Add error checking and improve constructor of Fl_BMP_Image

- use new features of Fl_Image_Reader (read error and EOF checks)
- add length argument to constructor reading from memory
This commit is contained in:
Albrecht Schlosser
2021-09-27 19:21:21 +02:00
parent 1d847fec00
commit e0d630ed72
2 changed files with 155 additions and 104 deletions
+6 -6
View File
@@ -1,7 +1,7 @@
//
// BMP image header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2020 by Bill Spitzak and others.
// Copyright 1998-2021 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
@@ -27,14 +27,14 @@
*/
class FL_EXPORT Fl_BMP_Image : public Fl_RGB_Image {
public:
public:
Fl_BMP_Image(const char* filename);
Fl_BMP_Image(const char* imagename, const unsigned char *data);
Fl_BMP_Image(const char* filename);
Fl_BMP_Image(const char* imagename, const unsigned char *data, const long length = -1);
protected:
protected:
void load_bmp_(class Fl_Image_Reader &rdr);
void load_bmp_(class Fl_Image_Reader &rdr);
};
+149 -98
View File
@@ -1,7 +1,7 @@
//
// Fl_BMP_Image class for the Fast Light Tool Kit (FLTK).
//
// Copyright 2011-2020 by Bill Spitzak and others.
// Copyright 2011-2021 by Bill Spitzak and others.
// Copyright 1997-2010 by Easy Software Products.
// Image support by Matthias Melcher, Copyright 2000-2009.
//
@@ -40,20 +40,20 @@
/**
\brief This constructor loads the named BMP image from the given BMP filename.
This constructor loads the named BMP image from the given BMP filename.
The destructor frees all memory and server resources that are used by
the image.
The destructor frees all memory and server resources that are used by
the image.
Use Fl_Image::fail() to check if Fl_BMP_Image failed to load. fail() returns
ERR_FILE_ACCESS if the file could not be opened or read, ERR_FORMAT if the
BMP format could not be decoded, and ERR_NO_IMAGE if the image could not
be loaded for another reason.
Use Fl_Image::fail() to check if Fl_BMP_Image failed to load. fail() returns
ERR_FILE_ACCESS if the file could not be opened or read, ERR_FORMAT if the
BMP format could not be decoded, and ERR_NO_IMAGE if the image could not
be loaded for another reason.
\param[in] filename a full path and name pointing to a valid BMP file.
\param[in] filename a full path and name pointing to a BMP file.
\see Fl_BMP_Image::Fl_BMP_Image(const char *imagename, const unsigned char *data)
*/
\see Fl_BMP_Image::Fl_BMP_Image(const char* imagename, const unsigned char *data, const long length = -1);
*/
Fl_BMP_Image::Fl_BMP_Image(const char *filename) // I - File to read
: Fl_RGB_Image(0,0,0)
{
@@ -66,29 +66,44 @@ Fl_BMP_Image::Fl_BMP_Image(const char *filename) // I - File to read
}
/**
\brief Read a BMP image from memory.
This constructor loads a BMP image from memory.
Construct an image from a block of memory inside the application. Fluid offers
"binary data" chunks as a great way to add image data into the C++ source code.
imagename can be NULL. If a name is given, the image is added to the list of
shared images and will be available by that name.
Construct an image from a block of memory inside the application. Fluid offers
"binary data" chunks as a great way to add image data into the C++ source code.
\p imagename can be NULL. If a name is given, the image is added to the list of
shared images and will be available by that name.
Use Fl_Image::fail() to check if Fl_BMP_Image failed to load. fail() returns
ERR_FILE_ACCESS if the image could not be read from memory, ERR_FORMAT if the
BMP format could not be decoded, and ERR_NO_IMAGE if the image could not
be loaded for another reason.
The destructor frees all memory and server resources that are used by
the image.
\param[in] imagename A name given to this image or NULL
\param[in] data Pointer to the start of the BMP image in memory. This code will not check for buffer overruns.
The (new and optional) third parameter \p length \b should be used so buffer
overruns (i.e. truncated images) can be checked. See note below.
\see Fl_BMP_Image::Fl_BMP_Image(const char *filename)
\see Fl_Shared_Image
If \p length is not used
- it defaults to -1 (unlimited size)
- buffer overruns will not be checked.
\note The optional parameter \p length is available since FLTK 1.4.0.
Not using it is deprecated and old code should be modified to use it.
This parameter will likely become mandatory in a future FLTK version.
Use Fl_Image::fail() to check if Fl_BMP_Image failed to load. fail() returns
ERR_FILE_ACCESS if the image could not be read from memory, ERR_FORMAT if the
BMP format could not be decoded, and ERR_NO_IMAGE if the image could not
be loaded for another reason.
\param[in] imagename A name given to this image or NULL
\param[in] data Pointer to the start of the BMP image in memory.
\param[in] length Length of the BMP image in memory.
