[3019] | 1 | /* |
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| 2 | * see COPYRIGHT |
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| 3 | */ |
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| 4 | |
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| 5 | #include <stdio.h> |
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| 6 | #include <stdlib.h> |
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| 7 | #include "bzscreen.h" |
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| 8 | |
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| 9 | /* |
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| 10 | * functions to draw the bezier curves in text mode |
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| 11 | */ |
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| 12 | |
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| 13 | double |
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| 14 | fmin(a,b) |
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| 15 | double a, b; |
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| 16 | { |
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| 17 | if(a<b) |
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| 18 | return a; |
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| 19 | else |
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| 20 | return b; |
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| 21 | } |
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| 22 | |
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| 23 | int |
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| 24 | abs(x) |
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| 25 | int x; |
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| 26 | { |
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| 27 | if(x<0) |
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| 28 | return -x; |
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| 29 | else |
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| 30 | return x; |
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| 31 | } |
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| 32 | |
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| 33 | void |
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| 34 | initscreen(physx, physy, cols, rows, xoff, yoff, minx, miny, maxx, maxy) |
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| 35 | unsigned physx, physy, cols, rows, xoff, yoff, minx, miny, maxx, maxy; |
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| 36 | { |
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| 37 | int i,j; |
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| 38 | double yxscale; |
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| 39 | |
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| 40 | if(screen.dots != NULL) |
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| 41 | free(screen.dots); |
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| 42 | |
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| 43 | if(physx==0 || physy==0 || rows==0 || cols==0) { |
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| 44 | fprintf(stderr, "*** negative or zero screen size\n"); |
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| 45 | exit(1); |
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| 46 | } |
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| 47 | |
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| 48 | if(physx+xoff > cols || physy+yoff > rows) { |
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| 49 | fprintf(stderr, "*** drawable area out of screen\n"); |
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| 50 | exit(1); |
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| 51 | } |
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| 52 | |
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| 53 | if(minx>maxx || miny>maxy) { |
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| 54 | fprintf(stderr, "*** empty drawable area\n"); |
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| 55 | exit(1); |
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| 56 | } |
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| 57 | |
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| 58 | screen.physx = physx; |
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| 59 | screen.physy = physy; |
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| 60 | screen.rows = rows; |
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| 61 | screen.cols = cols+2; /* for '\n\0' */ |
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| 62 | screen.xoff = xoff; |
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| 63 | screen.yoff = yoff; |
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| 64 | screen.minx = minx; |
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| 65 | screen.miny = miny; |
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| 66 | |
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| 67 | if(( screen.dots=malloc(screen.rows*screen.cols) )==NULL) { |
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| 68 | perror("*** no memory for screen: "); |
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| 69 | exit(1); |
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| 70 | } |
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| 71 | |
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| 72 | j=screen.rows*screen.cols; |
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| 73 | for(i=0; i<j; i++) |
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| 74 | screen.dots[i]=' '; |
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| 75 | |
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| 76 | /* scale of Y to X on the screen, i.e. x=YXSCALE*y */ |
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| 77 | /* 3/4 is the approx. ratio of Y/X sizes of the physical screen */ |
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| 78 | yxscale = ((double)physx/(double)physy*3.0/4.0); |
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| 79 | |
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| 80 | /* scale of "logical" to "physical", i.e. physical=PHYSSCALE*logical */ |
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| 81 | screen.yscale = fmin( ((double)physy-0.51)/(maxy+1-miny), |
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| 82 | ((double)physx-0.51)/yxscale/(maxx+1-minx) ); |
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| 83 | screen.xscale = yxscale * screen.yscale; |
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| 84 | } |
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| 85 | |
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| 86 | void |
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| 87 | drawcurve(mark, ax,ay, bx,by, cx,cy, dx,dy) |
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| 88 | int mark, ax,ay, bx,by, cx,cy, dx,dy; |
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| 89 | { |
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| 90 | int i,j,n,c; |
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| 91 | int maxn=(screen.physx + screen.physy)*2; |
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| 92 | |
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| 93 | ax-=screen.minx; bx-=screen.minx; cx-=screen.minx; dx-=screen.minx; |
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| 94 | ay-=screen.miny; by-=screen.miny; cy-=screen.miny; dy-=screen.miny; |
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| 95 | |
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| 96 | for(i=0; i<=maxn; i++) { |
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| 97 | double t, t2, t3, nt, nt2, nt3; |
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| 98 | |
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| 99 | t=(double)i/(double)maxn; t2=t*t; t3=t2*t; |
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| 100 | nt=1-t; nt2=nt*nt; nt3=nt2*nt; |
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| 101 | |
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| 102 | setfdot( |
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| 103 | mark, |
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| 104 | ( ax*t3 + bx*3*t2*nt + cx*3*t*nt2 + dx*nt3 ), |
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| 105 | ( ay*t3 + by*3*t2*nt + cy*3*t*nt2 + dy*nt3 ) |
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| 106 | ); |
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| 107 | } |
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| 108 | } |
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| 109 | |
