mirrors/foot
1
0
Fork 0
mirror of https://codeberg.org/dnkl/foot.git synced 2026-02-05 04:06:08 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

box-drawing: implement LIGHT diagonal lines using pixman

Browse source 
Use trapezoids to rasterize the diagonal lines.
This commit is contained in:
Daniel Eklöf 2021-05-05 15:03:30 +02:00
parent 19fa1b30b8
commit e05a510a7c
No known key found for this signature in database
GPG key ID: 5BBD4992C116573F
1 changed files with 52 additions and 30 deletions
Download patch file Download diff file Expand all files Collapse all files

82
box-drawing.c
View file

@ -1363,44 +1363,66 @@ draw_box_drawings_light_arc(wchar_t wc, struct buf *buf)
}
}
static void
draw_box_drawings_light_diagonal(struct buf *buf, double k, double c)
{
#define linear_equation(x) (k * (x) + c)
int num_samples = buf->width * 16;
for (int i = 0; i < num_samples; i++) {
double x = i / 16.;
int col = round(x);
int row = round(linear_equation(x));
if (row >= 0 && row < buf->height) {
size_t ofs = col / 8;
size_t bit_no = col % 8;
buf->data[row * buf->stride + ofs] |= 1 << bit_no;
}
}
#undef linear_equation
}
static void
draw_box_drawings_light_diagonal_upper_right_to_lower_left(struct buf *buf)
{
/* y = k * x + c */
double c = buf->height - 1;
double k = (0 - (buf->height - 1)) / (double)(buf->width - 1 - 0);
draw_box_drawings_light_diagonal(buf, k, c);
pixman_trapezoid_t trap = {
.top = pixman_int_to_fixed(0),
.bottom = pixman_int_to_fixed(buf->height),
.left = {
.p1 = {
.x = pixman_double_to_fixed(buf->width - thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(0),
},
.p2 = {
.x = pixman_double_to_fixed(0 - thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(buf->height),
},
},
.right = {
.p1 = {
.x = pixman_double_to_fixed(buf->width + thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(0),
},
.p2 = {
.x = pixman_double_to_fixed(0 + thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(buf->height),
},
},
};
pixman_rasterize_trapezoid(buf->pix, &trap, 0, 0);
}
static void
draw_box_drawings_light_diagonal_upper_left_to_lower_right(struct buf *buf)
{
/* y = k * x + c */
double c = 0;
double k = (buf->height - 1 - 0) / (double)(buf->width - 1 - 0);
draw_box_drawings_light_diagonal(buf, k, c);
pixman_trapezoid_t trap = {
.top = pixman_int_to_fixed(0),
.bottom = pixman_int_to_fixed(buf->height),
.left = {
.p1 = {
.x = pixman_double_to_fixed(0 - thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(0),
},
.p2 = {
.x = pixman_double_to_fixed(buf->width - thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(buf->height),
},
},
.right = {
.p1 = {
.x = pixman_double_to_fixed(0 + thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(0),
},
.p2 = {
.x = pixman_double_to_fixed(buf->width + thickness(LIGHT) / 2.),
.y = pixman_int_to_fixed(buf->height),
},
},
};
pixman_rasterize_trapezoid(buf->pix, &trap, 0, 0);
}
static void