////////////////////////////////////////////////////////////////////// // LibFile: drawing.scad // This file includes stroke(), which converts a path into a // geometric object, like drawing with a pen. It even works on // three-dimensional paths. You can make a dashed line or add arrow // heads. The turtle() function provides a turtle graphics style // approach for producing paths. The arc() function produces arc paths, // and helix() produces helical paths. // Includes: // include // FileGroup: Basic Modeling // FileSummary: Create and draw 2D and 3D paths: arc, helix, turtle graphics // FileFootnotes: STD=Included in std.scad ////////////////////////////////////////////////////////////////////// // Section: Line Drawing // Module: stroke() // Usage: // stroke(path, [width], [closed], [endcaps], [endcap_width], [endcap_length], [endcap_extent], [trim]); // stroke(path, [width], [closed], [endcap1], [endcap2], [endcap_width1], [endcap_width2], [endcap_length1], [endcap_length2], [endcap_extent1], [endcap_extent2], [trim1], [trim2]); // Topics: Paths (2D), Paths (3D), Drawing Tools // See Also: offset_stroke(), path_sweep() // Description: // Draws a 2D or 3D path with a given line width. Joints and each endcap can be replaced with // various marker shapes, and can be assigned different colors. If passed a region instead of // a path, draws each path in the region as a closed polygon by default. If `closed=false` is // given with a region or list of paths, then each path is drawn without the closing line segment. // To facilitate debugging, stroke() accepts "paths" that have a single point. These are drawn with // the style of endcap1, but have their own scale parameter, `singleton_scale`, which defaults to 2 // so that singleton dots with endcap "round" are clearly visible. // . // In 2d the stroke module works by creating a sequence of rectangles (or trapezoids if line width varies) and // filling in the gaps with rounded wedges. This is fast and produces a good result. In 3d the modules // creates a cylinders (or cones) and fills the gaps with rounded wedges made using rotate_extrude. This process will be slow for // long paths due to the 3d unions, and the faces on sequential cylinders may not line up. In many cases, {{path_sweep()}} will be // a better choice, both running faster and producing superior output, when working in three dimensions. // Figure(Med,NoAxes,2D,VPR=[0,0,0],VPD=250): Endcap Types // cap_pairs = [ // ["butt", "chisel" ], // ["round", "square" ], // ["line", "cross" ], // ["x", "diamond"], // ["dot", "block" ], // ["tail", "arrow" ], // ["tail2", "arrow2" ] // ]; // for (i = idx(cap_pairs)) { // fwd((i-len(cap_pairs)/2+0.5)*13) { // stroke([[-20,0], [20,0]], width=3, endcap1=cap_pairs[i][0], endcap2=cap_pairs[i][1]); // color("black") { // stroke([[-20,0], [20,0]], width=0.25, endcaps=false); // left(28) text(text=cap_pairs[i][0], size=5, halign="right", valign="center"); // right(28) text(text=cap_pairs[i][1], size=5, halign="left", valign="center"); // } // } // } // Arguments: // path = The path to draw along. // width = The width of the line to draw. If given as a list of widths, (one for each path point), draws the line with varying thickness to each point. // closed = If true, draw an additional line from the end of the path to the start. // joints = Specifies the joint shape for each joint of the line. If a 2D polygon is given, use that to draw custom joints. // endcaps = Specifies the endcap type for both ends of the line. If a 2D polygon is given, use that to draw custom endcaps. // endcap1 = Specifies the endcap type for the start of the line. If a 2D polygon is given, use that to draw a custom endcap. // endcap2 = Specifies the endcap type for the end of the line. If a 2D polygon is given, use that to draw a custom endcap. // dots = Specifies both the endcap and joint types with one argument. If given `true`, sets both to "dot". If a 2D polygon is given, uses that to draw custom dots. // joint_width = Some joint shapes are wider than the line. This specifies the width of the shape, in multiples of the line width. // endcap_width = Some endcap types are wider than the line. This specifies the size of endcaps, in multiples of the line width. // endcap_width1 = This specifies the size of starting endcap, in multiples of the line width. // endcap_width2 = This specifies the size of ending endcap, in multiples of the line width. // dots_width = This specifies the size of the joints and endcaps, in multiples of the line width. // joint_length = Length of joint shape, in multiples of the line width. // endcap_length = Length of endcaps, in multiples of the line width. // endcap_length1 = Length of starting endcap, in multiples of the line width. // endcap_length2 = Length of ending endcap, in multiples of the line width. // dots_length = Length of both joints and endcaps, in multiples of the line width. // joint_extent = Extents length of joint shape, in multiples of the line width. // endcap_extent = Extents length of endcaps, in multiples of the line width. // endcap_extent1 = Extents length of starting endcap, in multiples of the line width. // endcap_extent2 = Extents length of ending endcap, in multiples of the line width. // dots_extent = Extents length of both joints and endcaps, in multiples of the line width. // joint_angle = Extra rotation given to joint shapes, in degrees. If not given, the shapes are fully spun (for 3D lines). // endcap_angle = Extra rotation given to endcaps, in degrees. If not given, the endcaps are fully spun (for 3D lines). // endcap_angle1 = Extra rotation given to a starting endcap, in degrees. If not given, the endcap is fully spun (for 3D lines). // endcap_angle2 = Extra rotation given to a ending endcap, in degrees. If not given, the endcap is fully spun (for 3D lines). // dots_angle = Extra rotation given to both joints and endcaps, in degrees. If not given, the endcap is fully spun (for 3D lines). // trim = Trim the the start and end line segments by this much, to keep them from interfering