/* fundamental custom window opening program */ /* based upon the program in "INSIDE Amiga Graphics" */ #include /* All the standard garbage */ #include #include #include struct IntuitionBase *IntuitionBase; /* And our wonderful libraries */ struct GfxBase *GfxBase; struct IntuiMessage *message; struct Screen *Scr; /* Our very own custom Screen */ struct Window *Wdw; /* and Window */ struct ViewPort *WVP; /* and ViewPort structures */ ULONG MessageClass; /* If we want messages from Intuition*/ USHORT code; /* these will be handy */ #define Rp Wdw->RPort /* And this will save some typing */ long multi, divis; /* These will specify our pixel coverage ratios */ int polycolor = 15; /* This will specify our polygon Pen color */ PLANEPTR workspace; /* We'll need a workspace and TmpRas for filling */ struct TmpRas myTmpRas; /* the Amiga's standard circles */ static USHORT colormap [16] = { 0x000,0x110,0x220,0x330,0x440,0x550,0x660,0x770,0x880, 0x990,0xAA0,0xBB0,0xCC0,0xDD0,0xEE0,0xFF0 }; /* This is our range of colors from black to full yellow */ struct TextAttr StdFont = /* Font structure */ { "topaz.font", TOPAZ_EIGHTY, FS_NORMAL, FPF_ROMFONT, }; struct NewScreen NewScr = /* for our custom screen - 4 bit planes */ { 0,0, /* Left Edge, Top Edge */ 320,200, 4, 1,0, NULL, CUSTOMSCREEN, &StdFont, "Test Screen", NULL, NULL }; struct NewWindow NewWdw = /* full screen window for drawing in */ { 0,0, /* Left Edge, Top Edge */ 320,200, /* Width, Height */ 0,5, /* Block Pen, Detail Pen */ CLOSEWINDOW , /* IDCMP Flags */ SMART_REFRESH | ACTIVATE | WINDOWCLOSE, /* Flags */ NULL, /* Pointer to First Gadget */ NULL, /* Pointer to Checkmark image */ "Anti-Aliasing Demo by Miles Kurland", /* Title */ NULL, /* Pointer to Screen structure (Dummy) */ NULL, /* Pointer to custom Bitmap */ 10,10, /* Minimum Width, Height */ 320,200, /* Maximum Width, Height */ CUSTOMSCREEN }; main() /* Here we go, action kids! */ { /* open the intuition and graphics libraries. get pointer to Writable Control Store routines (ROM for all intents), if = 0, libraries aren't available */ IntuitionBase = (struct IntuitionBase *) OpenLibrary("intuition.library",LIBRARY_VERSION); if (IntuitionBase == NULL) exit (FALSE); GfxBase = (struct GfxBase *) OpenLibrary("graphics.library",LIBRARY_VERSION); if (GfxBase == NULL) { CloseLibrary(IntuitionBase); /* end of the line, get some memory!*/ exit (FALSE); } /* Open screen and window . if they return 0, it didn't work! */ if (( NewWdw.Screen = Scr = (struct Screen *)OpenScreen(&NewScr)) == NULL) { CloseLibrary(GfxBase); CloseLibrary(IntuitionBase); /* go home early */ exit (FALSE); } if (( Wdw = (struct Window *)OpenWindow(&NewWdw)) == NULL) { CloseScreen(Scr); CloseLibrary(GfxBase); /* be nice, and clean up your room */ CloseLibrary(IntuitionBase); exit(FALSE); } WVP = (struct ViewPort *)ViewPortAddress(Wdw); /* Specify our View Port */ workspace = AllocRaster(320,200); /* Try to grab a workspace for Flood */ if (workspace == 0) { CloseWindow(Wdw); CloseScreen(Scr); /* If failure, close shop */ CloseLibrary(GfxBase); CloseLibrary(IntuitionBase); exit(FALSE); } InitTmpRas(&myTmpRas,workspace,RASSIZE(320,200)); /* Do this so Intuition */ Rp->TmpRas = &myTmpRas; /* will be able to use Flood */ LoadRGB4(WVP,&colormap,16); /* Set up the colormap with our values */ SetAPen(Rp,15); /* Draw a few concentric filled Ellipses */ DrawEllipse(Rp,230,100,60,60); Flood(Rp,1,(short)230,(short)100); SetAPen(Rp,0); DrawEllipse(Rp,230,100,45,45); Flood(Rp,1,(short)230,(short)100); SetAPen(Rp,15); DrawEllipse(Rp,230,100,30,30); Flood(Rp,1,(short)230,(short)100); SetAPen(Rp,0); DrawEllipse(Rp,230,100,15,15); Flood(Rp,1,(short)230,(short)100); polycolor = 15; /* Draw some ANTIALIASED FILLED CIRCLES!! */ SetAPen(Rp,15); aacircle(90,100,60); polycolor = 0; SetAPen(Rp,0); aacircle(90,100,45); polycolor = 15; SetAPen(Rp,15); aacircle(90,100,30); polycolor = 0; SetAPen(Rp,0); aacircle(90,100,15); for (;;) /* wait until user closes his window */ { if (message = (struct IntuiMessage *)GetMsg(Wdw->UserPort)) { MessageClass = message->Class; code = message->Code; ReplyMsg(message); if (MessageClass == CLOSEWINDOW) { FreeRaster(workspace,320,200); CloseWindow(Wdw); CloseScreen(Scr); CloseLibrary(GfxBase); CloseLibrary(IntuitionBase); return; } } } } /* aacircle draws an antialiased, filled circle */ aacircle(xcent, ycent, rad) int xcent, ycent, rad; /* center of circle, and radius (in pixels) */ { int x,y; /* current x, y position in quadrant */ int r; /* remainder žo factor division out of the loop*/ y = 0; /* start on the x-axis */ x = rad; /* with x=radius */ r = x; /* initialize remainder for round off. */ /* the left and right edges, the top and bottom are assumed */ /* to exactly cover a whole pixel, I fill those in first */ fill(xcent-rad,ycent,xcent+rad); /* draw middle line in */ wdot(xcent,ycent+rad,polycolor); /* the top dot, */ wdot(xcent,ycent-rad,polycolor); /* and bottom dot */ while (y++ < x) /* loop for all scan lines in 1/2 quadrant */ { r = r-y; /* do next step in iterative division */ if (r<0) /* when underflow occurs, it's time to */ { x=x-1; /* subtract a whole pixel from x */ r=r+x; /* and push the remainder back up */ /* fill in a line in the top and bottom */ fill(xcent-y+1,ycent+x,xcent+y-1); /* sections of the */ fill(xcent-y+1,ycent-x,xcent+y-1); /* circle */ } fill(xcent-x+1,ycent+y,xcent+x-1); /* always fill a line across */ fill(xcent-x+1,ycent-y,xcent+x-1); /* the center of the circle */ multi = r; /* set the globals that specify the color */ divis = x; /* coverage ratio for this edge pixel */ adot(xcent-x,ycent+y); /* replicate this dot in all four quadrants */ adot(xcent+x,ycent+y); adot(xcent-x,ycent-y); adot(xcent+x,ycent-y); adot(xcent-y,ycent-x); /* and use xy symmetry to generate the upper */ adot(xcent+y,ycent-x); /* half of each quadrant */ adot(xcent-y,ycent+x); adot(xcent+y,ycent+x); } return; } wdot(x,y,color) /* writes a dot of 'color' to screen */ int x,y,color; { SetAPen(Rp,color); WritePixel(Rp,x,y); return; } fill(x1,y1,x2) /* fills in pixels between two points in "polycolor" */ int x1,y1,x2; { SetAPen(Rp,polycolor); Move(Rp,x1,y1); Draw(Rp,x2,y1); return; } adot(x,y) /* routine to write one anti-aliased polygon edge dot */ int x,y; { int color; /* storage for calculated color */ int v; /* color of pixel to be written over */ int d; /* distance between pixel and polycolor */ v = ReadPixel(Rp,x,y); /* read present color of pixel */ d = v - polycolor; /* calculate difference of pixels */ d = d*multi/divis; /* and interpolate new distances between */ /* these two colors */ color = (v-d); /* calculate the new color, between two original colors*/ wdot(x,y,color); /* write the pixel out */ return; /* th-th-that's all folks */ } /* Acknowledgement to Mike Higgens, who provided this algorithm, as well as example programs, which I liberally adapted to my own nefarious purposes */