+++ /dev/null
-/*
- * rdtarga.c
- *
- * Copyright (C) 1991-1996, 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 read input images in Targa format.
- *
- * These routines may need modification for non-Unix environments or
- * specialized applications. As they stand, they assume input from
- * an ordinary stdio stream. They further assume that reading begins
- * at the start of the file; start_input may need work if the
- * user interface has already read some data (e.g., to determine that
- * the file is indeed Targa format).
- *
- * Based on code contributed by Lee Daniel Crocker.
- */
-
-#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
-
-#ifdef TARGA_SUPPORTED
-
-
-/* Macros to deal with unsigned chars as efficiently as compiler allows */
-
-#ifdef HAVE_UNSIGNED_CHAR
-typedef unsigned char U_CHAR;
-#define UCH(x) ((int) (x))
-#else /* !HAVE_UNSIGNED_CHAR */
-#ifdef CHAR_IS_UNSIGNED
-typedef char U_CHAR;
-#define UCH(x) ((int) (x))
-#else
-typedef char U_CHAR;
-#define UCH(x) ((int) (x) & 0xFF)
-#endif
-#endif /* HAVE_UNSIGNED_CHAR */
-
-
-#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
-
-
-/* Private version of data source object */
-
-typedef struct _tga_source_struct * tga_source_ptr;
-
-typedef struct _tga_source_struct {
- struct cjpeg_source_struct pub; /* public fields */
-
- j_compress_ptr cinfo; /* back link saves passing separate parm */
-
- JSAMPARRAY colormap; /* Targa colormap (converted to my format) */
-
- jvirt_sarray_ptr whole_image; /* Needed if funny input row order */
- JDIMENSION current_row; /* Current logical row number to read */
-
- /* Pointer to routine to extract next Targa pixel from input file */
- JMETHOD(void, read_pixel, (tga_source_ptr sinfo));
-
- /* Result of read_pixel is delivered here: */
- U_CHAR tga_pixel[4];
-
- int pixel_size; /* Bytes per Targa pixel (1 to 4) */
-
- /* State info for reading RLE-coded pixels; both counts must be init to 0 */
- int block_count; /* # of pixels remaining in RLE block */
- int dup_pixel_count; /* # of times to duplicate previous pixel */
-
- /* This saves the correct pixel-row-expansion method for preload_image */
- JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo,
- cjpeg_source_ptr sinfo));
-} tga_source_struct;
-
-
-/* For expanding 5-bit pixel values to 8-bit with best rounding */
-
-static const UINT8 c5to8bits[32] = {
- 0, 8, 16, 25, 33, 41, 49, 58,
- 66, 74, 82, 90, 99, 107, 115, 123,
- 132, 140, 148, 156, 165, 173, 181, 189,
- 197, 206, 214, 222, 230, 239, 247, 255
-};
-
-
-
-LOCAL(int)
-read_byte (tga_source_ptr sinfo)
-/* Read next byte from Targa file */
-{
- register FILE *infile = sinfo->pub.input_file;
- register int c;
-
- if ((c = getc(infile)) == EOF)
- ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
- return c;
-}
-
-
-LOCAL(void)
-read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize)
-/* Read the colormap from a Targa file */
-{
- int i;
-
- /* Presently only handles 24-bit BGR format */
- if (mapentrysize != 24)
- ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP);
-
- for (i = 0; i < cmaplen; i++) {
- sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
- sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
- sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
- }
-}
-
-
-/*
- * read_pixel methods: get a single pixel from Targa file into tga_pixel[]
- */
-
-METHODDEF(void)
-read_non_rle_pixel (tga_source_ptr sinfo)
-/* Read one Targa pixel from the input file; no RLE expansion */
-{
- register FILE *infile = sinfo->pub.input_file;
- register int i;
-
- for (i = 0; i < sinfo->pixel_size; i++) {
- sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
- }
-}
-
-
-METHODDEF(void)
-read_rle_pixel (tga_source_ptr sinfo)
-/* Read one Targa pixel from the input file, expanding RLE data as needed */
-{
- register FILE *infile = sinfo->pub.input_file;
- register int i;
-
- /* Duplicate previously read pixel? */
- if (sinfo->dup_pixel_count > 0) {
- sinfo->dup_pixel_count--;
- return;
- }
-
- /* Time to read RLE block header? */
- if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */
- i = read_byte(sinfo);
- if (i & 0x80) { /* Start of duplicate-pixel block? */
- sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */
- sinfo->block_count = 0; /* then read new block header */
- } else {
- sinfo->block_count = i & 0x7F; /* number of pixels after this one */
- }
- }
-
- /* Read next pixel */
- for (i = 0; i < sinfo->pixel_size; i++) {
- sinfo->tga_pixel[i] = (U_CHAR) getc(infile);
- }
-}
-
-
-/*
- * Read one row of pixels.
