// http://astronomy.swin.edu.au/~pbourke/geometry/polyarea/
vec2 barycenter(const Polygon2d& P) {
gx_assert(P.size() > 0) ;
double A = signed_area(P) ;
if(::fabs(A) < 1e-30) {
return P[0] ;
}
double x = 0.0 ;
double y = 0.0 ;
for(unsigned int i=0; i<P.size(); i++) {
unsigned int j = (i+1) % P.size() ;
const vec2& t1 = P[i] ;
const vec2& t2 = P[j] ;
double d = (t1.x * t2.y - t2.x * t1.y) ;
x += (t1.x + t2.x) * d ;
y += (t1.y + t2.y) * d ;
}
return vec2(
x / (6.0 * A),
y / (6.0 * A)
) ;
}
bool GD_EXTENSION_API SingleTileCollision(std::map<gd::String, std::vector<RuntimeObject*>*> tileMapList,
int layer,
int column,
int row,
std::map<gd::String, std::vector<RuntimeObject*>*> objectLists,
bool conditionInverted)
{
return TwoObjectListsTest(tileMapList, objectLists, conditionInverted, [layer, column, row](RuntimeObject* tileMapObject_, RuntimeObject * object) {
RuntimeTileMapObject *tileMapObject = dynamic_cast<RuntimeTileMapObject*>(tileMapObject_);
if(!tileMapObject || tileMapObject->tileSet.Get().IsDirty())
return false;
//Get the tile hitbox
int tileId = tileMapObject->tileMap.Get().GetTile(layer, column, row);
if(tileId < 0 || tileId >= tileMapObject->tileSet.Get().GetTilesCount())
return false;
Polygon2d tileHitbox = tileMapObject->tileSet.Get().GetTileHitbox(tileId).hitbox;
tileHitbox.Move(tileMapObject->GetX() + column * tileMapObject->tileSet.Get().tileSize.x,
tileMapObject->GetY() + row * tileMapObject->tileSet.Get().tileSize.y);
//Get the object hitbox
std::vector<Polygon2d> objectHitboxes = object->GetHitBoxes();
for(std::vector<Polygon2d>::iterator hitboxIt = objectHitboxes.begin(); hitboxIt != objectHitboxes.end(); ++hitboxIt)
{
if(PolygonCollisionTest(tileHitbox, *hitboxIt).collision)
{
return true;
}
}
return false;
});
}
std::vector<Polygon2d> GenerateHitboxes(TileSet &tileSet, TileMap &tileMap)
{
std::vector<Polygon2d> hitboxes;
const int tileWidth = tileSet.tileSize.x;
const int tileHeight = tileSet.tileSize.y;
if(tileSet.IsDirty())
return hitboxes;
for(int layer = 0; layer < 3; layer++)
{
for(int col = 0; col < tileMap.GetColumnsCount(); col++)
{
for(int row = 0; row < tileMap.GetRowsCount(); row++)
{
//Note : a hitbox is also added for empty/non-collidable tiles to ease the hitbox update when changing a tile
Polygon2d newPolygon;
if(tileMap.GetTile(layer, col, row) != -1 && tileSet.GetTileHitbox(tileMap.GetTile(layer, col, row)).collidable)
{
newPolygon = tileSet.GetTileHitbox(tileMap.GetTile(layer, col, row)).hitbox;
}
newPolygon.Move(col * tileWidth, row * tileHeight);
hitboxes.push_back(newPolygon);
}
}
}
return hitboxes;
}
std::vector<Polygon2d> RuntimeObject::GetHitBoxes() const {
std::vector<Polygon2d> mask;
Polygon2d rectangle = Polygon2d::CreateRectangle(GetWidth(), GetHeight());
rectangle.Rotate(GetAngle() / 180 * 3.14159);
rectangle.Move(GetX() + GetCenterX(), GetY() + GetCenterY());
mask.push_back(rectangle);
return mask;
}
void minimum_area_enclosing_rectangle(
const Polygon2d& PP,
vec2& S, vec2& T
) {
// Note: this implementation has O(n2) complexity :-(
// (where n is the number of vertices in the convex hull)
// If this appears to be a bottleneck, use a smarter
// implementation with better complexity.
