// Bézier-Kurven; (C) C. Marschner, 1996 // PsZeichnen: // Zeichnet nach den Informatinen im Array (s.u.) den Buchstaben "P" // in verschiedenen Größen #include #include #include #include #include #include #include #include #include double Bezier(struct RastPort *, double,double,double,double, double,double,double,double,double,int); // Die Daten, um leichter skaliert werden zu können, etwa zwischen 0 u. 1 static double p[][4][2] = { // "P" {{ 0.000,0.000},{0.150,0.050}, {0.200,0.050}, {0.250,0.030}}, {{ 0.250,0.030},{0.300,0.010}, {0.350,0.000}, {0.400,0.000}}, {{ 0.400,0.000},{0.700,0.000}, {0.775,0.250}, {0.775,0.400}}, {{ 0.775,0.400},{0.775,0.650}, {0.700,0.700}, {0.450,0.700}}, {{ 0.450,0.700},{0.350,0.700}, {0.330,0.660}, {0.270,0.660}}, {{ 0.270,0.660},{0.230,0.660}, {0.200,0.660}, {0.200,0.700}}, {{ 0.200,0.700},{0.200,0.700}, {0.200,0.950}, {0.200,0.950}}, {{ 0.200,0.950},{0.180,1.000}, {0.160,1.000}, {0.250,1.030}}, {{ 0.250,1.030},{0.320,1.045}, {0.340,1.040}, {0.360,1.075}}, {{ 0.360,1.075},{0.170,1.040}, {0.100,1.030}, {-0.08,1.100}}, {{ -0.08,1.100},{-0.10,1.050}, {-0.06,1.025}, {0.030,1.025}}, {{ 0.030,1.025},{0.100,1.010}, {0.100,1.010}, {0.100,0.950}}, {{ 0.100,0.950},{0.100,0.950}, {0.100,0.200}, {0.100,0.200}}, {{ 0.100,0.200},{0.100,0.110}, {0.090,0.100}, {0.000,0.100}}, {{ 0.000,0.100},{0.000,0.010}, {0.000,0.000}, {0.000,0.000}}, {{ 0.200,0.150},{0.210,0.080}, {0.300,0.050}, {0.450,0.050}}, {{ 0.450,0.050},{0.590,0.050}, {0.650,0.150}, {0.650,0.400}}, {{ 0.650,0.400},{0.650,0.600}, {0.630,0.650}, {0.450,0.650}}, {{ 0.450,0.650},{0.400,0.650}, {0.400,0.650}, {0.350,0.630}}, {{ 0.350,0.630},{0.260,0.605}, {0.300,0.610}, {0.200,0.610}}, {{ 0.200,0.610},{0.200,0.610}, {0.200,0.150}, {0.200,0.150}}, }; /* struct Screen *scn = OpenScreenTags (NULL, SA_Depth, 2, SA_Width, 640, SA_Height, 523, SA_Quiet, TRUE, SA_Type, CUSTOMSCREEN|AUTOSCROLL, SA_DisplayID, PAL_MONITOR_ID|HIRESLACE_KEY, SA_Pens, pens, TAG_END ); */ struct Window *win = OpenWindowTags (NULL, WA_Flags, WFLG_ACTIVATE|WFLG_CLOSEGADGET|WFLG_DEPTHGADGET|WFLG_DRAGBAR| WFLG_NOCAREREFRESH|WFLG_SIMPLE_REFRESH| WFLG_DEPTHGADGET|WFLG_REPORTMOUSE, WA_Top, 11, WA_Width, 640, WA_Height, 512, WA_Left, 0, WA_IDCMP, IDCMP_CLOSEWINDOW|IDCMP_MOUSEBUTTONS|IDCMP_MOUSEMOVE, /* WA_CustomScreen, scn, */ WA_BlockPen, 4, WA_DetailPen, 3, WA_Title, (char*)"Bézier-Kurven...", TAG_END ); struct RastPort *rp = win->RPort; int status = 0; void main() { double k1x,k1y,k2x,k2y,k3x,k3y,k4x,k4y; int zaehler = 0; TmpRas tmpr; AreaInfo ai; if(!win) { CloseWindow(win); return }; try { SetAPen(rp,1); // Das Programm benutzt AreaMove/AreaDraw, um den Buchstaben zu füllen. // Dazu muß erstmal ein TmpRas besorgt, eine AreaInfo fertiggemacht und // das ganze in den RastPort eingetragen werden // 1. Raster für AreaDraw fertigmachen: PLANEPTR tr = AllocRaster(640,512); // anfordern if(!tr) // -> Fehler Nummer drei auswerfen throw(3); InitTmpRas(&tmpr, tr, RASSIZE(640,512)); // initialisieren rp->TmpRas = &tmpr; // und eintragen char *buffer = (char*)new WORD[25*5*21+50]; // Puffer für Koordinaten InitArea(&ai, buffer, 50*21); // AreaInfo-Liste AreaInfo *old = rp->AreaInfo; // und austauschen rp->AreaInfo = &ai; BNDRYOFF(rp); // Ausschalten des Rahmen-Pens // 2. Jetzt kann AreaMove/Draw benutzt werden. // 6 mal zeichnen for(int j = 0; j < 6; j++) { double range = 0; SetAPen(rp,1); // Das äußere vom "P": zwei Reihen a 3 Buchstaben; 6 Größen for(int i=0; i<15; i++) { // Die Transformation ist weniger kompliziert, als sie aussieht // Die Figur wird auf 150 Punkt gestreckt, wobei bei jedem weiteren // "P" die Figur um 15 Pkt. größer wird. Schließlich wird noch der // Nullpunkt verschoben, wobei ab j=3 eine zweite Zeile aufgemacht wird k1x = p[i][0][0] * (120.0+ 20*j) + 50.0 + 160.0 * (j<3?j:j-3); k1y = p[i][0][1] * (120.0+ 20*j) + 50.0 + 190.0 * (j>2); k2x = p[i][1][0] * (120.0+ 20*j) + 50.0 + 160.0 * (j<3?j:j-3); k2y = p[i][1][1] * (120.0+ 20*j) + 50.0 + 190.0 * (j>2); k3x = p[i][2][0] * (120.0+ 20*j) + 50.0 + 160.0 * (j<3?j:j-3); k3y = p[i][2][1] * (120.0+ 20*j) + 50.0 + 190.0 * (j>2); k4x = p[i][3][0] * (120.0+ 20*j) + 50.0 + 160.0 * (j<3?j:j-3); k4y = p[i][3][1] * (120.0+ 20*j) + 50.0 + 190.0 * (j>2); if(!i) AreaMove(rp,(long)k1x,(long)k1y); Bezier(rp,k1x,k1y,k2x,k2y,k3x,k3y,k4x,k4y,0,0); } AreaEnd(rp); SetAPen(rp,0); for(i=15; i<21; i++) { k1x = p[i][0][0] * (120.0+20*j) + 50.0 + 160.0 * (j<3?j:j-3); k1y = p[i][0][1] * (120.0+20*j) + 50.0 + 190.0 * (j>2); k2x = p[i][1][0] * (120.0+20*j) + 50.0 + 160.0 * (j<3?j:j-3); k2y = p[i][1][1] * (120.0+20*j) + 50.0 + 190.0 * (j>2); k3x = p[i][2][0] * (120.0+20*j) + 50.0 + 160.0 * (j<3?j:j-3); k3y = p[i][2][1] * (120.0+20*j) + 50.0 + 190.0 * (j>2); k4x = p[i][3][0] * (120.0+20*j) + 50.0 + 160.0 * (j<3?j:j-3); k4y = p[i][3][1] * (120.0+20*j) + 50.0 + 190.0 * (j>2); if(i==15) AreaMove(rp,(long)k1x,(long)k1y); Bezier(rp,k1x,k1y,k2x,k2y,k3x,k3y,k4x,k4y,0,0); } AreaEnd(rp); } Delay(250); // 5 Sekunden warten // 3. alte Werte wieder zurückschreiben: delete buffer; rp->AreaInfo = old; rp->TmpRas = 0; FreeRaster(tr,640,512); } catch(int n) { if(n>1) cout << "Fehler "<< n << "\n"; } CloseWindow(win); } double Bezier(struct RastPort *rp, double k0x,double k0y,double k1x,double k1y, double k2x,double k2y,double k3x,double k3y, double nr,int flag) { double bx, by, emt, emt2, t2, tm3, emtm3; // improvisierte Abschätzung der Schrittweite: const double range = floor(10+(fabs(k0y-k1y)+fabs(k0x-k1x)+fabs(k1x-k2x)+ fabs(k1y-k2y)+fabs(k2x-k3x)+fabs(k2y-k3y))/30.0); const double step = 1.0/range; const double rst = range*step; // Konstante z. schnelleren Bearbeiten AreaDraw(rp,(long)k0x,(long)k0y); for(double t = step; t <= rst; t+= step) { emt = 1-t; emt2=emt*emt; t2=t*t; tm3=3*t; emtm3 = 3*emt; bx = emt2*(emt*k0x + tm3*k1x) + t2*(emtm3*k2x + t*k3x); by = emt2*(emt*k0y + tm3*k1y) + t2*(emtm3*k2y + t*k3y); AreaDraw(rp,(long)bx,(long)by); } return range; }