void GrEllipseArc(int xc,int yc,int xa,int ya,int start,int end,int style,GrColor c)
{
int (*pnts)[2];
setup_ALLOC();
pnts = ALLOC(sizeof(int) * 2 * (GR_MAX_ELLIPSE_POINTS + 1));
if (pnts != NULL)
{
GrFillArg fval;
int npts = GrGenerateEllipseArc(xc,yc,xa,ya,start,end,pnts);
int close = FALSE;
switch(style) {
case GR_ARC_STYLE_CLOSE2:
pnts[npts][0] = xc;
pnts[npts][1] = yc;
npts++;
case GR_ARC_STYLE_CLOSE1:
close = TRUE;
break;
}
fval.color = c;
_GrDrawPolygon(npts,pnts,&_GrSolidFiller,fval,close);
FREE(pnts);
}
reset_ALLOC();
}
void GrPolyLine(int n,int pt[][2],GrColor c)
{
GrFillArg fval;
fval.color = c;
_GrDrawPolygon(n,pt,&_GrSolidFiller,fval,FALSE);
}
/**
* grx_draw_polyline:
* @n_points: the number of points in @points
* @points: (array length=n_points): an array of #GrxPoint
* @c: the color
*
* Draw a multi-segment line on the current context that connects each point in
* the @points array using the specified color.
*/
void grx_draw_polyline(int n,GrxPoint *pt,GrxColor c)
{
GrFillArg fval;
fval.color = c;
_GrDrawPolygon(n,pt,&_GrSolidFiller,fval,FALSE);
}
void _GrScanEllipse(int xc,int yc,int xa,int ya,GrFiller *f,GrFillArg c,int filled)
{
int x1,x2,y1,y2;
if(xa < 0) xa = (-xa);
if(ya < 0) ya = (-ya);
x1 = xc - xa;
y1 = yc - ya;
x2 = xc + xa;
y2 = yc + ya;
clip_ordbox(CURC,x1,y1,x2,y2);
mouse_block(CURC,x1,y1,x2,y2);
setup_ALLOC();
if((xa == 0) || (ya == 0)) (*f->line)(
(x1 + CURC->gc_xoffset),
(y1 + CURC->gc_yoffset),
(x2 - x1),
(y2 - y1),
c
);
else if((xa > MAXR) || (ya > MAXR)) { /* Bresenham would overflow !! */
int (*points)[2] = ALLOC(sizeof(int) * 2 * GR_MAX_ELLIPSE_POINTS);
if(points != NULL) {
int count = GrGenerateEllipse(xc,yc,xa,ya,points);
if(filled) _GrScanConvexPoly(count,points,f,c);
else _GrDrawPolygon(count,points,f,c,TRUE);
FREE(points);
}
}
else {
int *scans = ALLOC(sizeof(int) * (ya + 1));
int row = ya;
int col = 0;
if(scans != NULL) {
long yasq = umul32(ya,ya);
long xasq = umul32(xa,xa);
long xasq2 = xasq + xasq;
long yasq2 = yasq + yasq;
long xasq4 = xasq2 + xasq2;
long yasq4 = yasq2 + yasq2;
long error = (xasq2 * (row - 1) * row) +
(yasq2 * (1 - xasq)) +
xasq;
while((xasq * row) > (yasq * col)) {
if(error >= 0) {
scans[row] = col;
row--;
error -= xasq4 * row;
}
error += yasq2 * (3 + (col << 1));
col++;
}
error = (yasq2 * (col + 1) * col) +
(xasq2 * ((row * (row - 2)) + 1)) +
(yasq * (1 - xasq2));
while(row >= 0) {
scans[row] = col;
if(error <= 0) {
col++;
error += yasq4 * col;
}
row--;
error += xasq2 * (2 - (row << 1));
}
for(row = y1; row <= y2; row++) {
col = iabs(yc - row);
if(!filled && (col < ya)) {
x1 = xc - scans[col];
x2 = xc - scans[col + 1];
if(x1 < x2) x2--;
do {
clip_ordxrange_(CURC,x1,x2,break,CLIP_EMPTY_MACRO_ARG);
(*f->scan)(
(x1 + CURC->gc_xoffset),
(row + CURC->gc_yoffset),
(x2 - x1 + 1),
c
);
} while (0);
x1 = xc + scans[col + 1];
x2 = xc + scans[col];
if(x1 < x2) x1++;
}
else {
x1 = xc - scans[col];
x2 = xc + scans[col];
}
clip_ordxrange_(CURC,x1,x2,continue,CLIP_EMPTY_MACRO_ARG);
(*f->scan)(
(x1 + CURC->gc_xoffset),
(row + CURC->gc_yoffset),
(x2 - x1 + 1),
c
);
}