- *
- * We provide several different versions depending on input file format.
- */
-
-
-METHODDEF(JDIMENSION)
-get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading 8-bit grayscale pixels */
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- register JSAMPROW ptr;
- register JDIMENSION col;
-
- ptr = source->pub.buffer[0];
- for (col = cinfo->image_width; col > 0; col--) {
- (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
- *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
- }
- return 1;
-}
-
-METHODDEF(JDIMENSION)
-get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading 8-bit colormap indexes */
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- register int t;
- register JSAMPROW ptr;
- register JDIMENSION col;
- register JSAMPARRAY colormap = source->colormap;
-
- ptr = source->pub.buffer[0];
- for (col = cinfo->image_width; col > 0; col--) {
- (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
- t = UCH(source->tga_pixel[0]);
- *ptr++ = colormap[0][t];
- *ptr++ = colormap[1][t];
- *ptr++ = colormap[2][t];
- }
- return 1;
-}
-
-METHODDEF(JDIMENSION)
-get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading 16-bit pixels */
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- register int t;
- register JSAMPROW ptr;
- register JDIMENSION col;
-
- ptr = source->pub.buffer[0];
- for (col = cinfo->image_width; col > 0; col--) {
- (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
- t = UCH(source->tga_pixel[0]);
- t += UCH(source->tga_pixel[1]) << 8;
- /* We expand 5 bit data to 8 bit sample width.
- * The format of the 16-bit (LSB first) input word is
- * xRRRRRGGGGGBBBBB
- */
- ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F];
- t >>= 5;
- ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F];
- t >>= 5;
- ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F];
- ptr += 3;
- }
- return 1;
-}
-
-METHODDEF(JDIMENSION)
-get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading 24-bit pixels */
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- register JSAMPROW ptr;
- register JDIMENSION col;
-
- ptr = source->pub.buffer[0];
- for (col = cinfo->image_width; col > 0; col--) {
- (*source->read_pixel) (source); /* Load next pixel into tga_pixel */
- *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */
- *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]);
- *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]);
- }
- return 1;
-}
-
-/*
- * Targa also defines a 32-bit pixel format with order B,G,R,A.
- * We presently ignore the attribute byte, so the code for reading
- * these pixels is identical to the 24-bit routine above.
- * This works because the actual pixel length is only known to read_pixel.
- */
-
-#define get_32bit_row get_24bit_row
-
-
-/*
- * This method is for re-reading the input data in standard top-down
- * row order. The entire image has already been read into whole_image
- * with proper conversion of pixel format, but it's in a funny row order.
- */
-
-METHODDEF(JDIMENSION)
-get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- JDIMENSION source_row;
-
- /* Compute row of source that maps to current_row of normal order */
- /* For now, assume image is bottom-up and not interlaced. */
- /* NEEDS WORK to support interlaced images! */
- source_row = cinfo->image_height - source->current_row - 1;
-
- /* Fetch that row from virtual array */
- source->pub.buffer = (*cinfo->mem->access_virt_sarray)
- ((j_common_ptr) cinfo, source->whole_image,
- source_row, (JDIMENSION) 1, FALSE);
-
- source->current_row++;
- return 1;
-}
-
-
-/*
- * This method loads the image into whole_image during the first call on
- * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
- * get_memory_row on subsequent calls.
- */
-
-METHODDEF(JDIMENSION)
-preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- JDIMENSION row;
- cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
-
- /* Read the data into a virtual array in input-file row order. */
- for (row = 0; row < cinfo->image_height; row++) {
- if (progress != NULL) {
- progress->pub.pass_counter = (long) row;
- progress->pub.pass_limit = (long) cinfo->image_height;
- (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
- }
- source->pub.buffer = (*cinfo->mem->access_virt_sarray)
- ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE);
- (*source->get_pixel_rows) (cinfo, sinfo);
- }
- if (progress != NULL)
- progress->completed_extra_passes++;
-
- /* Set up to read from the virtual array in unscrambled order */
- source->pub.get_pixel_rows = get_memory_row;
- source->current_row = 0;
- /* And read the first row */
- return get_memory_row(cinfo, sinfo);
-}
-
-
-/*
- * Read the file header; return image size and component count.
