+++ /dev/null
-/* This file contains code to read and write four byte rgbe file format
- * developed by Greg Ward. It handles the conversions between rgbe and
- * pixels consisting of floats. The data is assumed to be an array of floats.
- * By default there are three floats per pixel in the order red, green, blue.
- * (RGBE_DATA_??? values control this.)
- *
- * written by Bruce Walter (bjw@graphics.cornell.edu) 5/26/95
- * based on code written by Greg Ward
- * minor modifications by John Tsiombikas (nuclear@member.fsf.org) apr.9 2007
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <math.h>
-#include <ctype.h>
-#include <errno.h>
-#include "imago2.h"
-#include "ftype_module.h"
-
-
-typedef struct {
- int valid; /* indicate which fields are valid */
- char programtype[16]; /* listed at beginning of file to identify it
- * after "#?". defaults to "RGBE" */
- float gamma; /* image has already been gamma corrected with
- * given gamma. defaults to 1.0 (no correction) */
- float exposure; /* a value of 1.0 in an image corresponds to
- * <exposure> watts/steradian/m^2.
- * defaults to 1.0 */
-} rgbe_header_info;
-
-
-static int check(struct img_io *io);
-static int read(struct img_pixmap *img, struct img_io *io);
-static int write(struct img_pixmap *img, struct img_io *io);
-
-static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info);
-static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines);
-
-
-int img_register_rgbe(void)
-{
- static struct ftype_module mod = {".rgbe", check, read, write};
- return img_register_module(&mod);
-}
-
-
-static int check(struct img_io *io)
-{
- int xsz, ysz, res;
- long pos = io->seek(0, SEEK_CUR, io->uptr);
-
- rgbe_header_info hdr;
- res = rgbe_read_header(io, &xsz, &ysz, &hdr);
-
- io->seek(pos, SEEK_SET, io->uptr);
- return res;
-}
-
-static int read(struct img_pixmap *img, struct img_io *io)
-{
- int xsz, ysz;
- rgbe_header_info hdr;
-
- if(rgbe_read_header(io, &xsz, &ysz, &hdr) == -1) {
- return -1;
- }
-
- if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGBF, 0) == -1) {
- return -1;
- }
- if(rgbe_read_pixels_rle(io, img->pixels, xsz, ysz) == -1) {
- return -1;
- }
- return 0;
-}
-
-static int write(struct img_pixmap *img, struct img_io *io)
-{
- return -1; /* TODO */
-}
-
-
-static int iofgetc(struct img_io *io)
-{
- char c;
- return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
-}
-
-static char *iofgets(char *buf, int size, struct img_io *io)
-{
- int c;
- char *ptr = buf;
-
- while(--size > 0 && (c = iofgetc(io)) != -1) {
- *ptr++ = c;
- if(c == '\n') break;
- }
- *ptr = 0;
-
- return ptr == buf ? 0 : buf;
-}
-
-
-/* flags indicating which fields in an rgbe_header_info are valid */
-#define RGBE_VALID_PROGRAMTYPE 0x01
-#define RGBE_VALID_GAMMA 0x02
-#define RGBE_VALID_EXPOSURE 0x04
-
-/* return codes for rgbe routines */
-#define RGBE_RETURN_SUCCESS 0
-#define RGBE_RETURN_FAILURE -1
-
-
-#if defined(__cplusplus) || defined(GNUC) || __STDC_VERSION >= 199901L
-#define INLINE inline
-#else
-#define INLINE
-#endif
-
-/* offsets to red, green, and blue components in a data (float) pixel */
-#define RGBE_DATA_RED 0
-#define RGBE_DATA_GREEN 1
-#define RGBE_DATA_BLUE 2
-
-/* number of floats per pixel */
-#define RGBE_DATA_SIZE 3
-
-enum rgbe_error_codes {
- rgbe_read_error,
- rgbe_write_error,
- rgbe_format_error,
- rgbe_memory_error
-};
-
-
-/* default error routine. change this to change error handling */
-static int rgbe_error(int rgbe_error_code, char *msg)
-{
- switch (rgbe_error_code) {
- case rgbe_read_error:
- fprintf(stderr, "RGBE read error: %s\n", strerror(errno));
- break;
-
- case rgbe_write_error:
- fprintf(stderr, "RGBE write error: %s\n", strerror(errno));
- break;
-
- case rgbe_format_error:
- fprintf(stderr, "RGBE bad file format: %s\n", msg);
- break;
-
- default:
- case rgbe_memory_error:
- fprintf(stderr, "RGBE error: %s\n", msg);
- }
- return RGBE_RETURN_FAILURE;
-}
-
-/* standard conversion from float pixels to rgbe pixels */
-/*static INLINE void float2rgbe(unsigned char rgbe[4], float red, float green, float blue)
-{
- float v;
- int e;
-
- v = red;
- if(green > v)
- v = green;
- if(blue > v)
- v = blue;
- if(v < 1e-32) {
- rgbe[0] = rgbe[1] = rgbe[2] = rgbe[3] = 0;
- } else {
- v = frexp(v, &e) * 256.0 / v;
- rgbe[0] = (unsigned char)(red * v);
- rgbe[1] = (unsigned char)(green * v);
- rgbe[2] = (unsigned char)(blue * v);
- rgbe[3] = (unsigned char)(e + 128);
- }
-}*/
-
-/* standard conversion from rgbe to float pixels */
-/* note: Ward uses ldexp(col+0.5,exp-(128+8)). However we wanted pixels */
-/* in the range [0,1] to map back into the range [0,1]. */
-static INLINE void rgbe2float(float *red, float *green, float *blue, unsigned char rgbe[4])
-{
- float f;
-
- if(rgbe[3]) { /*nonzero pixel */
- f = ldexp(1.0, rgbe[3] - (int)(128 + 8));
- *red = rgbe[0] * f;
- *green = rgbe[1] * f;
- *blue = rgbe[2] * f;
- } else
- *red = *green = *blue = 0.0;
-}
-
-#if 0
-/* default minimal header. modify if you want more information in header */
-static int rgbe_write_header(FILE * fp, int width, int height, rgbe_header_info * info)
-{
- char *programtype = "RGBE";
-
- if(info && (info->valid & RGBE_VALID_PROGRAMTYPE))
- programtype = info->programtype;
- if(fprintf(fp, "#?%s\n", programtype) < 0)
- return rgbe_error(rgbe_write_error, NULL);
- /* The #? is to identify file type, the programtype is optional. */
- if(info && (info->valid & RGBE_VALID_GAMMA)) {
- if(fprintf(fp, "GAMMA=%g\n", info->gamma) < 0)
- return rgbe_error(rgbe_write_error, NULL);
- }
- if(info && (info->valid & RGBE_VALID_EXPOSURE)) {
- if(fprintf(fp, "EXPOSURE=%g\n", info->exposure) < 0)
- return rgbe_error(rgbe_write_error, NULL);
- }
- if(fprintf(fp, "FORMAT=32-bit_rle_rgbe\n\n") < 0)
- return rgbe_error(rgbe_write_error, NULL);
- if(fprintf(fp, "-Y %d +X %d\n", height, width) < 0)
- return rgbe_error(rgbe_write_error, NULL);
- return RGBE_RETURN_SUCCESS;
-}
-#endif
-
-/* minimal header reading. modify if you want to parse more information */
-static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info)
-{
- char buf[128];
- float tempf;
- int i;
-
- if(info) {
- info->valid = 0;
- info->programtype[0] = 0;
- info->gamma = info->exposure = 1.0;
- }
- if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == NULL)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
- if((buf[0] != '#') || (buf[1] != '?')) {
- /* if you want to require the magic token then uncomment the next line */
- /*return rgbe_error(rgbe_format_error,"bad initial token"); */
- } else if(info) {
- info->valid |= RGBE_VALID_PROGRAMTYPE;
- for(i = 0; i < sizeof(info->programtype) - 1; i++) {
- if((buf[i + 2] == 0) || isspace(buf[i + 2]))
- break;
- info->programtype[i] = buf[i + 2];
- }
- info->programtype[i] = 0;
- if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
- return rgbe_error(rgbe_read_error, NULL);
- }
- for(;;) {
- if((buf[0] == 0) || (buf[0] == '\n'))
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "no FORMAT specifier found");*/
- else if(strcmp(buf, "FORMAT=32-bit_rle_rgbe\n") == 0)
- break; /* format found so break out of loop */
- else if(info && (sscanf(buf, "GAMMA=%g", &tempf) == 1)) {
- info->gamma = tempf;
- info->valid |= RGBE_VALID_GAMMA;
- } else if(info && (sscanf(buf, "EXPOSURE=%g", &tempf) == 1)) {
- info->exposure = tempf;
- info->valid |= RGBE_VALID_EXPOSURE;
- }
- if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
- }
- if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
