bool PerPixelCollisionStrategy::execute(
const Sprite& obj1, const Sprite& obj2) const {
RectangularCollisionStrategy strategy;
if ( not strategy.execute(obj1, obj2) ) return false;
// If we got this far, we know that the sprite rectangles intersect!
Vector2f p1 = obj1.getPosition();
Vector2f p2 = obj2.getPosition();
const Frame * const frame1 = obj1.getFrame();
const Frame * const frame2 = obj2.getFrame();
int o1Left = p1[0];
int o1Right = o1Left+frame1->getWidth();
int o2Left = p2[0];
int o2Right = o2Left+frame2->getWidth();
std::vector<int> x;
x.reserve(4);
x.push_back( o1Left );
x.push_back( o1Right );
x.push_back( o2Left );
x.push_back( o2Right );
std::sort( x.begin(), x.end() );
int o1Up = p1[1];
int o1Down = o1Up+frame1->getHeight();
int o2Up = p2[1];
int o2Down = o2Up+frame2->getHeight();
std::vector<int> y;
y.reserve(4);
y.push_back( o1Up );
y.push_back( o1Down );
y.push_back( o2Up );
y.push_back( o2Down );
std::sort( y.begin(), y.end() );
SDL_Surface* surface1 = frame1->getSurface();
SDL_Surface* surface2 = frame2->getSurface();
SDL_LockSurface(surface1);
SDL_LockSurface(surface2);
unsigned pixels1;
unsigned pixels2;
for (int i = x[1]; i < x[2]; ++i) {
for (int j = y[1]; j < y[2]; ++j) {
// check pixels in obj1 and obj2!
pixels1 = obj1.getPixel(i, j);
pixels2 = obj2.getPixel(i, j);
if ( pixels1 != 0xff00ff && pixels2 != 0xff00ff) {
SDL_UnlockSurface(surface1);
SDL_UnlockSurface(surface2);
return true;
}
}
}
SDL_UnlockSurface(surface1);
SDL_UnlockSurface(surface2);
return false;
}
bool PerPixelCollisionStrategy::execute(
const Drawable& obj1, const Drawable& obj2) const {
RectangularCollisionStrategy strategy;
if ( not strategy.execute(obj1, obj2) ) return false;
// If we got this far, we know that the sprite rectangles intersect!
Vector2f p1 = obj1.getPosition();
Vector2f p2 = obj2.getPosition();
const Frame * const frame1 = obj1.getFrame();
const Frame * const frame2 = obj2.getFrame();
int o1Left = p1[0];
int o1Right = o1Left+frame1->getWidth();
int o2Left = p2[0];
int o2Right = o2Left+frame2->getWidth();
std::vector<int> sides;
sides.reserve(4);
sides.push_back( o1Left );
sides.push_back( o1Right );
sides.push_back( o2Left );
sides.push_back( o2Right );
std::sort( sides.begin(), sides.end() );
int o1Up = p1[1];
int o1Down = o1Up+frame1->getHeight();
int o2Up = p2[1];
int o2Down = o2Up+frame2->getHeight();
std::vector<int> lids;
lids.reserve(4);
lids.push_back( o1Up );
lids.push_back( o1Down );
lids.push_back( o2Up );
lids.push_back( o2Down );
std::sort( lids.begin(), lids.end() );
SDL_Surface* surface1 = frame1->getSurface();
SDL_Surface* surface2 = frame2->getSurface();
SDL_LockSurface(surface1);
SDL_LockSurface(surface2);
unsigned pixels1;
unsigned pixels2;
for (int i = sides[1]; i < sides[2]; ++i) {
for (int j = lids[1]; j < lids[2]; ++j) {
// check pixels in obj1 and obj2!
pixels1 = obj1.getPixel(i, j);
pixels2 = obj2.getPixel(i, j);
if ( pixels1 != surface1->format->colorkey &&
pixels2 != surface2->format->colorkey) {
SDL_UnlockSurface(surface1);
SDL_UnlockSurface(surface2);
return true;
}
}
}
SDL_UnlockSurface(surface1);
SDL_UnlockSurface(surface2);
return false;
}