Polygon2d P ;
convex_hull(PP, P) ;
int N = P.size() ;
// Add the first vertex at the end of P
P.push_back(P[0]) ;
double min_area = Numeric::big_double ;
for(int i=1; i<=N; i++) {
vec2 Si = P[i] - P[i-1] ;
if( ( Si.length2() ) < 1e-20) {
continue ;
}
vec2 Ti(-Si.y, Si.x) ;
normalize(Si) ;
normalize(Ti) ;
double s0 = Numeric::big_double ;
double s1 = -Numeric::big_double ;
double t0 = Numeric::big_double ;
double t1 = -Numeric::big_double ;
for(int j=1; j<N; j++) {
vec2 D = P[j] - P[0] ;
double s = dot(Si, D) ;
s0 = gx_min(s0, s) ;
s1 = gx_max(s1, s) ;
double t = dot(Ti, D) ;
t0 = gx_min(t0, t) ;
t1 = gx_max(t1, t) ;
}
double area = (s1 - s0) * (t1 - t0) ;
if(area < min_area) {
min_area = area ;
if((s1 - s0) < (t1 - t0)) {
S = Si ;
T = Ti ;
} else {
S = Ti ;
T = Si ;
}
}
}
}
void convex_clip_segment(
Segment2d& S, const Polygon2d& window
) {
gx_parano_assert(polygon_is_convex(window)) ;
bool invert = (signed_area(window) < 0) ;
for(unsigned int i=0; i<window.size(); i++) {
unsigned int j = ((i+1) % window.size()) ;
clip_segment_by_half_plane(S, window[i], window[j], invert) ;
}
}
// http://astronomy.swin.edu.au/~pbourke/geometry/polyarea/
double signed_area(const Polygon2d& P) {
double result = 0 ;
for(unsigned int i=0; i<P.size(); i++) {
unsigned int j = (i+1) % P.size() ;
const vec2& t1 = P[i] ;
const vec2& t2 = P[j] ;
result += t1.x * t2.y - t2.x * t1.y ;
}
result /= 2.0 ;
return result ;
}
Polygon2d Polygon2d::scaleaboutcentroid(float scale) {
Polygon2d n;
V2d cen=centroid();
for (int i=1;i<=vs.len;i++) {
V2d x=vs.num(i);
x=x-cen;
x=x*scale;
x=x+cen;
n.add(x);
}
return n;
}
void save_polygon(const Polygon2d& P, const std::string& file_name) {
std::ofstream out(file_name.c_str()) ;
{for(unsigned int i=0; i<P.size(); i++) {
out << "v " << P[i].x << " " << P[i].y << std::endl ;
out << "vt " << P[i].x << " " << P[i].y << std::endl ;
}}
out << "f " ;
{for(unsigned int i=0; i<P.size(); i++) {
out << i+1 << "/" << i+1 << " " ;
}}
out << std::endl ;
}
vec2 vertices_barycenter(const Polygon2d& P) {
gx_assert(P.size() != 0) ;
double x = 0 ;
double y = 0 ;
for(unsigned int i=0; i<P.size(); i++) {
x += P[i].x ;
y += P[i].y ;
}
x /= double(P.size()) ;
y /= double(P.size()) ;
return vec2(x,y) ;
}
void clip_polygon_by_half_plane(
const Polygon2d& P,
const vec2& q1,
const vec2& q2,
Polygon2d& result,
bool invert
) {
result.clear() ;
if(P.size() == 0) {
return ;
}
if(P.size() == 1) {
if(point_is_in_half_plane(P[0], q1, q2, invert)) {
result.push_back(P[0]) ;
}
return ;
}
vec2 prev_p = P[P.size() - 1] ;
Sign prev_status = point_is_in_half_plane(
prev_p, q1, q2, invert
) ;
for(unsigned int i=0; i<P.size(); i++) {
vec2 p = P[i] ;
Sign status = point_is_in_half_plane(
