struct psGfx *psOpen(char *fileName,
double userWidth, double userHeight, /* Dimension of image in user's units. */
double ptWidth, double ptHeight, /* Dimension of image in points. */
double ptMargin) /* Image margin in points. */
/* Open up a new postscript file. If ptHeight is 0, it will be
* calculated to keep pixels square. */
{
struct psGfx *ps;
/* Allocate structure and open file. */
AllocVar(ps);
ps->f = mustOpen(fileName, "w");
/* Save page dimensions and calculate scaling factors. */
ps->userWidth = userWidth;
ps->userHeight = userHeight;
ps->ptWidth = ptWidth;
ps->xScale = (ptWidth - 2*ptMargin)/userWidth;
if (ptHeight != 0.0)
{
ps->ptHeight = ptHeight;
ps->yScale = (ptHeight - 2*ptMargin) / userHeight;
}
else
{
ps->yScale = ps->xScale;
ptHeight = ps->ptHeight = userHeight * ps->yScale + 2*ptMargin;
}
/* 0.5, 0.5 is the center of the pixel in upper-left corner which corresponds to (0,0) */
ps->xOff = ptMargin;
ps->yOff = ptMargin;
ps->fontHeight = 10;
/* Cope with fact y coordinates are bottom to top rather
* than top to bottom. */
ps->yScale = -ps->yScale;
ps->yOff = ps->ptHeight - ps->yOff;
psWriteHeader(ps->f, ptWidth, ptHeight);
/* adding a gsave here fixes an old ghostview bug with cliprestore */
fprintf(ps->f, "gsave\n");
/* Set initial clipping rectangle. */
psClipRect(ps, 0, 0, ps->userWidth, ps->userHeight);
/* Set line width to a single pixel. */
psSetLineWidth(ps,1);
return ps;
}
void pscmSetClip(struct pscmGfx *pscm, int x, int y, int width, int height)
/* Set clipping rectangle. */
{
double x2 = x + width;
double y2 = y + height;
pscm->clipMinX = x;
pscm->clipMinY = y;
pscm->clipMaxX = x2; /* one beyond actual last pixel */
pscm->clipMaxY = y2;
/* adjust to pixel-centered coordinates */
x2 -= 1;
y2 -= 1;
double x1 = x;
double y1 = y;
/* pad a half-pixel all the way around the box */
x1 -= 0.5;
y1 -= 0.5;
x2 += 0.5;
y2 += 0.5;
psClipRect(pscm->ps, x1, y1, x2-x1, y2-y1);
}
