+#define SQR(x) ((x)*(x))
+
+unsigned char* antialize(unsigned char*data, int width, int height, int newwidth, int newheight, int palettesize)
+{
+ if((newwidth<2 || newheight<2) ||
+ (width<=newwidth || height<=newheight))
+ return 0;
+ unsigned char*newdata;
+ int x,y;
+ newdata= (unsigned char*)malloc(newwidth*newheight);
+ int t;
+ double fx = (double)(width)/newwidth;
+ double fy = (double)(height)/newheight;
+ double px = 0;
+ int blocksize = (int)(8192/(fx*fy));
+ int r = 8192*256/palettesize;
+ for(x=0;x<newwidth;x++) {
+ double ex = px + fx;
+ int fromx = (int)px;
+ int tox = (int)ex;
+ int xweight1 = (int)(((fromx+1)-px)*256);
+ int xweight2 = (int)((ex-tox)*256);
+ double py =0;
+ for(y=0;y<newheight;y++) {
+ double ey = py + fy;
+ int fromy = (int)py;
+ int toy = (int)ey;
+ int yweight1 = (int)(((fromy+1)-py)*256);
+ int yweight2 = (int)((ey-toy)*256);
+ int a = 0;
+ int xx,yy;
+ for(xx=fromx;xx<=tox;xx++)
+ for(yy=fromy;yy<=toy;yy++) {
+ int b = 1-data[width*yy+xx];
+ int weight=256;
+ if(xx==fromx) weight = (weight*xweight1)/256;
+ if(xx==tox) weight = (weight*xweight2)/256;
+ if(yy==fromy) weight = (weight*yweight1)/256;
+ if(yy==toy) weight = (weight*yweight2)/256;
+ a+=b*weight;
+ }
+ //if(a) a=(palettesize-1)*r/blocksize;
+ newdata[y*newwidth+x] = (a*blocksize)/r;
+ py = ey;
+ }
+ px = ex;
+ }
+ return newdata;
+}
+