GUI for setting image scale using cursors

#pragma TextEncoding="UTF-8"
#pragma rtGlobals=3
#pragma IndependentModule=ImageScaleGUI
#pragma version=1.70

// GUI for setting image scaling using cursors

// How to use:

// Either select "Load, Display and Scale Image..." from Load Waves menu,
// or create a new image plot, right click, and select 'Set Image Scale'.

// Position cursors and enter desired values for cursor positions.

// Right click and select 'Done with Set Image Scale'.

// Uncomment the definition below to add items to trace popup menu that allow
// scaling to be transferred from one displayed image to another:

//#define CopyPasteScaling

#ifdef CopyPasteScaling
menu "TracePopup", dynamic
    ImageScaleGUI#ScaleMenuString(0), /Q, ImageScaleGUI#CopyImageScale()
    ImageScaleGUI#ScaleMenuString(1), /Q, ImageScaleGUI#PasteImageScale()
end
#endif

menu "TracePopup", dynamic
    ImageScaleGUI#ImageTraceMenu(), /Q, ImageScaleGUI#ScaleImageInGraph()
end

menu "Load Waves"
    "Load, Display and Scale Image...", /Q, ImageScaleGUI#LoadAndScaleImage()
end

function /S ScaleMenuString(int paste)
    if (WinType("") != 1)
        return "" // don't do anything if Igor is just rebuilding the menu
    endif
    // figure out graph and trace names
    GetLastUserMenuInfo
    if (strlen(ImageNameList(s_graphname, ";")) == 0)
        return ""
    endif
    if (paste == 0)
        return "Copy Image Scale"
    elseif (cmpstr(GetScrapText()[0,7], "SetScale") == 0)
        return "Paste Image Scale"
    endif
    return ""
end

function CopyImageScale()
    GetLastUserMenuInfo
    wave /Z w = ImageNameToWaveRef(s_graphname, StringFromList(0, ImageNameList(s_graphname, ";")))
    if (WaveExists(w) == 0)
        return 0
    endif
    string cmd = ""
    sprintf cmd, "SetScale /P x, %g, %g, ###; SetScale /P y, %g, %g, ###;", DimOffset(w, 0), DimDelta(w, 0), DimOffset(w, 1), DimDelta(w, 1)
    PutScrapText cmd
end

function PasteImageScale()
    GetLastUserMenuInfo
    string strImage = StringFromList(0, ImageNameList(s_graphname, ";"))
    wave /Z wImage = ImageNameToWaveRef(s_graphname, strImage)
    if (WaveExists(wImage) == 0)
        return 0
    endif
   
    variable x0, dx, y0, dy
    sscanf GetScrapText(), "SetScale /P x, %g, %g, ###; SetScale /P y, %g, %g, ###;", x0, dx, y0, dy
    if (V_flag != 4)
        return 0
    endif
   
    int autoscale, dim
    string strAxis = "", strInfo = "", strFlags = ""
    strInfo = ImageInfo("", strImage, 0)
    variable indexMin, indexMax, delta, oldDelta
   
    for (dim=0;dim<2;dim+=1)
        autoscale = 1
        strAxis = StringByKey(SelectString(dim, "XAXIS", "YAXIS"), strInfo)
        strFlags = StringByKey("SETAXISFLAGS", AxisInfo("", strAxis))
       
        oldDelta = DimDelta(wImage, dim)
        delta = dim ? dY : dX
       
        if (GrepString(strFlags, "/")==0)
            GetAxis /Q $strAxis
            indexMin = scaleToIndex(wImage, V_min, dim)
            indexMax = scaleToIndex(wImage, V_max, dim)
            autoscale = 0
        endif
        if (dim == 0)
            SetScale /P x, x0, delta, wImage
        else
            SetScale /P y, y0, delta, wImage
        endif
        if (autoscale == 0)
            v_min = IndexToScale(wImage, indexMin, dim)
            v_max = IndexToScale(wImage, indexMax, dim)
            if (v_min > v_max)
                SetAxis /R $strAxis v_min, v_max
            else
                SetAxis $strAxis v_min, v_max
            endif
        endif
        if (sign(oldDelta) != sign(delta))
            // switch the axis limits so that image is not flipped
            if (GrepString(strFlags, "/R"))
                SetAxis /A $strAxis
            elseif (GrepString(strFlags, "/A"))
                SetAxis /A/R $strAxis
            endif
        endif
    endfor
end

