sij/mapnik
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Handle straight lines specially.

Browse source 
Add comment about coordinate systems.
This commit is contained in:
Hermann Kraus 2010-08-11 02:26:14 +00:00
parent 635562ee08
commit a88ab24a72
1 changed files with 51 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

82
src/metawriter.cpp
View file

@ -165,60 +165,80 @@ void metawriter_json_stream::add_text(placement const& p,
CoordTransform const& t,
metawriter_properties const& properties)
{
/* Note:
Map coordinate system (and starting_{x,y}) starts in upper left corner
and grows towards lower right corner.
Font + placement vertex coordinate system starts in lower left corner
and grows towards upper right corner.
Therefore y direction is different. Keep this in mind while doing calculations.
The y value returned by vertex() is always the baseline.
Lowest y = baseline of bottom line
Hightest y = baseline of top line
*/
// if (p.placements.size()) std::cout << p.info.get_string() << "\n";
for (unsigned n = 0; n < p.placements.size(); n++) {
placement_element & current_placement = const_cast<placement_element &>(p.placements[n]);
bool inside = false;
bool straight = true;
int c; double x, y, angle;
for (int i = 0; i < current_placement.num_nodes(); ++i) {
current_placement.rewind();
int cx = current_placement.starting_x;
int cy = current_placement.starting_y;
int c; double x, y, angle;
current_placement.vertex(&c, &x, &y, &angle);
if (x+cx >= 0 && x+cx < width_ && y+cy >= 0 && y+cy < height_) {
inside = true;
break;
}
if (x+cx >= 0 && x+cx < width_ && y+cy >= 0 && y+cy < height_) inside = true;
if (angle > 0.001 || angle < -0.001) straight = false;
if (inside && !straight) break;
}
if (!inside) continue;
write_feature_header("MultiPolygon");
*f_ << "[";
current_placement.rewind();
int c = ' ';
if (straight) {
//Reduce number of polygons
double minx = INT_MAX, miny = INT_MAX, maxx = INT_MIN, maxy = INT_MIN;
for (int i = 0; i < current_placement.num_nodes(); ++i) {
current_placement.vertex(&c, &x, &y, &angle);
font_face_set::dimension_t ci = face->character_dimensions(c);
if (x < minx) minx = x;
if (x+ci.width > maxx) maxx = x+ci.width;
if (y+ci.height+ci.ymin > maxy) maxy = y+ci.height+ci.ymin;
if (y+ci.ymin < miny) miny = y+ci.ymin;
// std::cout << (char) c << " height:" << ci.height << " ymin:" << ci.ymin << " y:" << y << " miny:"<< miny << " maxy:"<< maxy <<"\n";
}
add_box(box2d<double>(current_placement.starting_x+minx,
current_placement.starting_y-miny,
current_placement.starting_x+maxx,
current_placement.starting_y-maxy), feature, t, properties);
continue;
}
write_feature_header("MultiPolygon");
*f_ << "[";
c = ' ';
for (int i = 0; i < current_placement.num_nodes(); ++i) {
if (c != ' ') {
*f_ << ",";
}
double x, y, angle;
current_placement.vertex(&c, &x, &y, &angle);
if (c == ' ') continue;
font_face_set::dimension_t ci = face->character_dimensions(c);
//TODO: Optimize for angle == 0
double x0, y0, x1, y1, x2, y2, x3, y3;
if (abs(angle) > 0.01) {
double sina = sin(angle);
double cosa = cos(angle);
x0 = current_placement.starting_x + x - sina*ci.ymin;
y0 = current_placement.starting_y - y - cosa*ci.ymin;
x1 = x0 + ci.width * cosa;
y1 = y0 - ci.width * sina;
x2 = x0 + (ci.width * cosa - ci.height * sina);
y2 = y0 - (ci.width * sina + ci.height * cosa);
x3 = x0 - ci.height * sina;
y3 = y0 - ci.height * cosa;
} else {
x0 = current_placement.starting_x + x;
y0 = current_placement.starting_y - y - ci.ymin;
x1 = x0 + ci.width;
y1 = y0;
x2 = x0 + ci.width;
y2 = y0 - ci.height;
x3 = x0;
y3 = y0 - ci.height;
}
double sina = sin(angle);
double cosa = cos(angle);
x0 = current_placement.starting_x + x - sina*ci.ymin;
y0 = current_placement.starting_y - y - cosa*ci.ymin;
x1 = x0 + ci.width * cosa;
y1 = y0 - ci.width * sina;
x2 = x0 + (ci.width * cosa - ci.height * sina);
y2 = y0 - (ci.width * sina + ci.height * cosa);
x3 = x0 - ci.height * sina;
y3 = y0 - ci.height * cosa;
*f_ << "\n [[";
write_point(t, x0, y0);