another mountain thing
- Posted by Michael Packard <lgp at EXO.COM> Feb 16, 1998
- 696 views
Here's a 640x480 version of it. I changed the way I got polygon coordinates, converting the whole matrix x,y,z to screenx, screeny before doing the polygons, instead of doing poly verticies for each face, so I only have to compute the points once instead of 4 times. One thing that does perplex me is that if I create multiple landscapes (press any key after each one is finished and it'll do another one) the second landscape is way faster to create than the first one. On an 8th level landscape the numbers are like this: First Landscape Second Landscape (3rd,4th,etc...) Landscape creation: 6.59 3.51 Convert time 10.66 3.62 3D draw time 22.96 15.96 It's even more dramatic on a 9th level, the first one takes 202 seconds while the second is only 64 seconds. I'm doing exactly the same amount of computations, on the same number of data points and drawing the same number of polygons. Certainly there should be some variability in compute\draw times, but not that much, in fact from landscape numbers 2-50 the total time varies by only a second. If anyone can give me a good explanation why I'd appreciate it. Also I'm computing intermediate times for each routine, but the total time isn't the sum of the other times and I dunno why. Obviously I'm doing the checks wrong somehow, but I can't find the problem. Someone find the problem and tell me what I'm doing wrong. Michael Packard Lord Generic Productions ---------------------------------------- ---------------------------------- -- Fractal Landscape Generator - -- Version .76 2/16/98 - -- Copyright 1998 - -- Lord Generic Productions - ---------------------------------- without type_check include get.e include machine.e include image.e include graphics.e include pic_load.e integer G,D1,MX,MY,MZ atom SR1,SR2,CR1,CR2,SR3,CR3,roll atom seed,Arand,Nrand,GaussAdd,GaussFac sequence X,pal,screen integer maxlevel,addition,i,N,wire integer D,d,bench atom sigma,H,delta,max,min,time1,time2 ---------------------------- -- vga palette for mountain pal= {63,63,63}} ------------------------------------------- --initization of Gaussian random thingy Nrand=4 Arand=1000 seed=1234 GaussAdd=sqrt(3*Nrand) GaussFac=2*GaussAdd/(Nrand * Arand) --set_rand(seed) ------------------------------------------ function Gauss() atom sum sum=0 for i = 1 to Nrand do sum=sum+rand(Arand) end for return(GaussFac * sum - GaussAdd) end function ------------------------------------------- function f3(atom delta, atom x0, atom x1, atom x2) atom y,z z=Gauss() y=(x0+x1+x2)/3+delta*Gauss() return(y) end function -------------------------------------------- function f4(atom delta, atom x0, atom x1, atom x2, atom x3) atom y,z z=Gauss() y=(x0+x1+x2+x3)/4+delta*Gauss() return(y) end function --------------------------------------------- --initial parameters sigma=1.25 -- Initial Standard Deviation Determines max height H=.8 -- Fractal Dimention = 3-H Determines smoothness addition=1 -- Add extra randomness to points? --------------------------------------------- procedure mtn() atom k min=time() N=power(2,maxlevel)+1 delta=sigma X=repeat(0,N) for o=1 to N do X[o]=repeat(0,N) end for screen=X X[1][1]=delta*Gauss() X[1][N]=delta*Gauss() X[N][1]=delta*Gauss() X[N][N]=delta*Gauss() D=N-1 d=D/2 for stage= 1 to maxlevel do position(1,50) puts(1,"Working on Stage #")?(stage) -- going from grid type I to type II delta = delta * power(.5,.5*H) -- interpolate and offset points for x=d+1 to N-d+1 by D do for y=d+1 to N-d+1 by D do X[x][y]=f4(delta,X[x+d][y+d],X[x+d][y-d],X[x-d][y+d],X[x-d][y-d]) end for end for --displace other points also if necessary if addition then for x=1 to N+1 by D do for y=1 to N+1 by D do X[x][y]=X[x][y] + delta * Gauss() end for end for end if -- going from grid type II to type I delta= delta*power(.5,.5*H) -- interpolate and offset boundary grid points for x = d+1 to N-d+1 by D do X[x][1]=f3(delta,X[x+d][1],X[x-d][1],X[x][d]) X[x][N]=f3(delta,X[x+d][N],X[x-d][N],X[x][N-d]) X[1][x]=f3(delta,X[1][x+d],X[1][x-d],X[d][x]) X[N][x]=f3(delta,X[N][x+d],X[N][x-d],X[N-d][x]) end for --interpolate and offset interior grid points for x = d+1 to N-d by D do for y = D+1 to N-d by D do X[x][y] = f4(delta, X[x][y+d], X[x][y-d], X[x+d][y], X[x-d][y]) end for end for for x = D+1 to N-d by D do for y = d+1 to N-d+1 by D do X[x][y] = f4(delta, X[x][y+d], X[x][y-d], X[x+d][y], X[x-d][y]) end for end for if addition then for x=1 to N by D do for y=1 to N by D do X[x][y]=X[x][y] + delta * Gauss() end for end for for x=d+1 to N-d+1 by D do for y=d+1 to N-d+1 by D do X[x][y]=X[x][y] + delta * Gauss() end for end for end if D=D/2 d=floor(d/2) end for max=time()-min position(3,50) puts(1,"Time: ") ?