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qdbmp.cpp
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qdbmp.cpp
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#include "qdbmp.h"
#include <stdlib.h>
#include <string.h>
/* Bitmap header */
typedef struct _BMP_Header
{
USHORT Magic; /* Magic identifier: "BM" */
UINT FileSize; /* Size of the BMP file in bytes */
USHORT Reserved1; /* Reserved */
USHORT Reserved2; /* Reserved */
UINT DataOffset; /* Offset of image data relative to the file's start */
UINT HeaderSize; /* Size of the header in bytes */
UINT Width; /* Bitmap's width */
UINT Height; /* Bitmap's height */
USHORT Planes; /* Number of color planes in the bitmap */
USHORT BitsPerPixel; /* Number of bits per pixel */
UINT CompressionType; /* Compression type */
UINT ImageDataSize; /* Size of uncompressed image's data */
UINT HPixelsPerMeter; /* Horizontal resolution (pixels per meter) */
UINT VPixelsPerMeter; /* Vertical resolution (pixels per meter) */
UINT ColorsUsed; /* Number of color indexes in the color table that are actually used by the bitmap */
UINT ColorsRequired; /* Number of color indexes that are required for displaying the bitmap */
} BMP_Header;
/* Private data structure */
struct _BMP
{
BMP_Header Header;
UCHAR* Palette;
UCHAR* Data;
};
/* Holds the last error code */
static BMP_STATUS BMP_LAST_ERROR_CODE = BMP_OK;
/* Error description strings */
static const char* BMP_ERROR_STRING[] =
{
"",
"General error",
"Could not allocate enough memory to complete the operation",
"File input/output error",
"File not found",
"File is not a supported BMP variant (must be uncompressed 8, 24 or 32 BPP)",
"File is not a valid BMP image",
"An argument is invalid or out of range",
"The requested action is not compatible with the BMP's type"
};
/* Size of the palette data for 8 BPP bitmaps */
#define BMP_PALETTE_SIZE ( 256 * 4 )
/*********************************** Forward declarations **********************************/
int ReadHeader ( BMP* bmp, FILE* f );
int WriteHeader ( BMP* bmp, FILE* f );
int ReadUINT ( UINT* x, FILE* f );
int ReadUSHORT ( USHORT *x, FILE* f );
int WriteUINT ( UINT x, FILE* f );
int WriteUSHORT ( USHORT x, FILE* f );
/*********************************** Public methods **********************************/
/**************************************************************
Creates a blank BMP image with the specified dimensions
and bit depth.
**************************************************************/
BMP* BMP_Create( UINT width, UINT height, USHORT depth )
{
BMP* bmp;
int bytes_per_pixel = depth >> 3;
UINT bytes_per_row;
if ( height <= 0 || width <= 0 )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return NULL;
}
if ( depth != 8 && depth != 24 && depth != 32 )
{
BMP_LAST_ERROR_CODE = BMP_FILE_NOT_SUPPORTED;
return NULL;
}
/* Allocate the bitmap data structure */
bmp = (BMP*)calloc( 1, sizeof( BMP ) );
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
return NULL;
}
/* Set header' default values */
bmp->Header.Magic = 0x4D42;
bmp->Header.Reserved1 = 0;
bmp->Header.Reserved2 = 0;
bmp->Header.HeaderSize = 40;
bmp->Header.Planes = 1;
bmp->Header.CompressionType = 0;
bmp->Header.HPixelsPerMeter = 0;
bmp->Header.VPixelsPerMeter = 0;
bmp->Header.ColorsUsed = 0;
bmp->Header.ColorsRequired = 0;
/* Calculate the number of bytes used to store a single image row. This is always
rounded up to the next multiple of 4. */
bytes_per_row = width * bytes_per_pixel;
bytes_per_row += ( bytes_per_row % 4 ? 4 - bytes_per_row % 4 : 0 );
/* Set header's image specific values */
bmp->Header.Width = width;
bmp->Header.Height = height;
bmp->Header.BitsPerPixel = depth;
bmp->Header.ImageDataSize = bytes_per_row * height;
bmp->Header.FileSize = bmp->Header.ImageDataSize + 54 + ( depth == 8 ? BMP_PALETTE_SIZE : 0 );
bmp->Header.DataOffset = 54 + ( depth == 8 ? BMP_PALETTE_SIZE : 0 );
/* Allocate palette */
if ( bmp->Header.BitsPerPixel == 8 )
{
bmp->Palette = (UCHAR*) calloc( BMP_PALETTE_SIZE, sizeof( UCHAR ) );
if ( bmp->Palette == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
free( bmp );
return NULL;
}
}
else
{
bmp->Palette = NULL;
}
/* Allocate pixels */
bmp->Data = (UCHAR*) calloc( bmp->Header.ImageDataSize, sizeof( UCHAR ) );
if ( bmp->Data == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
free( bmp->Palette );
free( bmp );
return NULL;
}
BMP_LAST_ERROR_CODE = BMP_OK;
return bmp;
}
/**************************************************************
Frees all the memory used by the specified BMP image.
