tei/MapLibreParticleLab
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Port scanline algorithm from _getCoveringTiles()

Browse Source 
fixes #22
This commit is contained in:
Konstantin Käfer
2014-03-04 14:50:17 +01:00
parent ed5e335da1
commit ba5070bf52
7 changed files with 133 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/map/transform.cpp
View File

@@ -271,33 +271,37 @@ double Transform::getAngle() const {
return angle;
}
void Transform::mapCornersToBox(uint32_t z, box& b) const {
box Transform::mapCornersToBox(uint32_t z) const {
const double ref_scale = pow(2, z);
// Keep the map as upright as possible.
double local_angle = angle;
if (local_angle >= M_PI_2) local_angle -= M_PI;
if (local_angle < -M_PI_2) local_angle += M_PI;
const double angle_sin = sin(-local_angle);
const double angle_cos = cos(-local_angle);
const double angle_sin = sin(-angle);
const double angle_cos = cos(-angle);
const double w_2 = width / 2;
const double h_2 = height / 2;
const double ss_1 = ref_scale / (scale * util::tileSize);
const double ss_2 = (scale * util::tileSize) / 2;
const double ss_0 = scale * util::tileSize;
const double ss_1 = ref_scale / ss_0;
const double ss_2 = ss_0 / 2.0;
// Calculate the corners of the map view. The resulting coordinates will be
// in fractional tile coordinates.
box b;
b.tl.x = ((-w_2) * angle_cos - (-h_2) * angle_sin + ss_2 - x) * ss_1;
b.tl.y = ((-w_2) * angle_sin + (-h_2) * angle_cos + ss_2 - y) * ss_1;
b.tr.x = ((+w_2) * angle_cos - (-h_2) * angle_sin + ss_2 - x) * ss_1;
b.tr.y = ((+w_2) * angle_sin + (-h_2) * angle_cos + ss_2 - y) * ss_1;
b.bl.x = ((-w_2) * angle_cos - (+h_2) * angle_sin + ss_2 - x) * ss_1;
b.bl.y = ((-w_2) * angle_sin + (+h_2) * angle_cos + ss_2 - y) * ss_1;
b.br.x = ((+w_2) * angle_cos - (+h_2) * angle_sin + ss_2 - x) * ss_1;
b.br.y = ((+w_2) * angle_sin + (+h_2) * angle_cos + ss_2 - y) * ss_1;
// Quick hack: use the entire non-rotated bounding box.
b.center.x = (ss_2 - x) * ss_1;
b.center.y = (ss_2 - y) * ss_1;
return b;
}