diff options
Diffstat (limited to 'saga/gfx.cpp')
| -rw-r--r-- | saga/gfx.cpp | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/saga/gfx.cpp b/saga/gfx.cpp index 78712dc485..978cfc29e6 100644 --- a/saga/gfx.cpp +++ b/saga/gfx.cpp @@ -1076,4 +1076,29 @@ void Gfx::setCursor(int best_white) { _system->setMouseCursor(cursor_img, R_CURSOR_W, R_CURSOR_H, 4, 4, keycolor); } +bool Gfx::hitTestPoly(Point *points, unsigned int npoints, Point test_point) { + int yflag0; + int yflag1; + bool inside_flag = false; + unsigned int pt; + + Point *vtx0 = &points[npoints - 1]; + Point *vtx1 = &points[0]; + + yflag0 = (vtx0->y >= test_point.y); + for (pt = 0; pt < npoints; pt++, vtx1++) { + yflag1 = (vtx1->y >= test_point.y); + if (yflag0 != yflag1) { + if (((vtx1->y - test_point.y) * (vtx0->x - vtx1->x) >= + (vtx1->x - test_point.x) * (vtx0->y - vtx1->y)) == yflag1) { + inside_flag = !inside_flag; + } + } + yflag0 = yflag1; + vtx0 = vtx1; + } + + return inside_flag; +} + } // End of namespace Saga |