VDisplayColorImage
Name
VDisplayColorImage - displays a truecolor image.
Synopsis
VDisplayColorImage(win, data, xloc, yloc, width, height, bits_per_rgb,
min, max)
Window win;
unsigned char *data;
int xloc, yloc;
int width, height;
int bits_per_rgb;
unsigned long max, min;
Description
VDisplayColorImage displays a truecolor image within a rectangle in the
image window or one of its subwindows. If the visual class is PseudoColor or
DirectoColor, then VTurnOnTruecolor should be called before calling
VDisplayColorImage. VTurnOnTruecolor turns the truecolor on and updates the
colormap. After the color image has been removed, VTurnOffTruecolor should be
called to turn off the truecolor and put back the previous colormap. The input
data format is RGB, RGB, ..., RGB. If the bits_per_rgb is 8, the input data is
assigned a character pointer type; if the bits_per_rgb is 16, the input
data is assigned a short pointer type.
Return Value
0 - work successfully.
1 - memory allocation error.
6 - invalid window ID.
222 - cannot display a truecolor image in GrayScale visual class.
230 - cannot display a truecolor image in the PseudoColor or DirectColor
visual class since truecolor is not on.
240 - image displayed is out of window boundary.
Parameters
win - the image window ID or one of its subwindows ID.
data - Specifies an array of data to be displayed in the image window.
xloc, yloc - specifies x and y coordinates of the upper left corner of the
rectangle relative to the origin of the image window.
width, height - specifies the width and height in pixels of the image.
bits_per_rgb - specifies the number of bits of each RGB component, the
value will be 8 or 16.
min, max - the minimum and maximum gray values of the image data.
Side Effects
None.
Entry Conditions
VTurnOnTrueColor should be called first. If the value xloc, yloc, width,
height, or bits_per_rgb is not valid, or data is NULL, or the image to be
displayed in totally out of the specified window boundary, or VCreateColormap
is not called earlier, then VDisplayColorImage prints an error message to the
standard error stream, produces a core dump file and exits from the current
process.
Related Functions
VDisplayGrayImage,
VPrepareColorImage,
VPrepareGrayImage,
VPutImage,
VGetImage,
VTurnOnTruecolor,
VTurnOffTruecolor.