Category : C Source Code
Archive : CADSRC.ZIP
Filename : T-4.C
Output of file : T-4.C contained in archive : CADSRC.ZIP
t-4.c
FUNCTION: Draws a solid 3D sphere using plane equation
method of hidden surface removal.
Compatibility: Supports VGA/EGA graphics adapters and monitors
using 640x200, 16 color mode.
NOTE: You need the *.BGI files that come with Turbo-C for
this to run.
___________________________________________________________________
INCLUDE FILES */
#include
#include
#include
#include
#include
/*________________________________________________________________
DECLARATIONS */
void keyboard(void);void quit_pgm(void);void calc_3d(void);
void rotation(void);void window(void); void graphics_setup(void);
void coords(void); void draw_poly(void); void notice(int x, int y);
void visibility_test(void);void polycenter(void);
void sphere_coords(void); void draw_4poly(void);
void draw_3polynorth(void);void draw_3polysouth(void);
void upper_coords(void); void lower_coords(void);
float x=0.0,y=0.0,z=0.0;
float x1=0.0,x2=0.0,x3=0.0,x4=0.0;
float y01=0.0,y2=0.0,y3=0.0,y4=0.0;
float z1=0.0,z2=0.0,z3=0.0,z4=0.0;
float sx1=0.0,sx2=0.0,sx3=0.0,sx4=0.0,sx5=0.0;
float sy1=0.0,sy2=0.0,sy3=0.0,sy4=0.0,sy5=0.0;
float sx=0.0,sy=0.0;
float xa=0.0,ya=0.0,za=0.0;
float d=1200.0;
double r1=6.19592;
double r2=0.523590;
double r3=5.39778;
double sr1=0,sr2=0,sr3=0;
double cr1=0,cr2=0,cr3=0;
float mx=0,my=0.0,mz=-150.0;
int maxx=639,minx=0,maxy=199,miny=0;
float screen_x=639,screen_y=199;
float rx=0,ry=0;
int t=0,t1=0,t2=0, p1=0;
int C0=0,C1=1,C2=2,C3=3,C4=4,C5=5,C6=6,C7=7,C8=8,C9=9,C10=10,
C11=11,C12=12,C13=13,C14=14,C15=15,mode_flag=0;
int key_matte_clr=6, edge_clr=7, solid_clr=0;
float x_res,y_res;
float sp=0.0;
float sp1=0.0,sp2=0.0, sp3=0.0;
float xlarge=0.0,xsmall=0.0;
float ylarge=0.0,ysmall=0.0;
float zlarge=0.0,zsmall=0.0;
float x6=0.0,x7=0.0,y6=0.0,y7=0.0,z6=0.0,z7=0.0;
int q=0,q1=0,q2=0;
double r4=6.28319,r5=6.28319;
float B11[36][3];
float B12[36][3];
float B21[36][2];
float B22[36][2];
double sr4=0.0,cr4=0.0,sr5=0.0,cr5=0.0;
/*___________________________________________________________
MAIN ROUTINE */
main()
{
graphics_setup();
setviewport(0,0,maxx,maxy,1);
key_matte_clr=C6;
edge_clr=C7;solid_clr=C0;
rotation();
r5=0.0;r4=0.0;x=30;sphere_coords();calc_3d(); window();
B11[0][0]=x;B11[0][1]=y;B11[0][2]=z;
B21[0][0]=sx;B21[0][1]=sy;
x=30;r5=0.17453;r4=0.0;lower_coords();
for (q1=0;q1<=35;q1++)
{
q2=q1+1; if (q2>35) q2=0;
draw_3polynorth();
keyboard();
}
r5=0.17453;
for (t2=1;t2<=16;t2++)
{
x=30;r4=0.0;upper_coords();
x=30;r5=r5+0.17453;r4=0.0;lower_coords();
for (q1=0;q1<=35;q1++)
{
q2=q1+1; if (q2>35) q2=0;
draw_4poly();
keyboard();
}
}
r5=3.14159;r4=0.0;x=30;sphere_coords();calc_3d();window();
B11[0][0]=x;B11[0][1]=y;B11[0][2]=z;
B21[0][0]=sx;B21[0][1]=sy;
x=30;r5=2.96706;r4=0.0;upper_coords();
for (q1=0;q1<=35;q1++)
{
q2=q1+1; if (q2>35) q2=0;
draw_3polysouth();
keyboard();
}
setcolor(C7);notice(0,0);
for (t1=1;t1!=2; ) keyboard();
quit_pgm();
}
/*_________________________________________________________________
FUNCTION: calculate and store coords for belt
*/
void upper_coords(void)
{
for (t=0;t<=35;t++)
{
x=30;sphere_coords();calc_3d();window();
B11[t][0]=x;B11[t][1]=y;B11[t][2]=z;
B21[t][0]=sx;B21[t][1]=sy;
r4=r4+0.17453;
keyboard();
}
return;
}
void lower_coords(void)
{
for (t=0;t<=35;t++)
{
x=30;sphere_coords();calc_3d();window();
B12[t][0]=x;B12[t][1]=y;B12[t][2]=z;
B22[t][0]=sx;B22[t][1]=sy;
r4=r4+0.17453;
keyboard();
}
return;
}
/*_________________________________________________________________
FUNCTION: calculate world coordinates for sphere
*/
void sphere_coords(void)
{
sr4=sin(r4);cr4=cos(r4);sr5=sin(r5);
cr5=cos(r5);x1=sr5*x;y=cr5*x;x=cr4*x1;z=sr4*x1;
return;
}
/*_________________________________________________________________
FUNCTION: draw 4-sided polygonal surface on sphere.
