avfilter/vf_ciescope: switch to anti-aliased lines

This commit is contained in:
Paul B Mahol 2023-01-11 21:30:35 +01:00
parent 6b8adbfe03
commit e6b9191e92

View File

@ -1010,27 +1010,44 @@ static void draw_line(uint16_t *const pixels, int linesize,
int w, int h,
const uint16_t *const rgbcolor)
{
int dx = FFABS(x1 - x0), sx = x0 < x1 ? 1 : -1;
int dy = FFABS(y1 - y0), sy = y0 < y1 ? 1 : -1;
int err = (dx > dy ? dx : -dy) / 2, e2;
int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1, x2;
int dx = FFABS(x1-x0), dy = FFABS(y1-y0), err = dx * dx + dy * dy;
int e2 = err == 0 ? 1 : 0xffffff / (dx + dy);
dx *= e2;
dy *= e2;
err = dx - dy;
for (;;) {
pixels[y0 * linesize + x0 * 4 + 0] = rgbcolor[0];
pixels[y0 * linesize + x0 * 4 + 1] = rgbcolor[1];
pixels[y0 * linesize + x0 * 4 + 2] = rgbcolor[2];
pixels[y0 * linesize + x0 * 4 + 3] = rgbcolor[3];
if (x0 == x1 && y0 == y1)
break;
pixels[y0 * linesize + x0 * 4 + 0] = rgbcolor[0]-(FFABS(err - dx + dy) >> 8);
pixels[y0 * linesize + x0 * 4 + 1] = rgbcolor[1]-(FFABS(err - dx + dy) >> 8);
pixels[y0 * linesize + x0 * 4 + 2] = rgbcolor[2]-(FFABS(err - dx + dy) >> 8);
pixels[y0 * linesize + x0 * 4 + 3] = rgbcolor[3]-(FFABS(err - dx + dy) >> 8);
e2 = err;
if (e2 >-dx) {
x2 = x0;
if (2 * e2 >= -dx) {
if (x0 == x1)
break;
if (e2 + dy < 0xff0000) {
pixels[(y0 + sy) * linesize + x0 * 4 + 0] = rgbcolor[0]-(FFABS(e2 + dy) >> 8);
pixels[(y0 + sy) * linesize + x0 * 4 + 1] = rgbcolor[1]-(FFABS(e2 + dy) >> 8);
pixels[(y0 + sy) * linesize + x0 * 4 + 2] = rgbcolor[2]-(FFABS(e2 + dy) >> 8);
pixels[(y0 + sy) * linesize + x0 * 4 + 3] = rgbcolor[3]-(FFABS(e2 + dy) >> 8);
}
err -= dy;
x0 += sx;
}
if (e2 < dy) {
if (2 * e2 <= dy) {
if (y0 == y1)
break;
if (dx - e2 < 0xff0000) {
pixels[y0 * linesize + (x2 + sx) * 4 + 0] = rgbcolor[0]-(FFABS(dx - e2) >> 8);
pixels[y0 * linesize + (x2 + sx) * 4 + 1] = rgbcolor[1]-(FFABS(dx - e2) >> 8);
pixels[y0 * linesize + (x2 + sx) * 4 + 2] = rgbcolor[2]-(FFABS(dx - e2) >> 8);
pixels[y0 * linesize + (x2 + sx) * 4 + 3] = rgbcolor[3]-(FFABS(dx - e2) >> 8);
}
err += dx;
y0 += sy;
}