nuclear@14: /* This file contains code to read and write four byte rgbe file format
nuclear@14:  * developed by Greg Ward.  It handles the conversions between rgbe and
nuclear@14:  * pixels consisting of floats.  The data is assumed to be an array of floats.
nuclear@14:  * By default there are three floats per pixel in the order red, green, blue.
nuclear@14:  * (RGBE_DATA_??? values control this.)
nuclear@14:  *
nuclear@14:  * written by Bruce Walter  (bjw@graphics.cornell.edu)  5/26/95
nuclear@14:  * based on code written by Greg Ward
nuclear@14:  * minor modifications by John Tsiombikas (nuclear@member.fsf.org) apr.9 2007
nuclear@14:  */
nuclear@14: 
nuclear@14: #include <stdio.h>
nuclear@14: #include <stdlib.h>
nuclear@14: #include <string.h>
nuclear@14: #include <math.h>
nuclear@14: #include <ctype.h>
nuclear@14: #include <errno.h>
nuclear@14: #include "imago2.h"
nuclear@14: #include "ftype_module.h"
nuclear@14: 
nuclear@14: 
nuclear@14: typedef struct {
nuclear@14: 	int valid;				/* indicate which fields are valid */
nuclear@14: 	char programtype[16];	/* listed at beginning of file to identify it
nuclear@14: 							 * after "#?".  defaults to "RGBE" */
nuclear@14: 	float gamma;			/* image has already been gamma corrected with
nuclear@14: 							 * given gamma.  defaults to 1.0 (no correction) */
nuclear@14: 	float exposure;			/* a value of 1.0 in an image corresponds to
nuclear@14: 							 * <exposure> watts/steradian/m^2.
nuclear@14: 							 * defaults to 1.0 */
nuclear@14: } rgbe_header_info;
nuclear@14: 
nuclear@14: 
nuclear@14: static int check(struct img_io *io);
nuclear@14: static int read(struct img_pixmap *img, struct img_io *io);
nuclear@14: static int write(struct img_pixmap *img, struct img_io *io);
nuclear@14: 
nuclear@14: static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info);
nuclear@14: static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines);
nuclear@14: 
nuclear@14: 
nuclear@14: int img_register_rgbe(void)
nuclear@14: {
nuclear@14: 	static struct ftype_module mod = {".rgbe", check, read, write};
nuclear@14: 	return img_register_module(&mod);
nuclear@14: }
nuclear@14: 
nuclear@14: 
nuclear@14: static int check(struct img_io *io)
nuclear@14: {
nuclear@14: 	int xsz, ysz, res;
nuclear@14: 	long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@14: 
nuclear@14: 	rgbe_header_info hdr;
nuclear@14: 	res = rgbe_read_header(io, &xsz, &ysz, &hdr);
nuclear@14: 
nuclear@14: 	io->seek(pos, SEEK_SET, io->uptr);
nuclear@14: 	return res;
nuclear@14: }
nuclear@14: 
nuclear@14: static int read(struct img_pixmap *img, struct img_io *io)
nuclear@14: {
nuclear@14: 	int xsz, ysz;
nuclear@14: 	rgbe_header_info hdr;
nuclear@14: 
nuclear@14: 	if(rgbe_read_header(io, &xsz, &ysz, &hdr) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGBF, 0) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 	if(rgbe_read_pixels_rle(io, img->pixels, xsz, ysz) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 	return 0;
nuclear@14: }
nuclear@14: 
nuclear@14: static int write(struct img_pixmap *img, struct img_io *io)
nuclear@14: {
nuclear@14: 	return -1;	/* TODO */
nuclear@14: }
nuclear@14: 
nuclear@14: 
nuclear@14: static int iofgetc(struct img_io *io)
nuclear@14: {
nuclear@14: 	char c;
nuclear@14: 	return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
nuclear@14: }
nuclear@14: 
nuclear@14: static char *iofgets(char *buf, int size, struct img_io *io)
nuclear@14: {
nuclear@14: 	int c;
nuclear@14: 	char *ptr = buf;
nuclear@14: 
