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NewBitmap

LabWindows/CVI

NewBitmap

int NewBitmap (int bytesPerRow, int pixelDepth, int width, int height, int colorTable[], unsigned char bits[], unsigned char mask[], int *bitmapID);

Purpose

Note Note  This function has been superseded by NewBitmapEx, which supports alpha-channel transparency.

Creates a bitmap object and returns a bitmap ID. You can pass the bitmap ID to any function that accepts a bitmap, such as CanvasDrawBitmap or ClipboardPutBitmap.

You can discard the bitmap object by passing its ID to DiscardBitmap.

Parameters

Input
Name Type Description
bytesPerRow int Number of bytes on each scan line of the image.

If bytesPerRow is a positive number, then the bits for each scan line must start on a byte boundary. Depending on pixelDepth and width, the number of bits per line in the bits array might not be an even multiple of eight. In this case, you must pad the bits array to get to the next byte boundary.

If bytesPerRow is -1, no padding occurs. The bits for each scan line immediately follow the bits for the previous scan line.
pixelDepth int Number of bits per pixel.

The valid values for the pixelDepth parameter are 1, 4, 8, 24, and 32. This depth determines how LabWindows/CVI interprets the data you pass in the bits parameter.

Regardless of the color depth that you specify, the new bitmap matches the color depth of the display screen.
width int Width of the image, in pixels.
height int Height of the image, in pixels.
colorTable int [] Array of RGB color values, or NULL if pixelDepth is greater than 8.

If pixelDepth is 8 or less, the bits array contains indices into the colorTable array. The number of entries in the colorTable array must equal 2n, where n is the value of the pixelDepth parameter.

If pixelDepth is greater than 8, the colorTable parameter is not used. The bits array contains actual RGB color values rather than indices into the colorTable array.
bits unsigned char [] Array of bits that determines the colors to display on each pixel in the image. The first pixel in the bits array is at the upper-left corner of the image. The pixels in the array are stored in row-major order.

The number of bits per pixel is equal to the pixelDepth value. If pixelDepth is 8 or less, the bits array contains indices into the colorTable array. If pixelDepth is greater than 8, the colorTable array is not used, and the bits array contains the actual RGB values.

If pixelDepth is 24, each pixel is represented by a 24-bit RGB value of the form RRGGBB, where RR, GG, and BB represent the red, green, and blue components of the color value. The RR byte is at the lowest memory address of the three bytes.

If pixelDepth is 32, each pixel is represented by a 32-bit RGB value of the form 0x00RRGGBB, where RR, GG, and BB represent the red, green, and blue components of the color value. The 32-bit value is treated as a native 32-bit integer value. The BB byte is in the least significant byte and, therefore, is at the lowest memory address of the four bytes. The most significant byte of this integer is ignored. Notice that this byte ordering scheme differs from the byte ordering scheme when pixelDepth is 24.

When pixelDepth is 24 or 32, valid RR, GG, and BB values range from 0 to 255.
mask unsigned char [] Array that determines which pixels in the image to draw. Use the mask array to achieve binary transparency.

The mask array contains one bit for each pixel in the image. A mask array bit value of 1 indicates that the pixel is drawn; a mask array bit value of 0 indicates that the pixel is not drawn.

When pixelDepth is 1, the pixels that have a bits array value of 1 are always drawn, regardless of the mask array value. In this case, the mask array affects only the pixels that have a bits array value of 0.

You must pad each row of the mask array to the nearest even-byte boundary. For example, if the width of the image is 21 pixels, then each row of the mask array must have 32 bits (four bytes) of data.

Pass NULL if you do not need a mask.
Output
Name Type Description
bitmapID int ID that serves as a handle to the bitmap object.

You can pass the ID to functions that accept a bitmap, such as CanvasDrawBitmap and ClipboardPutBitmap.

To discard the bitmap, pass the ID to DiscardBitmap.

Zero is not a valid bitmap ID.

Return Value

Name Type Description
status int Return value indicating whether the function was successful. A negative number indicates that an error occurred.

Additional Information

Library: User Interface Library

Include file: userint.h

LabWindows/CVI compatibility: LabWindows/CVI 4.0 and later

Example

Refer to userint\ICOViewer.cws for an example of using the NewBitmap function.