ls027b7dh01_begin_draw :: Quanser C Functions

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ls027b7dh01_begin_draw

Put the Sharp LS027B7DH01 LCD display into drawing mode.

Description

The ls027b7dh01_begin_draw function puts the Sharp LS027B7DH01 LCD display into drawing mode so that the display is not updated until ls027b7dh01_end_draw is called. This allows both graphics and text to be mixed on the display as an atomic update.

Prototype

t_error
ls027b7dh01_begin_draw(t_ls027b7dh01 display);

Parameters

t_ls027b7dh01 display

A handle to the display returned by the ls027b7dh01_open function.

Return value

The return value is 0 if the operation is successful. Otherwise a negative error code is returned. Error codes are defined in quanser_errors.h. A suitable error message may be retrieved using msg_get_error_message.

Error codes

QERR_INVALID_ARGUMENT

One of the arguments is invalid.

Requirements

Include Files	Libraries
quanser_lcd_display.h	quanser_devices.lib;quanser_communications.lib;quanser_runtime.lib;quanser_common.lib

Examples

t_ls027b7dh01 display;
t_error result = 
    ls027b7dh01_open("spi-cpu://localhost:1?word='8',baud='45000000',polarity='on',phase='on',memsize='8192',frame='0'", LCD_ACCESS_EXCLUSIVE, &display);
if (result == 0) {
    ls027b7dh01_begin_draw(display);
    ls027b7dh01_draw_image(display, 0, 0, 400, 240, background_image);
    ls027b7dh01_print(display, 6, 9, "Quanser", 7);
    ls027b7dh01_end_draw(display);
    ...
    ls027b7dh01_close(display);
} else {
    TCHAR message[512];
    msg_get_error_message(NULL, result, message, sizeof(message));
    _tprintf(_T("Failed to open LCD display. %s (error %d)\n"), message, -result);
}