first commit

libs/simple-slider.lua

@@ -0,0 +1,138 @@
+--[[
+Copyright (c) 2016 George Prosser
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+]]
+
+local slider = {}
+slider.__index = slider
+
+function newSlider(x, y, length, value, min, max, setter, style)
+    local s = {}
+    s.value = (value - min) / (max - min)
+    s.min = min
+    s.max = max
+    s.setter = setter
+    s.x = x
+    s.y = y
+    s.length = length
+
+    local p = style or {}
+    s.width = p.width or length * 0.1
+    s.orientation = p.orientation or 'horizontal'
+    s.track = p.track or 'rectangle'
+    s.knob = p.knob or 'rectangle'
+
+    s.grabbed = false
+    s.wasDown = true
+    s.ox = 0
+    s.oy = 0
+
+    return setmetatable(s, slider)
+end
+
+function slider:update(mouseX, mouseY, mouseDown)
+    local x = mouseX or love.mouse.getX()
+    local y = mouseY or love.mouse.getY()
+    local down = love.mouse.isDown(1)
+    if mouseDown ~= nil then
+        down = mouseDown
+    end
+
+    local knobX = self.x
+    local knobY = self.y
+    if self.orientation == 'horizontal' then
+        knobX = self.x - self.length/2 + self.length * self.value
+    elseif self.orientation == 'vertical' then
+        knobY = self.y + self.length/2 - self.length * self.value
+    end
+
+    local ox = x - knobX
+    local oy = y - knobY
+
+    local dx = ox - self.ox
+    local dy = oy - self.oy
+
+    if down then
+        if self.grabbed then
+            if self.orientation == 'horizontal' then
+                self.value = self.value + dx / self.length
+            elseif self.orientation == 'vertical' then
+                self.value = self.value - dy / self.length
+            end
+        elseif (x > knobX - self.width/2 and x < knobX + self.width/2 and y > knobY - self.width/2 and y < knobY + self.width/2) and not self.wasDown then
+            self.ox = ox
+            self.oy = oy
+            self.grabbed = true
+        end
+    else
+        self.grabbed = false
+    end
+
+    self.value = math.max(0, math.min(1, self.value))
+
+    if self.setter ~= nil then
+        self.setter(self.min + self.value * (self.max - self.min))
+    end
+
+    self.wasDown = down
+end
+
+function slider:draw()
+    if self.track == 'rectangle' then
+        if self.orientation == 'horizontal' then
+            love.graphics.rectangle('line', self.x - self.length/2 - self.width/2, self.y - self.width/2, self.length + self.width, self.width)
+        elseif self.orientation == 'vertical' then
+            love.graphics.rectangle('line', self.x - self.width/2, self.y - self.length/2 - self.width/2, self.width, self.length + self.width)
+        end
+    elseif self.track == 'line' then
+        if self.orientation == 'horizontal' then
+            love.graphics.line(self.x - self.length/2, self.y, self.x + self.length/2, self.y)
+        elseif self.orientation == 'vertical' then
+            love.graphics.line(self.x, self.y - self.length/2, self.x, self.y + self.length/2)
+        end
+    elseif self.track == 'roundrect' then
+        if self.orientation == 'horizontal' then
+            love.graphics.rectangle('line', self.x - self.length/2 - self.width/2, self.y - self.width/2, self.length + self.width, self.width, self.width/2, self.width)
+        elseif self.orientation == 'vertical' then
+            love.graphics.rectangle('line', self.x - self.width/2, self.y - self.length/2 - self.width/2, self.width, self.length + self.width, self.width, self.width/2)
+        end
+    end
+
+    local knobX = self.x
+    local knobY = self.y
+    if self.orientation == 'horizontal' then
+        knobX = self.x - self.length/2 + self.length * self.value
+    elseif self.orientation == 'vertical' then
+        knobY = self.y + self.length/2 - self.length * self.value
+    end
+
+    if self.knob == 'rectangle' then
+        love.graphics.rectangle('fill', knobX - self.width/2, knobY - self.width/2, self.width, self.width)
+    elseif self.knob == 'circle' then
+        love.graphics.circle('fill', knobX, knobY, self.width/2)
+    end
+end
+
+function slider:getValue()
+    return self.min + self.value * (self.max - self.min)
+end