void
picture_rep::internal_copy_to (int x, int y, picture dest,
int x1, int y1, int x2, int y2)
{
for (int yy= y1; yy < y2; yy++)
for (int xx= x1; xx < x2; xx++)
dest->internal_set_pixel (x + xx, y + yy, internal_get_pixel (xx, yy));
}
color
picture_rep::internal_smooth_pixel (double x, double y) {
x -= 0.5;
y -= 0.5;
int x1= (int) floor (x);
int y1= (int) floor (y);
int x2= x1 + 1;
int y2= y1 + 1;
double ix1= x2 - x;
double ix2= x - x1;
double iy1= y2 - y;
double iy2= y - y1;
color cx1y1= internal_get_pixel (x1, y1);
color cx1y2= internal_get_pixel (x1, y2);
color cx2y1= internal_get_pixel (x2, y1);
color cx2y2= internal_get_pixel (x2, y2);
return mix (cx1y1, ix1*iy1, cx1y2, ix1*iy2,
cx2y1, ix2*iy1, cx2y2, ix2*iy2);
}
inline color get_pixel (int x, int y) {
return internal_get_pixel (x + get_origin_x (), y + get_origin_y ()); }
