Access to a window's pixel data.
get_window_pointer3 enables (in some window systems) the direct access to the bitmap. Result values are the three pointers on the color extracts of a 24-bit window (ImageRed, ImageGreen, ImageBlue), as well as the window size (Width, Height). In the language C the type of the image points is unsigned char.
get_window_pointer3 is usable only for window type 'pixmap'.
|
WindowHandle (input_control) |
window -> integer |
| Window identifier. | |
|
ImageRed (output_control) |
integer -> integer |
| Pointer on red channel of pixel data. | |
|
ImageGreen (output_control) |
integer -> integer |
| Pointer on green channel of pixel data. | |
|
ImageBlue (output_control) |
integer -> integer |
| Pointer on blue channel of pixel data. | |
|
Width (output_control) |
extent.x -> integer |
| Length of an image line. | |
|
Height (output_control) |
extent.y -> integer |
| Number of image lines. | |
If a window of type 'pixmap' exists and it is valid get_window_pointer3 returns 2 (H_MSG_TRUE). If necessary an exception handling is raised.
get_window_pointer3 is reentrant, local, and processed without parallelization.
System