nuclear@14: 	while(--size > 0 && (c = iofgetc(io)) != -1) {
nuclear@14: 		*ptr++ = c;
nuclear@14: 		if(c == '\n') break;
nuclear@14: 	}
nuclear@14: 	*ptr = 0;
nuclear@14: 
nuclear@14: 	return ptr == buf ? 0 : buf;
nuclear@14: }
nuclear@14: 
nuclear@14: 
nuclear@14: /* flags indicating which fields in an rgbe_header_info are valid */
nuclear@14: #define RGBE_VALID_PROGRAMTYPE 0x01
nuclear@14: #define RGBE_VALID_GAMMA       0x02
nuclear@14: #define RGBE_VALID_EXPOSURE    0x04
nuclear@14: 
nuclear@14: /* return codes for rgbe routines */
nuclear@14: #define RGBE_RETURN_SUCCESS 0
nuclear@14: #define RGBE_RETURN_FAILURE -1
nuclear@14: 
nuclear@14: 
nuclear@14: #if defined(__cplusplus) || defined(GNUC) || __STDC_VERSION >= 199901L
nuclear@14: #define INLINE inline
nuclear@14: #else
nuclear@14: #define INLINE
nuclear@14: #endif
nuclear@14: 
nuclear@14: /* offsets to red, green, and blue components in a data (float) pixel */
nuclear@14: #define RGBE_DATA_RED	0
nuclear@14: #define RGBE_DATA_GREEN  1
nuclear@14: #define RGBE_DATA_BLUE   2
nuclear@14: 
nuclear@14: /* number of floats per pixel */
nuclear@14: #define RGBE_DATA_SIZE   3
nuclear@14: 
nuclear@14: enum rgbe_error_codes {
nuclear@14: 	rgbe_read_error,
nuclear@14: 	rgbe_write_error,
nuclear@14: 	rgbe_format_error,
nuclear@14: 	rgbe_memory_error
nuclear@14: };
nuclear@14: 
nuclear@14: 
nuclear@14: /* default error routine.  change this to change error handling */
nuclear@14: static int rgbe_error(int rgbe_error_code, char *msg)
nuclear@14: {
nuclear@14: 	switch (rgbe_error_code) {
nuclear@14: 	case rgbe_read_error:
nuclear@14: 		fprintf(stderr, "RGBE read error: %s\n", strerror(errno));
nuclear@14: 		break;
nuclear@14: 
nuclear@14: 	case rgbe_write_error:
nuclear@14: 		fprintf(stderr, "RGBE write error: %s\n", strerror(errno));
nuclear@14: 		break;
nuclear@14: 
nuclear@14: 	case rgbe_format_error:
nuclear@14: 		fprintf(stderr, "RGBE bad file format: %s\n", msg);
nuclear@14: 		break;
nuclear@14: 
nuclear@14: 	default:
nuclear@14: 	case rgbe_memory_error:
nuclear@14: 		fprintf(stderr, "RGBE error: %s\n", msg);
nuclear@14: 	}
nuclear@14: 	return RGBE_RETURN_FAILURE;
nuclear@14: }
nuclear@14: 
nuclear@14: /* standard conversion from float pixels to rgbe pixels */
nuclear@14: /*static INLINE void float2rgbe(unsigned char rgbe[4], float red, float green, float blue)
nuclear@14: {
nuclear@14: 	float v;
nuclear@14: 	int e;
nuclear@14: 
nuclear@14: 	v = red;
nuclear@14: 	if(green > v)
nuclear@14: 		v = green;
nuclear@14: 	if(blue > v)
nuclear@14: 		v = blue;
nuclear@14: 	if(v < 1e-32) {
nuclear@14: 		rgbe[0] = rgbe[1] = rgbe[2] = rgbe[3] = 0;
nuclear@14: 	} else {
nuclear@14: 		v = frexp(v, &e) * 256.0 / v;
nuclear@14: 		rgbe[0] = (unsigned char)(red * v);
nuclear@14: 		rgbe[1] = (unsigned char)(green * v);
nuclear@14: 		rgbe[2] = (unsigned char)(blue * v);
nuclear@14: 		rgbe[3] = (unsigned char)(e + 128);
nuclear@14: 	}
nuclear@14: }*/
nuclear@14: 
nuclear@14: /* standard conversion from rgbe to float pixels */
nuclear@14: /* note: Ward uses ldexp(col+0.5,exp-(128+8)). However we wanted pixels */
nuclear@14: /*       in the range [0,1] to map back into the range [0,1]. */
nuclear@14: static INLINE void rgbe2float(float *red, float *green, float *blue, unsigned char rgbe[4])
nuclear@14: {
nuclear@14: 	float f;
nuclear@14: 
nuclear@14: 	if(rgbe[3]) {				/*nonzero pixel */
nuclear@14: 		f = ldexp(1.0, rgbe[3] - (int)(128 + 8));
nuclear@14: 		*red = rgbe[0] * f;
nuclear@14: 		*green = rgbe[1] * f;
nuclear@14: 		*blue = rgbe[2] * f;
