int
gx_forward_fill_trapezoid(gx_device * dev,
const gs_fixed_edge * left,
const gs_fixed_edge * right,
fixed ybot, fixed ytop, bool swap_axes,
const gx_drawing_color * pdcolor,
gs_logical_operation_t lop)
{
gx_device_forward * const fdev = (gx_device_forward *)dev;
gx_device *tdev = fdev->target;
dev_proc_fill_trapezoid((*proc)) =
(tdev == 0 ? (tdev = dev, gx_default_fill_trapezoid) :
dev_proc(tdev, fill_trapezoid));
return proc(tdev, left, right, ybot, ytop, swap_axes, pdcolor, lop);
}
/* We should swap axes to get best accuracy, but we don't. */
int
gx_default_fill_triangle(gx_device * dev,
fixed px, fixed py, fixed ax, fixed ay, fixed bx, fixed by,
const gx_device_color * pdevc, gs_logical_operation_t lop)
{
fixed t;
fixed ym;
dev_proc_fill_trapezoid((*fill_trapezoid)) =
dev_proc(dev, fill_trapezoid);
gs_fixed_edge left, right;
int code;
/* Ensure ay >= 0, by >= 0. */
if (ay < 0)
px += ax, py += ay, bx -= ax, by -= ay, ax = -ax, ay = -ay;
if (by < 0)
px += bx, py += by, ax -= bx, ay -= by, bx = -bx, by = -by;
/* Ensure ay <= by. */
if (ay > by)
SWAP(ax, bx, t), SWAP(ay, by, t);
/*
* Make a special check for a flat bottom or top,
* which we can handle with a single call on fill_trapezoid.
*/
left.start.x = right.start.x = px;
left.start.y = right.start.y = py;
if (ay == 0) {
/* Flat top */
if (ax < 0)
left.start.x = px + ax;
else
right.start.x = px + ax;
left.end.x = right.end.x = px + bx;
left.end.y = right.end.y = py + by;
ym = py;
} else if (ay == by) {
/* Flat bottom */
if (ax < bx)
left.end.x = px + ax, right.end.x = px + bx;
else
left.end.x = px + bx, right.end.x = px + ax;
left.end.y = right.end.y = py + by;
ym = py;
} else {
ym = py + ay;
if (fixed_mult_quo(bx, ay, by) < ax) {
/* The 'b' line is to the left of the 'a' line. */
left.end.x = px + bx, left.end.y = py + by;
right.end.x = px + ax, right.end.y = py + ay;
code = (*fill_trapezoid) (dev, &left, &right, py, ym,
false, pdevc, lop);
right.start = right.end;
right.end = left.end;
} else {
/* The 'a' line is to the left of the 'b' line. */
left.end.x = px + ax, left.end.y = py + ay;
right.end.x = px + bx, right.end.y = py + by;
code = (*fill_trapezoid) (dev, &left, &right, py, ym,
false, pdevc, lop);
left.start = left.end;
left.end = right.end;
}
if (code < 0)
return code;
}
return (*fill_trapezoid) (dev, &left, &right, ym, right.end.y,
false, pdevc, lop);
}
/* We must be very careful to follow the center-of-pixel rule in all cases. */
int
gx_default_fill_parallelogram(gx_device * dev,
fixed px, fixed py, fixed ax, fixed ay, fixed bx, fixed by,
const gx_device_color * pdevc, gs_logical_operation_t lop)
{
fixed t;
fixed qx, qy, ym;
dev_proc_fill_trapezoid((*fill_trapezoid));
gs_fixed_edge left, right;
int code;
/* Make a special fast check for rectangles. */
if (PARALLELOGRAM_IS_RECT(ax, ay, bx, by)) {
gs_int_rect r;
INT_RECT_FROM_PARALLELOGRAM(&r, px, py, ax, ay, bx, by);
vd_rect(int2fixed(r.p.x), int2fixed(r.p.y), int2fixed(r.q.x), int2fixed(r.q.y),
1, (int)pdevc->colors.pure);
return gx_fill_rectangle_device_rop(r.p.x, r.p.y, r.q.x - r.p.x,
r.q.y - r.p.y, pdevc, dev, lop);
}
/*
* Not a rectangle. Ensure that the 'a' line is to the left of
* the 'b' line. Testing ax <= bx is neither sufficient nor
* necessary: in general, we need to compare the slopes.
*/
/* Ensure ay >= 0, by >= 0. */
if (ay < 0)
px += ax, py += ay, ax = -ax, ay = -ay;
if (by < 0)
px += bx, py += by, bx = -bx, by = -by;
qx = px + ax + bx;
if ((ax ^ bx) < 0) { /* In this case, the test ax <= bx is sufficient. */
if (ax > bx)
SWAP(ax, bx, t), SWAP(ay, by, t);
} else { /*
* Compare the slopes. We know that ay >= 0, by >= 0,
* and ax and bx have the same sign; the lines are in the
* correct order iff
* ay/ax >= by/bx, or
* ay*bx >= by*ax
* Eventually we can probably find a better way to test this,
* without using floating point.
*/
if ((double)ay * bx < (double)by * ax)
SWAP(ax, bx, t), SWAP(ay, by, t);
}
fill_trapezoid = dev_proc(dev, fill_trapezoid);
qy = py + ay + by;
left.start.x = right.start.x = px;
left.start.y = right.start.y = py;
left.end.x = px + ax;
left.end.y = py + ay;
right.end.x = px + bx;
right.end.y = py + by;
#define ROUNDED_SAME(p1, p2)\
(fixed_pixround(p1) == fixed_pixround(p2))
if (ay < by) {
if (!ROUNDED_SAME(py, left.end.y)) {
code = (*fill_trapezoid) (dev, &left, &right, py, left.end.y,
false, pdevc, lop);
if (code < 0)
return code;
}
left.start = left.end;
left.end.x = qx, left.end.y = qy;
ym = right.end.y;
if (!ROUNDED_SAME(left.start.y, ym)) {
code = (*fill_trapezoid) (dev, &left, &right, left.start.y, ym,
false, pdevc, lop);
if (code < 0)
return code;
}
right.start = right.end;
right.end.x = qx, right.end.y = qy;
} else {
if (!ROUNDED_SAME(py, right.end.y)) {
code = (*fill_trapezoid) (dev, &left, &right, py, right.end.y,
false, pdevc, lop);
if (code < 0)
return code;
}
right.start = right.end;
right.end.x = qx, right.end.y = qy;
ym = left.end.y;
if (!ROUNDED_SAME(right.start.y, ym)) {
code = (*fill_trapezoid) (dev, &left, &right, right.start.y, ym,
false, pdevc, lop);
if (code < 0)
return code;
}
left.start = left.end;
left.end.x = qx, left.end.y = qy;
}
if (!ROUNDED_SAME(ym, qy))
return (*fill_trapezoid) (dev, &left, &right, ym, qy,
false, pdevc, lop);
else
return 0;
#undef ROUNDED_SAME
}
