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'************************************************************************************* ' ' File name: MdispOverlay.vb ' Location: See Matrox Example Launcher in the MIL Control Center ' ' ' Synopsis: This program shows how to display an image while creating ' text and graphics annotations on top of it using MIL ' graphic functions and windows GDI drawing under Windows. ' If the target system supports grabbing, the annotations ' are done on top of a continuous grab. ' ' Copyright (C) Matrox Electronic Systems Ltd., 1992-2016. ' All Rights Reserved '************************************************************************************* Imports Microsoft.VisualBasic Imports System Imports System.Collections.Generic Imports System.Text Imports System.Drawing Imports System.Runtime.InteropServices Imports Matrox.MatroxImagingLibrary Namespace MDispOverlay Friend Class Program ' Target image. Private Const IMAGE_FILE As String = MIL.M_IMAGE_PATH & "Board.mim" ' Title for the display window. Private Const WINDOW_TITLE As String = "Custom Title" Shared Sub Main(ByVal args() As String) Dim MilApplication As MIL_ID = MIL.M_NULL ' Application identifier. Dim MilSystem As MIL_ID = MIL.M_NULL ' System identifier. Dim MilDisplay As MIL_ID = MIL.M_NULL ' Display identifier. Dim MilDigitizer As MIL_ID = MIL.M_NULL ' Digitizer identifier. Dim MilImage As MIL_ID = MIL.M_NULL ' Image identifier. ' Allocate defaults MIL.MappAllocDefault(MIL.M_DEFAULT, MilApplication, MilSystem, MilDisplay, CType(MIL.M_NULL, IntPtr), CType(MIL.M_NULL, IntPtr)) ' If the system have a digitizer, use it. If MIL.MsysInquire(MilSystem, MIL.M_DIGITIZER_NUM, MIL.M_NULL) > 0 Then MIL.MdigAlloc(MilSystem, MIL.M_DEFAULT, "M_DEFAULT", MIL.M_DEFAULT, MilDigitizer) MIL.MbufAllocColor(MilSystem, _ MIL.MdigInquire(MilDigitizer, MIL.M_SIZE_BAND, MIL.M_NULL), _ MIL.MdigInquire(MilDigitizer, MIL.M_SIZE_X, MIL.M_NULL), _ MIL.MdigInquire(MilDigitizer, MIL.M_SIZE_Y, MIL.M_NULL), _ 8 + MIL.M_UNSIGNED, MIL.M_IMAGE + MIL.M_DISP + MIL.M_PROC + MIL.M_GRAB, _ MilImage) MIL.MbufClear(MilImage, 0) Else ' Restore a static image. MIL.MbufRestore(IMAGE_FILE, MilSystem, MilImage) End If ' Change display window title. MIL.MdispControl(MilDisplay, MIL.M_TITLE, WINDOW_TITLE) ' Display the image buffer. MIL.MdispSelect(MilDisplay, MilImage) ' Draw text and graphics annotations in the display overlay. OverlayDraw(MilDisplay) ' If the system supports it, grab continuously in the displayed image. If MilDigitizer <> MIL.M_NULL Then MIL.MdigGrabContinuous(MilDigitizer, MilImage) End If ' Pause to show the image. Console.Write(Constants.vbLf + "OVERLAY ANNOTATIONS:" + Constants.vbLf) Console.Write("--------------------" + Constants.vbLf + Constants.vbLf) Console.Write("Displaying an image with overlay annotations." + Constants.vbLf) Console.Write("Press <Enter> to continue." + Constants.vbLf + Constants.vbLf) Console.ReadKey() ' Stop the continuous grab and free digitizer if needed. If MilDigitizer <> MIL.M_NULL Then MIL.MdigHalt(MilDigitizer) MIL.MdigFree(MilDigitizer) ' Pause to show the result. Console.Write("Displaying the last grabbed image." + Constants.vbLf) Console.Write("Press <Enter> to end." + Constants.vbLf + Constants.vbLf) Console.ReadKey() End If ' Free image. MIL.MbufFree(MilImage) ' Free default allocations. MIL.MappFreeDefault(MilApplication, MilSystem, MilDisplay, MIL.M_NULL, MIL.M_NULL) End Sub ' --------------------------------------------------------------- ' Name: OverlayDraw ' Synopsis: This function draws annotations in the display overlay. Private Shared Sub OverlayDraw(ByVal MilDisplay As MIL_ID) Dim DefaultGraphicContext As MIL_ID = MIL.M_DEFAULT Dim MilOverlayImage As MIL_ID = MIL.M_NULL Dim ImageWidth, ImageHeight As MIL_INT Dim hCustomDC As IntPtr = IntPtr.Zero ' Prepare overlay buffer. '*************************** ' Enable the display of overlay annotations. MIL.MdispControl(MilDisplay, MIL.M_OVERLAY, MIL.M_ENABLE) ' Inquire the overlay