nuclear@14: 	} else
nuclear@14: 		*red = *green = *blue = 0.0;
nuclear@14: }
nuclear@14: 
nuclear@14: #if 0
nuclear@14: /* default minimal header. modify if you want more information in header */
nuclear@14: static int rgbe_write_header(FILE * fp, int width, int height, rgbe_header_info * info)
nuclear@14: {
nuclear@14: 	char *programtype = "RGBE";
nuclear@14: 
nuclear@14: 	if(info && (info->valid & RGBE_VALID_PROGRAMTYPE))
nuclear@14: 		programtype = info->programtype;
nuclear@14: 	if(fprintf(fp, "#?%s\n", programtype) < 0)
nuclear@14: 		return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	/* The #? is to identify file type, the programtype is optional. */
nuclear@14: 	if(info && (info->valid & RGBE_VALID_GAMMA)) {
nuclear@14: 		if(fprintf(fp, "GAMMA=%g\n", info->gamma) < 0)
nuclear@14: 			return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	}
nuclear@14: 	if(info && (info->valid & RGBE_VALID_EXPOSURE)) {
nuclear@14: 		if(fprintf(fp, "EXPOSURE=%g\n", info->exposure) < 0)
nuclear@14: 			return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	}
nuclear@14: 	if(fprintf(fp, "FORMAT=32-bit_rle_rgbe\n\n") < 0)
nuclear@14: 		return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	if(fprintf(fp, "-Y %d +X %d\n", height, width) < 0)
nuclear@14: 		return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }
nuclear@14: #endif
nuclear@14: 
nuclear@14: /* minimal header reading.  modify if you want to parse more information */
nuclear@14: static int rgbe_read_header(struct img_io *io, int *width, int *height, rgbe_header_info * info)
nuclear@14: {
nuclear@14: 	char buf[128];
nuclear@14: 	float tempf;
nuclear@14: 	int i;
nuclear@14: 
nuclear@14: 	if(info) {
nuclear@14: 		info->valid = 0;
nuclear@14: 		info->programtype[0] = 0;
nuclear@14: 		info->gamma = info->exposure = 1.0;
nuclear@14: 	}
nuclear@14: 	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == NULL)
nuclear@14: 		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
nuclear@14: 	if((buf[0] != '#') || (buf[1] != '?')) {
nuclear@14: 		/* if you want to require the magic token then uncomment the next line */
nuclear@14: 		/*return rgbe_error(rgbe_format_error,"bad initial token"); */
nuclear@14: 	} else if(info) {
nuclear@14: 		info->valid |= RGBE_VALID_PROGRAMTYPE;
nuclear@14: 		for(i = 0; i < sizeof(info->programtype) - 1; i++) {
nuclear@14: 			if((buf[i + 2] == 0) || isspace(buf[i + 2]))
nuclear@14: 				break;
nuclear@14: 			info->programtype[i] = buf[i + 2];
nuclear@14: 		}
nuclear@14: 		info->programtype[i] = 0;
nuclear@14: 		if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
nuclear@14: 			return rgbe_error(rgbe_read_error, NULL);
nuclear@14: 	}
nuclear@14: 	for(;;) {
nuclear@14: 		if((buf[0] == 0) || (buf[0] == '\n'))
nuclear@14: 			return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "no FORMAT specifier found");*/
nuclear@14: 		else if(strcmp(buf, "FORMAT=32-bit_rle_rgbe\n") == 0)
nuclear@14: 			break;				/* format found so break out of loop */
nuclear@14: 		else if(info && (sscanf(buf, "GAMMA=%g", &tempf) == 1)) {
nuclear@14: 			info->gamma = tempf;
nuclear@14: 			info->valid |= RGBE_VALID_GAMMA;
nuclear@14: 		} else if(info && (sscanf(buf, "EXPOSURE=%g", &tempf) == 1)) {
nuclear@14: 			info->exposure = tempf;
nuclear@14: 			info->valid |= RGBE_VALID_EXPOSURE;
nuclear@14: 		}
nuclear@14: 		if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
nuclear@14: 			return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
nuclear@14: 	}
nuclear@14: 	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
