lib/curses/overlay.c

   1 /****************************************************************/
   2 /* Overlay() and overwrite() functions of the PCcurses package  */
   3 /*                                                              */
   4 /****************************************************************/
   5 /* This version of curses is based on ncurses, a curses version */
   6 /* Originally written by Pavel Curtis at Cornell University.    */
   7 /* I have made substantial changes to make it run on IBM PC's,  */
   8 /* And therefore consider myself free to make it public domain. */
   9 /*              Bjorn Larsson (...mcvax!enea!infovax!bl)        */
  10 /****************************************************************/
  11 /* 1.0: Release:                                        870515  */
  12 /****************************************************************/
  13 /* Modified to run under the MINIX operating system by Don Cope */
  14 /* These changes are also released into the public domain.      */
  15 /*                                                      900906  */
  16 /****************************************************************/
  17
  18 #include <curses.h>
  19 #include "curspriv.h"
  20
  21 /****************************************************************/
  22 /* Overlay() overwrites 'win1' upon 'win2', with origins alig-  */
  23 /* Ned. Overlay is transparent; blanks from 'win1' are not      */
  24 /* Copied to 'win2'.                                            */
  25 /****************************************************************/
  26 void overlay(win1, win2)
  27 WINDOW *win1, *win2;
  28 {
  29   int *minchng;
  30   int *maxchng;
  31   int *w1ptr;
  32   int *w2ptr;
  33   int attrs;
  34   int col;
  35   int line;
  36   int last_line;
  37   int last_col;
  38
  39   last_col = min(win1->_maxx, win2->_maxx);
  40   last_line = min(win1->_maxy, win2->_maxy);
  41   attrs = win2->_attrs & ATR_MSK;
  42   minchng = win2->_minchng;
  43   maxchng = win2->_maxchng;
  44
  45   for (line = 0; line <= last_line; line++) {
  46         register short fc, lc = 0;
  47         w1ptr = win1->_line[line];
  48         w2ptr = win2->_line[line];
  49         fc = _NO_CHANGE;
  50         for (col = 0; col <= last_col; col++) {
  51                 if ((*w1ptr & CHR_MSK) != ' ') {
  52                         *w2ptr = (*w1ptr & CHR_MSK) | attrs;
  53                         if (fc == _NO_CHANGE) fc = col;
  54                         lc = col;
  55                 }
  56                 w1ptr++;
  57                 w2ptr++;
  58         }
  59
  60         if (*minchng == _NO_CHANGE) {
  61                 *minchng = fc;
  62                 *maxchng = lc;
  63         } else if (fc != _NO_CHANGE) {
  64                 if (fc < *minchng) *minchng = fc;
  65                 if (lc > *maxchng) *maxchng = lc;
  66         }
  67         minchng++;
  68         maxchng++;
  69   }                             /* for */
  70 }                               /* overlay */
  71
  72 /****************************************************************/
  73 /* Overwrite() overwrites 'win1' upon 'win2', with origins      */
  74 /* Aligned. Overwrite is non-transparent; blanks from 'win1'    */
  75 /* Are copied to 'win2'.                                        */
  76 /****************************************************************/
  77 void overwrite(win1, win2)
  78 WINDOW *win1, *win2;
  79 {
  80   int *minchng;
  81   int *maxchng;
  82   int *w1ptr;
  83   int *w2ptr;
  84   int attrs;
  85   int col;
  86   int line;
  87   int last_line;
  88   int last_col;
  89
  90   last_col = min(win1->_maxx, win2->_maxx);
  91   last_line = min(win1->_maxy, win2->_maxy);
  92   attrs = win2->_attrs & ATR_MSK;
  93   minchng = win2->_minchng;
  94   maxchng = win2->_maxchng;
  95
  96   for (line = 0; line <= last_line; line++) {
  97         register short fc, lc = 0;
  98
  99         w1ptr = win1->_line[line];
 100         w2ptr = win2->_line[line];
 101         fc = _NO_CHANGE;
 102
 103         for (col = 0; col <= last_col; col++) {
 104                 if ((*w1ptr & CHR_MSK) != (*w2ptr & CHR_MSK)) {
 105                         *w2ptr = (*w1ptr & CHR_MSK) | attrs;
 106
 107                         if (fc == _NO_CHANGE) fc = col;
 108                         lc = col;
 109                 }
 110                 w1ptr++;
 111                 w2ptr++;
 112         }                       /* for */
 113
 114         if (*minchng == _NO_CHANGE) {
 115                 *minchng = fc;
 116                 *maxchng = lc;
 117         } else if (fc != _NO_CHANGE) {
 118                 if (fc < *minchng) *minchng = fc;
 119                 if (lc > *maxchng) *maxchng = lc;
 120         }
 121         minchng++;
 122         maxchng++;
 123   }
 124 }