AcDbImage

Class Hierarchy

AcRxObject
    AcGiDrawable
        AcDbObject
            AcDbEntity
                AcDbImage
                    AcDbRasterImage

C++

class AcDbImage : public AcDbEntity;

File

dbimage.h

Description

Abstract base class for immediate mode raster-based entities, including AcDbRasterImage. Every time entities derived from this class are drawn on the screen or plotted, the getScanLines method is called by the display or plot driver to get the pixels needed for display in the image format and scale required by the driver. These objects must be drawn at regen time using the AcGiViewportGeometry::rasterImageDc() method accessible through AcGiViewportDraw::geometry() in the entity's viewportDraw method.

For more information about the AcGiRequestScanLines, refer to the RequestScanLines structure in the ADI 4.3 specification, but note that they are not identical. In particular, the pixToDc parameter specified in AcGiViewportGeometry::rasterImageDc() is returned in the AcGiRequestScanLines::mPixelToDc field, but is not used by the driver. It should be set to the 2D source image pixel-to-dc (logical coordinate) transform. When AcDbImage::getScanLines() is called, this transform must be combined with the dc-to-device pixel transform (pan, zoom) implied by the AcGiRequestScanLines::mPixelMinX, AcGiRequestScanLines::mPixelMinY, AcGiRequestScanLines::mPixelMaxX, AcGiRequestScanLines::mPixelMaxY parameters (device coordinates), and AcGiRequestScanLines::mLowerLeft, AcGiRequestScanLines::mUpperRight parameters (dc or logical coordinates) to create the complete source image pixel to device pixel transform. This complete transform is either an affine transform or a perspective transform.

Links

AcDbImage Methods

See Also

AcDbObject, AcDbEntity, AcDbRasterImage