RasterPaintDibInfo Class

This class describes the image data expected by the custom paint callbacks. It is used with the RasterPaintCallbacks callbacks.

Object Model

Syntax

Visual Basic
C#
Objective-C
Java
C++

public class RasterPaintDibInfo

'Declaration
 
Public Class RasterPaintDibInfo

'Usage
 
Dim instance As RasterPaintDibInfo

public ref class RasterPaintDibInfo

Remarks

The user will typically allocate this class and return it from the RasterImagePaintCallbackFunction.GetDibInfoCallback callback.

Example

This example will show how to indicate that the graphics device expects a 16-bit image with the image data in the low 12 bits. Also, this particular card expected the data to be top-down, unlike the usual GDI functions which expect the data to be upside-down.

The example is in C++/CLI because this is the most useful language for implementing these classes.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

// macro that calculates the number of bytes per line, rounding up to a multiple of 4 bytes
#define DIB_WIDTH_BYTES(pixels) ((((pixels) + 31) & ~31) >> 3)
             
Object^ myPaintCallbacks::GetDibInfoCallback(RasterImage^ image, array<Object^>^ args)
{
   // make sure the parameters are correct
   if(args->Length != 2 || image == nullptr)
   {
      throw gcnew RasterException(RasterExceptionCode::InvalidParameter);
      return nullptr;
   }
   UInt32 uWidth = (UInt32)args[1];
   RasterPaintDibInfo^ pDibInfo = gcnew RasterPaintDibInfo;
   if(pDibInfo == nullptr)
   {
      throw gcnew RasterException(RasterExceptionCode::NoMemory);
      return nullptr;
   }
            
   pDibInfo->Default();
   pDibInfo->BitsPerPixel = 16;          // paint using 16-bit data, although there are only 12 significant bits
   pDibInfo->PlaneCount = 1;             // One plane
   pDibInfo->BytesPerLine = DIB_WIDTH_BYTES(uWidth * 16);   // bytes per line is a multiple of 4 bytes
   pDibInfo->ViewPerspective = RasterViewPerspective::TopLeft; // the data should be TOP_LEFT, not BOTTOM_LEFT like the data in the regular GDI functions
   pDibInfo->Order = RasterByteOrder::Gray;         // gray bitmap
            
   // indicate that the data should be in the low 12 bits
   pDibInfo->Flags = RasterPaintDibInfoFlags::LowHighBitValid;
   pDibInfo->LowBit = 0;
   pDibInfo->HighBit = 11;
            
   return pDibInfo;
}

Requirements

Target Platforms

Reference

RasterPaintDibInfo Members
Leadtools.Drawing Namespace
RasterPaintCallbacks Class
RasterPaintProperties.PaintCallbacks
Implementing custom paint