libptouch / file revision

 /****************************************************************************

  * Project:   P-touch printer driver library

  * Developer: Philip Pemberton

  * Purpose:   Make Brother P-touch (PT-series) printers do something besides

  *            gather dust.

  *

  *            Currently supports:

  *              PT-2450DX

  ****************************************************************************/

 // TODO: disable

 #define DEBUG

 // This debug option forces Request Status to always "see" a good status

 // block. Mostly useful for testing using write-to-file mode.

 #define DEBUG_SKIP_STATUS_READ

 #include <stdio.h>

 #include <stdlib.h>

 #include <stdbool.h>

 #include <string.h>

 #include <gd.h>

 #include "hexdump.h"

 #include "ptouch.h"

 #define ESC 0x1b

 pt_Device *pt_Initialise(char *path)

 {

 	pt_Device	*dev;

 	FILE		*prn;

 	// Try and open the printer device

 	prn = fopen(path, "r+b");

 	if (prn == NULL) {

 		return NULL;

 	}

 	// Printer device open, send an init command and read the status

 	fprintf(prn, "%c%c", ESC, '@');

 	// Allocate memory for the device block

 	dev = malloc(sizeof(pt_Device));

 	if (dev == NULL) {

 		fclose(prn);

 		return NULL;

 	}

 	// Store the file pointer

 	dev->fp = prn;

 	// Memory allocation OK, now get the printer's status

 	if (pt_GetStatus(dev) == 0) {

 		return dev;

 	} else {

 		free(dev);

 		return NULL;

 	}

 }

 int pt_GetStatus(pt_Device *dev)

 {

 #ifdef DEBUG_SKIP_STATUS_READ

 	unsigned char buf[32];

 	memset(buf, 0x00, 32);

 	buf[0] = 0x80;

 	buf[1] = 0x20;

 	buf[2] = 0x42;

 	buf[3] = 0x30;

 	buf[4] = 0x4b;

 	buf[5] = 0x30;

 	buf[10] = 0x0c;

 	buf[11] = 0x01;

 #else

 	// REQUEST STATUS

 	fprintf(dev->fp, "%c%c%c", ESC, 'i', 'S');

 	// Read status buffer from printer

 	unsigned char buf[32];

 	int timeout = 128;

 	do {

 		fread(buf, 1, 32, dev->fp);

 	} while ((buf[0] != 0x80) && (timeout-- > 0));

 	// Check for timeout

 	if (timeout == 0) {

 		// Timeout

 		return PT_ERR_TIMEOUT;

 	}

 #endif

 #ifdef DEBUG

 	printf("DEBUG: Printer status buffer = \n");

 	hex_dump(buf, 32);

 #endif

 	// Decode the status buffer, store the results in the device object

 	dev->errorInfo[0] = buf[8];

 	dev->errorInfo[1] = buf[9];

 	dev->mediaWidth   = buf[10];

 	dev->mediaType    = buf[11];

 	dev->mediaLength  = buf[17];

 	dev->statusType   = buf[18];

 	dev->phaseType    = buf[19];

 	dev->phaseHi      = buf[20];

 	dev->phaseLo      = buf[21];

 	dev->notification = buf[22];

 	// Set pixel width (label width in pixels)

 	if (dev->mediaWidth >= 24) {

 		// Label tape is 24mm or wider. Print head is 128 dots at 180dpi,

 		// which is 18.06mm. Thus, we can only print on the centre 18mm

 		// of a tape that is wider than 18mm.

 		dev->pixelWidth = 128;

 	} else {

 		// Print head is 180dpi. Pixel size is mediaWidth * dpi. If we

 		// multiply by ten, then divide by 254, we can avoid using

 		// floating point to convert from inches to mm. The -2 is a

 		// safety margin -- one pixel on either side of the label.

 		// This is far closer than Brother suggest, but hey-ho.

 		dev->pixelWidth = ((dev->mediaWidth * 180 * 10) / 254) - 2;

 	}

 	// Set printing parameters to defaults --

 	//   Mirror off

 	//   Autocut on

 	dev->mirror = false;

 	dev->autocut = false;

 	// Operation succeeded

 	return PT_ERR_SUCCESS;

 }

 int pt_SetOption(pt_Device *dev, PT_E_OPTION option, int value)

 {

 	// trap dev == NULL

 	if (dev == NULL) {

 		return PT_ERR_BAD_PARAMETER;

 	}

 	// set option

 	switch(option) {

 		case PT_OPTION_MIRROR:			// Mirror

 			dev->mirror = (value ? 1 : 0);

 			return PT_ERR_SUCCESS;

 		case PT_OPTION_AUTOCUT:		// Auto-cutter enable/disable

 			dev->autocut = (value ? 1 : 0);

 			return PT_ERR_SUCCESS;

 		default:

 			return PT_ERR_BAD_PARAMETER;

 	}

 }

 int pt_GetOption(pt_Device *dev, PT_E_OPTION option, int *value)

 {

 	// trap dev == NULL or value == NULL

 	if ((dev == NULL) || (value == NULL)) {

 		return PT_ERR_BAD_PARAMETER;

 	}

 	// get option value

 	switch(option) {

 		case PT_OPTION_MIRROR:			// Mirror

 			*value = dev->mirror;

 			return PT_ERR_SUCCESS;

 		case PT_OPTION_AUTOCUT:		// Auto-cutter enable/disable

 			*value = dev->autocut;

 			return PT_ERR_SUCCESS;

 		default:

 			return PT_ERR_BAD_PARAMETER;

 	}

 }

 int pt_Print(pt_Device *dev, gdImagePtr *labels, int count)