**************************************************************/
void BMP_Free( BMP* bmp )
{
if ( bmp == NULL )
{
return;
}
if ( bmp->Palette != NULL )
{
free( bmp->Palette );
}
if ( bmp->Data != NULL )
{
free( bmp->Data );
}
free( bmp );
BMP_LAST_ERROR_CODE = BMP_OK;
}
/**************************************************************
Reads the specified BMP image file.
**************************************************************/
BMP* BMP_ReadFile( const char* filename )
{
BMP* bmp;
FILE* f;
if ( filename == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return NULL;
}
/* Allocate */
bmp = (BMP*)calloc( 1, sizeof( BMP ) );
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
return NULL;
}
/* Open file */
f = fopen( filename, "rb" );
if ( f == NULL )
{
BMP_LAST_ERROR_CODE = BMP_FILE_NOT_FOUND;
free( bmp );
return NULL;
}
/* Read header */
if ( ReadHeader( bmp, f ) != BMP_OK || bmp->Header.Magic != 0x4D42 )
{
BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
fclose( f );
free( bmp );
return NULL;
}
/* Verify that the bitmap variant is supported */
if ( ( bmp->Header.BitsPerPixel != 32 && bmp->Header.BitsPerPixel != 24 && bmp->Header.BitsPerPixel != 8 )
|| bmp->Header.CompressionType != 0 || bmp->Header.HeaderSize != 40 )
{
BMP_LAST_ERROR_CODE = BMP_FILE_NOT_SUPPORTED;
fclose( f );
free( bmp );
return NULL;
}
/* Allocate and read palette */
if ( bmp->Header.BitsPerPixel == 8 )
{
bmp->Palette = (UCHAR*) malloc( BMP_PALETTE_SIZE * sizeof( UCHAR ) );
if ( bmp->Palette == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
fclose( f );
free( bmp );
return NULL;
}
if ( fread( bmp->Palette, sizeof( UCHAR ), BMP_PALETTE_SIZE, f ) != BMP_PALETTE_SIZE )
{
BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
fclose( f );
free( bmp->Palette );
free( bmp );
return NULL;
}
}
else /* Not an indexed image */
{
bmp->Palette = NULL;
}
/* Allocate memory for image data */
bmp->Data = (UCHAR*) malloc( bmp->Header.ImageDataSize );
if ( bmp->Data == NULL )
{
BMP_LAST_ERROR_CODE = BMP_OUT_OF_MEMORY;
fclose( f );
free( bmp->Palette );
free( bmp );
return NULL;
}
/* Read image data */
if ( fread( bmp->Data, sizeof( UCHAR ), bmp->Header.ImageDataSize, f ) != bmp->Header.ImageDataSize )
{
BMP_LAST_ERROR_CODE = BMP_FILE_INVALID;
fclose( f );
free( bmp->Data );
free( bmp->Palette );
free( bmp );
return NULL;
}
fclose( f );
BMP_LAST_ERROR_CODE = BMP_OK;
return bmp;
}
/**************************************************************
Writes the BMP image to the specified file.
