diff options
Diffstat (limited to 'geom.lua')
-rw-r--r-- | geom.lua | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/geom.lua b/geom.lua deleted file mode 100644 index 891e98d..0000000 --- a/geom.lua +++ /dev/null @@ -1,168 +0,0 @@ -geom = {} - -function geom.on_shape(x,y, drawing, shape) - if shape.mode == 'freehand' then - return geom.on_freehand(x,y, drawing, shape) - elseif shape.mode == 'line' then - return geom.on_line(x,y, drawing, shape) - elseif shape.mode == 'manhattan' then - local p1 = drawing.points[shape.p1] - local p2 = drawing.points[shape.p2] - if p1.x == p2.x then - if x ~= p1.x then return false end - local y1,y2 = p1.y, p2.y - if y1 > y2 then - y1,y2 = y2,y1 - end - return y >= y1-2 and y <= y2+2 - elseif p1.y == p2.y then - if y ~= p1.y then return false end - local x1,x2 = p1.x, p2.x - if x1 > x2 then - x1,x2 = x2,x1 - end - return x >= x1-2 and x <= x2+2 - end - elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then - return geom.on_polygon(x,y, drawing, shape) - elseif shape.mode == 'circle' then - local center = drawing.points[shape.center] - local dist = geom.dist(center.x,center.y, x,y) - return dist > shape.radius*0.95 and dist < shape.radius*1.05 - elseif shape.mode == 'arc' then - local center = drawing.points[shape.center] - local dist = geom.dist(center.x,center.y, x,y) - if dist < shape.radius*0.95 or dist > shape.radius*1.05 then - return false - end - return geom.angle_between(center.x,center.y, x,y, shape.start_angle,shape.end_angle) - elseif shape.mode == 'deleted' then - else - print(shape.mode) - assert(false) - end -end - -function geom.on_freehand(x,y, drawing, shape) - local prev - for _,p in ipairs(shape.points) do - if prev then - if geom.on_line(x,y, drawing, {p1=prev, p2=p}) then - return true - end - end - prev = p - end - return false -end - -function geom.on_line(x,y, drawing, shape) - local p1,p2 - if type(shape.p1) == 'number' then - p1 = drawing.points[shape.p1] - p2 = drawing.points[shape.p2] - else - p1 = shape.p1 - p2 = shape.p2 - end - if p1.x == p2.x then - if math.abs(p1.x-x) > 2 then - return false - end - local y1,y2 = p1.y,p2.y - if y1 > y2 then - y1,y2 = y2,y1 - end - return y >= y1-2 and y <= y2+2 - end - -- has the right slope and intercept - local m = (p2.y - p1.y) / (p2.x - p1.x) - local yp = p1.y + m*(x-p1.x) - if yp < y-2 or yp > y+2 then - return false - end - -- between endpoints - local k = (x-p1.x) / (p2.x-p1.x) - return k > -0.005 and k < 1.005 -end - -function geom.on_polygon(x,y, drawing, shape) - local prev - for _,p in ipairs(shape.vertices) do - if prev then - if geom.on_line(x,y, drawing, {p1=prev, p2=p}) then - return true - end - end - prev = p - end - return geom.on_line(x,y, drawing, {p1=shape.vertices[1], p2=shape.vertices[#shape.vertices]}) -end - --- are (x3,y3) and (x4,y4) on the same side of the line between (x1,y1) and (x2,y2) -function geom.same_side(x1,y1, x2,y2, x3,y3, x4,y4) - if x1 == x2 then - return math.sign(x3-x1) == math.sign(x4-x1) - end - if y1 == y2 then - return math.sign(y3-y1) == math.sign(y4-y1) - end - local m = (y2-y1)/(x2-x1) - return math.sign(m*(x3-x1) + y1-y3) == math.sign(m*(x4-x1) + y1-y4) -end - -function math.sign(x) - if x > 0 then - return 1 - elseif x == 0 then - return 0 - elseif x < 0 then - return -1 - end -end - -function geom.angle_with_hint(x1, y1, x2, y2, hint) - local result = geom.angle(x1,y1, x2,y2) - if hint then - -- Smooth the discontinuity where angle goes from positive to negative. - -- The hint is a memory of which way we drew it last time. - while result > hint+math.pi/10 do - result = result-math.pi*2 - end - while result < hint-math.pi/10 do - result = result+math.pi*2 - end - end - return result -end - --- result is from -π/2 to 3π/2, approximately adding math.atan2 from Lua 5.3 --- (LÖVE is Lua 5.1) -function geom.angle(x1,y1, x2,y2) - local result = math.atan((y2-y1)/(x2-x1)) - if x2 < x1 then - result = result+math.pi - end - return result -end - --- is the line between x,y and cx,cy at an angle between s and e? -function geom.angle_between(ox,oy, x,y, s,e) - local angle = geom.angle(ox,oy, x,y) - if s > e then - s,e = e,s - end - -- I'm not sure this is right or ideal.. - angle = angle-math.pi*2 - if s <= angle and angle <= e then - return true - end - angle = angle+math.pi*2 - if s <= angle and angle <= e then - return true - end - angle = angle+math.pi*2 - return s <= angle and angle <= e -end - -function geom.dist(x1,y1, x2,y2) return ((x2-x1)^2+(y2-y1)^2)^0.5 end |