api: trim down color gradient function

* avoid division through zero in unitframes
* make use of gradient func in unitframes

api/api.lua

@@ -849,61 +849,37 @@ end
 
 -- [ GetColorGradient ] --
 -- 'perc'     percentage (0-1)
--- 'color1' table or r,g,b tuple
--- 'color2' table or r,g,b tuple
--- ..
--- 'colorN' table or r,g,b tuple
 -- return r,g,b and hexcolor
-local color_tuples = {}
-function pfUI.api.GetColorGradient(perc, ...)
-  local num = arg.n
-  local r,g,b,hex
-  assert(tonumber(perc), "GetColorGradient: "..tostring(perc).." is not a number")
-  assert((type(arg[1])=="number" and num>5) or (type(arg[1])=="table" and num>1), "GetColorGradient: needs at least 2 colors")
-  perc = pfUI.api.clamp(perc,0,1)
-  if type(arg[1])=="number" then -- called with r,g,b tuples
-    -- shortcircuit the edge cases
-    if perc == 1 then
-      r,g,b = arg[num-2], arg[num-1], arg[num]
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
-    elseif perc == 0 then
-      r,g,b = arg[1], arg[2], arg[3]
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
-    end
-    num = num/3
-    local segment, relativepercent = pfUI.api.modf(perc*(num-1))
-    local r1,g1,b1, r2,g2,b2
-    r1,g1,b1 = arg[segment*3+1], arg[segment*3+2], arg[segment*3+3]
-    r2,g2,b2 = arg[segment*3+4], arg[segment*3+5], arg[segment*3+6]
-    if not r2 or not g2 or not b2 then
-      r,g,b = r1,g1,b1
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
+local gradientcolors = {}
+function pfUI.api.GetColorGradient(perc)
+  if perc < 0 or perc > 1 then return nil,nil,nil,nil end
+
+  if not gradientcolors[perc] then
+    local r1, g1, b1, r2, g2, b2
+    if perc <= 0.5 then
+      perc = perc * 2
+      r1, g1, b1 = 1, 0, 0
+      r2, g2, b2 = 1, 1, 0
     else
-      r,g,b = r1 + (r2-r1)*relativepercent, g1 + (g2-g1)*relativepercent, b1 + (b2-b1)*relativepercent
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
+      perc = perc * 2 - 1
+      r1, g1, b1 = 1, 1, 0
+      r2, g2, b2 = 0, 1, 0
     end
-  elseif type(arg[1])=="table" then -- called with color tables
-    -- shortcircuit the edge cases
-    if perc == 1 then
-      r,g,b = arg[num][1] or arg[num].r, arg[num][2] or arg[num].g, arg[num][3] or arg[num].b
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
-    elseif perc == 0 then
-      r,g,b = arg[1][1] or arg[1].r, arg[1][2] or arg[1].g, arg[1][3] or arg[1].b
-      hex = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
-      return r,g,b,hex
-    end
-    pfUI.api.wipe(color_tuples)
-    for _,c in ipairs(arg) do
-      local r,g,b = c[1] or c.r, c[2] or c.g, c[3] or c.b
-      color_tuples[table.getn(color_tuples)+1] = r
-      color_tuples[table.getn(color_tuples)+1] = g
-      color_tuples[table.getn(color_tuples)+1] = b
-    end
-    return pfUI.api.GetColorGradient(perc,unpack(color_tuples))
+
+    local r = r1 + (r2 - r1)*perc
+    local g = g1 + (g2 - g1)*perc
+    local b = b1 + (b2 - b1)*perc
+    local h = string.format("|cff%02x%02x%02x", r*255, g*255, b*255)
+
+    gradientcolors[perc] = {}
+    gradientcolors[perc].r = r
+    gradientcolors[perc].g = g
+    gradientcolors[perc].b = b
+    gradientcolors[perc].h = h
   end
+
+  return gradientcolors[perc].r,
+    gradientcolors[perc].g,
+    gradientcolors[perc].b,
+    gradientcolors[perc].h
 end