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/*
* jwrtarga.c
*
* Copyright (C) 1991, 1992, 1993, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to write output images in Targa format.
*
* These routines may need modification for non-Unix environments or
* specialized applications. As they stand, they assume output to
* an ordinary stdio stream.
*
* These routines are invoked via the methods put_pixel_rows, put_color_map,
* and output_init/term.
*
* Based on code contributed by Lee Daniel Crocker.
*/
#include "jinclude.h"
#ifdef TARGA_SUPPORTED
/*
* To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
* This is not yet implemented.
*/
#ifndef EIGHT_BIT_SAMPLES
Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
#endif
/*
* On most systems, writing individual bytes with putc() is drastically less
* efficient than buffering a row at a time for fwrite(). But we must
* allocate the row buffer in near data space on PCs, because we are assuming
* small-data memory model, wherein fwrite() can't reach far memory. If you
* need to process very wide images on a PC, you may have to use the putc()
* approach. Also, there are still a few systems around wherein fwrite() is
* actually implemented as a putc() loop, in which case this buffer is a waste
* of space. So the putc() method can be used by defining USE_PUTC_OUTPUT.
*/
#ifndef USE_PUTC_OUTPUT
static char * row_buffer; /* holds 1 pixel row's worth of output */
#endif
LOCAL void
write_header (decompress_info_ptr cinfo, int num_colors)
/* Create and write a Targa header */
{
char targaheader[18];
/* Set unused fields of header to 0 */
MEMZERO(targaheader, SIZEOF(targaheader));
if (num_colors > 0) {
targaheader[1] = 1; /* color map type 1 */
targaheader[5] = (char) (num_colors & 0xFF);
targaheader[6] = (char) (num_colors >> 8);
targaheader[7] = 24; /* 24 bits per cmap entry */
}
targaheader[12] = (char) (cinfo->image_width & 0xFF);
targaheader[13] = (char) (cinfo->image_width >> 8);
targaheader[14] = (char) (cinfo->image_height & 0xFF);
targaheader[15] = (char) (cinfo->image_height >> 8);
targaheader[17] = 0x20; /* Top-down, non-interlaced */
if (cinfo->out_color_space == CS_GRAYSCALE) {
targaheader[2] = 3; /* image type = uncompressed gray-scale */
targaheader[16] = 8; /* bits per pixel */
} else { /* must be RGB */
if (num_colors > 0) {
targaheader[2] = 1; /* image type = colormapped RGB */
targaheader[16] = 8;
} else {
targaheader[2] = 2; /* image type = uncompressed RGB */
targaheader[16] = 24;
}
}
if (JFWRITE(cinfo->output_file, targaheader, 18) != (size_t) 18)
ERREXIT(cinfo->emethods, "Could not write Targa header");
}
/*
* Write the file header.
*/
METHODDEF void
output_init (decompress_info_ptr cinfo)
{
if (cinfo->out_color_space == CS_GRAYSCALE) {
/* Targa doesn't have a mapped grayscale format, so we will */
/* demap quantized gray output. Never emit a colormap. */
write_header(cinfo, 0);
#ifndef USE_PUTC_OUTPUT
/* allocate space for row buffer: 1 byte/pixel */
row_buffer = (char *) (*cinfo->emethods->alloc_small)
((size_t) (SIZEOF(char) * cinfo->image_width));
#endif
} else if (cinfo->out_color_space == CS_RGB) {
/* For quantized output, defer writing header until put_color_map time. */
if (! cinfo->quantize_colors)
write_header(cinfo, 0);
#ifndef USE_PUTC_OUTPUT
/* allocate space for row buffer: 3 bytes/pixel */
row_buffer = (char *) (*cinfo->emethods->alloc_small)
((size_t) (3 * SIZEOF(char) * cinfo->image_width));
#endif
} else {
ERREXIT(cinfo->emethods, "Targa output must be grayscale or RGB");
}
}
/*
* Write some pixel data.
