1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/imago/file_rgbe.c	Sun Nov 01 00:36:56 2015 +0200
     1.3 @@ -0,0 +1,501 @@
     1.4 +/* This file contains code to read and write four byte rgbe file format
     1.5 + * developed by Greg Ward.  It handles the conversions between rgbe and
     1.6 + * pixels consisting of floats.  The data is assumed to be an array of floats.
     1.7 + * By default there are three floats per pixel in the order red, green, blue.
     1.8 + * (RGBE_DATA_??? values control this.)
     1.9 + *
    1.10 + * written by Bruce Walter  (bjw@graphics.cornell.edu)  5/26/95
    1.11 + * based on code written by Greg Ward
    1.12 + * minor modifications by John Tsiombikas (nuclear@member.fsf.org) apr.9 2007
    1.13 + */
    1.14 +
    1.15 +#include <stdio.h>
    1.16 +#include <stdlib.h>
    1.17 +#include <string.h>
    1.18 +#include <math.h>
    1.19 +#include <ctype.h>
    1.20 +#include <errno.h>
    1.21 +#include "imago2.h"
    1.22 +#include "ftype_module.h"
    1.23 +
    1.24 +
    1.25 +typedef struct {
    1.26 +	int valid;				/* indicate which fields are valid */
    1.27 +	char programtype[16];	/* listed at beginning of file to identify it
    1.28 +							 * after "#?".  defaults to "RGBE" */
    1.29 +	float gamma;			/* image has already been gamma corrected with
    1.30 +							 * given gamma.  defaults to 1.0 (no correction) */
    1.31 +	float exposure;			/* a value of 1.0 in an image corresponds to
    1.32 +							 * <exposure> watts/steradian/m^2.
    1.33 +							 * defaults to 1.0 */
    1.34 +} rgbe_header_info;
    1.35 +
    1.36 +
    1.37 +static int check(struct img_io *io);
    1.38 +static int readbuf(struct img_pixmap *img, struct img_io *io);
    1.39 +static int writebuf(struct img_pixmap *img, struct img_io *io);
    1.40 +
    1.41 +static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info);
    1.42 +static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines);
    1.43 +
    1.44 +
    1.45 +int img_register_rgbe(void)
    1.46 +{
    1.47 +	static struct ftype_module mod = {".rgbe", check, readbuf, writebuf};
    1.48 +	return img_register_module(&mod);
    1.49 +}
    1.50 +
    1.51 +
    1.52 +static int check(struct img_io *io)
    1.53 +{
    1.54 +	int xsz, ysz, res;
    1.55 +	long pos = io->seek(0, SEEK_CUR, io->uptr);
    1.56 +
    1.57 +	rgbe_header_info hdr;
    1.58 +	res = rgbe_read_header(io, &xsz, &ysz, &hdr);
    1.59 +
    1.60 +	io->seek(pos, SEEK_SET, io->uptr);
    1.61 +	return res;
    1.62 +}
    1.63 +
    1.64 +static int readbuf(struct img_pixmap *img, struct img_io *io)
    1.65 +{
    1.66 +	int xsz, ysz;
    1.67 +	rgbe_header_info hdr;
    1.68 +
    1.69 +	if(rgbe_read_header(io, &xsz, &ysz, &hdr) == -1) {
    1.70 +		return -1;
    1.71 +	}
    1.72 +
    1.73 +	if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGBF, 0) == -1) {
    1.74 +		return -1;
    1.75 +	}
    1.76 +	if(rgbe_read_pixels_rle(io, img->pixels, xsz, ysz) == -1) {
    1.77 +		return -1;
    1.78 +	}
    1.79 +	return 0;
    1.80 +}
    1.81 +
    1.82 +static int writebuf(struct img_pixmap *img, struct img_io *io)
    1.83 +{
    1.84 +	return -1;	/* TODO */
    1.85 +}
    1.86 +
    1.87 +
    1.88 +static int iofgetc(struct img_io *io)
    1.89 +{
    1.90 +	char c;
    1.91 +	return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