buffer associated with the display. MIL.MdispInquire(MilDisplay, MIL.M_OVERLAY_ID, MilOverlayImage) ' Clear the overlay to transparent. MIL.MdispControl(MilDisplay, MIL.M_OVERLAY_CLEAR, MIL.M_DEFAULT) ' Disable the overlay display update to accelerate annotations. MIL.MdispControl(MilDisplay, MIL.M_OVERLAY_SHOW, MIL.M_DISABLE) ' Inquire overlay size. ImageWidth = MIL.MbufInquire(MilOverlayImage, MIL.M_SIZE_X, MIL.M_NULL) ImageHeight = MIL.MbufInquire(MilOverlayImage, MIL.M_SIZE_Y, MIL.M_NULL) ' Draw MIL overlay annotations. '********************************* ' Set the graphic text background to transparent. MIL.MgraControl(DefaultGraphicContext, MIL.M_BACKGROUND_MODE, MIL.M_TRANSPARENT) ' Print a white string in the overlay image buffer. MIL.MgraColor(DefaultGraphicContext, MIL.M_COLOR_WHITE) MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth / 9, ImageHeight / 5, " -------------------- ") MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth / 9, ImageHeight / 5 + 25, " - MIL Overlay Text - ") MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth / 9, ImageHeight / 5 + 50, " -------------------- ") ' Print a green string in the overlay image buffer. MIL.MgraColor(DefaultGraphicContext, MIL.M_COLOR_GREEN) MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth * 11 / 18, ImageHeight / 5, " ---------------------") MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth * 11 / 18, ImageHeight / 5 + 25, " - MIL Overlay Text - ") MIL.MgraText(DefaultGraphicContext, MilOverlayImage, ImageWidth * 11 / 18, ImageHeight / 5 + 50, " ---------------------") ' Re-enable the overlay display after all annotations are done. MIL.MdispControl(MilDisplay, MIL.M_OVERLAY_SHOW, MIL.M_ENABLE) ' Draw GDI color overlay annotation. '*********************************** ' The inquire might not be supported MIL.MappControl(MIL.M_ERROR, MIL.M_PRINT_DISABLE) ' Create a device context to draw in the overlay buffer with GDI. MIL.MbufControl(MilOverlayImage, MIL.M_DC_ALLOC, MIL.M_DEFAULT) ' Inquire the device context. hCustomDC = CType(MIL.MbufInquire(MilOverlayImage, MIL.M_DC_HANDLE, MIL.M_NULL), IntPtr) MIL.MappControl(MIL.M_ERROR, MIL.M_PRINT_ENABLE) ' Perform operation if GDI drawing is supported. If (Not hCustomDC.Equals(IntPtr.Zero)) Then ' NOTE : The Using/ End Using blocks will automatically call the Dipose method on the GDI objects. ' This ensures that resources are freed even if an exception occurs. ' Create a System.Drawing.Graphics object from the Device context Using DrawingGraphics As Graphics = Graphics.FromHdc(hCustomDC) ' Draw a blue cross. Using DrawingPen As New Pen(Color.Blue) ' Draw a blue cross in the overlay image DrawingGraphics.DrawLine(DrawingPen, 0, CInt(Fix(ImageHeight / 2)), ImageWidth, CInt(Fix(ImageHeight / 2))) DrawingGraphics.DrawLine(DrawingPen, CInt(Fix(ImageWidth / 2)), 0, CInt(Fix(ImageWidth / 2)), ImageHeight) ' Prepare transparent text annotations. ' Define the Brushes and fonts used to draw text Using LeftBrush As New SolidBrush(Color.Red) Using RightBrush As New SolidBrush(Color.Yellow) Using OverlayFont As New Font(FontFamily.GenericSansSerif, 10, FontStyle.Bold) ' Write text in the overlay image Dim GDITextSize As SizeF = DrawingGraphics.MeasureString("GDI Overlay Text", OverlayFont) DrawingGraphics.DrawString("GDI Overlay Text", _ OverlayFont, _ LeftBrush, _ System.Convert.ToInt32(CSng(ImageWidth) / 4 - GDITextSize.Width / 2), _ System.Convert.ToInt32(CSng(ImageHeight) * 3 / 4 - GDITextSize.Height / 2)) DrawingGraphics.DrawString("GDI Overlay Text", _ OverlayFont, _ RightBrush, _ System.Convert.ToInt32(CSng(ImageWidth) * 3 / 4 - GDITextSize.Width / 2), _ System.Convert.ToInt32(CSng(ImageHeight) * 3 / 4 - GDITextSize.Height / 2)) End Using End Using End Using End Using End Using ' // Delete device context. MIL.MbufControl(MilOverlayImage, MIL.M_DC_FREE, MIL.M_DEFAULT) ' // Signal MIL that the overlay buffer was modified. MIL.MbufControl(MilOverlayImage, MIL.M_MODIFIED, MIL.M_DEFAULT) End If End Sub End Class End Namespace