/*
* pixman_composite_trapezoids()
*
* All the trapezoids are conceptually rendered to an infinitely big image.
* The (0, 0) coordinates of this image are then aligned with the (x, y)
* coordinates of the source image, and then both images are aligned with
* the (x, y) coordinates of the destination. Then, in principle, compositing
* of these three images takes place across the entire destination.
*
* FIXME: However, there is currently a bug, where we restrict this compositing
* to the bounding box of the trapezoids. This is incorrect for operators such
* as SRC and IN where blank source pixels do have an effect on the destination.
*/
PIXMAN_EXPORT void
pixman_composite_trapezoids (pixman_op_t op,
pixman_image_t * src,
pixman_image_t * dst,
pixman_format_code_t mask_format,
int x_src,
int y_src,
int x_dst,
int y_dst,
int n_traps,
const pixman_trapezoid_t * traps)
{
int i;
if (n_traps <= 0)
return;
_pixman_image_validate (src);
_pixman_image_validate (dst);
if (op == PIXMAN_OP_ADD &&
(src->common.flags & FAST_PATH_IS_OPAQUE) &&
(mask_format == dst->common.extended_format_code) &&
!(dst->common.have_clip_region))
{
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
if (!pixman_trapezoid_valid (trap))
continue;
pixman_rasterize_trapezoid (dst, trap, x_dst, y_dst);
}
}
else
{
pixman_image_t *tmp;
pixman_box32_t box;
box.x1 = INT32_MAX;
box.y1 = INT32_MAX;
box.x2 = INT32_MIN;
box.y2 = INT32_MIN;
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
int y1, y2;
if (!pixman_trapezoid_valid (trap))
continue;
y1 = pixman_fixed_to_int (trap->top);
if (y1 < box.y1)
box.y1 = y1;
y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
if (y2 > box.y2)
box.y2 = y2;
#define EXTEND_MIN(x) \
if (pixman_fixed_to_int ((x)) < box.x1) \
box.x1 = pixman_fixed_to_int ((x));
#define EXTEND_MAX(x) \
if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box.x2) \
box.x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
#define EXTEND(x) \
EXTEND_MIN(x); \
EXTEND_MAX(x);
EXTEND(trap->left.p1.x);
EXTEND(trap->left.p2.x);
EXTEND(trap->right.p1.x);
EXTEND(trap->right.p2.x);
}
if (box.x1 >= box.x2 || box.y1 >= box.y2)
return;
tmp = pixman_image_create_bits (
mask_format, box.x2 - box.x1, box.y2 - box.y1, NULL, -1);
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
if (!pixman_trapezoid_valid (trap))
continue;
pixman_rasterize_trapezoid (tmp, trap, - box.x1, - box.y1);
}
pixman_image_composite (op, src, tmp, dst,
x_src + box.x1, y_src + box.y1,
0, 0,
x_dst + box.x1, y_dst + box.y1,
box.x2 - box.x1, box.y2 - box.y1);
pixman_image_unref (tmp);
}
}
static pixman_bool_t
get_trap_extents (pixman_op_t op, pixman_image_t *dest,
const pixman_trapezoid_t *traps, int n_traps,
pixman_box32_t *box)
{
int i;
/* When the operator is such that a zero source has an
* effect on the underlying image, we have to
* composite across the entire destination
*/
if (!zero_src_has_no_effect [op])
{
box->x1 = 0;
box->y1 = 0;
box->x2 = dest->bits.width;
box->y2 = dest->bits.height;
return TRUE;
}
box->x1 = INT32_MAX;
box->y1 = INT32_MAX;
box->x2 = INT32_MIN;
box->y2 = INT32_MIN;
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
int y1, y2;
if (!pixman_trapezoid_valid (trap))
continue;
y1 = pixman_fixed_to_int (trap->top);
if (y1 < box->y1)
box->y1 = y1;
y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
if (y2 > box->y2)
box->y2 = y2;
#define EXTEND_MIN(x) \
if (pixman_fixed_to_int ((x)) < box->x1) \
box->x1 = pixman_fixed_to_int ((x));
#define EXTEND_MAX(x) \
if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box->x2) \
box->x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
#define EXTEND(x) \
EXTEND_MIN(x); \
EXTEND_MAX(x);
EXTEND(trap->left.p1.x);
EXTEND(trap->left.p2.x);
EXTEND(trap->right.p1.x);
EXTEND(trap->right.p2.x);
}
if (box->x1 >= box->x2 || box->y1 >= box->y2)
return FALSE;
return TRUE;
}