    1.92 +}
    1.93 +
    1.94 +static char *iofgets(char *buf, int size, struct img_io *io)
    1.95 +{
    1.96 +	int c;
    1.97 +	char *ptr = buf;
    1.98 +
    1.99 +	while(--size > 0 && (c = iofgetc(io)) != -1) {
   1.100 +		*ptr++ = c;
   1.101 +		if(c == '\n') break;
   1.102 +	}
   1.103 +	*ptr = 0;
   1.104 +
   1.105 +	return ptr == buf ? 0 : buf;
   1.106 +}
   1.107 +
   1.108 +
   1.109 +/* flags indicating which fields in an rgbe_header_info are valid */
   1.110 +#define RGBE_VALID_PROGRAMTYPE 0x01
   1.111 +#define RGBE_VALID_GAMMA       0x02
   1.112 +#define RGBE_VALID_EXPOSURE    0x04
   1.113 +
   1.114 +/* return codes for rgbe routines */
   1.115 +#define RGBE_RETURN_SUCCESS 0
   1.116 +#define RGBE_RETURN_FAILURE -1
   1.117 +
   1.118 +
   1.119 +#if defined(__cplusplus) || defined(GNUC) || __STDC_VERSION >= 199901L
   1.120 +#define INLINE inline
   1.121 +#else
   1.122 +#define INLINE
   1.123 +#endif
   1.124 +
   1.125 +/* offsets to red, green, and blue components in a data (float) pixel */
   1.126 +#define RGBE_DATA_RED	0
   1.127 +#define RGBE_DATA_GREEN  1
   1.128 +#define RGBE_DATA_BLUE   2
   1.129 +
   1.130 +/* number of floats per pixel */
   1.131 +#define RGBE_DATA_SIZE   3
   1.132 +
   1.133 +enum rgbe_error_codes {
   1.134 +	rgbe_read_error,
   1.135 +	rgbe_write_error,
   1.136 +	rgbe_format_error,
   1.137 +	rgbe_memory_error
   1.138 +};
   1.139 +
   1.140 +
   1.141 +/* default error routine.  change this to change error handling */
   1.142 +static int rgbe_error(int rgbe_error_code, char *msg)
   1.143 +{
   1.144 +	switch (rgbe_error_code) {
   1.145 +	case rgbe_read_error:
   1.146 +		fprintf(stderr, "RGBE read error: %s\n", strerror(errno));
   1.147 +		break;
   1.148 +
   1.149 +	case rgbe_write_error:
   1.150 +		fprintf(stderr, "RGBE write error: %s\n", strerror(errno));
   1.151 +		break;
   1.152 +
   1.153 +	case rgbe_format_error:
   1.154 +		fprintf(stderr, "RGBE bad file format: %s\n", msg);
   1.155 +		break;
   1.156 +
   1.157 +	default:
   1.158 +	case rgbe_memory_error:
   1.159 +		fprintf(stderr, "RGBE error: %s\n", msg);
   1.160 +	}
   1.161 +	return RGBE_RETURN_FAILURE;
   1.162 +}
   1.163 +
   1.164 +/* standard conversion from float pixels to rgbe pixels */
   1.165 +/*static INLINE void float2rgbe(unsigned char rgbe[4], float red, float green, float blue)
   1.166 +{
   1.167 +	float v;
   1.168 +	int e;
   1.169 +
   1.170 +	v = red;
   1.171 +	if(green > v)
   1.172 +		v = green;
   1.173 +	if(blue > v)
   1.174 +		v = blue;
   1.175 +	if(v < 1e-32) {
   1.176 +		rgbe[0] = rgbe[1] = rgbe[2] = rgbe[3] = 0;
   1.177 +	} else {
   1.178 +		v = frexp(v, &e) * 256.0 / v;
   1.179 +		rgbe[0] = (unsigned char)(red * v);
   1.180 +		rgbe[1] = (unsigned char)(green * v);
   1.181 +		rgbe[2] = (unsigned char)(blue * v);
   1.182 +		rgbe[3] = (unsigned char)(e + 128);
   1.183 +	}
   1.184 +}*/
   1.185 +
   1.186 +/* standard conversion from rgbe to float pixels */
   1.187 +/* note: Ward uses ldexp(col+0.5,exp-(128+8)). However we wanted pixels */
   1.188 +/*       in the range [0,1] to map back into the range [0,1]. */
   1.189 +static INLINE void rgbe2float(float *red, float *green, float *blue, unsigned char rgbe[4])
   1.190 +{
   1.191 +	float f;
   1.192 +
   1.193 +	if(rgbe[3]) {				/*nonzero pixel */
