/**************************************************************************** * apps/graphics/tiff/tiff_utils.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "graphics/tiff.h" #include "tiff_internal.h" /**************************************************************************** * Pre-Processor Definitions ****************************************************************************/ /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: tiff_put/get16/32 * * Description: * Put and get 16 and 32 values in the correct byte order at the specified * position. * * Input Parameters: * dest - The location to store the multi-byte data (put only) * src - The location to get the multi-byte data (get only) * value - The value to be stored (put only) * * Returned Value: * None (put) * The extracted value (get) * ****************************************************************************/ void tiff_put16(FAR uint8_t *dest, uint16_t value) { #ifdef CONFIG_ENDIAN_BIG *dest++ = (uint8_t)(value >> 8); *dest = (uint8_t)(value & 0xff); #else *dest++ = (uint8_t)(value & 0xff); *dest = (uint8_t)(value >> 8); #endif } void tiff_put32(FAR uint8_t *dest, uint32_t value) { #ifdef CONFIG_ENDIAN_BIG tiff_put16(dest, (uint16_t)(value >> 16)); tiff_put16(dest+2, (uint16_t)(value & 0xffff)); #else tiff_put16(dest, (uint16_t)(value & 0xffff)); tiff_put16(dest+2, (uint16_t)(value >> 16)); #endif } uint16_t tiff_get16(FAR uint8_t *src) { #ifdef CONFIG_ENDIAN_BIG return (uint16_t)src[0] << 8 | (uint16_t)src[1]; #else return (uint16_t)src[1] << 8 | (uint16_t)src[0]; #endif } uint32_t tiff_get32(FAR uint8_t *src) { #ifdef CONFIG_ENDIAN_BIG return (uint32_t)tiff_get16(src) << 16 | (uint32_t)tiff_get16(src+2); #else return (uint32_t)tiff_get16(src+2) << 16 | (uint32_t)tiff_get16(src); #endif } /**************************************************************************** * Name: tiff_read * * Description: * Read TIFF data from the specified file * * Input Parameters: * fd - Open file descriptor to read from * buffer - Read-only buffer containing the data to be written * count - The number of bytes to write * * Returned Value: * On success, then number of bytes read; Zero is returned on EOF. * Otherwise, a negated errno value on failure. * ****************************************************************************/ ssize_t tiff_read(int fd, FAR void *buffer, size_t count) { size_t ntotal; ssize_t nbytes; int errval; /* This loop retries the write until either: (1) it completes successfully, * or (2) until an irrecoverble error occurs. */ for (ntotal = 0; ntotal < count; ) { /* Do the read. The number of bytes left to read is the total * requested size (count) minus the amount that we have already read * (ntotal). */ nbytes = read(fd, buffer, count-ntotal); /* Check for an error */ if (nbytes < 0) { /* EINTR is not an error.. this just means that the write was * interrupted by a signal. */ errval = errno; if (errval != EINTR) { /* Other errors are bad news and we will break out with an error */ return -errval; } } /* Zero is a special case and means that the end of file was encountered. */ else if (nbytes == 0) { break; } /* What if read returns some number of bytes other than the requested number? * This probably means that the end-of-file will be encountered the next time * that we call read(). */ else { buffer += nbytes; ntotal += nbytes; } } return ntotal; } /**************************************************************************** * Name: tiff_write * * Description: * Write TIFF data to the specified file * * Input Parameters: * fd - Open file descriptor to write to * buffer - Read-only buffer containing the data to be written * count - The number of bytes to write * * Returned Value: * Zero (OK) on success. A negated errno value on failure. * ****************************************************************************/ int tiff_write(int fd, FAR const void *buffer, size_t count) { ssize_t nbytes; int errval; /* This loop retries the write until either: (1) it completes successfully, * or (2) until an irrecoverble error occurs. */ while (count > 0) { /* Do the write */ nbytes = write(fd, buffer, count); /* Check for an error */ if (nbytes < 0) { /* EINTR is not an error.. this just means that the write was * interrupted by a signal. */ errval = errno; if (errval != EINTR) { /* Other errors are bad news and we will break out with an error */ return -errval; } } /* What if write returns some number of bytes other than the requested number? */ else { DEBUGASSERT(nbytes == count); buffer += nbytes; count -= nbytes; } } return OK; } /**************************************************************************** * Name: tiff_putint16 * * Description: * Write two bytes to the outfile. * * Input Parameters: * fd - File descriptor to be used. * value - The 2-byte, uint16_t value to write * * Returned Value: * Zero (OK) on success. A negated errno value on failure. * ****************************************************************************/ int tiff_putint16(int fd, uint16_t value) { uint8_t bytes[2]; /* Write the two bytes to the output file */ tiff_put16(bytes, value); return tiff_write(fd, bytes, 2); } /**************************************************************************** * Name: tiff_putint32 * * Description: * Write four bytes to the outfile. * * Input Parameters: * fd - File descriptor to be used. * value - The 4-byte, uint32_t value to write * * Returned Value: * Zero (OK) on success. A negated errno value on failure. * ****************************************************************************/ int tiff_putint32(int fd, uint32_t value) { uint8_t bytes[4]; /* Write the four bytes to the output file */ tiff_put32(bytes, value); return tiff_write(fd, bytes, 4); } /**************************************************************************** * Name: tiff_putstring * * Description: * Write a string of fixed length to the outfile. * * Input Parameters: * fd - File descriptor to be used. * string - A pointer to the memory containing the string * len - The length of the string (including the NUL terminator) * * Returned Value: * Zero (OK) on success. A negated errno value on failure. * ****************************************************************************/ int tiff_putstring(int fd, FAR const char *string, int len) { #ifdef CONFIG_DEBUG_GRAPHICS int actual = strlen(string); DEBUGASSERT(len = actual+1); #endif return tiff_write(fd, string, len); } /**************************************************************************** * Name: tiff_wordalign * * Description: * Pad a file with zeros as necessary to achieve word alignament. * * Input Parameters: * fd - File descriptor to be used. * size - The current size of the file * * Returned Value: * The new size of the file on success. A negated errno value on failure. * ****************************************************************************/ ssize_t tiff_wordalign(int fd, size_t size) { unsigned int remainder; int ret; remainder = size & 3; if (remainder > 0) { unsigned int nbytes = 4 - remainder; uint32_t value = 0; ret = tiff_write(fd, &value, nbytes); if (ret < 0) { return (ssize_t)ret; } size += nbytes; } return size; }