 {

 	int err;

 	gdImagePtr *curLabel = labels;

 	// trap dev == NULL

 	if (dev == NULL) {

 		return PT_ERR_BAD_PARAMETER;

 	}

 	// trap labels == NULL

 	if (labels == NULL) {

 		return PT_ERR_BAD_PARAMETER;

 	}

 	// trap count == 0

 	if (count == 0) {

 		return PT_ERR_BAD_PARAMETER;

 	}

 	// Request current status from the printer

 	if ((err = pt_GetStatus(dev)) != PT_ERR_SUCCESS) {

 		return err;

 	}

 	// Make sure the printer has tape, and is ready

 	if ((dev->errorInfo[0] != 0x00) || (dev->errorInfo[1] != 0x00)) {

 		return PT_ERR_PRINTER_NOT_READY;

 	}

 	// Send the print initialisation commands

 	//

 	// ESC i M -- Set Mode

 	fprintf(dev->fp, "%ciM%c", ESC,

 			(dev->autocut ? 0x40 : 0x00) | (dev->mirror ? 0x80 : 0x00));

 	// ESC i K -- Set Expanded Mode

 	fprintf(dev->fp, "%ciK%c", ESC, 0x00);

 	// ESC i R {n1} -- Set Raster Graphics Transfer Mode

 	//   {n1} = 0x01 ==> Raster Graphics mode

 	fprintf(dev->fp, "%ciR%c", ESC, 0x01);

 	// M {n1} -- Set Compression Mode

 	//   {n1} = 0x00 ==> no compression

 	//   	Doesn't seem to work on the PT-2450DX...

 	//   {n1} = 0x01 ==> reserved

 	//   {n1} = 0x02 ==> TIFF/Packbits

 	//   	But this works fine on the PT-2450DX...

 	fprintf(dev->fp, "M%c", 0x02);

 	// Loop over the images that were passed in

 	for (int imnum=0; imnum < count; imnum++) {

 		// Make sure image is the right size for this label tape

 		if (gdImageSY(*curLabel) != dev->pixelWidth) {

 			return PT_ERR_LABEL_TOO_WIDE;

 		}

 		// Trap a label with a width of zero

 		// I'm not sure if this can happen, but it's a single if statement, so

 		// probably worth checking anyway...

 		if (gdImageSX(*curLabel) == 0) {

 			return PT_ERR_LABEL_ZERO_LENGTH;

 		}

 		// Get the index of the colour "white" (RGB:255,255,255) in the Gd image

 		int col_white = gdImageColorResolve(*curLabel, 255, 255, 255);

 		// Iterate left-to-right over the source image

 		for (int xpos = 0; xpos < gdImageSX(*curLabel); xpos++) {

 			char bitbuf[128/8];		// 128-dot printhead, 8 bits per byte

 			int rowclear = true;	// TRUE if entire row is clear, else FALSE

 			// Fill bit buffer with zeroes

 			memset(bitbuf, 0x00, sizeof(bitbuf));

 			// Calculate left-side margin for this label size

 			// Again, 128-dot printhead.

 			int margin = (128 / 2) - (dev->pixelWidth / 2);

 			// Copy data from the image to the bit-buffer

 			for (int ypos = 0; ypos < gdImageSY(*curLabel); ypos++) {

 				// Get pixel from gd, is it white?

 				if (gdImageGetPixel(*curLabel, xpos, ypos) != col_white) {

 					// No. Set the bit.

 					int bit = 1 << (7 - ((margin+ypos) % 8));

 					bitbuf[(margin+ypos) / 8] |= bit;

 					// Clear the "row is clear" flag

 					rowclear = false;

 				}

 			}

 			// We now have the image data in bitbuf, and a flag to say whether

 			// there are any black pixels in the buffer. We can pack full-rows

 			// by sending a "Z" character, i.e. "this row is entirely blank".

 			// If not, we have to send a (128/8)=16 byte chunk of image data.

 			if (rowclear) {

 				// Row is clear -- send a "clear row" command

 				fprintf(dev->fp, "Z");

 			} else {

 				// Row is not clear -- send the pixel data

 				//

 				// TODO: the printer supports Packbits compression. Implement!

 				// TODO: After Packbits is implemented, ((128/8)+1) must be

 				//   changed to the length of the Packbits compressed data.

 				//   (note: 128/8 is the printhead size in bytes, the +1 is for

 				//   the control byte we add below...)

 				fprintf(dev->fp, "G%c%c", ((128/8)+1) & 0xff, ((128/8)+1) >> 8);

 				// This printer asks for Packbits compressed data. In this

 				// case, we send a "run of N" control byte and fake it...

 				fputc(sizeof(bitbuf) - 1, dev->fp);

 				for (int i=0; i<sizeof(bitbuf); i++) {

 					fputc(bitbuf[i], dev->fp);

 				}

 			}

 		}

 		// Is this the last label?

 		if (imnum == (count-1)) {

 			// Yes, send an End Job command

 			fprintf(dev->fp, "%c", 0x1A);

 		} else {

 			// No, more labels to print. Send a formfeed.

 			fprintf(dev->fp, "%c", 0x0C);

 		}

 		// Move onto the next label

 		curLabel++;

 	}

 	// Operation successful.

 	return PT_ERR_SUCCESS;

 }

 void pt_Close(pt_Device *dev)

 {

 	// Sanity check -- make sure dev is not null

 	if (dev == NULL) return;

 	// Close the printer stream

 	fclose(dev->fp);

 	// Release the memory allocated to the status buffer

 	free(dev);

 }