p, q1, q2, invert
) ;
if(
status != prev_status &&
status != ZERO &&
prev_status != ZERO
) {
vec2 intersect ;
if(intersect_segments(prev_p, p, q1, q2, intersect)) {
result.push_back(intersect) ;
} else {
}
}
switch(status) {
case NEGATIVE:
break ;
case ZERO:
result.push_back(p) ;
break ;
case POSITIVE:
result.push_back(p) ;
break ;
}
prev_p = p ;
prev_status = status ;
}
}
void convex_hull(const Polygon2d& PP, Polygon2d& result) {
result.clear() ;
int n = PP.size() ;
vec2* P = new vec2[n+1] ;
{ for(int i=0; i<n; i++) {
P[i] = PP[i] ;
}}
int u = make_chain(P, n, cmpl);
P[n] = P[0];
int ch = u+make_chain(P+u, n-u+1, cmph);
{for(int i=0; i<ch; i++) {
result.push_back(P[i]) ;
}}
delete[] P ;
}
bool polygon_is_convex(const Polygon2d& P) {
Sign s = ZERO ;
for(unsigned int i=0; i<P.size(); i++) {
unsigned int j = ((i+1) % P.size()) ;
unsigned int k = ((j+1) % P.size()) ;
Sign cur_s = orient(P[i],P[j],P[k]) ;
if(s != ZERO && cur_s != ZERO && cur_s != s) {
return false ;
}
if(cur_s != ZERO) {
s = cur_s ;
}
}
return true ;
}
PolygonShape::PolygonShape(const Polygon2d& polygon, Material& attrs):
m_polygon(polygon) {
b2Vec2* vertecies = new b2Vec2[polygon.VerteciesCount()];
const Vertecies& polygonVertecies = polygon.GetVertecies();
for (size_t vertexNo = 0; vertexNo < polygonVertecies.size(); ++vertexNo) {
vertecies[vertexNo] = ToBox2dVec(polygonVertecies[vertexNo]);
}
m_polygonShapePtr = new b2PolygonShape();
m_polygonShapePtr->Set(vertecies, polygon.VerteciesCount());
delete[] vertecies;
Construct(m_polygonShapePtr, attrs);
}
bool point_is_in_kernel(const Polygon2d& P, const vec2& p) {
Sign sign = ZERO ;
for(unsigned int i=0 ; i<P.size() ; i++) {
unsigned int j = (i+1) % P.size() ;
const vec2& p1 = P[i] ;
const vec2& p2 = P[j] ;
Sign cur_sign = orient(p, p1, p2) ;
if(sign == ZERO) {
sign = cur_sign ;
} else {
if(cur_sign != ZERO && cur_sign != sign) {
return false ;
}
}
}
return true ;
}
// Clipping with convex window using Sutherland-Hogdman reentrant clipping
void convex_clip_polygon(
const Polygon2d& P, const Polygon2d& clip, Polygon2d& result
) {
gx_parano_assert(polygon_is_convex(clip)) ;
Polygon2d tmp1 = P ;
bool invert = (signed_area(tmp1) != signed_area(clip)) ;
Polygon2d tmp2 ;
Polygon2d* src = &tmp1 ;
Polygon2d* dst = &tmp2 ;
for(unsigned int i=0; i<clip.size(); i++) {
unsigned int j = ((i+1) % clip.size()) ;
const vec2& p1 = clip[i] ;
const vec2& p2 = clip[j] ;
clip_polygon_by_half_plane(*src, p1, p2, *dst, invert) ;
gx_swap(src, dst) ;
}
result = *src ;
}
// Compute the kernel using Sutherland-Hogdman reentrant clipping
// The kernel is obtained by clipping the polygon with each
// half-plane yielded by its sides.