**************************************************************/
void BMP_WriteFile( BMP* bmp, const char* filename )
{
FILE* f;
if ( filename == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return;
}
/* Open file */
f = fopen( filename, "wb" );
if ( f == NULL )
{
BMP_LAST_ERROR_CODE = BMP_FILE_NOT_FOUND;
return;
}
/* Write header */
if ( WriteHeader( bmp, f ) != BMP_OK )
{
BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
fclose( f );
return;
}
/* Write palette */
if ( bmp->Palette )
{
if ( fwrite( bmp->Palette, sizeof( UCHAR ), BMP_PALETTE_SIZE, f ) != BMP_PALETTE_SIZE )
{
BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
fclose( f );
return;
}
}
/* Write data */
if ( fwrite( bmp->Data, sizeof( UCHAR ), bmp->Header.ImageDataSize, f ) != bmp->Header.ImageDataSize )
{
BMP_LAST_ERROR_CODE = BMP_IO_ERROR;
fclose( f );
return;
}
BMP_LAST_ERROR_CODE = BMP_OK;
fclose( f );
}
/**************************************************************
Returns the image's width.
**************************************************************/
UINT BMP_GetWidth( BMP* bmp )
{
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return -1;
}
BMP_LAST_ERROR_CODE = BMP_OK;
return ( bmp->Header.Width );
}
/**************************************************************
Returns the image's height.
**************************************************************/
UINT BMP_GetHeight( BMP* bmp )
{
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return -1;
}
BMP_LAST_ERROR_CODE = BMP_OK;
return ( bmp->Header.Height );
}
/**************************************************************
Returns the image's color depth (bits per pixel).
**************************************************************/
USHORT BMP_GetDepth( BMP* bmp )
{
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
return -1;
}
BMP_LAST_ERROR_CODE = BMP_OK;
return ( bmp->Header.BitsPerPixel );
}
/**************************************************************
Populates the arguments with the specified pixel's RGB
values.
**************************************************************/
void BMP_GetPixelRGB( BMP* bmp, UINT x, UINT y, UCHAR* r, UCHAR* g, UCHAR* b )
{
UCHAR* pixel;
UINT bytes_per_row;
UCHAR bytes_per_pixel;
if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else
{
BMP_LAST_ERROR_CODE = BMP_OK;
bytes_per_pixel = bmp->Header.BitsPerPixel >> 3;
/* Row's size is rounded up to the next multiple of 4 bytes */
bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
/* Calculate the location of the relevant pixel (rows are flipped) */
pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x * bytes_per_pixel );
/* In indexed color mode the pixel's value is an index within the palette */
if ( bmp->Header.BitsPerPixel == 8 )
{
pixel = bmp->Palette + *pixel * 4;
}
/* Note: colors are stored in BGR order */
if ( r ) *r = *( pixel + 2 );
if ( g ) *g = *( pixel + 1 );
if ( b ) *b = *( pixel + 0 );
}
}
/**************************************************************
Sets the specified pixel's RGB values.
**************************************************************/
void BMP_SetPixelRGB( BMP* bmp, UINT x, UINT y, UCHAR r, UCHAR g, UCHAR b )
{
UCHAR* pixel;
UINT bytes_per_row;
UCHAR bytes_per_pixel;
if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else if ( bmp->Header.BitsPerPixel != 24 && bmp->Header.BitsPerPixel != 32 )
{
BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
}
else
{
BMP_LAST_ERROR_CODE = BMP_OK;
bytes_per_pixel = bmp->Header.BitsPerPixel >> 3;
/* Row's size is rounded up to the next multiple of 4 bytes */
bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
/* Calculate the location of the relevant pixel (rows are flipped) */
pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x * bytes_per_pixel );
/* Note: colors are stored in BGR order */
*( pixel + 2 ) = r;
*( pixel + 1 ) = g;
*( pixel + 0 ) = b;
}
}
/**************************************************************
Gets the specified pixel's color index.
