prj/tech/libsrc/dev2d/genmono.c

   1 /*
   2  * $Source: x:/prj/tech/libsrc/dev2d/RCS/genmono.c $
   3  * $Revision: 1.3 $
   4  * $Author: KEVIN $
   5  * $Date: 1996/07/03 13:58:47 $
   6  *
   7  * Routines for clipping monochrome bitmaps to a rectangle.
   8  *
   9  * This file is part of the dev2d library.
  10  *
  11  */
  12
  13 #include <clip.h>
  14 #include <grd.h>
  15 #include <bmftype.h>
  16
  17 void gen_mono_bitmap (grs_bitmap *bm, int x, int y, int code, gdubm_func *ubm_func)
  18 {
  19    int extra;
  20    grs_bitmap bm_save = *bm;
  21
  22    if (code & CLIP_LEFT) {             /* off left edge */
  23       extra = grd_clip.left - x;
  24       bm->w -= extra;
  25       extra += bm->align;
  26       bm->align = extra&7;
  27       bm->bits += extra>>3;
  28       x = grd_clip.left;
  29    }
  30    if (code & CLIP_RIGHT) {            /* off right edge */
  31       bm->w = grd_clip.right - x;
  32    }
  33    if (bm->w<=0) goto punt;
  34
  35    if (code & CLIP_TOP) {             /* off top */
  36       extra = grd_clip.top - y;
  37       bm->h -= extra;
  38       bm->bits += bm->row*extra;
  39       y = grd_clip.top;
  40    }
  41    if (code & CLIP_BOT) {      /* off bottom */
  42       bm->h = grd_clip.bot - y;
  43    }
  44    if (bm->h>0)
  45       ubm_func(bm, x, y);
  46
  47 punt:
  48    *bm = bm_save;
  49 }