nuclear@14: 		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
nuclear@14: 	if(strcmp(buf, "\n") != 0)
nuclear@14: 		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing blank line after FORMAT specifier");*/
nuclear@14: 	if(iofgets(buf, sizeof(buf) / sizeof(buf[0]), io) == 0)
nuclear@14: 		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_read_error, NULL);*/
nuclear@14: 	if(sscanf(buf, "-Y %d +X %d", height, width) < 2)
nuclear@14: 		return RGBE_RETURN_FAILURE;/*rgbe_error(rgbe_format_error, "missing image size specifier");*/
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }
nuclear@14: 
nuclear@14: #if 0
nuclear@14: /* simple write routine that does not use run length encoding */
nuclear@14: 
nuclear@14: /* These routines can be made faster by allocating a larger buffer and
nuclear@14:    fread-ing and fwrite-ing the data in larger chunks */
nuclear@14: static int rgbe_write_pixels(FILE * fp, float *data, int numpixels)
nuclear@14: {
nuclear@14: 	unsigned char rgbe[4];
nuclear@14: 
nuclear@14: 	while(numpixels-- > 0) {
nuclear@14: 		float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
nuclear@14: 		data += RGBE_DATA_SIZE;
nuclear@14: 		if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1)
nuclear@14: 			return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 	}
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }
nuclear@14: #endif
nuclear@14: 
nuclear@14: /* simple read routine.  will not correctly handle run length encoding */
nuclear@14: static int rgbe_read_pixels(struct img_io *io, float *data, int numpixels)
nuclear@14: {
nuclear@14: 	unsigned char rgbe[4];
nuclear@14: 
nuclear@14: 	while(numpixels-- > 0) {
nuclear@14: 		if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1)
nuclear@14: 			return rgbe_error(rgbe_read_error, NULL);
nuclear@14: 		rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
nuclear@14: 		data += RGBE_DATA_SIZE;
nuclear@14: 	}
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }
nuclear@14: 
nuclear@14: #if 0
nuclear@14: /* The code below is only needed for the run-length encoded files. */
nuclear@14: 
nuclear@14: /* Run length encoding adds considerable complexity but does */
nuclear@14: 
nuclear@14: /* save some space.  For each scanline, each channel (r,g,b,e) is */
nuclear@14: 
nuclear@14: /* encoded separately for better compression. */
nuclear@14: 
nuclear@14: static int rgbe_write_bytes_rle(struct img_io *io, unsigned char *data, int numbytes)
nuclear@14: {
nuclear@14: #define MINRUNLENGTH 4
nuclear@14: 	int cur, beg_run, run_count, old_run_count, nonrun_count;
nuclear@14: 	unsigned char buf[2];
nuclear@14: 
nuclear@14: 	cur = 0;
nuclear@14: 	while(cur < numbytes) {
nuclear@14: 		beg_run = cur;
nuclear@14: 		/* find next run of length at least 4 if one exists */
nuclear@14: 		run_count = old_run_count = 0;
nuclear@14: 		while((run_count < MINRUNLENGTH) && (beg_run < numbytes)) {
nuclear@14: 			beg_run += run_count;
nuclear@14: 			old_run_count = run_count;
nuclear@14: 			run_count = 1;
nuclear@14: 			while((beg_run + run_count < numbytes) && (run_count < 127)
nuclear@14: 				  && (data[beg_run] == data[beg_run + run_count]))
nuclear@14: 				run_count++;
nuclear@14: 		}
nuclear@14: 		/* if data before next big run is a short run then write it as such */
nuclear@14: 		if((old_run_count > 1) && (old_run_count == beg_run - cur)) {
nuclear@14: 			buf[0] = 128 + old_run_count;	/*write short run */
nuclear@14: 			buf[1] = data[cur];