   1.194 +		f = ldexp(1.0, rgbe[3] - (int)(128 + 8));
   1.195 +		*red = rgbe[0] * f;
   1.196 +		*green = rgbe[1] * f;
   1.197 +		*blue = rgbe[2] * f;
   1.198 +	} else
   1.199 +		*red = *green = *blue = 0.0;
   1.200 +}
   1.201 +
   1.202 +#if 0
   1.203 +/* default minimal header. modify if you want more information in header */
   1.204 +static int rgbe_write_header(FILE * fp, int width, int height, rgbe_header_info * info)
   1.205 +{
   1.206 +	char *programtype = "RGBE";
   1.207 +
   1.208 +	if(info && (info->valid & RGBE_VALID_PROGRAMTYPE))
   1.209 +		programtype = info->programtype;
   1.210 +	if(fprintf(fp, "#?%s\n", programtype) < 0)
   1.211 +		return rgbe_error(rgbe_write_error, NULL);
   1.212 +	/* The #? is to identify file type, the programtype is optional. */
   1.213 +	if(info && (info->valid & RGBE_VALID_GAMMA)) {
   1.214 +		if(fprintf(fp, "GAMMA=%g\n", info->gamma) < 0)
   1.215 +			return rgbe_error(rgbe_write_error, NULL);
   1.216 +	}
   1.217 +	if(info && (info->valid & RGBE_VALID_EXPOSURE)) {
   1.218 +		if(fprintf(fp, "EXPOSURE=%g\n", info->exposure) < 0)
   1.219 +			return rgbe_error(rgbe_write_error, NULL);
   1.220 +	}
   1.221 +	if(fprintf(fp, "FORMAT=32-bit_rle_rgbe\n\n") < 0)
   1.222 +		return rgbe_error(rgbe_write_error, NULL);
   1.223 +	if(fprintf(fp, "-Y %d +X %d\n", height, width) < 0)
   1.224 +		return rgbe_error(rgbe_write_error, NULL);
   1.225 +	return RGBE_RETURN_SUCCESS;
   1.226 +}
   1.227 +#endif
   1.228 +
   1.229 +/* minimal header reading.  modify if you want to parse more information */
   1.230 +static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info)
   1.231 +{
   1.232 +	char buf[128];
   1.233 +	float tempf;
   1.234 +	int i;
   1.235 +
   1.236 +	if(info) {
   1.237 +		info->valid = 0;
   1.238 +		info->programtype[0] = 0;
   1.239 +		info->gamma = info->exposure = 1.0;
   1.240 +	}
   1.241 +	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == NULL)
   1.242 +		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
   1.243 +	if((buf[0] != '#') || (buf[1] != '?')) {
   1.244 +		/* if you want to require the magic token then uncomment the next line */
   1.245 +		/*return rgbe_error(rgbe_format_error,"bad initial token"); */
   1.246 +	} else if(info) {
   1.247 +		info->valid |= RGBE_VALID_PROGRAMTYPE;
   1.248 +		for(i = 0; i < sizeof(info->programtype) - 1; i++) {
   1.249 +			if((buf[i + 2] == 0) || isspace(buf[i + 2]))
   1.250 +				break;
   1.251 +			info->programtype[i] = buf[i + 2];
   1.252 +		}
   1.253 +		info->programtype[i] = 0;
   1.254 +		if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
   1.255 +			return rgbe_error(rgbe_read_error, NULL);
   1.256 +	}
   1.257 +	for(;;) {
   1.258 +		if((buf[0] == 0) || (buf[0] == '\n'))
   1.259 +			return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "no FORMAT specifier found");*/
   1.260 +		else if(strcmp(buf, "FORMAT=32-bit_rle_rgbe\n") == 0)
   1.261 +			break;				/* format found so break out of loop */
   1.262 +		else if(info && (sscanf(buf, "GAMMA=%g", &tempf) == 1)) {
   1.263 +			info->gamma = tempf;
   1.264 +			info->valid |= RGBE_VALID_GAMMA;
   1.265 +		} else if(info && (sscanf(buf, "EXPOSURE=%g", &tempf) == 1)) {
   1.266 +			info->exposure = tempf;
   1.267 +			info->valid |= RGBE_VALID_EXPOSURE;
   1.268 +		}
   1.269 +		if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
