aluckdog
这是更快但不太准确的东西，对于碰撞检查或2D物理很有用。 Point[] MakePoly(BufferedImage spr,int d,int angle){//creates an outline of a transparent image, points are stored in an array//arg0 - BufferedImage source image //arg1 - Int detail (lower = better)//arg2 - Int angle threshold in degrees (will remove points with angle differences below this level; 15 is a good value)// making this larger will make the body faster but less accurate; int w= spr.getWidth(null); int h= spr.getHeight(null); // increase array size from 255 if needed int[] vertex_x=new int[255], vertex_y=new int[255], vertex_k=new int[255]; int numPoints=0, tx=0,ty=0,fy=-1,lx=0,ly=0; vertex_x[0]=0; vertex_y[0]=0; vertex_k[0]=1; for (tx=0;tx<w;tx+=d) for (ty=0;ty<h;ty+=1) if((spr.getRGB(tx,ty)>>24) != 0x00 ) {vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints++; if (fy<0) fy=ty; lx=tx; ly=ty; break; } for (ty=0;ty<h;ty+=d) for (tx=w-1;tx>=0;tx-=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && ty > ly) {vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints++; lx=tx; ly=ty; break; } for (tx=w-1;tx>=0;tx-=d) for (ty=h-1;ty>=0;ty-=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && tx < lx) {vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints ++; lx=tx; ly=ty; break; } for (ty=h-1;ty>=0;ty-=d) for (tx=0;tx<w;tx+=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && ty < ly && ty > fy) {vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints ++; lx=tx; ly=ty; break; } double ang1,ang2; for (int i=0;i<numPoints-2;i++) { ang1 = PointDirection(vertex_x[i],vertex_y[i], vertex_x[i+1],vertex_y[i+1]); ang2 = PointDirection(vertex_x[i+1],vertex_y[i+1], vertex_x[i+2],vertex_y[i+2]); if (Math.abs(ang1-ang2) <= angle) vertex_k[i+1] = 0; } ang1 = PointDirection(vertex_x[numPoints-2],vertex_y[numPoints-2], vertex_x[numPoints-1],vertex_y[numPoints-1]); ang2 = PointDirection(vertex_x[numPoints-1],vertex_y[numPoints-1], vertex_x[0],vertex_y[0]); if (Math.abs(ang1-ang2) <= angle) vertex_k[numPoints-1] = 0; ang1 = PointDirection(vertex_x[numPoints-1],vertex_y[numPoints-1], vertex_x[0],vertex_y[0]); ang2 = PointDirection(vertex_x[0],vertex_y[0], vertex_x[1],vertex_y[1]); if (Math.abs(ang1-ang2) <= angle) vertex_k[0] = 0; int n=0;for (int i=0;i<numPoints;i++)if(vertex_k[i]==1)n++; Point[] poly= new Point[n]; n=0; for (int i=0;i<numPoints;i++) if (vertex_k[i]==1) { poly[n]=new Point(); poly[n].x=vertex_x[i]; poly[n].y=h-vertex_y[i];n++;} return poly;}double PointDirection(double xfrom,double yfrom,double xto,double yto){ return Math.atan2(yto-yfrom,xto-xfrom)*180/Math.PI ;}