ref: d1cebf608b05e45b148108ac6c16ae94f6862097
dir: /sys/src/cmd/postscript/common/bbox.c/
/* * * Boundingbox code for PostScript translators. The boundingbox for each page * is accumulated in bbox - the one for the whole document goes in docbbox. A * call to writebbox() puts out an appropriate comment, updates docbbox, and * resets bbox for the next page. The assumption made at the end of writebbox() * is that we're really printing the current page only if output is now going * to stdout - a valid assumption for all supplied translators. Needs the math * library. * */ #include <stdio.h> #include <ctype.h> #include <sys/types.h> #include <fcntl.h> #include <math.h> #include "comments.h" /* PostScript file structuring comments */ #include "gen.h" /* a few general purpose definitions */ #include "ext.h" /* external variable declarations */ typedef struct bbox { int set; double llx, lly; double urx, ury; } Bbox; Bbox bbox = {FALSE, 0.0, 0.0, 0.0, 0.0}; Bbox docbbox = {FALSE, 0.0, 0.0, 0.0, 0.0}; double ctm[6] = {1.0, 0.0, 0.0, 1.0, 0.0, 0.0}; double matrix1[6], matrix2[6]; /*****************************************************************************/ cover(x, y) double x, y; { /* * * Adds point (x, y) to bbox. Coordinates are in user space - the transformation * to default coordinates happens in writebbox(). * */ if ( bbox.set == FALSE ) { bbox.llx = bbox.urx = x; bbox.lly = bbox.ury = y; bbox.set = TRUE; } else { if ( x < bbox.llx ) bbox.llx = x; if ( y < bbox.lly ) bbox.lly = y; if ( x > bbox.urx ) bbox.urx = x; if ( y > bbox.ury ) bbox.ury = y; } /* End else */ } /* End of cover */ /*****************************************************************************/ writebbox(fp, keyword, slop) FILE *fp; /* the comment is written here */ char *keyword; /* the boundingbox comment string */ int slop; /* expand (or contract?) the box a bit */ { Bbox ubbox; /* user space bounding box */ double x, y; /* * * Transforms the numbers in the bbox[] using ctm[], adjusts the corners a bit * (depending on slop) and then writes comment. If *keyword is BoundingBox use * whatever's been saved in docbbox, otherwise assume the comment is just for * the current page. * */ if ( strcmp(keyword, BOUNDINGBOX) == 0 ) bbox = docbbox; if ( bbox.set == TRUE ) { ubbox = bbox; bbox.set = FALSE; /* so cover() works properly */ x = ctm[0] * ubbox.llx + ctm[2] * ubbox.lly + ctm[4]; y = ctm[1] * ubbox.llx + ctm[3] * ubbox.lly + ctm[5]; cover(x, y); x = ctm[0] * ubbox.llx + ctm[2] * ubbox.ury + ctm[4]; y = ctm[1] * ubbox.llx + ctm[3] * ubbox.ury + ctm[5]; cover(x, y); x = ctm[0] * ubbox.urx + ctm[2] * ubbox.ury + ctm[4]; y = ctm[1] * ubbox.urx + ctm[3] * ubbox.ury + ctm[5]; cover(x, y); x = ctm[0] * ubbox.urx + ctm[2] * ubbox.lly + ctm[4]; y = ctm[1] * ubbox.urx + ctm[3] * ubbox.lly + ctm[5]; cover(x, y); bbox.llx -= slop + 0.5; bbox.lly -= slop + 0.5; bbox.urx += slop + 0.5; bbox.ury += slop + 0.5; fprintf(fp, "%s %d %d %d %d\n", keyword, (int)bbox.llx, (int)bbox.lly,(int)bbox.urx, (int)bbox.ury); bbox = ubbox; } /* End if */ resetbbox((fp == stdout) ? TRUE : FALSE); } /* End of writebbox */ /*****************************************************************************/ resetbbox(output) int output; { /* * * Adds bbox to docbbox and resets bbox for the next page. Only update docbbox * if we really did output on the last page. * */ if ( docbbox.set == TRUE ) { cover(docbbox.llx, docbbox.lly); cover(docbbox.urx, docbbox.ury); } /* End if */ if ( output == TRUE ) { docbbox = bbox; docbbox.set = TRUE; } /* End if */ bbox.set = FALSE; } /* End of resetbbox */ /*****************************************************************************/ scale(sx, sy) double sx, sy; { /* * * Scales the default matrix. * */ matrix1[0] = sx; matrix1[1] = 0; matrix1[2] = 0; matrix1[3] = sy; matrix1[4] = 0; matrix1[5] = 0; concat(matrix1); } /* End of scale */ /*****************************************************************************/ translate(tx, ty) double tx, ty; { /* * * Translates the default matrix. * */ matrix1[0] = 1.0; matrix1[1] = 0.0; matrix1[2] = 0.0; matrix1[3] = 1.0; matrix1[4] = tx; matrix1[5] = ty; concat(matrix1); } /* End of translate */ /*****************************************************************************/ rotate(angle) double angle; { /* * * Rotates by angle degrees. * */ angle *= PI / 180; matrix1[0] = matrix1[3] = cos(angle); matrix1[1] = sin(angle); matrix1[2] = -matrix1[1]; matrix1[4] = 0.0; matrix1[5] = 0.0; concat(matrix1); } /* End of rotate */ /*****************************************************************************/ concat(m1) double m1[]; { double m2[6]; /* * * Replaces the ctm[] by the result of the matrix multiplication m1[] x ctm[]. * */ m2[0] = ctm[0]; m2[1] = ctm[1]; m2[2] = ctm[2]; m2[3] = ctm[3]; m2[4] = ctm[4]; m2[5] = ctm[5]; ctm[0] = m1[0] * m2[0] + m1[1] * m2[2]; ctm[1] = m1[0] * m2[1] + m1[1] * m2[3]; ctm[2] = m1[2] * m2[0] + m1[3] * m2[2]; ctm[3] = m1[2] * m2[1] + m1[3] * m2[3]; ctm[4] = m1[4] * m2[0] + m1[5] * m2[2] + m2[4]; ctm[5] = m1[4] * m2[1] + m1[5] * m2[3] + m2[5]; } /* End of concat */ /*****************************************************************************/