**************************************************************/
void BMP_GetPixelIndex( BMP* bmp, UINT x, UINT y, UCHAR* val )
{
UCHAR* pixel;
UINT bytes_per_row;
if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else if ( bmp->Header.BitsPerPixel != 8 )
{
BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
}
else
{
BMP_LAST_ERROR_CODE = BMP_OK;
/* Row's size is rounded up to the next multiple of 4 bytes */
bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
/* Calculate the location of the relevant pixel */
pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x );
if ( val ) *val = *pixel;
}
}
/**************************************************************
Sets the specified pixel's color index.
**************************************************************/
void BMP_SetPixelIndex( BMP* bmp, UINT x, UINT y, UCHAR val )
{
UCHAR* pixel;
UINT bytes_per_row;
if ( bmp == NULL || x < 0 || x >= bmp->Header.Width || y < 0 || y >= bmp->Header.Height )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else if ( bmp->Header.BitsPerPixel != 8 )
{
BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
}
else
{
BMP_LAST_ERROR_CODE = BMP_OK;
/* Row's size is rounded up to the next multiple of 4 bytes */
bytes_per_row = bmp->Header.ImageDataSize / bmp->Header.Height;
/* Calculate the location of the relevant pixel */
pixel = bmp->Data + ( ( bmp->Header.Height - y - 1 ) * bytes_per_row + x );
*pixel = val;
}
}
/**************************************************************
Gets the color value for the specified palette index.
**************************************************************/
void BMP_GetPaletteColor( BMP* bmp, UCHAR index, UCHAR* r, UCHAR* g, UCHAR* b )
{
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else if ( bmp->Header.BitsPerPixel != 8 )
{
BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
}
else
{
if ( r ) *r = *( bmp->Palette + index * 4 + 2 );
if ( g ) *g = *( bmp->Palette + index * 4 + 1 );
if ( b ) *b = *( bmp->Palette + index * 4 + 0 );
BMP_LAST_ERROR_CODE = BMP_OK;
}
}
/**************************************************************
Sets the color value for the specified palette index.
**************************************************************/
void BMP_SetPaletteColor( BMP* bmp, UCHAR index, UCHAR r, UCHAR g, UCHAR b )
{
if ( bmp == NULL )
{
BMP_LAST_ERROR_CODE = BMP_INVALID_ARGUMENT;
}
else if ( bmp->Header.BitsPerPixel != 8 )
{
BMP_LAST_ERROR_CODE = BMP_TYPE_MISMATCH;
}
else
{
*( bmp->Palette + index * 4 + 2 ) = r;
*( bmp->Palette + index * 4 + 1 ) = g;
*( bmp->Palette + index * 4 + 0 ) = b;
BMP_LAST_ERROR_CODE = BMP_OK;
}
}
/**************************************************************
Returns the last error code.
**************************************************************/
BMP_STATUS BMP_GetError()
{
return BMP_LAST_ERROR_CODE;
}
/**************************************************************
Returns a description of the last error code.
**************************************************************/
const char* BMP_GetErrorDescription()
{
if ( BMP_LAST_ERROR_CODE > 0 && BMP_LAST_ERROR_CODE < BMP_ERROR_NUM )
{
return BMP_ERROR_STRING[ BMP_LAST_ERROR_CODE ];
}
else
{
return NULL;
}
}
/*********************************** Private methods **********************************/
/**************************************************************
Reads the BMP file's header into the data structure.
Returns BMP_OK on success.
**************************************************************/
int ReadHeader( BMP* bmp, FILE* f )
{
if ( bmp == NULL || f == NULL )
{
return BMP_INVALID_ARGUMENT;
}
/* The header's fields are read one by one, and converted from the format's
little endian to the system's native representation. */
if ( !ReadUSHORT( &( bmp->Header.Magic ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.FileSize ), f ) ) return BMP_IO_ERROR;
if ( !ReadUSHORT( &( bmp->Header.Reserved1 ), f ) ) return BMP_IO_ERROR;
if ( !ReadUSHORT( &( bmp->Header.Reserved2 ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.DataOffset ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.HeaderSize ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.Width ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.Height ), f ) ) return BMP_IO_ERROR;
if ( !ReadUSHORT( &( bmp->Header.Planes ), f ) ) return BMP_IO_ERROR;
if ( !ReadUSHORT( &( bmp->Header.BitsPerPixel ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.CompressionType ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.ImageDataSize ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.HPixelsPerMeter ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.VPixelsPerMeter ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.ColorsUsed ), f ) ) return BMP_IO_ERROR;
if ( !ReadUINT( &( bmp->Header.ColorsRequired ), f ) ) return BMP_IO_ERROR;
return BMP_OK;
}
/**************************************************************
Writes the BMP file's header into the data structure.
