void
fbSegment(DrawablePtr drawable, GCPtr gc,
int x1, int y1, int x2, int y2,
bool drawLast, int *dashOffset)
{
struct fbSegment data;
BoxRec box;
DBG(("%s (%d, %d), (%d, %d), drawLast?=%d\n",
__FUNCTION__, x1, y1, x2, y2, drawLast));
/* simple overestimate of line extents for clipping */
box.x1 = x1 - 1;
box.y1 = y1 - 1;
box.x2 = x2 + 1;
box.y2 = y2 + 1;
data.x1 = x1;
data.y1 = y1;
data.x2 = x2;
data.y2 = y2;
data.dashOffset = dashOffset;
data.drawLast = drawLast;
data.bres = fbSelectBres(drawable, gc);
fbDrawableRunUnclipped(drawable, gc, &box, _fbSegment, &data);
}
void
fbSegment1(DrawablePtr drawable, GCPtr gc, const BoxRec *b,
int x1, int y1, int x2, int y2,
bool drawLast, int *dashOffset)
{
struct fbSegment data;
DBG(("%s (%d, %d), (%d, %d), drawLast?=%d\n",
__FUNCTION__, x1, y1, x2, y2, drawLast));
data.x1 = x1;
data.y1 = y1;
data.x2 = x2;
data.y2 = y2;
data.dashOffset = dashOffset;
data.drawLast = drawLast;
data.bres = fbSelectBres(drawable, gc);
_fbSegment(drawable, gc, b, &data);
}
void
fbSegment(DrawablePtr pDrawable,
GCPtr pGC,
int x1, int y1, int x2, int y2, Bool drawLast, int *dashOffset)
{
FbBres *bres;
RegionPtr pClip = fbGetCompositeClip(pGC);
BoxPtr pBox;
int nBox;
int adx; /* abs values of dx and dy */
int ady;
int signdx; /* sign of dx and dy */
int signdy;
int e, e1, e2, e3; /* bresenham error and increments */
int len; /* length of segment */
int axis; /* major axis */
int octant;
int dashoff;
int doff;
unsigned int bias = miGetZeroLineBias(pDrawable->pScreen);
unsigned int oc1; /* outcode of point 1 */
unsigned int oc2; /* outcode of point 2 */
nBox = RegionNumRects(pClip);
pBox = RegionRects(pClip);
bres = fbSelectBres(pDrawable, pGC);
CalcLineDeltas(x1, y1, x2, y2, adx, ady, signdx, signdy, 1, 1, octant);
if (adx > ady) {
axis = X_AXIS;
e1 = ady << 1;
e2 = e1 - (adx << 1);
e = e1 - adx;
len = adx;
}
else {
axis = Y_AXIS;
e1 = adx << 1;
e2 = e1 - (ady << 1);
e = e1 - ady;
SetYMajorOctant(octant);
len = ady;
}
FIXUP_ERROR(e, octant, bias);
/*
* Adjust error terms to compare against zero
*/
e3 = e2 - e1;
e = e - e1;
/* we have bresenham parameters and two points.
all we have to do now is clip and draw.
*/
if (drawLast)
len++;
dashoff = *dashOffset;
*dashOffset = dashoff + len;
while (nBox--) {
oc1 = 0;
oc2 = 0;
OUTCODES(oc1, x1, y1, pBox);
OUTCODES(oc2, x2, y2, pBox);
if ((oc1 | oc2) == 0) {
(*bres) (pDrawable, pGC, dashoff,
signdx, signdy, axis, x1, y1, e, e1, e3, len);
break;
}
else if (oc1 & oc2) {
pBox++;
}
else {
int new_x1 = x1, new_y1 = y1, new_x2 = x2, new_y2 = y2;
int clip1 = 0, clip2 = 0;
int clipdx, clipdy;
int err;
if (miZeroClipLine(pBox->x1, pBox->y1, pBox->x2 - 1,
pBox->y2 - 1,
&new_x1, &new_y1, &new_x2, &new_y2,
adx, ady, &clip1, &clip2,
octant, bias, oc1, oc2) == -1) {
pBox++;
continue;
}
if (axis == X_AXIS)
len = abs(new_x2 - new_x1);
else
len = abs(new_y2 - new_y1);
if (clip2 != 0 || drawLast)
len++;
if (len) {
/* unwind bresenham error term to first point */
doff = dashoff;
err = e;
if (clip1) {
clipdx = abs(new_x1 - x1);
clipdy = abs(new_y1 - y1);
if (axis == X_AXIS) {
doff += clipdx;
err += e3 * clipdy + e1 * clipdx;
}
else {
doff += clipdy;
err += e3 * clipdx + e1 * clipdy;
}
}
(*bres) (pDrawable, pGC, doff,
signdx, signdy, axis, new_x1, new_y1,
err, e1, e3, len);
}
pBox++;
}
} /* while (nBox--) */
}