0024758: Sample DRAW scripts for demonstrating sweeping algorithm

Two scripts added:
samples/tcl/drill.tcl: creates model of a twist drill bit
samples/tcl/cutter.tcl: creates simplified model of a milling cutter
Added test cases bugs/modalg_5/bug24758_1 bug24758_2

samples/tcl/drill.tcl

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+# Sample: creation of simple twist drill bit
+
+pload MODELING VISUALIZATION
+
+# drill parameters (some terms taken from http://www.drill-bits.cn/drill-bits-quality.asp)
+dset R  4.    ;# outer radius
+dset D  2*R   ;# diameter
+dset Rr 3.5   ;# chisel radius (outer radius minus body clearance)
+
+dset b  1.    ;# web thickness (approximate)
+dset d  b/2
+
+dset H  80.   ;# height of the spiral part
+dset a  3.*pi ;# total angle of spiral rotation
+
+dset sigma 118 ;# point angle, in degrees
+
+# Create section profile by sequence of Boolean operations
+# on simple planar objects
+puts "Creating the drill section profile..."
+
+polyline rectangle1 d -R 0  R -R 0  -d R 0  -R R 0  d -R 0
+
+circle circle1 0 0 0  0 0 1 R
+mkedge circle1 circle1
+wire circle1 circle1
+
+circle circle2 0 0 0  0 0 1 Rr
+mkedge circle2 circle2
+wire circle2 circle2
+
+plane p0
+mkface rectangle1 p0 rectangle1
+mkface circle1 p0 circle1
+mkface circle2 p0 circle2
+
+bcommon sec rectangle1 circle1
+# note use of 'fuse' instead of 'bfuse' -- we need to get single face
+fuse sec sec circle2
+
+# Construct flute profile so as to have cutting lip straight after sharpening.
+# Here we need to take into account spiral shift of the flute edge
+# along the point length -- the way to do that is to make spiral
+# from the desired cutting lip edge and then intersect it by plane
+polyline lip d -d/2 0  d -R -R/tan(sigma/2*pi/180)
+
+polyline sp 0 0 0  0 0 H
+cylinder cc 0 0 0  0 0 1  0 -4 0  4
+line ll 0 0 a 80
+trim ll ll 0 sqrt(a*a+H*H)
+
+vertex v1 0 -R 0
+vertex v2 0 -R H
+trotate v2 0 0 0 0 0 1 180.*a/pi
+mkedge ee ll cc v1 v2
+wire gg ee
+ 
+mksweep sp
+setsweep -G gg 0 0
+addsweep lip
+buildsweep spiral -S
+
+mkface f0 p0 -R R -R R
+bsection sflute spiral f0
+
+# here we rely on that section curve is parameterized from 0 to 1 
+# and directed as cutting lip edge;
+# note that this can change if intersection algorithm is modified
+explode sflute e
+mkcurve cflute sflute_1
+cvalue cflute 0. x0 y0 z0
+cvalue cflute 1. x1 y1 z1
+vertex vf0 x0 y0 z0 
+vertex vf1 x1 y1 z1
+
+# -- variant: replace curve by arc with start at x0,y0,z0 and end at x1,y1,z1,
+# -- such that tanget at start point is along Y
+#dset Rflute ((x1-x0)*(x1-x0)+(y1-y0)*(y1-y0))/(2*(x1-x0))
+#circle aflute x0+Rflute y0 0  0 0 1  Rflute
+#mkedge sflute_1 aflute vf0 vf1
+
+# make rounding in the flute; use circle with radius Rr/2
+circle cround x0+Rr/2 y0 0  0 0 1 Rr/2
+vertex vf3 x0+Rr y0 0 
+mkedge sflute_2 cround vf3 vf0
+vertex vf2 R -R 0
+edge sflute_3 vf3 vf2
+edge sflute_4 vf2 vf1
+wire w2 sflute_1 sflute_2 sflute_3 sflute_4
+mkface flute p0 w2
+
+# cut flute from profile
+bcut sec sec flute
+trotate flute 0 0 0 0 0 1 180.
+bcut sec sec flute
+donly sec
+
+# sweep profile to get a drill body
+puts "Sweeping the profile..."
+
+mksweep sp
+setsweep -G gg 0 0
+explode sec w
+addsweep sec_1
+buildsweep base -S
+
+# sharpen the drill (see http://tool-land.ru/zatochka-sverla.php)
+puts "Sharpening..."
+
+dset theta a*R/H*sin((90-sigma/2)*pi/180)
+plane ax1 d 1.9*D "H+1.9*D/tan(pi/180.*sigma/2.)" 0 -1 -1
+pcone sh1 ax1 0 100*sin((sigma-90)/2*pi/180.) 100
+trotate sh1 0 0 0 0 0 1 -theta*180/pi
+tcopy sh1 sh2
+trotate sh2 0 0 0 0 0 1 180
+box sh -D/2 -D/2 72 D D 20
+bcommon qq sh1 sh2
+bcut sharpener sh qq
+
+bcut body base sharpener
+
+# make a shank
+puts "Making a shank..."
+plane pl2 0 0 -40  0 0 1
+pcylinder shank pl2 4 40
+pcone transit R 0 R
+plane pl3 0 0 -40  0 0 -0.5
+pcone tail pl3 R 0 0.5
+bfuse shank shank tail
+bfuse shank shank transit
+bfuse drill body shank
+
+# check result
+checkshape drill
+
+# show result
+puts "Displaying result..."
+incmesh drill 0.01
+vdisplay drill
+vsetdispmode drill 1
+vfit
+
+# show section and sweep path
+ttranslate sec_1 0 0 H; trotate sec_1 0 0 0 0 0 1 a*180/pi; incmesh gg 0.01; vdisplay gg sec_1