Returns BMP_OK on success.
**************************************************************/
int WriteHeader( BMP* bmp, FILE* f )
{
if ( bmp == NULL || f == NULL )
{
return BMP_INVALID_ARGUMENT;
}
/* The header's fields are written one by one, and converted to the format's
little endian representation. */
if ( !WriteUSHORT( bmp->Header.Magic, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.FileSize, f ) ) return BMP_IO_ERROR;
if ( !WriteUSHORT( bmp->Header.Reserved1, f ) ) return BMP_IO_ERROR;
if ( !WriteUSHORT( bmp->Header.Reserved2, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.DataOffset, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.HeaderSize, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.Width, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.Height, f ) ) return BMP_IO_ERROR;
if ( !WriteUSHORT( bmp->Header.Planes, f ) ) return BMP_IO_ERROR;
if ( !WriteUSHORT( bmp->Header.BitsPerPixel, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.CompressionType, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.ImageDataSize, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.HPixelsPerMeter, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.VPixelsPerMeter, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.ColorsUsed, f ) ) return BMP_IO_ERROR;
if ( !WriteUINT( bmp->Header.ColorsRequired, f ) ) return BMP_IO_ERROR;
return BMP_OK;
}
/**************************************************************
Reads a little-endian unsigned int from the file.
Returns non-zero on success.
**************************************************************/
int ReadUINT( UINT* x, FILE* f )
{
UCHAR little[ 4 ]; /* BMPs use 32 bit ints */
if ( x == NULL || f == NULL )
{
return 0;
}
if ( fread( little, 4, 1, f ) != 1 )
{
return 0;
}
*x = ( little[ 3 ] << 24 | little[ 2 ] << 16 | little[ 1 ] << 8 | little[ 0 ] );
return 1;
}
/**************************************************************
Reads a little-endian unsigned short int from the file.
Returns non-zero on success.
**************************************************************/
int ReadUSHORT( USHORT *x, FILE* f )
{
UCHAR little[ 2 ]; /* BMPs use 16 bit shorts */
if ( x == NULL || f == NULL )
{
return 0;
}
if ( fread( little, 2, 1, f ) != 1 )
{
return 0;
}
*x = ( little[ 1 ] << 8 | little[ 0 ] );
return 1;
}
/**************************************************************
Writes a little-endian unsigned int to the file.
Returns non-zero on success.
**************************************************************/
int WriteUINT( UINT x, FILE* f )
{
UCHAR little[ 4 ]; /* BMPs use 32 bit ints */
little[ 3 ] = (UCHAR)( ( x & 0xff000000 ) >> 24 );
little[ 2 ] = (UCHAR)( ( x & 0x00ff0000 ) >> 16 );
little[ 1 ] = (UCHAR)( ( x & 0x0000ff00 ) >> 8 );
little[ 0 ] = (UCHAR)( ( x & 0x000000ff ) >> 0 );
return ( f && fwrite( little, 4, 1, f ) == 1 );
}
/**************************************************************
Writes a little-endian unsigned short int to the file.
Returns non-zero on success.
**************************************************************/
int WriteUSHORT( USHORT x, FILE* f )
{
UCHAR little[ 2 ]; /* BMPs use 16 bit shorts */
little[ 1 ] = (UCHAR)( ( x & 0xff00 ) >> 8 );
little[ 0 ] = (UCHAR)( ( x & 0x00ff ) >> 0 );
return ( f && fwrite( little, 2, 1, f ) == 1 );
}