(max) position(4,50) puts(1,"Size: ") ?(length(X)*length(X)) min=255 max=0 for x= 1 to N do for y= 1 to N do k = X[x][y] if k!=0 then k=((k/2)*175)+25 end if if k<1 then k=1 end if X[x][y]=floor(k) if floor(k)<min then min=floor(k) end if if floor(k)>max then max=floor(k) end if end for end for end procedure ----------------------------------------- procedure drawit() if maxlevel<9 then display_image({0,0},X) end if end procedure ------------------------------------------------- --3d draw stuff procedure viewangle(atom pitch,atom yaw)--pitch and yaw angles in degrees pitch=pitch*(.0174533) --convert to radians yaw=yaw*(.0174533) roll=0 roll=roll*(.0174533) G=0 D1=-2000 MX=0 MY=-700 MZ=0 SR1=sin(yaw) CR1=cos(yaw) SR2=sin(roll) CR2=cos(roll) SR3=sin(pitch) CR3=cos(pitch) end procedure --------------------------------------------------- function perspective(atom x1,atom y1, atom z1) --gives screen coordinates atom xa,ya,za,sx,sy xa=CR1*x1-SR1*y1 ya=SR1*x1+CR1*y1 x1=CR2*xa+SR2*z1 za=CR2*z1-SR2*xa y1=CR3*ya-SR3*za z1=SR3*ya+CR3*za x1=x1+MX y1=y1+MY z1=z1+MZ sx=floor(D1*x1/y1)+650 sy=floor(D1*z1/y1)+530 bench=bench+1 return({sx,sy}) end function ------------------------------------------------ procedure convert_screen() --creates and NxN matix of screen coordinates for the landscape atom scale,vscale,ctime scale=257/N vscale=2 ctime=time() for x=1 to N do for y=1 to N do end for if floor(x/25)=x/25 then position(3,65)puts(1,"Converting:")?(x) end if end for position(5,50) puts(1,"Convert time: ") ?(time()-ctime) end procedure ------------------------------------------------ procedure test3d() --atom x1,y1,z1 atom scale,color,vscale,check sequence points,points2 sequence point1,point2,point3,point4 points=repeat(0,N) points2=repeat(0,N) scale=257/N check=time() vscale=2 convert_screen() for x=1 to N-1 do for y=1 to N-1 do point1=screen[x][y] --perspective(y*scale-129,x*scale-129,-X[x][y]/10)/vsca le point2=screen[x][y+1] --perspective((y+1)*scale-129,x*scale-129,-X[x][y+1]/10 )/vscale point3=screen[x+1][y+1] --perspective((y+1)*scale-129,(x+1)*scale-129,-X[x+1][y +1]/10)/vscale point4=screen[x+1][y] --perspective((y)*scale-129,(x+1)*scale-129,-X[x+1][y]/ 10)/vscale if color>240 then color=240 end if if color<0 then color=-color end if if wire=0 then polygon(0,1,{point1,point2,point3,point4,point1}) end if --if color>5 and color<150then pixel(color+rand(50),point1) --elsif color>150 then pixel(color-rand(50),point1) end if end for end for points=repeat(0,N+2) points2=points points2[N+2]=points[N+2] for x=2 to N+1 do points2[x]=perspective(N*scale-129,(x-1)*scale-129,-X[x-1][N]/8) /vscale end for polygon(0,1,points) polygon(0,1,points2) polygon(150,0,points) polygon(150,0,points2) --check=time()-check position(6,50) puts(1,"3D Draw Time: ") print(1,time()-check) position (7,50) puts(1,"bench: ")?(bench) end procedure ------------------------------------------------- --main program i=graphics_mode(256) all_palette(pal) for x= 1 to 50 do bench=0 time1=time() puts(1,"*******************************\n\r") puts(1,"* Fractal Landscape Generator *\n\r") puts(1,"* Version .76 2/16/98 *\n\r") puts(1,"* Copyright 1998 *\n\r") puts(1,"* Lord Generic Productions *\n\r") puts(1,"*******************************\n\r") wire=1 --0 for wireframe, 1 for filled polygons maxlevel=8 --High detail level but slow. Set lower for lower detail mtn() --Generates the fractal drawit() --Draw the 2D map viewangle(30,rand(90)) --Rotates the landscape for a good view. (pitch,yaw) test3d() --Makes 3D coordinates and draws polygons time2=time() position(8,50)puts(1,"Total creation time: ")?(time()-time1) position(23,1) puts(1,"Press any Key\n\rPress Q or ESC to quit") i=wait_key() if i=27 or i='q' then i= graphics_mode(-1) abort(0) end if if i='m' then i=save_screen(0,"3dland.bmp") end if clear_screen() end for i=graphics_mode(-1) ----------------------------------------------