with custom endcaps. // trim1 = Trim the the starting line segment by this much, to keep it from interfering with a custom endcap. // trim2 = Trim the the ending line segment by this much, to keep it from interfering with a custom endcap. // color = If given, sets the color of the line segments, joints and endcap. // endcap_color = If given, sets the color of both endcaps. Overrides `color=` and `dots_color=`. // endcap_color1 = If give, sets the color of the starting endcap. Overrides `color=`, `dots_color=`, and `endcap_color=`. // endcap_color2 = If given, sets the color of the ending endcap. Overrides `color=`, `dots_color=`, and `endcap_color=`. // joint_color = If given, sets the color of the joints. Overrides `color=` and `dots_color=`. // dots_color = If given, sets the color of the endcaps and joints. Overrides `color=`. // singleton_scale = Change the scale of the endcap shape drawn for singleton paths. Default: 2. // convexity = Max number of times a line could intersect a wall of an endcap. // Example(2D): Drawing a Path // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // stroke(path, width=20); // Example(2D): Closing a Path // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // stroke(path, width=20, endcaps=true, closed=true); // Example(2D): Fancy Arrow Endcaps // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // stroke(path, width=10, endcaps="arrow2"); // Example(2D): Modified Fancy Arrow Endcaps // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // stroke(path, width=10, endcaps="arrow2", endcap_width=6, endcap_length=3, endcap_extent=2); // Example(2D): Mixed Endcaps // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // stroke(path, width=10, endcap1="tail2", endcap2="arrow2"); // Example(2D): Plotting Points. Setting endcap_angle to zero results in the weird arrow orientation. // path = [for (a=[0:30:360]) [a-180, 60*sin(a)]]; // stroke(path, width=3, joints="diamond", endcaps="arrow2", endcap_angle=0, endcap_width=5, joint_angle=0, joint_width=5); // Example(2D): Joints and Endcaps // path = [for (a=[0:30:360]) [a-180, 60*sin(a)]]; // stroke(path, width=8, joints="dot", endcaps="arrow2"); // Example(2D): Custom Endcap Shapes // path = [[0,100], [100,100], [200,0], [100,-100], [100,0]]; // arrow = [[0,0], [2,-3], [0.5,-2.3], [2,-4], [0.5,-3.5], [-0.5,-3.5], [-2,-4], [-0.5,-2.3], [-2,-3]]; // stroke(path, width=10, trim=3.5, endcaps=arrow); // Example(2D): Variable Line Width // path = circle(d=50,$fn=18); // widths = [for (i=idx(path)) 10*i/len(path)+2]; // stroke(path,width=widths,$fa=1,$fs=1); // Example: 3D Path with Endcaps // path = rot([15,30,0], p=path3d(pentagon(d=50))); // stroke(path, width=2, endcaps="arrow2", $fn=18); // Example: 3D Path with Flat Endcaps // path = rot([15,30,0], p=path3d(pentagon(d=50))); // stroke(path, width=2, endcaps="arrow2", endcap_angle=0, $fn=18); // Example: 3D Path with Mixed Endcaps // path = rot([15,30,0], p=path3d(pentagon(d=50))); // stroke(path, width=2, endcap1="arrow2", endcap2="tail", endcap_angle2=0, $fn=18); // Example: 3D Path with Joints and Endcaps // path = [for (i=[0:10:360]) [(i-180)/2,20*cos(3*i),20*sin(3*i)]]; // stroke(path, width=2, joints="dot", endcap1="round", endcap2="arrow2", joint_width=2.0, endcap_width2=3, $fn=18); // Example: Coloring Lines, Joints, and Endcaps // path = [for (i=[0:15:360]) [(i-180)/3,20*cos(2*i),20*sin(2*i)]]; // stroke( // path, width=2, joints="dot", endcap1="dot", endcap2="arrow2", // color="lightgreen", joint_color="red", endcap_color="blue", // joint_width=2.0, endcap_width2=3, $fn=18 // ); // Example(2D): Simplified Plotting // path = [for (i=[0:15:360]) [(i-180)/3,20*cos(2*i)]]; // stroke(path, width=2, dots=true, color="lightgreen", dots_color="red", $fn=18); // Example(2D): Drawing a Region // rgn = [square(100,center=true), circle(d=60,$fn=18)]; // stroke(rgn, width=2); // Example(2D): Drawing a List of Lines // paths = [ // for (y=[-60:60:60]) [ // for (a=[-180:15:180]) // [a, 2*y+60*sin(a+y)] // ] // ]; // stroke(paths, closed=false, width=5); // Example(2D): Paths with a singleton. Note that the singleton is not a single point, but a list containing a single point. // stroke([ // [[0,0],[1,1]], // [[1.5,1.5]], // [[2,2],[3,3]] // ],width=0.2,closed=false,$fn=16); function stroke( path, width=1, closed, endcaps, endcap1, endcap2, joints, dots, endcap_width, endcap_width1, endcap_width2, joint_width, dots_width, endcap_length, endcap_length1, endcap_length2, joint_length, dots_length, endcap_extent, endcap_extent1, endcap_extent2, joint_extent, dots_extent, endcap_angle, endcap_angle1, endcap_angle2, joint_angle, dots_angle, endcap_color, endcap_color1, endcap_color2, joint_color, dots_color, color, trim, trim1, trim2, singleton_scale=2, convexity=10 ) = no_function("stroke"); module stroke( path, width=1, closed, endcaps, endcap1, endcap2, joints, dots, endcap_width, endcap_width1, endcap_width2, joint_width, dots_width, endcap_length, endcap_length1, endcap_length2, joint_length, dots_length, endcap_extent, endcap_extent1, endcap_extent2, joint_extent, dots_extent, endcap_angle, endcap_angle1, endcap_angle2, joint_angle, dots_angle, endcap_color, endcap_color1, endcap_color2, joint_color, dots_color, color, trim, trim1, trim2, singleton_scale=2, convexity=10 ) { no_children($children); module setcolor(clr) { if (clr==undef) { children(); } else { color(clr) children(); } } function _shape_defaults(cap) = cap==undef? [1.00, 0.00, 0.00] : cap==false? [1.00, 0.00, 0.00] : cap==true? [1.00, 1.00, 0.00] : cap=="butt"? [1.00, 0.00, 0.00] : cap=="round"? [1.00, 1.00, 0.00] : cap=="chisel"? [1.00, 1.00, 0.00] : cap=="square"? [1.00, 1.00, 0.00] : cap=="block"? [2.00, 1.00, 0.00] : cap=="diamond"? [2.50, 1.00, 0.00] : cap=="dot"? [2.00, 1.00, 0.00] : cap=="x"? [2.50, 0.40, 0.00] : cap=="cross"? [3.00, 0.33, 0.00] : cap=="line"? [3.50, 0.22, 0.00] : cap=="arrow"? [3.50, 0.40, 0.50] : cap=="arrow2"? [3.50, 1.00, 0.14] : cap=="tail"? [3.50, 0.47, 0.50] : cap=="tail2"? [3.50, 0.28, 0.50] : is_path(cap)? [0.00, 0.00, 