   1.270 +			return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
   1.271 +	}
   1.272 +	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
   1.273 +		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
   1.274 +	if(strcmp(buf, "\n") != 0)
   1.275 +		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing blank line after FORMAT specifier");*/
   1.276 +	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
   1.277 +		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
   1.278 +	if(sscanf(buf, "-Y %d +X %d", height, width) < 2)
   1.279 +		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing image size specifier");*/
   1.280 +	return RGBE_RETURN_SUCCESS;
   1.281 +}
   1.282 +
   1.283 +#if 0
   1.284 +/* simple write routine that does not use run length encoding */
   1.285 +
   1.286 +/* These routines can be made faster by allocating a larger buffer and
   1.287 +   fread-ing and fwrite-ing the data in larger chunks */
   1.288 +static int rgbe_write_pixels(FILE * fp, float *data, int numpixels)
   1.289 +{
   1.290 +	unsigned char rgbe[4];
   1.291 +
   1.292 +	while(numpixels-- > 0) {
   1.293 +		float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
   1.294 +		data += RGBE_DATA_SIZE;
   1.295 +		if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1)
   1.296 +			return rgbe_error(rgbe_write_error, NULL);
   1.297 +	}
   1.298 +	return RGBE_RETURN_SUCCESS;
   1.299 +}
   1.300 +#endif
   1.301 +
   1.302 +/* simple read routine.  will not correctly handle run length encoding */
   1.303 +static int rgbe_read_pixels(struct img_io *io, float *data, int numpixels)
   1.304 +{
   1.305 +	unsigned char rgbe[4];
   1.306 +
   1.307 +	while(numpixels-- > 0) {
   1.308 +		if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1)
   1.309 +			return rgbe_error(rgbe_read_error, NULL);
   1.310 +		rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
   1.311 +		data += RGBE_DATA_SIZE;
   1.312 +	}
   1.313 +	return RGBE_RETURN_SUCCESS;
   1.314 +}
   1.315 +
   1.316 +#if 0
   1.317 +/* The code below is only needed for the run-length encoded files. */
   1.318 +
   1.319 +/* Run length encoding adds considerable complexity but does */
   1.320 +
   1.321 +/* save some space.  For each scanline, each channel (r,g,b,e) is */
   1.322 +
   1.323 +/* encoded separately for better compression. */
   1.324 +
   1.325 +static int rgbe_write_bytes_rle(struct img_io *io, unsigned char *data, int numbytes)
   1.326 +{
   1.327 +#define MINRUNLENGTH 4
   1.328 +	int cur, beg_run, run_count, old_run_count, nonrun_count;
   1.329 +	unsigned char buf[2];
   1.330 +
   1.331 +	cur = 0;
   1.332 +	while(cur < numbytes) {
   1.333 +		beg_run = cur;
   1.334 +		/* find next run of length at least 4 if one exists */
   1.335 +		run_count = old_run_count = 0;
   1.336 +		while((run_count < MINRUNLENGTH) && (beg_run < numbytes)) {
   1.337 +			beg_run += run_count;
   1.338 +			old_run_count = run_count;
   1.339 +			run_count = 1;
   1.340 +			while((beg_run + run_count < numbytes) && (run_count < 127)
   1.341 +				  && (data[beg_run] == data[beg_run + run_count]))
   1.342 +				run_count++;
   1.343 +		}
   1.344 +		/* if data before next big run is a short run then write it as such */
   1.345 +		if((old_run_count > 1) && (old_run_count == beg_run - cur)) {