- */
-
-METHODDEF(void)
-start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-{
- tga_source_ptr source = (tga_source_ptr) sinfo;
- U_CHAR targaheader[18];
- int idlen, cmaptype, subtype, flags, interlace_type, components;
- unsigned int width, height, maplen;
- boolean is_bottom_up;
-
-#define GET_2B(offset) ((unsigned int) UCH(targaheader[offset]) + \
- (((unsigned int) UCH(targaheader[offset+1])) << 8))
-
- if (! ReadOK(source->pub.input_file, targaheader, 18))
- ERREXIT(cinfo, JERR_INPUT_EOF);
-
- /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */
- if (targaheader[16] == 15)
- targaheader[16] = 16;
-
- idlen = UCH(targaheader[0]);
- cmaptype = UCH(targaheader[1]);
- subtype = UCH(targaheader[2]);
- maplen = GET_2B(5);
- width = GET_2B(12);
- height = GET_2B(14);
- source->pixel_size = UCH(targaheader[16]) >> 3;
- flags = UCH(targaheader[17]); /* Image Descriptor byte */
-
- is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */
- interlace_type = flags >> 6; /* bits 6/7 are interlace code */
-
- if (cmaptype > 1 || /* cmaptype must be 0 or 1 */
- source->pixel_size < 1 || source->pixel_size > 4 ||
- (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */
- interlace_type != 0) /* currently don't allow interlaced image */
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
-
- if (subtype > 8) {
- /* It's an RLE-coded file */
- source->read_pixel = read_rle_pixel;
- source->block_count = source->dup_pixel_count = 0;
- subtype -= 8;
- } else {
- /* Non-RLE file */
- source->read_pixel = read_non_rle_pixel;
- }
-
- /* Now should have subtype 1, 2, or 3 */
- components = 3; /* until proven different */
- cinfo->in_color_space = JCS_RGB;
-
- switch (subtype) {
- case 1: /* Colormapped image */
- if (source->pixel_size == 1 && cmaptype == 1)
- source->get_pixel_rows = get_8bit_row;
- else
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
- TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height);
- break;
- case 2: /* RGB image */
- switch (source->pixel_size) {
- case 2:
- source->get_pixel_rows = get_16bit_row;
- break;
- case 3:
- source->get_pixel_rows = get_24bit_row;
- break;
- case 4:
- source->get_pixel_rows = get_32bit_row;
- break;
- default:
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
- break;
- }
- TRACEMS2(cinfo, 1, JTRC_TGA, width, height);
- break;
- case 3: /* Grayscale image */
- components = 1;
- cinfo->in_color_space = JCS_GRAYSCALE;
- if (source->pixel_size == 1)
- source->get_pixel_rows = get_8bit_gray_row;
- else
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
- TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height);
- break;
- default:
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
- break;
- }
-
- if (is_bottom_up) {
- /* Create a virtual array to buffer the upside-down image. */
- source->whole_image = (*cinfo->mem->request_virt_sarray)
- ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
- (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1);
- if (cinfo->progress != NULL) {
- cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
- progress->total_extra_passes++; /* count file input as separate pass */
- }
- /* source->pub.buffer will point to the virtual array. */
- source->pub.buffer_height = 1; /* in case anyone looks at it */
- source->pub.get_pixel_rows = preload_image;
- } else {
- /* Don't need a virtual array, but do need a one-row input buffer. */
- source->whole_image = NULL;
- source->pub.buffer = (*cinfo->mem->alloc_sarray)
- ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (JDIMENSION) width * components, (JDIMENSION) 1);
- source->pub.buffer_height = 1;
- source->pub.get_pixel_rows = source->get_pixel_rows;
- }
-
- while (idlen--) /* Throw away ID field */
- (void) read_byte(source);
-
- if (maplen > 0) {
- if (maplen > 256 || GET_2B(3) != 0)
- ERREXIT(cinfo, JERR_TGA_BADCMAP);
- /* Allocate space to store the colormap */
- source->colormap = (*cinfo->mem->alloc_sarray)
- ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3);
- /* and read it from the file */
- read_colormap(source, (int) maplen, UCH(targaheader[7]));
- } else {
- if (cmaptype) /* but you promised a cmap! */
- ERREXIT(cinfo, JERR_TGA_BADPARMS);
- source->colormap = NULL;
- }
-
- cinfo->input_components = components;
- cinfo->data_precision = 8;
- cinfo->image_width = width;
- cinfo->image_height = height;
-}
-
-
-/*
- * Finish up at the end of the file.
- */
-
-METHODDEF(void)
-finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-{
- /* no work */
-}
-
-
-/*
- * The module selection routine for Targa format input.
- */
-
-GLOBAL(cjpeg_source_ptr)
-jinit_read_targa (j_compress_ptr cinfo)
-{
- tga_source_ptr source;
-
- /* Create module interface object */
- source = (tga_source_ptr)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(tga_source_struct));
- source->cinfo = cinfo; /* make back link for subroutines */
- /* Fill in method ptrs, except get_pixel_rows which start_input sets */
- source->pub.start_input = start_input_tga;
- source->pub.finish_input = finish_input_tga;
-
- return (cjpeg_source_ptr) source;
-}
-
-#endif /* TARGA_SUPPORTED */
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