0.00] : assert(false, str("Invalid cap or joint: ",cap)); function _shape_path(cap,linewidth,w,l,l2) = ( cap=="butt" || cap==false || cap==undef ? [] : cap=="round" || cap==true ? scale([w,l], p=circle(d=1, $fn=max(8, segs(w/2)))) : cap=="chisel"? scale([w,l], p=circle(d=1,$fn=4)) : cap=="diamond"? circle(d=w,$fn=4) : cap=="square"? scale([w,l], p=square(1,center=true)) : cap=="block"? scale([w,l], p=square(1,center=true)) : cap=="dot"? circle(d=w, $fn=max(12, segs(w*3/2))) : cap=="x"? [for (a=[0:90:270]) each rot(a,p=[[w+l/2,w-l/2]/2, [w-l/2,w+l/2]/2, [0,l/2]]) ] : cap=="cross"? [for (a=[0:90:270]) each rot(a,p=[[l,w]/2, [-l,w]/2, [-l,l]/2]) ] : cap=="line"? scale([w,l], p=square(1,center=true)) : cap=="arrow"? [[0,0], [w/2,-l2], [w/2,-l2-l], [0,-l], [-w/2,-l2-l], [-w/2,-l2]] : cap=="arrow2"? [[0,0], [w/2,-l2-l], [0,-l], [-w/2,-l2-l]] : cap=="tail"? [[0,0], [w/2,l2], [w/2,l2-l], [0,-l], [-w/2,l2-l], [-w/2,l2]] : cap=="tail2"? [[w/2,0], [w/2,-l], [0,-l-l2], [-w/2,-l], [-w/2,0]] : is_path(cap)? cap : assert(false, str("Invalid endcap: ",cap)) ) * linewidth; closed = default(closed, is_region(path)); check1 = assert(is_bool(closed)); dots = dots==true? "dot" : dots; endcap1 = first_defined([endcap1, endcaps, dots, "round"]); endcap2 = first_defined([endcap2, endcaps, if (!closed) dots, "round"]); joints = first_defined([joints, dots, "round"]); check2 = assert(is_bool(endcap1) || is_string(endcap1) || is_path(endcap1)) assert(is_bool(endcap2) || is_string(endcap2) || is_path(endcap2)) assert(is_bool(joints) || is_string(joints) || is_path(joints)); endcap1_dflts = _shape_defaults(endcap1); endcap2_dflts = _shape_defaults(endcap2); joint_dflts = _shape_defaults(joints); endcap_width1 = first_defined([endcap_width1, endcap_width, dots_width, endcap1_dflts[0]]); endcap_width2 = first_defined([endcap_width2, endcap_width, dots_width, endcap2_dflts[0]]); joint_width = first_defined([joint_width, dots_width, joint_dflts[0]]); endcap_length1 = first_defined([endcap_length1, endcap_length, dots_length, endcap1_dflts[1]*endcap_width1]); endcap_length2 = first_defined([endcap_length2, endcap_length, dots_length, endcap2_dflts[1]*endcap_width2]); joint_length = first_defined([joint_length, dots_length, joint_dflts[1]*joint_width]); endcap_extent1 = first_defined([endcap_extent1, endcap_extent, dots_extent, endcap1_dflts[2]*endcap_width1]); endcap_extent2 = first_defined([endcap_extent2, endcap_extent, dots_extent, endcap2_dflts[2]*endcap_width2]); joint_extent = first_defined([joint_extent, dots_extent, joint_dflts[2]*joint_width]); endcap_angle1 = first_defined([endcap_angle1, endcap_angle, dots_angle]); endcap_angle2 = first_defined([endcap_angle2, endcap_angle, dots_angle]); joint_angle = first_defined([joint_angle, dots_angle]); check3 = assert(all_nonnegative([endcap_length1])) assert(all_nonnegative([endcap_length2])) assert(all_nonnegative([joint_length])); assert(all_nonnegative([endcap_extent1])) assert(all_nonnegative([endcap_extent2])) assert(all_nonnegative([joint_extent])); assert(is_undef(endcap_angle1)||is_finite(endcap_angle1)) assert(is_undef(endcap_angle2)||is_finite(endcap_angle2)) assert(is_undef(joint_angle)||is_finite(joint_angle)) assert(all_positive([singleton_scale])) assert(all_positive(width)); endcap_color1 = first_defined([endcap_color1, endcap_color, dots_color, color]); endcap_color2 = first_defined([endcap_color2, endcap_color, dots_color, color]); joint_color = first_defined([joint_color, dots_color, color]); // We want to allow "paths" with length 1, so we can't use the normal path/region checks paths = is_matrix(path) ? [path] : path; assert(is_list(paths),"The path argument must be a list of 2D or 3D points, or a region."); for (path = paths) { pathvalid = is_path(path,[2,3]) || same_shape(path,[[0,0]]) || same_shape(path,[[0,0,0]]); assert(pathvalid,"The path argument must be a list of 2D or 3D points, or a region."); path = deduplicate( closed? list_wrap(path) : path ); check4 = assert(is_num(width) || len(width)==len(path), "width must be a number or a vector the same length as the path (or all components of a region)"); width = is_num(width)? [for (x=path) width] : width; endcap_shape1 = _shape_path(endcap1, width[0], endcap_width1, endcap_length1, endcap_extent1); endcap_shape2 = _shape_path(endcap2, last(width), endcap_width2, endcap_length2, endcap_extent2); trim1 = width[0] * first_defined([ trim1, trim, (endcap1=="arrow")? endcap_length1-0.01 : (endcap1=="arrow2")? endcap_length1*3/4 : 0 ]); trim2 = last(width) * first_defined([ trim2, trim, (endcap2=="arrow")? endcap_length2-0.01 : (endcap2=="arrow2")? endcap_length2*3/4 : 0 ]); check10 = assert(is_finite(trim1)) assert(is_finite(trim2)); if (len(path) == 1) { if (len(path[0]) == 2) { // Endcap1 setcolor(endcap_color1) { translate(path[0]) { mat = is_undef(endcap_angle1)? ident(3) : zrot(endcap_angle1); multmatrix(mat) polygon(scale(singleton_scale,endcap_shape1)); } } } else { // Endcap1 setcolor(endcap_color1) { translate(path[0]) { $fn = segs(width[0]/2); if (is_undef(endcap_angle1)) { rotate_extrude(convexity=convexity) { right_half(planar=true) { polygon(endcap_shape1); } } } else { rotate([90,0,endcap_angle1]) { linear_extrude(height=max(widths[0],0.001), center=true, convexity=convexity) { polygon(endcap_shape1); } } } } } } } else { dummy=assert(trim10) theta = v_theta(v1) - sign(ang)*90; ang_eps = 0.1; if (!approx(ang,0)) arc(d=widths[i], angle=[theta-ang_eps, theta+ang+ang_eps], wedge=true); } } } } // Endcap1 setcolor(endcap_color1) { translate(path[0]) { mat = is_undef(endcap_angle1)? rot(from=BACK,to=start_vec) : zrot(endcap_angle1); multmatrix(mat) polygon(endcap_shape1); } } // Endcap2 setcolor(endcap_color2) { translate(last(path)) { mat = is_undef(endcap_angle2)? rot(from=BACK,to=end_vec) : zrot(endcap_angle2); multmatrix(mat) polygon(endcap_shape2); } } } else { rotmats = cumprod([ for (i = idx(path2,e=-2)) let( vec1 = i==0? UP : unit(path2[i]-path2[i-1], UP), vec2 = unit(path2[i+1]-path2[i], UP) ) rot(from=vec1,to=vec2) ]); sides = [ for (i = idx(path2,e=-2)) quantup(segs(max(widths[i],widths[i+1])/2),4) ]; // Straight segments setcolor(color) { for (i = idx(path2,e=-2)) { dist = norm(path2[i+1] - path2[i]); w1 = widths[i]/2; w2 = widths[i+1]/2; $fn = sides[i]; translate(path2[i]) { multmatrix(rotmats[i]) { cylinder(r1=w1, r2=w2, h=dist, center=false); } } } } // Joints setcolor(joint_color) { for (i = [1:1:len(path2)-2]) { $fn = sides[i]; translate(path2[i]) { if (joints != undef && joints != "round") { joint_shape = _shape_path( joints, width[i], joint_width, joint_length, joint_extent ); multmatrix(rotmats[i] * xrot(180)) { $fn = sides[i]; if (is_undef(joint_angle)) { rotate_extrude(convexity=convexity) { right_half(planar=true) { polygon(joint_shape); } } } else { rotate([90,0,joint_angle]) { linear_extrude(height=max(widths[i],0.001), center=true, convexity=convexity) { polygon(joint_shape); } } } } } else { corner = select(path2,i-1,i+1); axis = vector_axis(corner); ang = vector_angle(corner); if (!approx(ang,0)) { frame_map(x=path2[i-1]-path2[i], z=-axis) { zrot(90-0.5) { rotate_extrude(angle=180-ang+1) { arc(d=widths[i], start=-90, angle=180); } } } } } } } } // Endcap1 setcolor(endcap_color1) { translate(path[0]) { multmatrix(rotmats[0] * xrot(180)) { $fn = sides[0]; if (is_undef(endcap_angle1)) { rotate_extrude(convexity=convexity) { right_half(planar=true) { polygon(endcap_shape1); } } } else { rotate([90,0,endcap_angle1]) { linear_extrude(height=max(widths[0],0.001), center=true, convexity=convexity) { polygon(endcap_shape1); } } } } } } // Endcap2 setcolor(endcap_color2) { translate(last(path)) { multmatrix(last(rotmats)) { $fn = last(sides); if (is_undef(endcap_angle2)) { rotate_extrude(convexity=convexity) { right_half(planar=true) { polygon(endcap_shape2); } } } else { rotate([90,0,endcap_angle2]) { linear_extrude(height=max(last(widths),0.001), center=true, convexity=convexity) { polygon(endcap_shape2); } } } } } } } } } } // Function&Module: dashed_stroke() // Usage: As a Module // dashed_stroke(path, dashpat, [width=], [closed=]); // Usage: As a Function // dashes = dashed_stroke(path, dashpat, [closed=]); // Topics: Paths, Drawing Tools // See Also: stroke(), path_cut() // Description: // Given a path (or region) and a dash pattern, creates a dashed line that follows that // path or region boundary with the given dash pattern. // - When called as a function, returns a list of dash sub-paths. // - When called as a module, draws all those subpaths using `stroke()`. // When called as a module the dash pattern is multiplied by the line width. When called as // a function the dash pattern applies as you specify it. // Arguments: // path = The path or region to subdivide into dashes. // dashpat = A list of alternating dash lengths and space lengths for the dash pattern. This will be scaled by the width of the line. // --- // width = The width of the dashed line to draw. Module only. Default: 1 // closed = If true, treat path as a closed polygon. Default: false // fit = If true, shrink or stretch the dash pattern so that the path ends ofter a logical dash. Default: true // roundcaps = (Module only) If true, draws dashes with rounded caps. This often looks better. Default: true // mindash = (Function only) Specifies the minimal dash length to return at the end of a path when fit is false. Default: 0.5 // Example(2D): Open Path // path = [for (a=[-180:10:180]) [a/3,20*sin(a)]]; // dashed_stroke(path, [3,2], width=1); // Example(2D): Closed Polygon // path = circle(d=100,$fn=72); // dashpat = [10,2, 3,2, 3,2]; // dashed_stroke(path, dashpat, width=1, closed=true); // Example(FlatSpin,VPD=250): 3D Dashed Path // path = [for (a=[-180:5:180]) [a/3, 20*cos(3*a), 20*sin(3*a)]]; // dashed_stroke(path, [3,2], width=1); function dashed_stroke(path, dashpat=[3,3], closed=false, fit=true, mindash=0.5) = is_region(path) ? [ for (p = path) each dashed_stroke(p, dashpat, closed=true, fit=fit) ] : let( path = closed? list_wrap(path) : path, dashpat = len(dashpat)%2==0? dashpat : concat(dashpat,[0]), plen = path_length(path), dlen = sum(dashpat), doff = cumsum(dashpat), freps = plen / dlen, reps = max(1, fit? round(freps) : floor(freps)), tlen = !fit? plen : reps * dlen + (closed? 0 : dashpat[0]), sc = plen / tlen, cuts = [ for (i = [0:1:reps], off = doff*sc) let (x = i*dlen*sc + off) if (x > 0 && x < plen) x ], dashes = path_cut(path, cuts, closed=false), dcnt = len(dashes), evens = [ for (i = idx(dashes)) if (i % 2 == 0) let( dash = dashes[i] ) if (i < dcnt-1 || path_length(dash) > mindash) dashes[i] ] ) evens; module dashed_stroke(path, dashpat=[3,3], width=1, closed=false, fit=true, roundcaps=false) { no_children($children); segs = dashed_stroke(path, dashpat=dashpat*width, closed=closed, fit=fit, mindash=0.5*width); for (seg = segs) stroke(seg, width=width, endcaps=roundcaps? "round" : false); } // Section: Computing paths // Function&Module: arc() // Usage: 2D arc from 0ยบ to `angle` degrees. // path=arc(n, r|d=, angle); // Usage: 2D arc from START to END degrees. // path=arc(n, r|d=, angle=[START,END]); // Usage: 2D arc from `start` to `start+angle` degrees. // path=arc(n, r|d=, start=, angle=); // Usage: 2D circle segment by `width` and `thickness`, starting and ending on the X axis. // path=arc(n, width=, thickness=); // Usage: Shortest 2D or 3D arc around centerpoint `cp`, starting at P0 and ending on the vector pointing from `cp` to `P1`. // path=arc(n, cp=, points=[P0,P1], [long=], [cw=], [ccw=]); // Usage: 2D or 3D arc, starting at `P0`, passing through `P1` and ending at `P2`. // path=arc(n, points=[P0,P1,P2]); // Usage: 2D or 3D arc, fron tangent point on segment `[P0,P1]` to the tangent point on segment `[P1,P2]`. // path=arc(n, corner=[P0,P1,P2], r=); // Usage: as module // arc(...) [ATTACHMENTS]; // Topics: Paths (2D), Paths (3D), Shapes (2D), Path Generators // Description: // If called as a function, returns a 2D or 3D path forming an arc. // If called as a module, creates a 2D arc polygon or pie slice shape. // Arguments: // n = Number of vertices to form the arc curve from. // r = Radius of the