*/
#ifdef USE_PUTC_OUTPUT
METHODDEF void
put_pixel_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
/* used for unquantized full-color output */
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0, ptr1, ptr2;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
ptr1 = pixel_data[1][row];
ptr2 = pixel_data[2][row];
for (col = width; col > 0; col--) {
putc(GETJSAMPLE(*ptr2), outfile); /* write in BGR order */
ptr2++;
putc(GETJSAMPLE(*ptr1), outfile);
ptr1++;
putc(GETJSAMPLE(*ptr0), outfile);
ptr0++;
}
}
}
METHODDEF void
put_gray_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
/* used for grayscale OR quantized color output */
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
for (col = width; col > 0; col--) {
putc(GETJSAMPLE(*ptr0), outfile);
ptr0++;
}
}
}
#else /* use row buffering */
METHODDEF void
put_pixel_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
/* used for unquantized full-color output */
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0, ptr1, ptr2;
register char * row_bufferptr;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
ptr1 = pixel_data[1][row];
ptr2 = pixel_data[2][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
*row_bufferptr++ = (char) GETJSAMPLE(*ptr2++); /* BGR order */
*row_bufferptr++ = (char) GETJSAMPLE(*ptr1++);
*row_bufferptr++ = (char) GETJSAMPLE(*ptr0++);
}
(void) JFWRITE(outfile, row_buffer, 3*width);
}
}
METHODDEF void
put_gray_rows (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
/* used for grayscale OR quantized color output */
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr0;
register char * row_bufferptr;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr0 = pixel_data[0][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
*row_bufferptr++ = (char) GETJSAMPLE(*ptr0++);
}
(void) JFWRITE(outfile, row_buffer, width);
}
}
#endif /* USE_PUTC_OUTPUT */
/*
* Write some demapped pixel data when color quantization is in effect.
* For Targa, this is only applied to grayscale data.
*/
#ifdef USE_PUTC_OUTPUT
METHODDEF void
put_demapped_gray (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
register FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
putc(GETJSAMPLE(color_map0[pixval]), outfile);
}
}
}
#else /* use row buffering */
METHODDEF void
put_demapped_gray (decompress_info_ptr cinfo, int num_rows,
JSAMPIMAGE pixel_data)
{
FILE * outfile = cinfo->output_file;
register JSAMPROW ptr;
register char * row_bufferptr;
register JSAMPROW color_map0 = cinfo->colormap[0];
register int pixval;
register long col;
long width = cinfo->image_width;
int row;
for (row = 0; row < num_rows; row++) {
ptr = pixel_data[0][row];
row_bufferptr = row_buffer;
for (col = width; col > 0; col--) {
pixval = GETJSAMPLE(*ptr++);
*row_bufferptr++ = (char) GETJSAMPLE(color_map0[pixval]);
}
(void) JFWRITE(outfile, row_buffer, width);
}
}
#endif /* USE_PUTC_OUTPUT */
/*
* Write the color map.
*/
METHODDEF void
put_color_map (decompress_info_ptr cinfo, int num_colors, JSAMPARRAY colormap)
{
register FILE * outfile = cinfo->output_file;
int i;
if (cinfo->out_color_space == CS_RGB) {
/* We only support 8-bit colormap indexes, so only 256 colors */
if (num_colors > 256)
ERREXIT(cinfo->emethods, "Too many colors for Targa output");
/* Time to write the header */
write_header(cinfo, num_colors);
/* Write the colormap. Note Targa uses BGR byte order */
for (i = 0; i < num_colors; i++) {
putc(GETJSAMPLE(colormap[2][i]), outfile);
putc(GETJSAMPLE(colormap[1][i]), outfile);
putc(GETJSAMPLE(colormap[0][i]), outfile);
}
} else {
cinfo->methods->put_pixel_rows = put_demapped_gray;
}
}
/*
* Finish up at the end of the file.
*/
METHODDEF void
output_term (decompress_info_ptr cinfo)
{
/* No work except to make sure we wrote the output file OK */
fflush(cinfo->output_file);
if (ferror(cinfo->output_file))
ERREXIT(cinfo->emethods, "Output file write error --- out of disk space?");
}
/*
* The method selection routine for Targa format output.
* This should be called from d_ui_method_selection if Targa output is wanted.
*/
GLOBAL void
jselwtarga (decompress_info_ptr cinfo)
{
cinfo->methods->output_init = output_init;
cinfo->methods->put_color_map = put_color_map;
if (cinfo->out_color_space == CS_GRAYSCALE || cinfo->quantize_colors)
cinfo->methods->put_pixel_rows = put_gray_rows;
else
cinfo->methods->put_pixel_rows = put_pixel_rows;
cinfo->methods->output_term = output_term;
}
#endif /* TARGA_SUPPORTED */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.