*/
void draw_4poly(void)
{
x1=B11[q1][0];y01=B11[q1][1];z1=B11[q1][2];
x2=B11[q2][0];y2=B11[q2][1];z2=B11[q2][2];
x3=B12[q2][0];y3=B12[q2][1];z3=B12[q2][2];
x4=B12[q1][0];y4=B12[q1][1];z4=B12[q1][2];
visibility_test(); if (sp>-100) return;
sx1=B21[q1][0];sy1=B21[q1][1];
sx2=B21[q2][0];sy2=B21[q2][1];
sx3=B22[q2][0];sy3=B22[q2][1];
sx4=B22[q1][0];sy4=B22[q1][1];
polycenter();
draw_poly();
return;
}
/*_________________________________________________________________
FUNCTION: draw 3-sided polygonal surface on sphere.
*/
void draw_3polynorth(void)
{
x1=B12[q2][0];y01=B12[q2][1];z1=B12[q2][2];
x2=B12[q1][0];y2=B12[q1][1];z2=B12[q1][2];
x3=B11[0][0];y3=B11[0][1];z3=B11[0][2];
visibility_test(); if (sp>0) return;
sx1=B22[q2][0];sy1=B22[q2][1];
sx2=B22[q1][0];sy2=B22[q1][1];
sx3=B21[0][0];sy3=B21[0][1];
sx4=sx1;sy4=sy1;
x4=x1+0.5*(x2-x1);y4=y01+0.5*(y2-y01);z4=z1+0.5*(z2-z1);
x=x3+0.85*(x4-x3);y=y3+0.85*(y4-y3);z=z3+0.85*(z4-z3);
sx=d*x/z;sy=d*y/z;window();sx5=sx;sy5=sy;
draw_poly();
return;
}
void draw_3polysouth(void)
{
x1=B12[q1][0];y01=B12[q1][1];z1=B12[q1][2];
x2=B12[q2][0];y2=B12[q2][1];z2=B12[q2][2];
x3=B11[0][0];y3=B11[0][1];z3=B11[0][2];
visibility_test(); if (sp>0) return;
sx1=B22[q2][0];sy1=B22[q2][1];
sx2=B22[q1][0];sy2=B22[q1][1];
sx3=B21[0][0];sy3=B21[0][1];
sx4=sx1;sy4=sy1;
x4=x1+0.5*(x2-x1);y4=y01+0.5*(y2-y01);z4=z1+0.5*(z2-z1);
x=x3+0.85*(x4-x3);y=y3+0.85*(y4-y3);z=z3+0.85*(z4-z3);
sx=d*x/z;sy=d*y/z;window();sx5=sx;sy5=sy;
draw_poly();
return;
}
/*_________________________________________________________________
FUNCTION: identify center of polygon
*/
void polycenter(void)
{
x6=x2+0.5*(x1-x2);y6=y2+0.5*(y01-y2);z6=z2+0.5*(z1-z2);
x7=x3+0.5*(x4-x3);y7=y3+0.5*(y4-y3);z7=z3+0.5*(z4-z3);
x=x7+0.5*(x6-x7);y=y7+0.5*(y6-y7);z=z7+0.5*(z6-z7);
sx=d*x/z;sy=d*y/z;window();sx5=sx;sy5=sy;
return;
}
/*_________________________________________________________________
FUNCTION: calculate SIN,COS factors
*/
void rotation(void)
{
sr1=sin(r1);sr2=sin(r2);sr3=sin(r3);cr1=cos(r1);cr2=cos(r2);
cr3=cos(r3);
return;
}
/*_________________________________________________________________
FUNCTION: standard 3D formulas
*/
void calc_3d(void)
{
x=(-1)*x;xa=cr1*x-sr1*z;za=sr1*x+cr1*z;x=cr2*xa+sr2*y;
ya=cr2*y-sr2*xa;z=cr3*za-sr3*ya;y=sr3*za+cr3*ya;x=x+mx;y=y+my;
z=z+mz;sx=d*x/z;sy=d*y/z;
return;
}
/*_________________________________________________________________
FUNCTION: hidden surface visibility test
*/
void visibility_test(void)
{
sp1=x1*(y2*z3-y3*z2);sp1=(-1)*sp1;sp2=x2*(y3*z1-y01*z3);
sp3=x3*(y01*z2-y2*z1);sp=sp1-sp2-sp3;
return;
}
/*_____________________________________________________________
SUBROUTINE: draw 4-sided SOLID polygon in 3D space
*/
void draw_poly(void)
{
setlinestyle(USERBIT_LINE,0xffff,NORM_WIDTH);
setcolor(key_matte_clr);moveto(sx1,sy1);
lineto(sx2,sy2);lineto(sx3,sy3);lineto(sx4,sy4);lineto(sx1,sy1);
setfillstyle(SOLID_FILL,key_matte_clr);floodfill(sx5,sy5,key_matte_clr);
setcolor(edge_clr);moveto(sx1,sy1);
lineto(sx2,sy2);lineto(sx3,sy3);lineto(sx4,sy4);lineto(sx1,sy1);
setfillstyle(SOLID_FILL,solid_clr);floodfill(sx5,sy5,edge_clr);
return;
}
/*_________________________________________________________________
FUNCTION: map cartesian coords to physical screen coords.