arc. // angle = If a scalar, specifies the end angle in degrees (relative to start parameter). If a vector of two scalars, specifies start and end angles. // --- // d = Diameter of the arc. // cp = Centerpoint of arc. // points = Points on the arc. // corner = A path of two segments to fit an arc tangent to. // long = if given with cp and points takes the long arc instead of the default short arc. Default: false // cw = if given with cp and 2 points takes the arc in the clockwise direction. Default: false // ccw = if given with cp and 2 points takes the arc in the counter-clockwise direction. Default: false // width = If given with `thickness`, arc starts and ends on X axis, to make a circle segment. // thickness = If given with `width`, arc starts and ends on X axis, to make a circle segment. // start = Start angle of arc. // wedge = If true, include centerpoint `cp` in output to form pie slice shape. // endpoint = If false exclude the last point (function only). Default: true // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). (Module only) Default: `CENTER` // spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). (Module only) Default: `0` // Examples(2D): // arc(n=4, r=30, angle=30, wedge=true); // arc(r=30, angle=30, wedge=true); // arc(d=60, angle=30, wedge=true); // arc(d=60, angle=120); // arc(d=60, angle=120, wedge=true); // arc(r=30, angle=[75,135], wedge=true); // arc(r=30, start=45, angle=75, wedge=true); // arc(width=60, thickness=20); // arc(cp=[-10,5], points=[[20,10],[0,35]], wedge=true); // arc(points=[[30,-5],[20,10],[-10,20]], wedge=true); // Example(2D): Fit to three points. // arc(points=[[5,30],[-10,-10],[30,5]], wedge=true); // Example(2D): // path = arc(points=[[5,30],[-10,-10],[30,5]], wedge=true); // stroke(closed=true, path); // Example(FlatSpin,VPD=175): // path = arc(points=[[0,30,0],[0,0,30],[30,0,0]]); // stroke(path, dots=true, dots_color="blue"); // Example(2D): Fit to a corner. // pts = [[0,40], [-40,-10], [30,0]]; // path = arc(corner=pts, r=20); // stroke(pts, endcaps="arrow2"); // stroke(path, endcap2="arrow2", color="blue"); function arc(n, r, angle, d, cp, points, corner, width, thickness, start, wedge=false, long=false, cw=false, ccw=false, endpoint=true) = assert(is_bool(endpoint)) !endpoint ? assert(!wedge, "endpoint cannot be false if wedge is true") list_head(arc(u_add(n,1),r,angle,d,cp,points,corner,width,thickness,start,wedge,long,cw,ccw,true)) : assert(is_undef(n) || (is_integer(n) && n>=2), "Number of points must be an integer 2 or larger") // First try for 2D arc specified by width and thickness is_def(width) && is_def(thickness)? ( assert(!any_defined([r,cp,points]) && !any([cw,ccw,long]),"Conflicting or invalid parameters to arc") assert(width>0, "Width must be postive") assert(thickness>0, "Thickness must be positive") arc(n,points=[[width/2,0], [0,thickness], [-width/2,0]],wedge=wedge) ) : is_def(angle)? ( let( parmok = !any_defined([points,width,thickness]) && ((is_vector(angle,2) && is_undef(start)) || is_finite(angle)) ) assert(parmok,"Invalid parameters in arc") let( cp = first_defined([cp,[0,0]]), start = is_def(start)? start : is_vector(angle) ? angle[0] : 0, angle = is_vector(angle)? angle[1]-angle[0] : angle, r = get_radius(r=r, d=d) ) assert(is_vector(cp,2),"Centerpoint must be a 2d vector") assert(angle!=0, "Arc has zero length") assert(is_def(r) && r>0, "Arc radius invalid") let( n = is_def(n) ? n : max(3, ceil(segs(r)*abs(angle)/360)), arcpoints = [for(i=[0:n-1]) let(theta = start + i*angle/(n-1)) r*[cos(theta),sin(theta)]+cp], extra = wedge? [cp] : [] ) concat(extra,arcpoints) ) : is_def(corner)? ( assert(is_path(corner,[2,3]),"Point list is invalid") // Arc is 3D, so transform corner to 2D and make a recursive call, then remap back to 3D len(corner[0]) == 3? ( assert(!(cw || ccw), "(Counter)clockwise isn't meaningful in 3d, so `cw` and `ccw` must be false") assert(is_undef(cp) || is_vector(cp,3),"corner are 3d so cp must be 3d") let( plane = [is_def(cp) ? cp : corner[2], corner[0], corner[1]], center2d = is_def(cp) ? project_plane(plane,cp) : undef, points2d = project_plane(plane, corner) ) lift_plane(plane,arc(n,cp=center2d,corner=points2d,wedge=wedge,long=long)) ) : assert(is_path(corner) && len(corner) == 3) let(col = is_collinear(corner[0],corner[1],corner[2])) assert(!col, "Collinear inputs do not define an arc") let( r = get_radius(r=r, d=d) ) assert(is_finite(r) && r>0, "Must specify r= or d= when corner= is given.") let( ci = circle_2tangents(r, corner[0], corner[1], corner[2], tangents=true), cp = ci[0], nrm = ci[1], tp1 = ci[2], tp2 = ci[3], dir = det2([corner[1]-corner[0],corner[2]-corner[1]]) > 0, corner = dir? [tp1,tp2] : [tp2,tp1], theta_start = atan2(corner[0].y-cp.y, corner[0].x-cp.x), theta_end = atan2(corner[1].y-cp.y, corner[1].x-cp.x), angle = posmod(theta_end-theta_start, 360), arcpts = arc(n,cp=cp,r=r,start=theta_start,angle=angle,wedge=wedge) ) dir ? arcpts : reverse(arcpts) ) : assert(is_path(points,[2,3]),"Point list is invalid") // Arc is 3D, so transform points to 2D and make a recursive call, then remap back to 3D len(points[0]) == 3? ( assert(!(cw || ccw), "(Counter)clockwise isn't meaningful in 3d, so `cw` and `ccw` must be false") assert(is_undef(cp) || is_vector(cp,3),"points are 3d so cp must be 3d") let( plane = [is_def(cp) ? cp : points[2], points[0], points[1]], center2d = is_def(cp) ? project_plane(plane,cp) : undef, points2d = project_plane(plane, points) ) lift_plane(plane,arc(n,cp=center2d,points=points2d,wedge=wedge,long=long)) ) : is_def(cp)? ( // Arc defined by center plus two points, will have radius defined by center and points[0] // and extent defined by direction of point[1] from the center assert(is_vector(cp,2), "Centerpoint must be a 2d vector") assert(len(points)==2, "When pointlist has length 3 centerpoint is not allowed") assert(points[0]!=points[1], "Arc endpoints are equal") assert(cp!=points[0]&&cp!