void kernel(const Polygon2d& P, Polygon2d& result) {
Array1d<Sign> sign(P.size()) ;
for(unsigned int i=0; i<P.size(); i++) {
unsigned int j = ((i+1) % P.size()) ;
unsigned int k = ((j+1) % P.size()) ;
sign(j) = orient(P[i],P[j],P[k]) ;
}
bool invert = (signed_area(P) < 0) ;
Polygon2d tmp1 = P ;
Polygon2d tmp2 ;
Polygon2d* src = &tmp1 ;
Polygon2d* dst = &tmp2 ;
for(unsigned int i=0; i<P.size(); i++) {
unsigned int j = ((i+1) % P.size()) ;
const vec2& p1 = P[i] ;
const vec2& p2 = P[j] ;
if((p2-p1).length() == 0) {
std::cerr << "null edge in poly" << std::endl ;
continue ;
}
// Optimization: do not clip by convex-convex edges
// (Thanks to Rodrigo Toledo for the tip !)
if(!invert && sign(i) != NEGATIVE && sign(j) != NEGATIVE) {
continue ;
}
if(invert && sign(i) != POSITIVE && sign(j) != POSITIVE) {
continue ;
}
clip_polygon_by_half_plane(*src, p1, p2, *dst, invert) ;
gx_swap(src, dst) ;
}
result = *src ;
}
bool Polygon2d::overlaps(Polygon2d p) { // does not seem to work
// return overlaps(&p);
for (int i=1;i<=p.vs.len;i++)
if (crosses(p.linefrom(i)))
return true;
bool pin=true;
bool thisin=true;
for (int i=1;i<=p.vs.len && pin;i++)
if (!contains(p.vs.num(i)))
pin=false;
for (int i=1;i<=vs.len && thisin;i++)
if (!p.contains(vs.num(i)))
thisin=false;
if (pin)
return container; // this polygon completely contains p
if (thisin)
return contained;
return false;
}
void D3DRenderContext::RenderSolidPolygon(const Polygon2d& p, const ivec3& color) const {
WireGeometryVertex* points = new WireGeometryVertex[p.VerteciesCount() + 1];
for (uint i = 0; i <= p.VerteciesCount(); ++i) {
if (i == p.VerteciesCount()) {
points[i].x = p[0].x;
points[i].y = p[0].y;
points[i].z = MAX_ZCHOOORD;
points[i].color = D3DCOLOR_XRGB(color.x, color.y, color.z);
} else {
points[i].x = p[i].x;
points[i].y = p[i].y;
points[i].z = MAX_ZCHOOORD;
points[i].color = D3DCOLOR_XRGB(color.x, color.y, color.z);
}
}
m_d3dDevice->SetFVF(D3DFVF_WIRE_GEOMETRY_VERTEX);
m_d3dDevice->DrawPrimitiveUP(D3DPT_TRIANGLEFAN, p.VerteciesCount(), static_cast<void*>(points), sizeof(WireGeometryVertex));
delete[] points;
}
float offness(Polygon2d p) {
Region r=Region(p,oi->width,oi->height);
r.makelist();
V2d v=V2d(0,0);
int cnt=0;
for (int i=1;i<=r.list->len;i++) {
int x=r.list->num(i).x;
int y=r.list->num(i).y;
if (angs->inmap(x,y)) {
v=v+mag->pos[x][y]*V2d::rotate(V2d(1,0),angs->pos[x][y]);
cnt++;
}
}
float offness=v.mod()/(float)cnt;
printf("Quad has offness %f count %i area %f\n",offness,cnt,p.area());
return offness;
}
float areaofpoly(Polygon2d p) {
return p.area();
}
float Polygon2d::area(Polygon2d p) {
return p.area();
}
Polygon2d Polygon2d::operator*(float f) {
Polygon2d p;
for (int i=1;i<=vs.len;i++)
p.add(vs.num(i)*f);
return p;
}
bool TileMapImporter::ImportTileMap(TileSet &tileSet, TileMap &tileMap,
bool importTileMap, bool importTileSetConf, bool importTileSetImage,
bool importHitboxes, gd::Project &project)
{
//Checks the map type
if(m_map->GetOrientation() != Tmx::TMX_MO_ORTHOGONAL)
{
gd::LogError(_("Only orthogonal maps are supported !"));
return false;
}
//Get the tileset list
if(m_map->GetNumTilesets() < 1)
{