   1.346 +			buf[0] = 128 + old_run_count;	/*write short run */
   1.347 +			buf[1] = data[cur];
   1.348 +			if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
   1.349 +				return rgbe_error(rgbe_write_error, NULL);
   1.350 +			cur = beg_run;
   1.351 +		}
   1.352 +		/* write out bytes until we reach the start of the next run */
   1.353 +		while(cur < beg_run) {
   1.354 +			nonrun_count = beg_run - cur;
   1.355 +			if(nonrun_count > 128)
   1.356 +				nonrun_count = 128;
   1.357 +			buf[0] = nonrun_count;
   1.358 +			if(fwrite(buf, sizeof(buf[0]), 1, fp) < 1)
   1.359 +				return rgbe_error(rgbe_write_error, NULL);
   1.360 +			if(fwrite(&data[cur], sizeof(data[0]) * nonrun_count, 1, fp) < 1)
   1.361 +				return rgbe_error(rgbe_write_error, NULL);
   1.362 +			cur += nonrun_count;
   1.363 +		}
   1.364 +		/* write out next run if one was found */
   1.365 +		if(run_count >= MINRUNLENGTH) {
   1.366 +			buf[0] = 128 + run_count;
   1.367 +			buf[1] = data[beg_run];
   1.368 +			if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
   1.369 +				return rgbe_error(rgbe_write_error, NULL);
   1.370 +			cur += run_count;
   1.371 +		}
   1.372 +	}
   1.373 +	return RGBE_RETURN_SUCCESS;
   1.374 +#undef MINRUNLENGTH
   1.375 +}
   1.376 +
   1.377 +static int rgbe_write_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
   1.378 +{
   1.379 +	unsigned char rgbe[4];
   1.380 +	unsigned char *buffer;
   1.381 +	int i, err;
   1.382 +
   1.383 +	if((scanline_width < 8) || (scanline_width > 0x7fff))
   1.384 +		/* run length encoding is not allowed so write flat */
   1.385 +		return rgbe_write_pixels(io, data, scanline_width * num_scanlines);
   1.386 +	buffer = (unsigned char *)malloc(sizeof(unsigned char) * 4 * scanline_width);
   1.387 +	if(buffer == NULL)
   1.388 +		/* no buffer space so write flat */
   1.389 +		return rgbe_write_pixels(fp, data, scanline_width * num_scanlines);
   1.390 +	while(num_scanlines-- > 0) {
   1.391 +		rgbe[0] = 2;
   1.392 +		rgbe[1] = 2;
   1.393 +		rgbe[2] = scanline_width >> 8;
   1.394 +		rgbe[3] = scanline_width & 0xFF;
   1.395 +		if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1) {
   1.396 +			free(buffer);
   1.397 +			return rgbe_error(rgbe_write_error, NULL);
   1.398 +		}
   1.399 +		for(i = 0; i < scanline_width; i++) {
   1.400 +			float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
   1.401 +			buffer[i] = rgbe[0];
   1.402 +			buffer[i + scanline_width] = rgbe[1];
   1.403 +			buffer[i + 2 * scanline_width] = rgbe[2];
   1.404 +			buffer[i + 3 * scanline_width] = rgbe[3];
   1.405 +			data += RGBE_DATA_SIZE;
   1.406 +		}
   1.407 +		/* write out each of the four channels separately run length encoded */
   1.408 +		/* first red, then green, then blue, then exponent */
   1.409 +		for(i = 0; i < 4; i++) {
   1.410 +			if((err = rgbe_write_bytes_rle(fp, &buffer[i * scanline_width],
   1.411 +										  scanline_width)) != RGBE_RETURN_SUCCESS) {
   1.412 +				free(buffer);
   1.413 +				return err;
   1.414 +			}
   1.415 +		}
   1.416 +	}
   1.417 +	free(buffer);
   1.418 +	return RGBE_RETURN_SUCCESS;
   1.419 +}
   1.420 +#endif
   1.421 +
   1.422 +static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
   1.423 +{
   1.424 +	unsigned char rgbe[4], *scanline_buffer, *ptr, *ptr_end;
   1.425 +	int i, count;
   1.426 +	unsigned char buf[2];
   1.427 +
