The RGB Bitmap display is similar to the Bitmap dispaly in that it displays the data as a bitmap. However, compared to the Bitmap display the RGB Bitmap doesn't need a color palette to look up a color for a data item value. The RGB Bitmap interprets the data as three channels of Red, Green, and Blue intensities with 8-bit each. For 32-bit items the MSB byte is not used but skipped. Only 32-bit items allow DMA mode, see below.
The Data Item format dialog box for RGB Bitmap displays looks as follows:
Range
The Bitmap display maps an array item to a two dimensional display. The dimensions of the bitmap are determined by the Range setting. The x-Range determines the width of the bitmap in pixel, the height is the result of the dimension of the array item divided by the x-Range. Say you have an item of dimension 1024 and set the x-Range to 128 the resulting bitmap will be 128 pixel wide and 8 pixel high (The mapping to the horizontal/vertical dimensions can be changed with the Orientation setting). The y-Range is used to map the data values onto colors as outlined in the following paragraph.
Sizing Settings
If you choose fixed sizing the dimensions of the bitmap are mapped 1:1 to physical pixels on the screen. In variable mode you can resize the bitmap and it is mapped to physical pixels as appropriate. The fixed sizing mode is useful for getting an undistorted display and may be appropriate for larger bitmaps. The variable mode allows for an arbitrary sizing but might lead to distortions. In Fixed Sizing mode a zoom factor can be selected that will be from 25% to 400% of the original image size.
DMA Mode
RGB Bitmaps have a potentially large amount of pixels (array element items). So performance is critical. If your data block is layed out in a specific format GSEOS can use a very efficient access mechanism (direct memory access) which will speed up the display by several orders of magnitude. It will be automatically enabled when the following conditions are met:
- The data item is an array of 32-bit items with no gap and 32-bit DWORD aligned.
- The data item has little endian (INTEL) bit order.
An indicator in the DMA Mode group notifies you if DMA mode is active or inactive.