gd::LogError(_("There are no tilesets in this file !"));
return false;
}
else if(m_map->GetNumTilesets() > 1)
{
gd::LogWarning(_("Only the first tileset will be taken into account. Tiles from supplementary tilesets may be lost."));
}
//Import the tileset image if needed
if(importTileSetImage)
{
const Tmx::Image *importedImage = m_map->GetTileset(0)->GetImage();
wxFileName imageFileName(importedImage->GetSource());
imageFileName.MakeAbsolute(wxFileName(m_filePath).GetPath());
if(!imageFileName.FileExists())
{
gd::LogError(_("The image can't be found !"));
return false;
}
gd::String newResourceName = gd::NewNameGenerator::Generate(
u8"imported_" + imageFileName.GetFullName(),
[&project](const gd::String &name) -> bool { return project.GetResourcesManager().HasResource(name); }
);
gd::LogMessage(_("The image is imported as ") + "\"" + newResourceName + "\".");
imageFileName.MakeRelativeTo(wxFileName(project.GetProjectFile()).GetPath());
project.GetResourcesManager().AddResource(newResourceName, imageFileName.GetFullPath(), "image");
tileSet.textureName = newResourceName;
//Reload the texture
tileSet.LoadResources(project);
gd::LogStatus(_("Tileset image importation completed."));
}
//Import the tileset configuration if wanted
if(importTileSetConf)
{
const Tmx::Tileset *importedTileset = m_map->GetTileset(0);
if(importedTileset->GetImage()->GetWidth() != tileSet.GetWxBitmap().GetWidth() ||
importedTileset->GetImage()->GetHeight() != tileSet.GetWxBitmap().GetHeight())
{
gd::LogWarning(_("Tileset image size is not the same. Some tiles may not be rendered correctly."));
}
tileSet.tileSize.x = importedTileset->GetTileWidth();
tileSet.tileSize.y = importedTileset->GetTileHeight();
tileSet.tileSpacing.x = tileSet.tileSpacing.y = importedTileset->GetSpacing();
if(importedTileset->GetMargin() > 0)
{
gd::LogWarning(_("Tilemap objects don't handle tilesets with margins around the images. Consider cutting the picture."));
}
gd::LogStatus(_("Tileset configuration importation completed."));
}
//Import the tilemap tiles if wanted
if(importTileMap)
{
//Tilemap size
if(tileMap.GetColumnsCount() != m_map->GetWidth() || tileMap.GetRowsCount() != m_map->GetHeight())
gd::LogMessage(_("Tilemap size is different."));
tileMap.SetSize(0, 0);
tileMap.SetSize(m_map->GetWidth(), m_map->GetHeight());
if(!importTileSetConf && !importTileSetImage)
CheckTilesCount(tileSet);
//Import layers and tiles
if(m_map->GetNumTileLayers() > 3)
{
gd::LogWarning(_("There are more than 3 tiles layers. Only the 3 firsts will be imported."));
}
else if(m_map->GetNumTileLayers() < 3)
{
gd::LogMessage(_("There are less than 3 tiles layers. Upper layer(s) will be empty."));
}
for(std::size_t i = 0; i < std::min(3, m_map->GetNumTileLayers()); i++)
{
const Tmx::TileLayer *layer = m_map->GetTileLayer(i);
for(std::size_t x = 0; x < tileMap.GetColumnsCount(); x++)
{
for(std::size_t y = 0; y < tileMap.GetRowsCount(); y++)
{
//Only tiles provided by the first tileset are imported (and also tests for empty tiles)
if(m_map->FindTilesetIndex(layer->GetTileGid(x, y)) == 0)
{
tileMap.SetTile(i, x, y, layer->GetTileId(x, y));
}
}
}
