  while( !feof(fp) ){                          // reads in filenames from each filename 
+   fscanf( fp, "%s", fns[i][j]);               
    j++;
   }
-  fclose(fp);
+  fclose(fp);                                  // close file
  }
- howmany=j-1;
+ howmany=j-1;                                  // saves number of data filenames  
 }
 
-void readjet(){  //reads in color scale values
+void readjet(){               //reads in color scale values
  
  FILE* fp;
  int i, j; 
   
  fp=fopen( "jet.dat", "r" );  // opens file containing values
- for( i=0; i<64; i++ )       // reads in 64 sets of r, g, b values
+ for( i=0; i<64; i++ )        // reads in 64 sets of r, g, b values
   for( j=0; j<3; j++ )
    fscanf( fp, "%f", &jet[i][j] );
- fclose( fp );              // closes file
+ fclose( fp );                // closes file
 }
 
 
@@ -268,11 +306,14 @@
  FILE *fp;
  int i;
  
- fp=fopen( filename, "r" );  // opens the file containing data
- fseek( fp, (il-1)*NX*NY*4, SEEK_SET ); // seeks to the correct level using ilev
+ fp=fopen( filename, "r" );                  // opens the file containing data
+ fseek( fp, (il-1)*NX*NY*4, SEEK_SET );      // seeks to the correct place using ilev
  fread( arr, sizeof( arr[0] ), NX*NY, fp );  // reads in data to fill one level 
- fclose( fp );                         // close file
- //do_byteswap_f32( arr, NX*NY );          // swaps the binary data 
+ fclose( fp );                               // close file
+ for( i=0; i<NX*NY; i++ )                    
+  if( arr[i] < 0 )  arr[i] = pow(10, -20);   // sets negative values to 10^-20 
+
+ //do_byteswap_f32( arr, NX*NY );            // switches endian 
 }
 
 void do_byteswap_f32( float arr[], int nel ) // switches endian
@@ -290,62 +331,57 @@
    }
 }
 
-void parentfunc(){
- glClear( GL_COLOR_BUFFER_BIT );  // background to black
- glutSwapBuffers();
- glFlush();
-}
-
 int main( int argc, char *argv[] ){
  int i, tmpx, tmpy, winx, winy, parent;
  char filename[MAX];
 
- sscanf(argv[1], "%dx%d", &winx, &winy);
- winy-=20;
+ sscanf(argv[1], "%dx%d", &winx, &winy);  // reads screen resolution from command line
+ winy-=60;  winx-=20;                     // adjusts resolution so edges won't get cut off             
  
  printf( "Please enter x, y and z dimensions.\n" );   
- scanf( "%d %d %d", &NX, &NY, &MAXNZ );   //user-set NX, NY, NZ
+ scanf( "%d %d %d", &NX, &NY, &MAXNZ );           // prompts user for NX, NY, NZ
  printf( "Please enter filename.\n" );
- scanf( "%s", filename );   //filename contains names of data files 
+ scanf( "%s", filename );                         // prompts user for initial filenames 
  printf( "Please enter dimensions of data sets.\n" );
- scanf( "%dx%d", &setsx, &setsy);
+ scanf( "%dx%d", &setsx, &setsy);                 // prompts user for dimensions of subwindows
 
- readjet();                        // stores color values
- readnames( filename );   // gets list of filenames to read from
- global();                         // calculates max and min for all data
-
- glutInit( &argc, argv );
- glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); 
- glutInitWindowSize( winx, winy ); 
- glutInitWindowPosition( 10, 10 );
- parent=glutCreateWindow( WINDOW );
+ readjet();                               // stores color values
+ readnames( filename );                   // gets list of filenames to read from
+ global();                                // calculates max and min for all data
+
+ glutInit( &argc, argv );                 
+ glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );   // sets rgb mode and double buffering
+ glutInitWindowSize( winx, winy );                // parent window will cover screen
+ glutInitWindowPosition( 10, 10 );                // location of parent window
+ parent=glutCreateWindow( WINDOW );               // creates parent window
 
- glClearColor( 0, 0, 0, 0 );    // sets clear color to black
- gluOrtho2D( 0, winx , winy, 0 );  // sets how data is mapped to window
+ glClearColor( 0, 0, 0, 0 );                      // sets clear color to black
+ gluOrtho2D( 0, winx , winy, 0 );                 // sets(0,0) as top left corner 
  glutDisplayFunc( display );
- glutKeyboardFunc( key );   // called on key press
- glutSpecialFunc( specialkey );  // called on special key press (arrow keys)
+ glutKeyboardFunc( key );                         // called on key press
+ glutSpecialFunc( specialkey );                   // called on special key press (arrow keys)
 
  for( i=0; i<setsx*setsy; i++ ){
-  tmpx = (i%setsx)*(winx/setsx);
-  tmpy = (i/setsx)*(winy/setsy); 
+  tmpx = (i%setsx)*(winx/setsx);                  // x coordinate of top left corner of subwindow
+  tmpy = (i/setsx)*(winy/setsy);                  // y coordinate of top left corner of subwindow 
 
-  local( i, count, ilev );      // sets curr data array, finds local max/min 
+  local( i, count, ilev );                        // reads curr data array, finds local max/min 
 
-  win[i]=glutCreateSubWindow( parent, tmpx, tmpy, winx/setsx, winy/setsy ); 
-  gluOrtho2D( 0, NX+35, 0, NY+15 );  // sets how data is mapped to window
-  glutDisplayFunc( display );
-  glutKeyboardFunc( key );   // called on key press
-  glutSpecialFunc( specialkey );  // called on special key press (arrow keys)
-
-  glutCreateMenu( menu );   // adds a menu
-   glutAddMenuEntry( "Local Color Scale", 1 );   // describes choices
-   glutAddMenuEntry( "Global Color Scale", 2 );
-   glutAddMenuEntry( "User-Set Color Scale", 3 );
-  glutAttachMenu( GLUT_RIGHT_BUTTON );  // menu called on right click
+  win[i]=glutCreateSubWindow( parent, tmpx, tmpy, winx/setsx, winy/setsy ); // creates subwindow
+  gluOrtho2D( 0, NX+35, 0, NY+15 );               // sets how data is mapped to subwindow
+  glutDisplayFunc( display );                     // sets display func for subwindow
+  glutKeyboardFunc( key );                        // called on key press
+  glutSpecialFunc( specialkey );                  // called on special key press (arrow keys)
+
+  glutCreateMenu( menu );                         // adds a menu
+   glutAddMenuEntry( "Local Color Scale", 1 );    // adds a menu entry 
+   glutAddMenuEntry( "Global Color Scale", 2 );   // adds a menu entry 
+   glutAddMenuEntry( "User-Set Color Scale", 3 ); // adds a menu entry 
+   glutAddMenuEntry( "Log Scale (on/off)", 4 );   // adds a menu entry 
+  glutAttachMenu( GLUT_RIGHT_BUTTON );            // menu called on right click
  }
 
- glutMainLoop();
+ glutMainLoop();                                  // begin processing events
  return 0;
 }