=points[1], "Centerpoint equals an arc endpoint") assert(num_true([long,cw,ccw])<=1, str("Only one of `long`, `cw` and `ccw` can be true",cw,ccw,long)) let( angle = vector_angle(points[0], cp, points[1]), v1 = points[0]-cp, v2 = points[1]-cp, prelim_dir = sign(det2([v1,v2])), // z component of cross product dir = prelim_dir != 0 ? prelim_dir : assert(cw || ccw, "Collinear inputs don't define a unique arc") 1, r = norm(v1), final_angle = long || (ccw && dir<0) || (cw && dir>0) ? -dir*(360-angle) : dir*angle, sa = atan2(v1.y,v1.x) ) arc(n,cp=cp,r=r,start=sa,angle=final_angle,wedge=wedge) ) : ( // Final case is arc passing through three points, starting at point[0] and ending at point[3] let(col = is_collinear(points[0],points[1],points[2])) assert(!col, "Collinear inputs do not define an arc") let( cp = line_intersection(_normal_segment(points[0],points[1]),_normal_segment(points[1],points[2])), // select order to be counterclockwise dir = det2([points[1]-points[0],points[2]-points[1]]) > 0, points = dir? select(points,[0,2]) : select(points,[2,0]), r = norm(points[0]-cp), theta_start = atan2(points[0].y-cp.y, points[0].x-cp.x), theta_end = atan2(points[1].y-cp.y, points[1].x-cp.x), angle = posmod(theta_end-theta_start, 360), arcpts = arc(n,cp=cp,r=r,start=theta_start,angle=angle,wedge=wedge) ) dir ? arcpts : reverse(arcpts) ); module arc(n, r, angle, d, cp, points, corner, width, thickness, start, wedge=false, anchor=CENTER, spin=0) { path = arc(n=n, r=r, angle=angle, d=d, cp=cp, points=points, corner=corner, width=width, thickness=thickness, start=start, wedge=wedge); attachable(anchor,spin, two_d=true, path=path, extent=false) { polygon(path); children(); } } // Function: helix() // Usage: // path = helix(l|h, [turns=], [angle=], r=|r1=|r2=, d=|d1=|d2=); // Description: // Returns a 3D helical path on a cone, including the degerate case of flat spirals. // You can specify start and end radii. You can give the length, the helix angle, or the number of turns: two // of these three parameters define the helix. For a flat helix you must give length 0 and a turn count. // Helix will be right handed if turns is positive and left handed if it is negative. // The angle is calculateld based on the radius at the base of the helix. // Arguments: // h/l = Height/length of helix, zero for a flat spiral // --- // turns = Number of turns in helix, positive for right handed // angle = helix angle // r = Radius of helix // r1 = Radius of bottom of helix // r2 = Radius of top of helix // d = Diameter of helix // d1 = Diameter of bottom of helix // d2 = Diameter of top of helix // Example(3D): // stroke(helix(turns=2.5, h=100, r=50), dots=true, dots_color="blue"); // Example(3D): Helix that turns the other way // stroke(helix(turns=-2.5, h=100, r=50), dots=true, dots_color="blue"); // Example(3D): Flat helix (note points are still 3d) // stroke(helix(h=0,r1=50,r2=25,l=0, turns=4)); module helix(l,h,turns,angle, r, r1, r2, d, d1, d2) {no_module();} function helix(l,h,turns,angle, r, r1, r2, d, d1, d2)= let( r1=get_radius(r=r,r1=r1,d=d,d1=d1,dflt=1), r2=get_radius(r=r,r1=r2,d=d,d1=d2,dflt=1), length = first_defined([l,h]) ) assert(num_defined([length,turns,angle])==2,"Must define exactly two of l/h, turns, and angle") assert(is_undef(angle) || length!=0, "Cannot give length 0 with an angle") let( // length advances dz for each turn dz = is_def(angle) && length!=0 ? 2*PI*r1*tan(angle) : length/abs(turns), maxtheta = is_def(turns) ? 360*turns : 360*length/dz, N = segs(max(r1,r2)) ) [for(theta=lerpn(0,maxtheta, max(3,ceil(abs(maxtheta)*N/360)))) let(R=lerp(r1,r2,theta/maxtheta)) [R*cos(theta), R*sin(theta), abs(theta)/360 * dz]]; function _normal_segment(p1,p2) = let(center = (p1+p2)/2) [center, center + norm(p1-p2)/2 * line_normal(p1,p2)]; // Function: turtle() // Usage: // turtle(commands, [state], [full_state=], [repeat=]) // Topics: Shapes (2D), Path Generators (2D), Mini-Language // See Also: turtle3d() // Description: // Use a sequence of turtle graphics commands to generate a path. The parameter `commands` is a list of // turtle commands and optional parameters for each command. The turtle state has a position, movement direction, // movement distance, and default turn angle. If you do not give `state` as input then the turtle starts at the // origin, pointed along the positive x axis with a movement distance of 1. By default, `turtle` returns just // the computed turtle path. If you set `full_state` to true then it instead returns the full turtle state. // You can invoke `turtle` again with this full state to continue the turtle path where you left off. // . // The turtle state is a list with three entries: the path constructed so far, the current step as a 2-vector, the current default angle, // and the current arcsteps setting. // . // Commands | Arguments | What it does // ------------ | ------------------ | ------------------------------- // "move" | [dist] | Move turtle scale*dist units in the turtle direction. Default dist=1. // "xmove" | [dist] | Move turtle scale*dist units in the x direction. Default dist=1. Does not change turtle direction. // "ymove" | [dist] | Move turtle scale*dist units in the y direction. Default dist=1. Does not change turtle direction. // "xymove" | vector | Move turtle by the specified vector. Does not change turtle direction. // "untilx" | xtarget | Move turtle in turtle direction until x==xtarget. Produces an error if xtarget is not reachable. // "untily" | ytarget | Move turtle in turtle direction until y==ytarget. Produces an error if ytarget is not reachable. // "jump" | point | Move the turtle to the specified point // "xjump" | x | Move the turtle's x position to the specified value // "yjump | y | Move the turtle's y position to the specified value // "turn" | [angle] | Turn turtle direction by specified angle, or the turtle's default turn angle. The default angle starts at 90. // "left" | [angle] | Same as "turn" // "right" | [angle] | Same as "turn", -angle // "angle" | angle | Set the default turn angle. // "setdir" | dir | Set turtle direction. The parameter `dir` can be an angle or a vector. // "length" | length | Change the turtle move distance to `length` // "scale" | factor | Multiply turtle move distance by `factor` // "addlength" | length | Add `length` to the turtle move distance // "repeat" | count, commands | Repeats a list of commands `count` times. // "arcleft" | radius, [angle] | Draw an arc from the current position toward the left at the specified radius and angle. The turtle turns by `angle`. A negative angle draws the arc to the right instead of the left, and leaves the turtle facing right. A negative radius draws the arc to the right but leaves the turtle facing left. // "arcright" | radius, [angle] | Draw an arc from the current position toward the right at the specified radius and angle // "arcleftto" | radius, angle | Draw an arc at the given radius turning toward the left until reaching the specified absolute angle. // "arcrightto" | radius, angle | Draw an arc at the given radius turning toward the right until reaching the specified absolute angle. // "arcsteps" | count | Specifies the number of segments to use for drawing arcs. If you set it to zero then the standard `$fn`, `$fa` and `$fs` variables define the number of segments. // // Arguments: // commands = List of turtle commands // state = Starting turtle state (from previous call) or starting point. Default: start at the origin, pointing right. // --- // full_state = If true return the full turtle state for continuing the path in subsequent turtle calls. Default: false // repeat = Number of times to repeat the command list. Default: 1 // // Example(2D): Simple rectangle // path = turtle(["xmove",3, "ymove", "xmove",-3, "ymove",-1]); // stroke(path,width=.1); // Example(2D): Pentagon // path=turtle(["angle",360/5,"move","turn","move","turn","move","turn","move"]); // stroke(path,width=.1,closed=true); // Example(2D): Pentagon using the repeat argument // path=turtle(["move","turn",360/5],repeat=5); // stroke(path,width=.1,closed=true); // Example(2D): Pentagon using the repeat turtle command, setting the turn angle // path=turtle(["angle",360/5,"repeat",5,["move","turn"]]); // stroke(path,width=.1,closed=true); // Example(2D): Pentagram // path = turtle(["move","left",144], repeat=4); // stroke(path,width=.05,closed=true); // Example(2D): Sawtooth path // path = turtle([ // "turn", 55, // "untily", 2, // "turn", -55-90, // "untily", 0, // "turn", 55+90, // "untily", 2.5, // "turn", -55-90, // "untily", 0, // "turn", 55+90, // "untily", 3, // "turn", -55-90, // "untily", 0 // ]); // stroke(path, width=.1); // Example(2D): Simpler way to draw the sawtooth. The direction of the turtle is preserved when executing "yjump". // path = turtle([ // "turn", 55, // "untily", 2, // "yjump", 0, // "untily", 2.5, // "yjump", 0, // "untily", 3, // "yjump", 0, // ]); // stroke(path, width=.1); // Example(2DMed): square spiral // path = turtle(["move","left","addlength",1],repeat=50); // stroke(path,width=.2); // Example(2DMed): pentagonal spiral // path = turtle(["move","left",360/5,"addlength",1],repeat=50); // stroke(path,width=.7); // Example(2DMed): yet another spiral, without using `repeat` // path = turtle(concat(["angle",71],flatten(repeat(["move","left","addlength",1],50)))); // stroke(path,width=.7); // Example(2DMed): The previous spiral grows linearly and eventually intersects itself. This one grows geometrically and does not. // path = turtle(["move","left",71,"scale",1.05],repeat=50); // stroke(path,width=.15); // Example(2D): Koch Snowflake // function koch_unit(depth) = // depth==0 ? ["move"] : // concat( // koch_unit(depth-1), // ["right"], // koch_unit(depth-1), // ["left","left"], // koch_unit(depth-1), // ["right"], // koch_unit(depth-1) // ); // koch=concat(["angle",60,"repeat",3],[concat(koch_unit(3),["left","left"])]); // polygon(turtle(koch)); module turtle(commands, state=[[[0,0]],[1,0],90,0], full_state=false, repeat=1) {no_module();} function turtle(commands, state=[[[0,0]],[1,0],90,0], full_state=false, repeat=1) = let( state = is_vector(state) ? [[state],[1,0],90,0] : state ) repeat == 1? _turtle(commands,state,full_state) : _turtle_repeat(commands, state, full_state, repeat); function _turtle_repeat(commands, state, full_state, repeat) = repeat==1? _turtle(commands,state,full_state) : _turtle_repeat(commands, _turtle(commands, state, true), full_state, repeat-1); function _turtle_command_len(commands, index) = let( one_or_two_arg = ["arcleft","arcright", "arcleftto", "arcrightto"] ) commands[index] == "repeat"? 3 : // Repeat command requires 2 args // For these, the first arg is required, second arg is present if it is not a string in_list(commands[index], one_or_two_arg) && len(commands)>index+2 && !is_string(commands[index+2]) ? 3 : is_string(commands[index+1])? 1 : // If 2nd item is a string it's must be a new command 2; // Otherwise we have command and arg function _turtle(commands, state, full_state, index=0) = index < len(commands) ? _turtle(commands, _turtle_command(commands[index],commands[index+1],commands[index+2],state,index), full_state, index+_turtle_command_len(commands,index) ) : ( full_state ? state : state[0] ); // Turtle state: state = [path, step_vector, default angle, default arcsteps] function _turtle_command(command, parm, parm2, state, index) = command == "repeat"? assert(is_num(parm),str("\"repeat\" command requires a numeric repeat count at index ",index)) assert(is_list(parm2),str("\"repeat\" command requires a command list parameter at index ",index)) _turtle_repeat(parm2, state, true, parm) : let( path = 0, step=1, angle=2, arcsteps=3, parm = !is_string(parm) ? parm : undef, parm2 = !is_string(parm2) ? parm2 : undef, needvec = ["jump", "xymove"], neednum = ["untilx","untily","xjump","yjump","angle","length","scale","addlength"], needeither = ["setdir"], chvec = !in_list(command,needvec) || is_vector(parm,2), chnum = !in_list(command,neednum) || is_num(parm), vec_or_num = !in_list(command,needeither) || (is_num(parm) || is_vector(parm,2)), lastpt = last(state[path]) ) assert(chvec,str("\"",command,"\" requires a vector parameter at index ",index)) assert(chnum,str("\"",command,"\" requires