}
gd::LogStatus(_("Tilemap content importation completed."));
}
//Import the hitboxes
if(importHitboxes)
{
const Tmx::Tileset *importedTileset = m_map->GetTileset(0);
//Set all tiles not collidable in the tileset
tileSet.ResetHitboxes();
for(std::size_t i = 0; i < tileSet.GetTilesCount(); i++)
tileSet.SetTileCollidable(i, false);
if(!importTileSetConf && !importTileSetImage)
CheckTilesCount(tileSet);
bool hasMoreThanOneObjectPerTile = false;
bool hasNotPolygoneObject = false;
bool hasNotConvexPolygon = false;
for(auto it = importedTileset->GetTiles().cbegin();
it != importedTileset->GetTiles().cend();
++it)
{
const Tmx::Tile *importedTile = *it;
if(importedTile->GetId() < tileSet.GetTilesCount()) //Check if the tileset has enough tiles to receive the imported hitboxes
{
if(importedTile->HasObjects())
{
//Set the tile collidable and gets its hitbox
tileSet.SetTileCollidable(importedTile->GetId(), true);
TileHitbox &tileHitbox = tileSet.GetTileHitboxRef(importedTile->GetId());
//Warn the user if more than one hitbox per tile is found
if(importedTile->GetNumObjects() > 1)
hasMoreThanOneObjectPerTile = true;
const Tmx::Object *importedObj = importedTile->GetObject(0);
if(!importedObj->GetPolyline() && !importedObj->GetEllipse())
{
Polygon2d polygonHitbox;
if(!importedObj->GetPolygon())
{
//This is a rectangle
polygonHitbox = Polygon2d::CreateRectangle(importedObj->GetWidth(), importedObj->GetHeight());
polygonHitbox.Move(
importedObj->GetWidth() / 2.f,
importedObj->GetHeight() / 2.f
);
}
else
{
//This is a polygon
const Tmx::Polygon *importedPolygon = importedObj->GetPolygon();
for(int i = 0; i < importedPolygon->GetNumPoints(); i++)
{
polygonHitbox.vertices.emplace_back(
importedPolygon->GetPoint(i).x,
importedPolygon->GetPoint(i).y
);
}
}
polygonHitbox.Move(importedObj->GetX(), importedObj->GetY());
polygonHitbox.Rotate(importedObj->GetRot());
if(polygonHitbox.IsConvex())
tileHitbox.hitbox = polygonHitbox;
else
hasNotConvexPolygon = true;
}
else
{
//This is not a supported shape
hasNotPolygoneObject = true;
}
}
}
}
if(hasMoreThanOneObjectPerTile)
gd::LogWarning(_("Some tiles have more than 1 hitbox. Only the first one is imported."));
if(hasNotPolygoneObject)
gd::LogWarning(_("Some tiles have a polyline or a ellipsis hitbox. Only rectangle and polygon hitboxes are supported."));
if(hasNotConvexPolygon)
gd::LogWarning(_("Some tiles have a concave polygon. It has been ignored and set to a rectangular hitbox as this object only supports convex hitboxes for tiles."));
gd::LogStatus(_("Tiles hitboxes importation completed."));
}
return true;
}
CollisionResult GD_API PolygonCollisionTest(Polygon2d& p1,
Polygon2d& p2,
bool ignoreTouchingEdges) {
if (p1.vertices.size() < 3 || p2.vertices.size() < 3) {
CollisionResult result;
result.collision = false;
result.move_axis.x = 0.0f;
result.move_axis.y = 0.0f;
return result;
}
p1.ComputeEdges();
p2.ComputeEdges();
sf::Vector2f edge;
sf::Vector2f move_axis(0, 0);
sf::Vector2f mtd(0, 0);
float min_dist = FLT_MAX;
CollisionResult result;
// Iterate over all the edges composing the polygons
for (std::size_t i = 0; i < p1.vertices.size() + p2.vertices.size(); i++) {
