CompuServe Thread

OK, for those of you who have wondered about the circle paint routine I used for my benchmark, here it is. It's just a modified Bresenham routine which draws line between points reflected across the Y-axis (see Foley & Van Dam, p. 445): MichCircle(qrastport,radius,qcx,qcy,color) struct RastPort *qrastport; int radius,qcx,qcy,color; { register int cx,cy,x,y,d; register struct RastPort *rastport; cx = qcx; cy = qcy; rastport = qrastport; SetAPen(rastport,color); x = 0; y = radius; d = 3 – (radius+radius); while (x<y) { Move(rastport,cx-x,cy+y); Draw(rastport,cx+x,cy+y); Move(rastport,cx-y,cy+x); Draw(rastport,cx+y,cy+x); Move(rastport,cx-x,cy-y); Draw(rastport,cx+x,cy-y); Move(rastport,cx-y,cy-x); Draw(rastport,cx+y,cy-x); if (d < 0) d += (x << 2) + 6; else { d += ((x – y) << 2) + 10; y–; } x++; } if (x == y) { Move(rastport,cx-x,cy+y); Draw(rastport,cx+x,cy+y); Move(rastport,cx-y,cy+x); Draw(rastport,cx+y,cy+x); Move(rastport,cx-x,cy-y); Draw(rastport,cx+x,cy-y); Move(rastport,cx-y,cy-x); Draw(rastport,cx+y,cy-x); } } DoCircle(rastport) struct RastPort *rastport; { int i; int CMax = 200; struct timeval start,finish; printf(" paints %d circles in ",2*CMax); GetTime(&start); for (i=0; i < CMax; i++) { MichCircle(rastport,100,200,150,Black); MichCircle(rastport,100,200,150,White); } GetTime(&finish); delta(&finish,&start); printf("\n"); } GetTime(ctime) struct timeval *ctime; { DoIO(timerio); /* globally declared as struct timerequest */ ctime->tv_secs = timerio->tr_time.tv_secs; ctime->tv_micro = timerio->tr.time.tv_micro; } delta(finish,start) struct timeval *finish,*start; { ULONG dsec,dmic; dmic = finish->tv_micro – start->tv_micro; dsec = finish->tv_secs – start->tv_secs; if (dmic < 0) { dmic += 1000000; dsec–; } printf("%d.%d seconds",desc,dmic/100000); } Note, before you ask, yes I tried substituting RectFill for each Move/Draw pair. It was about 25% *slower* (108 seconds instead of 86). Also, I don't fully trust the timer routine and always verify my timings with a hand-held stopwatch. All timings were done with a monochrome (single bit-plane) 640×400 (interlaced) display. This was all done under 1.1; I still haven't tried it out under 1.2 (I have alpha-8). ..bfw..