A little demo for camera and zoomer on image

[TempodiBasic]

Hi friends
keep patience
I have thought that it is possible to make the square of area selected by mouse pointer by using OpenGl technology...
so this is the version of code in which the selected area by mouse uses OpenGl commands...

here a screenshot



and here the code

Code: (Select All)

Rem the idea is to show a piece of image (camera) around the mouse pointer into another canvas using _putimage

Rem a canvas is for the first image and a second canvas is for pointer camera so we can play with _putimage

Rem  joining cameraPointer and Zoomer stuff

Rem using hardware accelaration for a better performance on different hardwares

Rem using _display to avoid white square flickering on different hardwares

Rem using _Opengl to draw square area selected of the orginal image







Dim Lscreen As Long, Limage As Long, LHardImg As Long



Limage = _NewImage(600, 300, 32)

' make the original image object of the zoom

_Dest Limage

Cls , _RGBA32(0, 0, 0, 255)

For turn = 1 To 200

    Line (1 + Int(Rnd * 600), 1 + Int(Rnd * 300))-(10 + Int(Rnd * 590), 10 + Int(Rnd * 290)), _RGBA32(Int(Rnd * 200), Int(Rnd * 200), Int(Rnd * 200), 255), B

Next turn

LHardImg = _CopyImage(Limage, 33) ' it makes a hardware copy of Limage





Lscreen = _NewImage(800, 600, 32)

Screen Lscreen

' it makes the window's graphic

_Title "Camera moved by mouse pointer, mouse wheel modifies area camera (pointer Mode) / depth of zoom (zoom Mode)"

Dim As Integer Ix1, Iy1, Ix2, Iy2, Cx1, Cy1, Cside, Mz, Ax1, Ay1, increasing, glGo

Dim As String Mmode

Ix1 = 100: Iy1 = 90: Ix2 = 700: Iy2 = 390: Cx1 = 100: Cy1 = 440: Cside = 100: Mz = 10: Mmode = "Pointer"

Ax1 = 0: Ay1 = 0: increasing = 1: glGo = 0

_DisplayOrder _Software , _Hardware , _GLRender

Cls , _RGBA32(50, 100, 100, 255)

_PrintString (20, 60), "Original image"

_PrintString (200, 60), "Zoom ratio:" + Str$((increasing)) + " "

_PrintString (20, 410), "Image pointed"

_PrintString (150, 410), "Move mouse on the picture, roll mouse wheel, left click toggle Mode"

_MouseMove Ix1 + 1, Iy1 + 1

Do

    ' it shows orginal image in hardware mode

    _PutImage (Ix1, Iy1)-(Ix2, Iy2), LHardImg, 0

    ' it takes area of camera from source Limage and puts it on screen window in camera image place at zoom state

    Camera Ax1, Ay1, Ix1, Iy1, Cside, Cx1, Cy1, LHardImg, 0, increasing, Mz



    _PrintString (200, 60), "Zoom ratio:" + Str$((increasing)) + " "

    _Display ' to avoid flickering in some PCs



    If _MouseInput Then

        NMx = _MouseX

        NMy = _MouseY



        If IntheRange(Ix1, Ix2, NMx) And IntheRange(Iy1, Iy2, NMy) Then

            AreaCamera NMx, NMy, Cside, Ix1, Iy1, Ix2, Iy2, Ax1, Ay1

            If glGo = 1 Then glGo = 2



            If _MouseButton(1) Then

                ' it switches between modes Pointer / Zoomer

                If Mmode = "Pointer" Then Mmode = "Zoomer" Else Mmode = "Pointer"

            End If



            If Mmode = "Pointer" Then

                If _MouseWheel < 0 Then

                    ' it draws the background of camera

                    Line (Cx1, Cy1)-(Cx1 + Cside, Cy1 + Cside), _RGBA32(50, 100, 100, 255), BF



                    ' it decreases the Cside ranging between 100 and 160

                    Cside = Cside - 10

                    If Cside < 100 Then Cside = 100

                ElseIf _MouseWheel > 0 Then

                    ' it draws the background of camera

                    Line (Cx1, Cy1)-(Cx1 + Cside, Cy1 + Cside), _RGBA32(50, 100, 100, 255), BF



                    ' it increases the Cside ranging between 100 and 160

                    Cside = Cside + 10

                    If Cside > 160 Then Cside = 160

                End If



            ElseIf Mmode = "Zoomer" Then

                If _MouseWheel > 0 Then

                    If increasing < Mz Then increasing = increasing + 1

                ElseIf _MouseWheel < 0 Then

                    If increasing > 1 Then increasing = increasing - 1

                End If

            End If



        End If

    End If

Loop Until InKey$ <> ""

End





Function IntheRange (Min As Integer, Max As Integer, Test As Integer)

    IntheRange = 0

    If Min <= Test And Test <= Max Then IntheRange = -1

End Function



Sub AreaCamera (X As Integer, Y As Integer, Cside As Integer, Sx1 As Integer, Sy1 As Integer, Sx2 As Integer, Sy2 As Integer, Ax1 As Integer, Ay1 As Integer)

    Ax1 = X - Int(Cside / 2)

    If Ax1 < Sx1 Then

        Ax1 = Sx1

    ElseIf Ax1 + Cside > Sx2 Then

        Ax1 = Sx2 - Cside

    End If



    Ay1 = Y - Int(Cside / 2)

    If Ay1 < Sy1 Then

        Ay1 = Sy1

    ElseIf Ay1 + Cside > Sy2 Then

        Ay1 = Sy2 - Cside

    End If

End Sub



Sub Camera (AX As Integer, AY As Integer, Sx1 As Integer, Sy1 As Integer, Cside As Integer, Dx1 As Integer, Dy1 As Integer, Sh As Long, Dh As Long, Incr As Integer, Mz As Integer)

    ' it copies from source image to area of destination of camera image

    _PutImage (Dx1, Dy1)-Step(Cside, Cside), Sh, Dh, ((AX - Sx1) + (1 * Incr), (AY - Sy1) + (1 * Incr))-Step(Cside - (Mz * (Incr - 1)), Cside - (Mz * (Incr - 1)))

End Sub



Sub _GL ()

    Shared Ax1 As Integer, Ay1 As Integer, Cside As Integer, glGo As Integer

    ' initialization control

    If glGo = 0 Then

        ' initialization for OpenGl

        _glViewport 0, 0, _Width, _Height ' the new cohordinates for viewport of GlOperations

        _glClearColor 0, 0, 0, 0 ' the cancel color is transparent 100%

        glGo = 1

        Exit Sub

    ElseIf glGo = 1 Then

        Exit Sub 'it exits until data are not avaiable

    End If

    _glMatrixMode _GL_MODELVIEW ' it uses the actual view matrix

    _glTranslatef -1, 1, 0 ' it multiplies the current matrix with this scale's factors  x y z

    _glScalef (1 / (_Width / 2)), (-1 / (_Height / 2)), 1 ' it transforms the current matrix using the above definied matrix







    _glColor4ub 255, 255, 255, 255 ' it sets color of graphic to do using 4 bytes for a RGBA setting

    _glBegin _GL_LINE_LOOP ' it starts the OpenGl primitive graphic to execute

    _glVertex2i Ax1, Ay1 ' it defines the 4 vertexes of the square

    _glVertex2i (Ax1 + Cside), Ay1

    _glVertex2i (Ax1 + Cside), (Ay1 + Cside)

    _glVertex2i Ax1, (Ay1 + Cside)

    _glEnd ' it ends the OpenGl primitive graphic

    _glFlush ' it forcces to draw GlGraphic

End Sub

Thanks for feedbacks