直接放入Zframework文件

Zframework/mathExtend.lua

@@ -0,0 +1,88 @@
+local MATH={} for k,v in next,math do MATH[k]=v end
+
+local floor,ceil=math.floor,math.ceil
+local rnd=math.random
+local exp=math.exp
+
+MATH.tau=2*math.pi
+MATH.phi=(1+math.sqrt(5))/2
+MATH.inf=1/0
+MATH.nan=0/0
+
+function MATH.isnan(n)
+    return n~=n
+end
+
+function MATH.sign(a)
+    return a>0 and 1 or a<0 and -1 or 0
+end
+
+function MATH.roll(chance)
+    return rnd()<(chance or .5)
+end
+
+function MATH.coin(a,b)
+    if rnd()<.5 then
+        return a
+    else
+        return b
+    end
+end
+
+function MATH.clamp(v,low,high)
+    if v<=low then
+        return low
+    elseif v>=high then
+        return high
+    else
+        return v
+    end
+end
+
+function MATH.mix(s,e,t)
+    return s+(e-s)*t
+end
+
+do-- function MATH.listMix(list,t)
+    local clamp,mix=MATH.clamp,MATH.mix
+    function MATH.listMix(list,t)
+        local t2=(#list-1)*clamp(t,0,1)+1
+        return mix(list[floor(t2)],list[ceil(t2)],t2%1)
+    end
+end
+
+function MATH.expApproach(a,b,k)
+    return b+(a-b)*exp(-k)
+end
+
+function MATH.distance(x1,y1,x2,y2)
+    return ((x1-x2)^2+(y1-y2)^2)^.5
+end
+
+-- By Pedro Gimeno,donated to the public domain
+function MATH.pointInPolygon(x,y,poly,evenOddRule)
+    local x1,y1,x2,y2
+    local len=#poly
+    x2,y2=poly[len-1],poly[len]
+    local wn=0
+    for idx=1,len,2 do
+        x1,y1=x2,y2
+        x2,y2=poly[idx],poly[idx+1]
+        if y1>y then
+            if y2<=y and (x1-x)*(y2-y)<(x2-x)*(y1-y) then
+                wn=wn+1
+            end
+        else
+            if y2>y and (x1-x)*(y2-y)>(x2-x)*(y1-y) then
+                wn=wn-1
+            end
+        end
+    end
+    if evenOddRule then
+        return wn%2~=0
+    else-- non-zero winding rule
+        return wn~=0
+    end
+end
+
+return MATH