*/
void window(void)
{
sx=sx+399;sy=sy+299;rx=screen_x/799;ry=screen_y/599;sx=sx*rx;
sy=sy*ry;
return;
}
/*____________________________________________________________________
SUBROUTINE: press any key to quit... */
void keyboard(void)
{
if (bioskey(1) == 0) return;
else quit_pgm();
}
/*____________________________________________________________________
SUBROUTINE: graceful exit from the program */
void quit_pgm(void)
{
cleardevice(); restorecrtmode();exit(0);
}
/*___________________________________________________________________
SUBROUTINE: vga/ega/cga/mcga compatibility module */
void graphics_setup(void)
{
int graphics_adapter,graphics_mode;
detectgraph(&graphics_adapter,&graphics_mode);
if (graphics_adapter==VGA) goto VGA_mode;
if (graphics_mode==EGAHI) goto EGA_ECD_mode;
if (graphics_mode==EGALO) goto EGA_SCD_mode;
if (graphics_adapter==CGA) goto abort_message;
if (graphics_adapter==MCGA) goto abort_message;
goto abort_message;
VGA_mode:
graphics_adapter=VGA;graphics_mode=VGAHI;
initgraph(&graphics_adapter,&graphics_mode,"");
x_res=640;y_res=480;mode_flag=1;
maxx=639;minx=0;maxy=479;miny=0;screen_x=639;screen_y=479;
setcolor(7);moveto(0,472);
outtext("640x480 16-color VGA mode");
moveto (472,472);
outtext("Press any key to Quit");
moveto(168,0);
outtext("Using TURBO C to generate a solid 3D sphere");
return;
EGA_ECD_mode:
graphics_adapter=EGA;graphics_mode=EGAHI;
initgraph(&graphics_adapter,&graphics_mode,"");
x_res=640;y_res=350;mode_flag=2;
maxx=639;minx=0;maxy=349;miny=0;screen_x=639;screen_y=349;
setcolor(7);moveto(0,342);
outtext("640x350 16-color EGA mode");
moveto (472,342);
outtext("Press any key to Quit");
moveto(168,0);
outtext("Using TURBO C to generate a solid 3D sphere");
return;
EGA_SCD_mode:
graphics_adapter=EGA;graphics_mode=EGALO;
initgraph(&graphics_adapter,&graphics_mode,"");
x_res=640;y_res=200;mode_flag=3;
maxx=639;minx=0;maxy=199;miny=0;screen_x=639;screen_y=199;
setcolor(7);moveto(0,192);
outtext("640x200 16-color EGA mode");
moveto (472,192);
outtext("Press any key to Quit");
moveto(168,0);
outtext("Using TURBO C to generate a solid 3D sphere");
return;
abort_message:
printf("\n\nUnable to proceed.\n");
printf("Requires VGA or EGA adapter\n");
printf(" with appropriate monitor.\n");
printf("Please refer to LEE ADAMS book HIGH-Performance CAD Graphics in TURBO C.\n\n");
exit(0);
}
/*__________________________________________________________
SUBROUTINE: map 640x480 template to 2D screen */
void coords(void)
{
sx=sx*(x_res/640);sy=sy*(y_res/480);return;
}
/*__________________________________________________________
SUBROUTINE: copyright notice */
int copyright[][3]={0x7c00,0x0000,0x0000,0x8231,
0x819c,0x645e,0xba4a,0x4252,0x96d0,0xa231,0x8252,0x955e,0xba4a,
0x43d2,0xf442,0x8231,0x825c,0x945e,0x7c00,0x0000,0x0000};
void notice(int x, int y)
{
int a,b,c; int t1=0;
for (t1=0;t1<=6;t1++)
{
a=copyright[t1][0];b=copyright[t1][1];
c=copyright[t1][2];
setlinestyle(USERBIT_LINE,a,NORM_WIDTH);
moveto(x,y);lineto(x+15,y);
setlinestyle(USERBIT_LINE,b,NORM_WIDTH);
moveto(x+16,y);lineto(x+31,y);
setlinestyle(USERBIT_LINE,c,NORM_WIDTH);
moveto(x+32,y);lineto(x+47,y);y=y+1;
}
setlinestyle(USERBIT_LINE,0xFFFF,NORM_WIDTH);
return;
}
/* END */
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