CMM2 demo programs
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matherp Guru ![]() Joined: 11/12/2012 Location: United KingdomPosts: 10216 |
Rotating Dodecahedron Check the video ![]() option explicit option default none page write 1 const edgelength=200 'set the length of the verticies of the dodecahedron const zlocation=1000 'how far is the center of the dodecahedron away from us const viewplane=800 'how far is the viewplane away from us dim float xarr(4),yarr(4) dim float phi=(1+sqr(5))/2 ' golden ratio dim float x,y,x1,y1,z1 dim integer col(11), sortorder(11) dim float q1(4),depth(11),v(4), vout(4) ' data for location of verticies for dodecahedron of edge length 2 data phi,phi,phi data phi,phi,-phi data phi,-phi,phi data -phi,phi,phi data -phi,-phi,phi data -phi,phi,-phi data phi,-phi,-phi data -phi,-phi,-phi data 0,-(phi^2),1 data 0,phi^2,1 data 0,-(phi^2),-1 data 0,phi^2,-1 data phi^2,1,0 data -(phi^2),1,0 data phi^2,-1,0 data -(phi^2),-1,0 data 1,0,phi^2 data 1,0,-(phi^2) data -1,0,phi^2 data -1,0,-(phi^2) dim float dodec(2,19), ndodec(3,19) dim integer i,j,k ' read in the coordinates of the verticies and scale for j=0 to 19 for i=0 to 2 read dodec(i,j) dodec(i,j)=dodec(i,j)*edgelength/2 next i next j 'convert coordinates to normalised form for i=0 to 19 x1=dodec(0,i): y1=dodec(1,i): z1=dodec(2,i) create_vector(x1,y1,z1,v()) ndodec(0,i)=v(2): ndodec(1,i)=v(3): ndodec(2,i)=v(4): ndodec(3,i)=v(0) next i 'create a quarternion to rotate 5 degrees about a chosen axis 'play with the x,y,z vector which is the sxis of rotation create_normalised_quaternion(5,1,0.5,0.25,q1()) 'array to hold verticies for each face and its colour dim integer faces(4,11) data 10,6,17,19,7,rgb(red) data 7,19,5,13,15,rgb(blue) data 6,14,12,1,17,rgb(yellow) data 19,17,1,11,5,rgb(green) data 8,2,16,18,4,rgb(magenta) data 2,14,12,0,16,rgb(cyan) data 18,16,0,9,3,rgb(brown) data 4,18,3,13,15,rgb(white) data 12,0,9,11,1,rgb(gray) data 13,3,9,11,5,rgb(255,0,128) data 8,4,15,7,10,rgb(128,0,255) data 8,2,14,6,10,rgb(128,255,0) for j=0 to 11 for i=0 to 4 read faces(i,j) next i read col(j) next j do cls for i=0 to 19 'rotate coordinates v(2)=ndodec(0,i): v(3)=ndodec(1,i): v(4)=ndodec(2,i): v(0)=ndodec(3,i): v(1)=0 rotate_vector(vout(),v(),q1()) ndodec(0,i)=vout(2): ndodec(1,i)=vout(3): ndodec(2,i)=vout(4): ndodec(3,i)=vout(0) next i ' Now see which faces are furthest away by adding up the Z coordinates for i=0 to 11 depth(i)=0 sortorder(i)=i for j=0 to 4 depth(i)=depth(i)+ndodec(2,faces(j,i)) next j next i ' sort depth(),sortorder() for k=0 to 11 i=sortorder(11-k) 'get the index to the faces in order of nearest last for j=0 to 4 xarr(j)=ndodec(0,faces(j,i))*viewplane/(ndodec(2,faces(j,i))+zlocation)*ndodec(3,faces(j,i))+MM.HRES/2 yarr(j)=ndodec(1,faces(j,i))*viewplane/(ndodec(2,faces(j,i))+zlocation)*ndodec(3,faces(j,i))+MM.VRES/2 next j polygon 5,xarr(),yarr(),col(i),col(i) next k page copy 1 to 0,b loop ' sub create_normalised_quaternion(theta as float,x as float,y as float,z as float,q() as float) local float radians = theta/180.0*PI local float sineterm= sin(radians!/2) q(1)=cos(radians/2) q(2)=x* sineterm q(3)=y* sineterm q(4)=z* sineterm q(0)=sqr(q!(1)*q(1) + q(2)*q(2) + q(3)*q(3) + q(4)*q(4)) 'calculate the magnitude q(1)=q(1)/q(0) 'create a normalised quaternion q(2)=q(2)/q(0) q(3)=q(3)/q(0) q(4)=q(4)/q(0) q(0)=1 end sub ' sub invert_quaternion(n() as float,q() as float) n(0)=q(0) n(1)=q(1) n(2)=-q(2) n(3)=-q(3) n(4)=-q(4) end sub ' sub multiply_quaternion(n() as float,q1() as float,q2() as float) local float a1=q1(1),a2=q2(1),b1=q1(2),b2=q2(2),c1=q1(3),c2=q2(3),d1=q1(4),d2=q2(4) n(1)=a1*a2-b1*b2-c1*c2-d1*d2 n(2)=a1*b2+b1*a2+c1*d2-d1*c2 n(3)=a1*c2-b1*d2+c1*a2+d1*b2 n(4)=a1*d2+b1*c2-c1*b2+d1*a2 n(0)=q1(0)*q2(0) end sub ' sub create_vector(x as float,y as float ,z as float,v() as float) v(0)=sqr(x*x + y*y + z*z) v(1)=0 v(2)=x/v(0) v(3)=y/v(0) v(4)=z/v(0) end sub sub rotate_vector(vnew() as float,v() as float,q() as float) local float n(4),iq(4) multiply_quaternion(n(),q(),v()) invert_quaternion(iq(),q()) multiply_quaternion(vnew(),n(),iq()) end sub Edited 2020-05-24 00:30 by matherp |
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