if (i < p1.vertices.size()) // or <=
{
edge = p1.edges[i];
} else {
edge = p2.edges[i - p1.vertices.size()];
}
sf::Vector2f axis(
-edge.y, edge.x); // Get the axis to which polygons will be projected
normalise(axis);
float minA = 0;
float minB = 0;
float maxA = 0;
float maxB = 0;
project(axis, p1, minA, maxA);
project(axis, p2, minB, maxB);
float dist = distance(minA, maxA, minB, maxB);
if (dist > 0.0f || (dist == 0.0 && ignoreTouchingEdges)) {
// If the projections on the axis do not overlap, then
// there is no collision
result.collision = false;
result.move_axis.x = 0.0f;
result.move_axis.y = 0.0f;
return result;
}
float absDist = std::abs(dist);
if (absDist < min_dist) {
min_dist = absDist;
move_axis = axis;
}
}
result.collision = true;
sf::Vector2f d = p1.ComputeCenter() - p2.ComputeCenter();
if (dotProduct(d, move_axis) < 0.0f) move_axis = -move_axis;
result.move_axis = move_axis * min_dist;
return result;
}
RaycastResult GD_API PolygonRaycastTest(
Polygon2d& poly, float startX, float startY, float endX, float endY) {
RaycastResult result;
result.collision = false;
if (poly.vertices.size() < 2) {
return result;
}
poly.ComputeEdges();
sf::Vector2f p, q, r, s;
float minSqDist = FLT_MAX;
// Ray segment: p + t*r, with p = start and r = end - start
p.x = startX;
p.y = startY;
r.x = endX - startX;
r.y = endY - startY;
for (int i = 0; i < poly.edges.size(); i++) {
// Edge segment: q + u*s
q = poly.vertices[i];
s = poly.edges[i];
sf::Vector2f deltaQP = q - p;
float crossRS = crossProduct(r, s);
float t = crossProduct(deltaQP, s) / crossRS;
float u = crossProduct(deltaQP, r) / crossRS;
// Collinear
if (abs(crossRS) <= 0.0001 && abs(crossProduct(deltaQP, r)) <= 0.0001) {
// Project the ray and the edge to work on floats, keeping linearity
// through t
sf::Vector2f axis(r.x, r.y);
normalise(axis);
float rayA = 0.0f;
float rayB = dotProduct(axis, r);
float edgeA = dotProduct(axis, deltaQP);
float edgeB = dotProduct(axis, deltaQP + s);
// Get overlapping range
float minOverlap = std::max(std::min(rayA, rayB), std::min(edgeA, edgeB));
float maxOverlap = std::min(std::max(rayA, rayB), std::max(edgeA, edgeB));
if (minOverlap > maxOverlap) {
return result;
}
result.collision = true;
// Zero distance ray
if (rayB == 0.0f) {
result.closePoint = p;
result.closeSqDist = 0.0f;
result.farPoint = p;
result.farSqDist = 0.0f;
}
float t1 = minOverlap / abs(rayB);
float t2 = maxOverlap / abs(rayB);
result.closePoint = p + t1 * r;
result.closeSqDist = t1 * t1 * (r.x * r.x + r.y * r.y);
result.farPoint = p + t2 * r;
result.farSqDist = t2 * t2 * (r.x * r.x + r.y * r.y);
return result;
} else if (crossRS != 0 && 0 <= t && t <= 1 && 0 <= u && u <= 1) {
sf::Vector2f point = p + t * r;
float sqDist = (point.x - startX) * (point.x - startX) +
(point.y - startY) * (point.y - startY);
if (sqDist < minSqDist) {
if (!result.collision) {
result.farPoint = point;
result.farSqDist = sqDist;
}
minSqDist = sqDist;
result.closePoint = point;
result.closeSqDist = sqDist;
result.collision = true;
} else {
result.farPoint = point;
result.farSqDist = sqDist;
}
}
}
return result;
}