a numeric parameter at index ",index)) assert(vec_or_num,str("\"",command,"\" requires a vector or numeric parameter at index ",index)) command=="move" ? list_set(state, path, concat(state[path],[default(parm,1)*state[step]+lastpt])) : command=="untilx" ? ( let( int = line_intersection([lastpt,lastpt+state[step]], [[parm,0],[parm,1]]), xgood = sign(state[step].x) == sign(int.x-lastpt.x) ) assert(xgood,str("\"untilx\" never reaches desired goal at index ",index)) list_set(state,path,concat(state[path],[int])) ) : command=="untily" ? ( let( int = line_intersection([lastpt,lastpt+state[step]], [[0,parm],[1,parm]]), ygood = is_def(int) && sign(state[step].y) == sign(int.y-lastpt.y) ) assert(ygood,str("\"untily\" never reaches desired goal at index ",index)) list_set(state,path,concat(state[path],[int])) ) : command=="xmove" ? list_set(state, path, concat(state[path],[default(parm,1)*norm(state[step])*[1,0]+lastpt])): command=="ymove" ? list_set(state, path, concat(state[path],[default(parm,1)*norm(state[step])*[0,1]+lastpt])): command=="xymove" ? list_set(state, path, concat(state[path], [lastpt+parm])): command=="jump" ? list_set(state, path, concat(state[path],[parm])): command=="xjump" ? list_set(state, path, concat(state[path],[[parm,lastpt.y]])): command=="yjump" ? list_set(state, path, concat(state[path],[[lastpt.x,parm]])): command=="turn" || command=="left" ? list_set(state, step, rot(default(parm,state[angle]),p=state[step])) : command=="right" ? list_set(state, step, rot(-default(parm,state[angle]),p=state[step])) : command=="angle" ? list_set(state, angle, parm) : command=="setdir" ? ( is_vector(parm) ? list_set(state, step, norm(state[step]) * unit(parm)) : list_set(state, step, norm(state[step]) * [cos(parm),sin(parm)]) ) : command=="length" ? list_set(state, step, parm*unit(state[step])) : command=="scale" ? list_set(state, step, parm*state[step]) : command=="addlength" ? list_set(state, step, state[step]+unit(state[step])*parm) : command=="arcsteps" ? list_set(state, arcsteps, parm) : command=="arcleft" || command=="arcright" ? assert(is_num(parm),str("\"",command,"\" command requires a numeric radius value at index ",index)) let( myangle = default(parm2,state[angle]), lrsign = command=="arcleft" ? 1 : -1, radius = parm*sign(myangle), center = lastpt + lrsign*radius*line_normal([0,0],state[step]), steps = state[arcsteps]==0 ? segs(abs(radius)) : state[arcsteps], arcpath = myangle == 0 || radius == 0 ? [] : arc( steps, points = [ lastpt, rot(cp=center, p=lastpt, a=sign(parm)*lrsign*myangle/2), rot(cp=center, p=lastpt, a=sign(parm)*lrsign*myangle) ] ) ) list_set( state, [path,step], [ concat(state[path], list_tail(arcpath)), rot(lrsign * myangle,p=state[step]) ] ) : command=="arcleftto" || command=="arcrightto" ? assert(is_num(parm),str("\"",command,"\" command requires a numeric radius value at index ",index)) assert(is_num(parm2),str("\"",command,"\" command requires a numeric angle value at index ",index)) let( radius = parm, lrsign = command=="arcleftto" ? 1 : -1, center = lastpt + lrsign*radius*line_normal([0,0],state[step]), steps = state[arcsteps]==0 ? segs(abs(radius)) : state[arcsteps], start_angle = posmod(atan2(state[step].y, state[step].x),360), end_angle = posmod(parm2,360), delta_angle = -start_angle + (lrsign * end_angle < lrsign*start_angle ? end_angle+lrsign*360 : end_angle), arcpath = delta_angle == 0 || radius==0 ? [] : arc( steps, points = [ lastpt, rot(cp=center, p=lastpt, a=sign(radius)*delta_angle/2), rot(cp=center, p=lastpt, a=sign(radius)*delta_angle) ] ) ) list_set( state, [path,step], [ concat(state[path], list_tail(arcpath)), rot(delta_angle,p=state[step]) ] ) : assert(false,str("Unknown turtle command \"",command,"\" at index",index)) []; // Section: Debugging polygons // Module: debug_polygon() // Usage: // debug_polygon(points, paths, [vertices=], [edges=], [convexity=], [size=]); // Description: // A drop-in replacement for `polygon()` that renders and labels the path points and // edges. The start of each path is marked with a blue circle and the end with a pink diamond. // You can suppress the display of vertex or edge labeling using the `vertices` and `edges` arguments. // Arguments: // points = The array of 2D polygon vertices. // paths = The path connections between the vertices. // --- // vertices = if true display vertex labels and start/end markers. Default: true // edges = if true display edge labels. Default: true // convexity = The max number of walls a ray can pass through the given polygon paths. // size = The base size of the line and labels. // Example(Big2D): // debug_polygon( // points=concat( // regular_ngon(or=10, n=8), // regular_ngon(or=8, n=8) // ), // paths=[ // [for (i=[0:7]) i], // [for (i=[15:-1:8]) i] // ] // ); module debug_polygon(points, paths, vertices=true, edges=true, convexity=2, size=1) { no_children($children); paths = is_undef(paths)? [count(points)] : is_num(paths[0])? [paths] : paths; echo(points=points); echo(paths=paths); linear_extrude(height=0.01, convexity=convexity, center=true) { polygon(points=points, paths=paths, convexity=convexity); } dups = vector_search(points, EPSILON, points); if (vertices) color("red") { for (ind=dups){ numstr = str_join([for(i=ind) str(i)],","); up(0.2) { translate(points[ind[0]]) { linear_extrude(height=0.1, convexity=10, center=true) { text(text=numstr, size=size, halign="center", valign="center"); } } } } } if (edges) for (j = [0:1:len(paths)-1]) { path = paths[j]; if (vertices){ translate(points[path[0]]) { color("cyan") up(0.1) cylinder(d=size*1.5, h=0.01, center=false, $fn=12); } translate(points[path[len(path)-1]]) { color("pink") up(0.11) cylinder(d=size*1.5, h=0.01, center=false, $fn=4); } } for (i = [0:1:len(path)-1]) { midpt = (points[path[i]] + points[path[(i+1)%len(path)]])/2; color("blue") { up(0.2) { translate(midpt) { linear_extrude(height=0.1, convexity=10, center=true) { text(text=str(chr(65+j),i), size=size/2, halign="center", valign="center"); } } } } } } } // vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap