function TWM_OnLoad()
    TWM.running = false
    
    --Create the Texture
    local TWMtex = TWM_frame:CreateTexture(nil, "OVERLAY") --Moving Texture
    local TWMtex2 = TWM_frame:CreateTexture(nil, "Background") --Background for drag testing.
    TWMtex:SetTexture("Interface\\Addons\\TWM\\Maps\\AlteracValley.tga", false)
    TWMtex2:SetTexture("Interface\\Addons\\TWM\\Maps\\AlteracValley.tga", false)
    TWMtex:SetAllPoints(TWM_frame)
    TWMtex2:SetAllPoints(TWM_frame)
    TWM_frame.texture = TWMtex
    TWM_frame.texture2 = TWMtex2
end
 
function TWM_OnUpdate(self, elapsed)
    --Only running while Left Mouse Button is down.
    if TWM.running then
        local mouseX,mouseY = GetCursorPosition()
        local screenWidth,screenHeight = GetScreenWidth(), GetScreenHeight()
        local offsetX,offsetY = 0
        widthScale, heightScale. = TWM_frame:GetSize() --Get Width and Height for scale.
        
        --Get the scale of the size of the frame to the size of the screen.
        widthScale = widthScale / screenWidth
        heightScale = heightScale / screenHeight
        
        --Calculate the offset of the mouse cursor and convert it to (Hopefully) frame
        --coordinates while allowing the texture to go out of the frame.
        offsetX = ((mouseX- TWM.mouseStartX) / screenWidth) / widthScale
        offsetY = ((mouseY- TWM.mouseStartY) / screenHeight) / heightScale
        
        --Offset the current texture coordinates by the offset.
        TWM_frame.texture:SetTexCoord(x1 - offsetX, x2 - offsetX, y1 + offsetY, y2 + offsetY)
        
        --For debug: Print the current x,y offset and the starting Upper Left point of the texture.
        print(offsetX, offsetY, x1, y1)
    else
        --Keep track of the mouse for when the user starts to drag on the texture.
        TWM.mouseStartX,TWM.mouseStartY = GetCursorPosition(); 
        --Get Texture Coordinates.
        x1,y1, _, _, _, _, x2, y2 = TWM_frame.texture:GetTexCoord()
    end
end

<Ui xmlns="http://www.blizzard.com/wow/ui/"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <Script file="TWM.lua" />
    <Frame name="TWM_frame" parent="UIParent" toplevel="true" enableMouse="true" movable="true">
        <Size>
            <AbsDimension x="300" y="300" />
        </Size>
        <TitleRegion>
            <Size x="300" y="10"/>
            <Anchors><Anchor point="TOP"/></Anchors>
        </TitleRegion>
        <Backdrop bgFile="Interface\DialogFrame\UI-DialogBox-Background"
           edgeFile="Interface\DialogFrame\UI-DialogBox-Border" tile="true">
            <BackgroundInsets>
                <AbsInset left="-10" right="-10" top="-10" bottom="-10"/>
            </BackgroundInsets>
            <TileSize>
                <AbsValue val="32"/>
            </TileSize>
            <EdgeSize>
                <AbsValue val="32"/>
            </EdgeSize>
        </Backdrop>
        <Scripts>
            <OnLoad>
                TWM_OnLoad();
            </OnLoad>
            <OnMouseDown>
                if button == "LeftButton" then
                    TWM.running = true;
                    print(TWM.running);
                elseif button == "RightButton" then
                    self:Hide()
                end
            </OnMouseDown>
            <OnMouseUp>
                if button == "LeftButton" then
                    TWM.running = false;
                    print(TWM.running);
                end
            </OnMouseUp>
            <OnUpdate>
                TWM_OnUpdate(self, elapsed);
            </OnUpdate>
        </Scripts>
        <Anchors><Anchor point="CENTER" relativeTo="UIParent"/></Anchors>
        
    </Frame>
 </Ui>