- if(strcmp(buf, "\n") != 0)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing blank line after FORMAT specifier");*/
- if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
- if(sscanf(buf, "-Y %d +X %d", height, width) < 2)
- return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing image size specifier");*/
- return RGBE_RETURN_SUCCESS;
-}
-
-#if 0
-/* simple write routine that does not use run length encoding */
-
-/* These routines can be made faster by allocating a larger buffer and
- fread-ing and fwrite-ing the data in larger chunks */
-static int rgbe_write_pixels(FILE * fp, float *data, int numpixels)
-{
- unsigned char rgbe[4];
-
- while(numpixels-- > 0) {
- float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
- data += RGBE_DATA_SIZE;
- if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1)
- return rgbe_error(rgbe_write_error, NULL);
- }
- return RGBE_RETURN_SUCCESS;
-}
-#endif
-
-/* simple read routine. will not correctly handle run length encoding */
-static int rgbe_read_pixels(struct img_io *io, float *data, int numpixels)
-{
- unsigned char rgbe[4];
-
- while(numpixels-- > 0) {
- if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1)
- return rgbe_error(rgbe_read_error, NULL);
- rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
- data += RGBE_DATA_SIZE;
- }
- return RGBE_RETURN_SUCCESS;
-}
-
-#if 0
-/* The code below is only needed for the run-length encoded files. */
-
-/* Run length encoding adds considerable complexity but does */
-
-/* save some space. For each scanline, each channel (r,g,b,e) is */
-
-/* encoded separately for better compression. */
-
-static int rgbe_write_bytes_rle(struct img_io *io, unsigned char *data, int numbytes)
-{
-#define MINRUNLENGTH 4
- int cur, beg_run, run_count, old_run_count, nonrun_count;
- unsigned char buf[2];
-
- cur = 0;
- while(cur < numbytes) {
- beg_run = cur;
- /* find next run of length at least 4 if one exists */
- run_count = old_run_count = 0;
- while((run_count < MINRUNLENGTH) && (beg_run < numbytes)) {
- beg_run += run_count;
- old_run_count = run_count;
- run_count = 1;
- while((beg_run + run_count < numbytes) && (run_count < 127)
- && (data[beg_run] == data[beg_run + run_count]))
- run_count++;
- }
- /* if data before next big run is a short run then write it as such */
- if((old_run_count > 1) && (old_run_count == beg_run - cur)) {
- buf[0] = 128 + old_run_count; /*write short run */
- buf[1] = data[cur];
- if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
- return rgbe_error(rgbe_write_error, NULL);
- cur = beg_run;
- }
- /* write out bytes until we reach the start of the next run */
- while(cur < beg_run) {
- nonrun_count = beg_run - cur;
- if(nonrun_count > 128)
- nonrun_count = 128;
- buf[0] = nonrun_count;
- if(fwrite(buf, sizeof(buf[0]), 1, fp) < 1)
- return rgbe_error(rgbe_write_error, NULL);
- if(fwrite(&data[cur], sizeof(data[0]) * nonrun_count, 1, fp) < 1)
- return rgbe_error(rgbe_write_error, NULL);
- cur += nonrun_count;
- }
- /* write out next run if one was found */
- if(run_count >= MINRUNLENGTH) {
- buf[0] = 128 + run_count;
- buf[1] = data[beg_run];
- if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
- return rgbe_error(rgbe_write_error, NULL);
- cur += run_count;
- }
- }
- return RGBE_RETURN_SUCCESS;
-#undef MINRUNLENGTH
-}
-
-static int rgbe_write_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
-{
- unsigned char rgbe[4];
- unsigned char *buffer;
- int i, err;
-
- if((scanline_width < 8) || (scanline_width > 0x7fff))
- /* run length encoding is not allowed so write flat */
- return rgbe_write_pixels(io, data, scanline_width * num_scanlines);
- buffer = (unsigned char *)malloc(sizeof(unsigned char) * 4 * scanline_width);