function LoadAndScaleImage()
    try
        ImageLoad /T=any; AbortOnRTE
    catch
        // Clear the error silently.
        variable Verror = GetRTError(1) // 1 to clear the error
        doalert 0, "Could not load image"  
        return 0
    endtry
    if(v_flag == 0)
        return 0
    endif
    Display
    AppendImage $S_fileName
    SetAxis/A/R left
    ScaleImageInGraph()
end

function /T ImageTraceMenu()
    if (WinType("") != 1)
        return "" // don't do anything if Igor is just rebuilding the menu
    endif
    ControlInfo SetVarA
    if (v_flag != 0)
        return "Done with Set Image Scale"
    endif
    // figure out graph and trace names
    GetLastUserMenuInfo
    return SelectString(strlen(ImageNameList(s_graphname, ";")) > 0, "", "Set Image Scale")
end

function ScaleImageInGraph()
    ControlInfo SetVarA
    if (v_flag!=0) // SetVar exists, clean up
        SetWindow kwTopWin hook(setscaleGUI)=$""
        KillControl SetVarA; KillControl SetVarB; KillControl SetVarC; KillControl SetVarD
        Cursor /K A; Cursor /K B; Cursor /K C; Cursor /K D
        return 1
    endif
    string strImage = StringFromList(0, ImageNameList("", ";"))
    wave wImage = ImageNameToWaveRef("", strImage)
    variable hSize = DimSize(wImage, 0), vSize = DimSize(wImage,1)
    // vertical hairs for X cursors
    Cursor /N=1/S=2/I/H=2/C=(65535,0,0)/P A $strImage 0.1*hSize, 0.2*vSize
    Cursor /N=1/S=2/I/H=2/C=(65535,0,0)/P B $strImage 0.9*hSize, 0.2*vSize
    // horizontal hairs for Y cursors
    Cursor /N=1/S=2/I/H=3/C=(0,65535,0)/P C $strImage 0.2*hSize, 0.9*vSize
    Cursor /N=1/S=2/I/H=3/C=(0,65535,0)/P D $strImage 0.2*hSize, 0.1*vSize
   
    string strInfo = ImageInfo("", strImage, 0)
    string strXaxis = StringByKey("XAXIS",strInfo)
    string strYaxis = StringByKey("YAXIS",strInfo)
    STRUCT Point pt
   
    Make /free/T csr = {"A","B","C","D"}
    int i
    for (i=0;i<4;i+=1)
        SetVariable $"SetVar"+csr[i] title="", value=_NUM: i<2 ? xcsr($csr[i]) : vcsr($csr[i])
        SetVariable $"SetVar"+csr[i] limits={-Inf,Inf,0}, size={40,10}, fsize=14, Proc=ImageScaleGUI#Rescale
        SetVariable $"SetVar"+csr[i] valueColor=(65535*(i<2),65535*(i>1),0)
    endfor

    SetWindow kwTopWin hook(setscaleGUI)=ImageScaleGUI#ImgHook, hookevents=4
    // enter ImgHook function with resize event to reposition setvars
    STRUCT WMWinHookStruct s
    s.eventcode = 6
    ImgHook(s)
end

function ImgHook(STRUCT WMWinHookStruct &s)
    string strInfo, strXaxis, strYaxis
   
    switch (s.eventcode)
        case 6:
        case 7:
        case 8:
            strInfo = ImageInfo(s.winName, s.traceName, 0) // if s.tracename is empty this will be top image.
            strXaxis = StringByKey("XAXIS",strInfo)
            strYaxis = StringByKey("YAXIS",strInfo)
           
            if (s.eventcode == 7) // cursormoved
                if (GrepString(s.cursorName,"[A-D]") == 0)
                    return 0
                endif
                   
                // keep axis coordinates within bounds of axes
                variable ptX, ptY
                GetAxis /Q $strXaxis
                ptX = limit(xcsr($s.cursorName, s.winName), min(V_Min,V_Max), max(V_Min,V_Max))
                GetAxis /Q $strYaxis
                ptY = limit(vcsr($s.cursorName, s.winName), min(V_Min,V_Max), max(V_Min,V_Max))
           