   1.428 +	if((scanline_width < 8) || (scanline_width > 0x7fff))
   1.429 +		/* run length encoding is not allowed so read flat */
   1.430 +		return rgbe_read_pixels(io, data, scanline_width * num_scanlines);
   1.431 +	scanline_buffer = NULL;
   1.432 +	/* read in each successive scanline */
   1.433 +	while(num_scanlines > 0) {
   1.434 +		if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1) {
   1.435 +			free(scanline_buffer);
   1.436 +			return rgbe_error(rgbe_read_error, NULL);
   1.437 +		}
   1.438 +		if((rgbe[0] != 2) || (rgbe[1] != 2) || (rgbe[2] & 0x80)) {
   1.439 +			/* this file is not run length encoded */
   1.440 +			rgbe2float(&data[0], &data[1], &data[2], rgbe);
   1.441 +			data += RGBE_DATA_SIZE;
   1.442 +			free(scanline_buffer);
   1.443 +			return rgbe_read_pixels(io, data, scanline_width * num_scanlines - 1);
   1.444 +		}
   1.445 +		if((((int)rgbe[2]) << 8 | rgbe[3]) != scanline_width) {
   1.446 +			free(scanline_buffer);
   1.447 +			return rgbe_error(rgbe_format_error, "wrong scanline width");
   1.448 +		}
   1.449 +		if(scanline_buffer == NULL)
   1.450 +			scanline_buffer = (unsigned char *)
   1.451 +				malloc(sizeof(unsigned char) * 4 * scanline_width);
   1.452 +		if(scanline_buffer == NULL)
   1.453 +			return rgbe_error(rgbe_memory_error, "unable to allocate buffer space");
   1.454 +
   1.455 +		ptr = &scanline_buffer[0];
   1.456 +		/* read each of the four channels for the scanline into the buffer */
   1.457 +		for(i = 0; i < 4; i++) {
   1.458 +			ptr_end = &scanline_buffer[(i + 1) * scanline_width];
   1.459 +			while(ptr < ptr_end) {
   1.460 +				if(io->read(buf, sizeof(buf[0]) * 2, io->uptr) < 1) {
   1.461 +					free(scanline_buffer);
   1.462 +					return rgbe_error(rgbe_read_error, NULL);
   1.463 +				}
   1.464 +				if(buf[0] > 128) {
   1.465 +					/* a run of the same value */
   1.466 +					count = buf[0] - 128;
   1.467 +					if((count == 0) || (count > ptr_end - ptr)) {
   1.468 +						free(scanline_buffer);
   1.469 +						return rgbe_error(rgbe_format_error, "bad scanline data");
   1.470 +					}
   1.471 +					while(count-- > 0)
   1.472 +						*ptr++ = buf[1];
   1.473 +				} else {
   1.474 +					/* a non-run */
   1.475 +					count = buf[0];
   1.476 +					if((count == 0) || (count > ptr_end - ptr)) {
   1.477 +						free(scanline_buffer);
   1.478 +						return rgbe_error(rgbe_format_error, "bad scanline data");
   1.479 +					}
   1.480 +					*ptr++ = buf[1];
   1.481 +					if(--count > 0) {
   1.482 +						if(io->read(ptr, sizeof(*ptr) * count, io->uptr) < 1) {
   1.483 +							free(scanline_buffer);
   1.484 +							return rgbe_error(rgbe_read_error, NULL);
   1.485 +						}
   1.486 +						ptr += count;
   1.487 +					}
   1.488 +				}
   1.489 +			}
   1.490 +		}
   1.491 +		/* now convert data from buffer into floats */
   1.492 +		for(i = 0; i < scanline_width; i++) {
   1.493 +			rgbe[0] = scanline_buffer[i];
   1.494 +			rgbe[1] = scanline_buffer[i + scanline_width];
   1.495 +			rgbe[2] = scanline_buffer[i + 2 * scanline_width];
   1.496 +			rgbe[3] = scanline_buffer[i + 3 * scanline_width];
   1.497 +			rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
   1.498 +			data += RGBE_DATA_SIZE;
   1.499 +		}
   1.500 +		num_scanlines--;
   1.501 +	}
   1.502 +	free(scanline_buffer);
   1.503 +	return RGBE_RETURN_SUCCESS;
   1.504 +}