- if(buffer == NULL)
- /* no buffer space so write flat */
- return rgbe_write_pixels(fp, data, scanline_width * num_scanlines);
- while(num_scanlines-- > 0) {
- rgbe[0] = 2;
- rgbe[1] = 2;
- rgbe[2] = scanline_width >> 8;
- rgbe[3] = scanline_width & 0xFF;
- if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1) {
- free(buffer);
- return rgbe_error(rgbe_write_error, NULL);
- }
- for(i = 0; i < scanline_width; i++) {
- float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
- buffer[i] = rgbe[0];
- buffer[i + scanline_width] = rgbe[1];
- buffer[i + 2 * scanline_width] = rgbe[2];
- buffer[i + 3 * scanline_width] = rgbe[3];
- data += RGBE_DATA_SIZE;
- }
- /* write out each of the four channels separately run length encoded */
- /* first red, then green, then blue, then exponent */
- for(i = 0; i < 4; i++) {
- if((err = rgbe_write_bytes_rle(fp, &buffer[i * scanline_width],
- scanline_width)) != RGBE_RETURN_SUCCESS) {
- free(buffer);
- return err;
- }
- }
- }
- free(buffer);
- return RGBE_RETURN_SUCCESS;
-}
-#endif
-
-static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
-{
- unsigned char rgbe[4], *scanline_buffer, *ptr, *ptr_end;
- int i, count;
- unsigned char buf[2];
-
- if((scanline_width < 8) || (scanline_width > 0x7fff))
- /* run length encoding is not allowed so read flat */
- return rgbe_read_pixels(io, data, scanline_width * num_scanlines);
- scanline_buffer = NULL;
- /* read in each successive scanline */
- while(num_scanlines > 0) {
- if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1) {
- free(scanline_buffer);
- return rgbe_error(rgbe_read_error, NULL);
- }
- if((rgbe[0] != 2) || (rgbe[1] != 2) || (rgbe[2] & 0x80)) {
- /* this file is not run length encoded */
- rgbe2float(&data[0], &data[1], &data[2], rgbe);
- data += RGBE_DATA_SIZE;
- free(scanline_buffer);
- return rgbe_read_pixels(io, data, scanline_width * num_scanlines - 1);
- }
- if((((int)rgbe[2]) << 8 | rgbe[3]) != scanline_width) {
- free(scanline_buffer);
- return rgbe_error(rgbe_format_error, "wrong scanline width");
- }
- if(scanline_buffer == NULL)
- scanline_buffer = (unsigned char *)
- malloc(sizeof(unsigned char) * 4 * scanline_width);
- if(scanline_buffer == NULL)
- return rgbe_error(rgbe_memory_error, "unable to allocate buffer space");
-
- ptr = &scanline_buffer[0];
- /* read each of the four channels for the scanline into the buffer */
- for(i = 0; i < 4; i++) {
- ptr_end = &scanline_buffer[(i + 1) * scanline_width];
- while(ptr < ptr_end) {
- if(io->read(buf, sizeof(buf[0]) * 2, io->uptr) < 1) {
- free(scanline_buffer);
- return rgbe_error(rgbe_read_error, NULL);
- }
- if(buf[0] > 128) {
- /* a run of the same value */
- count = buf[0] - 128;
- if((count == 0) || (count > ptr_end - ptr)) {
- free(scanline_buffer);
- return rgbe_error(rgbe_format_error, "bad scanline data");
- }
- while(count-- > 0)
- *ptr++ = buf[1];
- } else {
- /* a non-run */
- count = buf[0];
- if((count == 0) || (count > ptr_end - ptr)) {
- free(scanline_buffer);
- return rgbe_error(rgbe_format_error, "bad scanline data");
- }
- *ptr++ = buf[1];
- if(--count > 0) {
- if(io->read(ptr, sizeof(*ptr) * count, io->uptr) < 1) {
- free(scanline_buffer);
- return rgbe_error(rgbe_read_error, NULL);
- }
- ptr += count;
- }
- }
- }
- }
- /* now convert data from buffer into floats */
- for(i = 0; i < scanline_width; i++) {
- rgbe[0] = scanline_buffer[i];
- rgbe[1] = scanline_buffer[i + scanline_width];
- rgbe[2] = scanline_buffer[i + 2 * scanline_width];
- rgbe[3] = scanline_buffer[i + 3 * scanline_width];
- rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
- data += RGBE_DATA_SIZE;
- }
- num_scanlines--;
- }
- free(scanline_buffer);
- return RGBE_RETURN_SUCCESS;
-}
projects / dosdemo / blobdiff