nuclear@14: 			if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
nuclear@14: 				return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 			cur = beg_run;
nuclear@14: 		}
nuclear@14: 		/* write out bytes until we reach the start of the next run */
nuclear@14: 		while(cur < beg_run) {
nuclear@14: 			nonrun_count = beg_run - cur;
nuclear@14: 			if(nonrun_count > 128)
nuclear@14: 				nonrun_count = 128;
nuclear@14: 			buf[0] = nonrun_count;
nuclear@14: 			if(fwrite(buf, sizeof(buf[0]), 1, fp) < 1)
nuclear@14: 				return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 			if(fwrite(&data[cur], sizeof(data[0]) * nonrun_count, 1, fp) < 1)
nuclear@14: 				return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 			cur += nonrun_count;
nuclear@14: 		}
nuclear@14: 		/* write out next run if one was found */
nuclear@14: 		if(run_count >= MINRUNLENGTH) {
nuclear@14: 			buf[0] = 128 + run_count;
nuclear@14: 			buf[1] = data[beg_run];
nuclear@14: 			if(fwrite(buf, sizeof(buf[0]) * 2, 1, fp) < 1)
nuclear@14: 				return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 			cur += run_count;
nuclear@14: 		}
nuclear@14: 	}
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: #undef MINRUNLENGTH
nuclear@14: }
nuclear@14: 
nuclear@14: static int rgbe_write_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
nuclear@14: {
nuclear@14: 	unsigned char rgbe[4];
nuclear@14: 	unsigned char *buffer;
nuclear@14: 	int i, err;
nuclear@14: 
nuclear@14: 	if((scanline_width < 8) || (scanline_width > 0x7fff))
nuclear@14: 		/* run length encoding is not allowed so write flat */
nuclear@14: 		return rgbe_write_pixels(io, data, scanline_width * num_scanlines);
nuclear@14: 	buffer = (unsigned char *)malloc(sizeof(unsigned char) * 4 * scanline_width);
nuclear@14: 	if(buffer == NULL)
nuclear@14: 		/* no buffer space so write flat */
nuclear@14: 		return rgbe_write_pixels(fp, data, scanline_width * num_scanlines);
nuclear@14: 	while(num_scanlines-- > 0) {
nuclear@14: 		rgbe[0] = 2;
nuclear@14: 		rgbe[1] = 2;
nuclear@14: 		rgbe[2] = scanline_width >> 8;
nuclear@14: 		rgbe[3] = scanline_width & 0xFF;
nuclear@14: 		if(fwrite(rgbe, sizeof(rgbe), 1, fp) < 1) {
nuclear@14: 			free(buffer);
nuclear@14: 			return rgbe_error(rgbe_write_error, NULL);
nuclear@14: 		}
nuclear@14: 		for(i = 0; i < scanline_width; i++) {
nuclear@14: 			float2rgbe(rgbe, data[RGBE_DATA_RED], data[RGBE_DATA_GREEN], data[RGBE_DATA_BLUE]);
nuclear@14: 			buffer[i] = rgbe[0];
nuclear@14: 			buffer[i + scanline_width] = rgbe[1];
nuclear@14: 			buffer[i + 2 * scanline_width] = rgbe[2];
nuclear@14: 			buffer[i + 3 * scanline_width] = rgbe[3];
nuclear@14: 			data += RGBE_DATA_SIZE;
nuclear@14: 		}
nuclear@14: 		/* write out each of the four channels separately run length encoded */
nuclear@14: 		/* first red, then green, then blue, then exponent */
nuclear@14: 		for(i = 0; i < 4; i++) {
nuclear@14: 			if((err = rgbe_write_bytes_rle(fp, &buffer[i * scanline_width],
nuclear@14: 										  scanline_width)) != RGBE_RETURN_SUCCESS) {
nuclear@14: 				free(buffer);
nuclear@14: 				return err;
nuclear@14: 			}
nuclear@14: 		}
nuclear@14: 	}
nuclear@14: 	free(buffer);
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }
nuclear@14: #endif
nuclear@14: 
nuclear@14: static int rgbe_read_pixels_rle(struct img_io *io, float *data, int scanline_width, int num_scanlines)
nuclear@14: {
nuclear@14: 	unsigned char rgbe[4], *scanline_buffer, *ptr, *ptr_end;
nuclear@14: 	int i, count;
nuclear@14: 	unsigned char buf[2];
nuclear@14: 