                STRUCT Point pt
                pt.h = PosFromAxisVal(s.winName, strXaxis, ptX)
                pt.v = PosFromAxisVal(s.winName, strYaxis, ptY)
               
                variable val = GrepString(s.cursorName,"[AB]") ? xcsr($s.cursorName, s.winName) : vcsr($s.cursorName, s.winName)
                       
                SetVariable $"SetVar"+s.cursorName win=$s.winName, value=_NUM:val, pos={pt.h-20,pt.v-10}, disable=0
                break
            endif
   
            // reposition or disable setvars when window is resized
            s.eventCode = 7 // prepare to reenter this function with cursormoved eventcode
            Make /free/T csr = {"A","B","C","D"}
            int i
            for (i=0;i<4;i+=1)
                s.cursorName = csr[i]
                variable csrpos = i > 1 ? vcsr($s.cursorName, s.winName) : xcsr($s.cursorName, s.winName)
                GetAxis /W=$s.winName/Q $SelectString(i>1, strXaxis, strYaxis)
                if (csrpos>min(v_max,v_min) && csrpos<max(v_max,v_min))
                    ImgHook(s)
                else
                    SetVariable $"setvar"+(s.cursorName), win=$s.winName, disable=1
                endif
            endfor
    endswitch
    return 0
end

function Rescale(STRUCT WMSetVariableAction &s)
    if (s.eventCode != 8)
        return 0
    endif
    string strImage = StringFromList(0, ImageNameList(s.win, ";"))
    wave wImage = ImageNameToWaveRef(s.win, strImage)
    int isX = GrepString((s.ctrlName), "[AB]"), autoscale = 1
   
    string strAxis, strInfo, strFlags
    strInfo = ImageInfo("", strImage, 0)
    strAxis = StringByKey(SelectString(isX, "YAXIS", "XAXIS"), strInfo)
    strFlags = StringByKey("SETAXISFLAGS", AxisInfo(s.win, strAxis))
    variable indexMin, indexMax
    if(GrepString(strFlags, "/")==0)
        GetAxis /Q $strAxis
        indexMin = scaleToIndex(wImage, V_min, 1-isX)
        indexMax = scaleToIndex(wImage, V_max, 1-isX)
        autoscale = 0
    endif
   
    variable ValAC, ValBD, delta, offset, oldDelta
    ControlInfo $SelectString(isX, "SetVarC", "SetVarA")
    ValAC = V_Value
    ControlInfo $SelectString(isX, "SetVarD", "SetVarB")
    ValBD = V_Value
           
    delta = isX ? (ValBD-ValAC)/(pcsr(B)-pcsr(A)) : (ValBD-ValAC)/(qcsr(D)-qcsr(C))
    offset = isX ? ValAC - delta*pcsr(A) : ValAC - delta*qcsr(C)
    oldDelta = DimDelta(wImage, 1-isX)
    if (isX)
        SetScale /P x, offset, delta, wImage
    else
        SetScale /P y, offset, delta, wImage
    endif
    if (autoscale == 0)
        // don't use IndexToScale, because ends of axis may fall outside of image
        v_min = DimOffset(wImage, 1-isX) + indexMin*DimDelta(wImage, 1-isX)
        v_max = DimOffset(wImage, 1-isX) + indexMax*DimDelta(wImage, 1-isX)
        if (v_min > v_max)
            SetAxis /R/W=$s.win $strAxis v_min, v_max
        else
            SetAxis /W=$s.win $strAxis v_min, v_max
        endif
    elseif ((sign(oldDelta)==sign(delta)) %^ GrepString(strFlags, "/R"))
        // switch the axis limits so that image is not flipped
        SetAxis /A/W=$s.win $strAxis
    else
        SetAxis /A/R/W=$s.win $strAxis
    endif
   
    return 0
end

function PosFromAxisVal(string graphNameStr, string axNameStr, variable val)
    variable pixel = PixelFromAxisVal(graphNameStr, axNameStr, val)
    variable resolution = ScreenResolution
    return resolution > 96 ? pixel * 72/resolution : pixel
end