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| 110 | /* draw curve and mark direction at the ends */ |
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| 111 | |
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| 112 | void |
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| 113 | drawcurvedir(mark, ax,ay, bx,by, cx,cy, dx,dy) |
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| 114 | int mark, ax,ay, bx,by, cx,cy, dx,dy; |
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| 115 | { |
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| 116 | int i,j,n,c; |
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| 117 | int maxn=(screen.physx + screen.physy)*2; |
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| 118 | double t, t2, t3, nt, nt2, nt3; |
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| 119 | int markb, marke; |
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| 120 | |
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| 121 | ax-=screen.minx; bx-=screen.minx; cx-=screen.minx; dx-=screen.minx; |
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| 122 | ay-=screen.miny; by-=screen.miny; cy-=screen.miny; dy-=screen.miny; |
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| 123 | |
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| 124 | if(bx==ax && by==ay) { |
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| 125 | markb=mark; |
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| 126 | } else if( abs(by-ay) > abs(bx-ax) ) { |
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| 127 | if(by>ay) |
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| 128 | markb='^'; |
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| 129 | else |
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| 130 | markb='v'; |
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| 131 | } else { |
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| 132 | if(bx>ax) |
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| 133 | markb='>'; |
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| 134 | else |
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| 135 | markb='<'; |
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| 136 | } |
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| 137 | |
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| 138 | if(dx==cx && dy==cy) { |
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| 139 | marke=mark; |
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| 140 | } else if( abs(dy-cy) > abs(dx-cx) ) { |
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| 141 | if(dy>cy) |
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| 142 | marke='^'; |
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| 143 | else |
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| 144 | marke='v'; |
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| 145 | } else { |
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| 146 | if(dx>cx) |
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| 147 | marke='>'; |
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| 148 | else |
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| 149 | marke='<'; |
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| 150 | } |
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| 151 | |
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| 152 | for(i=1; i<maxn; i++) { |
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| 153 | t=(double)i/(double)maxn; t2=t*t; t3=t2*t; |
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| 154 | nt=1-t; nt2=nt*nt; nt3=nt2*nt; |
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| 155 | |
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| 156 | setfdot( |
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| 157 | mark, |
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| 158 | ( ax*t3 + bx*3*t2*nt + cx*3*t*nt2 + dx*nt3 ), |
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| 159 | ( ay*t3 + by*3*t2*nt + cy*3*t*nt2 + dy*nt3 ) |
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| 160 | ); |
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| 161 | } |
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| 162 | /* mark the ends */ |
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| 163 | setfdot( markb, (double)ax, (double)ay ); |
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| 164 | setfdot( marke, (double)dx, (double)dy ); |
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| 165 | } |
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| 166 | |
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| 167 | void |
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| 168 | drawdot(mark, x, y) |
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| 169 | int mark; |
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| 170 | int x, y; |
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| 171 | { |
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| 172 | x=(int)((x-screen.minx)*screen.xscale+0.5); |
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| 173 | y=(int)((y-screen.miny)*screen.yscale+0.5); |
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| 174 | |
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| 175 | if(y<0 || y>=screen.physy || x<0 || x>=screen.physx) |
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| 176 | return; |
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| 177 | screendot(x,y)=mark; |
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| 178 | } |
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| 179 | |
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| 180 | void |
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| 181 | setabsdot(mark, x, y) |
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| 182 | int x, y, mark; |
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| 183 | { |
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| 184 | if(y<0 || y>=screen.rows || x<0 || x>=screen.cols-2) |
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| 185 | return; |
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| 186 | screenabsdot(x,y)=mark; |
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| 187 | } |
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| 188 | |
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| 189 | void |
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| 190 | setfdot(mark, fx, fy) |
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| 191 | int mark; |
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| 192 | double fx, fy; |
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| 193 | { |
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| 194 | int x, y; |
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| 195 | |
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| 196 | x=(int)(fx*screen.xscale+0.5); |
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| 197 | y=(int)(fy*screen.yscale+0.5); |
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| 198 | |
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| 199 | if(y<0 || y>=screen.physy || x<0 || x>=screen.physx) |
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| 200 | return; |
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| 201 | screendot(x,y)=mark; |
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| 202 | } |
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| 203 | |
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| 204 | /* destructive */ |
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| 205 | void |
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| 206 | printscreen(f) |
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| 207 | FILE *f; |
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| 208 | { |
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| 209 | int r; |
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| 210 | char *pi, *pc; |
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| 211 | |
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| 212 | for(r=screen.rows-1; r>=0; r--) { |
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| 213 | pc=&screenabsdot(0,r); |
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| 214 | for(pi=&screenabsdot(-2,r+1); pi>=pc && *pi == ' '; pi--) |
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| 215 | {} |
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| 216 | pi[1]='\n'; |
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| 217 | pi[2]=0; |
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| 218 | fputs(pc, f); |
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| 219 | } |
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| 220 | } |
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