nuclear@14: 	if((scanline_width < 8) || (scanline_width > 0x7fff))
nuclear@14: 		/* run length encoding is not allowed so read flat */
nuclear@14: 		return rgbe_read_pixels(io, data, scanline_width * num_scanlines);
nuclear@14: 	scanline_buffer = NULL;
nuclear@14: 	/* read in each successive scanline */
nuclear@14: 	while(num_scanlines > 0) {
nuclear@14: 		if(io->read(rgbe, sizeof(rgbe), io->uptr) < 1) {
nuclear@14: 			free(scanline_buffer);
nuclear@14: 			return rgbe_error(rgbe_read_error, NULL);
nuclear@14: 		}
nuclear@14: 		if((rgbe[0] != 2) || (rgbe[1] != 2) || (rgbe[2] & 0x80)) {
nuclear@14: 			/* this file is not run length encoded */
nuclear@14: 			rgbe2float(&data[0], &data[1], &data[2], rgbe);
nuclear@14: 			data += RGBE_DATA_SIZE;
nuclear@14: 			free(scanline_buffer);
nuclear@14: 			return rgbe_read_pixels(io, data, scanline_width * num_scanlines - 1);
nuclear@14: 		}
nuclear@14: 		if((((int)rgbe[2]) << 8 | rgbe[3]) != scanline_width) {
nuclear@14: 			free(scanline_buffer);
nuclear@14: 			return rgbe_error(rgbe_format_error, "wrong scanline width");
nuclear@14: 		}
nuclear@14: 		if(scanline_buffer == NULL)
nuclear@14: 			scanline_buffer = (unsigned char *)
nuclear@14: 				malloc(sizeof(unsigned char) * 4 * scanline_width);
nuclear@14: 		if(scanline_buffer == NULL)
nuclear@14: 			return rgbe_error(rgbe_memory_error, "unable to allocate buffer space");
nuclear@14: 
nuclear@14: 		ptr = &scanline_buffer[0];
nuclear@14: 		/* read each of the four channels for the scanline into the buffer */
nuclear@14: 		for(i = 0; i < 4; i++) {
nuclear@14: 			ptr_end = &scanline_buffer[(i + 1) * scanline_width];
nuclear@14: 			while(ptr < ptr_end) {
nuclear@14: 				if(io->read(buf, sizeof(buf[0]) * 2, io->uptr) < 1) {
nuclear@14: 					free(scanline_buffer);
nuclear@14: 					return rgbe_error(rgbe_read_error, NULL);
nuclear@14: 				}
nuclear@14: 				if(buf[0] > 128) {
nuclear@14: 					/* a run of the same value */
nuclear@14: 					count = buf[0] - 128;
nuclear@14: 					if((count == 0) || (count > ptr_end - ptr)) {
nuclear@14: 						free(scanline_buffer);
nuclear@14: 						return rgbe_error(rgbe_format_error, "bad scanline data");
nuclear@14: 					}
nuclear@14: 					while(count-- > 0)
nuclear@14: 						*ptr++ = buf[1];
nuclear@14: 				} else {
nuclear@14: 					/* a non-run */
nuclear@14: 					count = buf[0];
nuclear@14: 					if((count == 0) || (count > ptr_end - ptr)) {
nuclear@14: 						free(scanline_buffer);
nuclear@14: 						return rgbe_error(rgbe_format_error, "bad scanline data");
nuclear@14: 					}
nuclear@14: 					*ptr++ = buf[1];
nuclear@14: 					if(--count > 0) {
nuclear@14: 						if(io->read(ptr, sizeof(*ptr) * count, io->uptr) < 1) {
nuclear@14: 							free(scanline_buffer);
nuclear@14: 							return rgbe_error(rgbe_read_error, NULL);
nuclear@14: 						}
nuclear@14: 						ptr += count;
nuclear@14: 					}
nuclear@14: 				}
nuclear@14: 			}
nuclear@14: 		}
nuclear@14: 		/* now convert data from buffer into floats */
nuclear@14: 		for(i = 0; i < scanline_width; i++) {
nuclear@14: 			rgbe[0] = scanline_buffer[i];
nuclear@14: 			rgbe[1] = scanline_buffer[i + scanline_width];
nuclear@14: 			rgbe[2] = scanline_buffer[i + 2 * scanline_width];
nuclear@14: 			rgbe[3] = scanline_buffer[i + 3 * scanline_width];
nuclear@14: 			rgbe2float(&data[RGBE_DATA_RED], &data[RGBE_DATA_GREEN], &data[RGBE_DATA_BLUE], rgbe);
nuclear@14: 			data += RGBE_DATA_SIZE;
nuclear@14: 		}
nuclear@14: 		num_scanlines--;
nuclear@14: 	}
nuclear@14: 	free(scanline_buffer);
nuclear@14: 	return RGBE_RETURN_SUCCESS;
nuclear@14: }