\see Fl_BMP_Image::Fl_BMP_Image(const char *filename)
\see Fl_Shared_Image
*/
Fl_BMP_Image::Fl_BMP_Image(const char *imagename, const unsigned char *data)
Fl_BMP_Image::Fl_BMP_Image(const char *imagename, const unsigned char *data, const long length)
: Fl_RGB_Image(0,0,0)
{
Fl_Image_Reader rdr;
if (rdr.open(imagename, data) == -1) {
if (rdr.open(imagename, data, length) == -1) {
ld(ERR_FILE_ACCESS);
} else {
load_bmp_(rdr);
@@ -96,35 +111,55 @@ Fl_BMP_Image::Fl_BMP_Image(const char *imagename, const unsigned char *data)
}
/*
This method reads BMP image data and creates an RGB or RGBA image. The BMP
format supports only 1 bit for alpha. To avoid code duplication, we use
an Fl_Image_Reader that reads data from either a file or from memory.
*/
This macro can be used to check for end of file (EOF) or other read errors.
In case of an error or EOF an error message is issued and the image loading
is terminated with error code ERR_FORMAT.
*/
#define CHECK_ERROR \
if (rdr.error()) { \
Fl::error("[%d] Fl_BMP_Image: %s - unexpected EOF or read error at offset %ld", \
__LINE__, rdr.name(), rdr.tell()); \
ld(ERR_FORMAT); \
return; \
}
/*
This method reads BMP image data and creates an RGB or RGBA image. The BMP
format supports only 1 bit for alpha. To avoid code duplication, we use
an Fl_Image_Reader that reads data from either a file or from memory.
*/
void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
{
int info_size, // Size of info header
depth, // Depth of image (bits)
bDepth = 3, // Depth of image (bytes)
compression, // Type of compression
colors_used, // Number of colors used
x, y, // Looping vars
color, // Color of RLE pixel
repcount, // Number of times to repeat
temp, // Temporary color
align, // Alignment bytes
dataSize, // number of bytes in image data set
row_order, // 1 = normal; -1 = flipped row order
start_y, // Beginning Y
end_y; // Ending Y
long offbits; // Offset to image data
uchar bit, // Bit in image
byte; // Byte in image
uchar *ptr; // Pointer into pixels
uchar colormap[256][3]; // Colormap
uchar havemask; // Single bit mask follows image data
int use_5_6_5; // Use 5:6:5 for R:G:B channels in 16 bit images
int info_size, // Size of info header
width, // Width of image (pixels)
height, // Height of image (pixels)
depth, // Depth of image (bits)
bDepth = 3, // Depth of image (bytes)
compression, // Type of compression
colors_used, // Number of colors used
x, y, // Looping vars
color, // Color of RLE pixel
repcount, // Number of times to repeat
temp, // Temporary color
align, // Alignment bytes
dataSize, // number of bytes in image data set
row_order, // 1 = normal; -1 = flipped row order
start_y, // Beginning Y
end_y; // Ending Y
long offbits; // Offset to image data
uchar bit, // Bit in image
byte; // Byte in image
uchar *ptr; // Pointer into pixels
uchar colormap[256][3]; // Colormap
uchar havemask; // Single bit mask follows image data
int use_5_6_5; // Use 5:6:5 for R:G:B channels in 16 bit images
// Reader is already open at this point.
// Implementation notes: Reader is already open at this point.
// Use local variables (width, height) until image is complete
// so we can easily use CHECK_ERROR to return with ld(ERR_FORMAT).
// We use CHECK_ERROR only at some essential points.
w(0); h(0); d(0); ld(0); // make sure these are all zero
// Get the header...
byte = rdr.read_byte(); // Check "BM" sync chars
@@ -141,6 +176,7 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
// Then the bitmap information...
info_size = rdr.read_dword();
CHECK_ERROR
// printf("offbits = %ld, info_size = %d\n", offbits, info_size);
@@ -150,8 +186,8 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
if (info_size < 40) {
// Old Windows/OS2 BMP header...
w(rdr.read_word());
h(rdr.read_word());
width = rdr.read_word();
height = rdr.read_word();
rdr.read_word();
depth = rdr.read_word();
compression = BI_RGB;
@@ -160,11 +196,11 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
repcount = info_size - 12;
} else {
// New BMP header...
w(rdr.read_long());
width = rdr.read_long();
// If the height is negative, the row order is flipped
temp = rdr.read_long();
if (temp < 0) row_order = 1;
h(abs(temp));
height = abs(temp);
rdr.read_word();
depth = rdr.read_word();
compression = rdr.read_dword();
@@ -176,29 +212,29 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
repcount = info_size - 40;
if (!compression && depth>=8 && w()>32/depth) {
if (!compression && depth >= 8 && width > 32/depth) {
int Bpp = depth/8;
int maskSize = (((w()*Bpp+3)&~3)*h()) + (((((w()+7)/8)+3)&~3)*h());
if (maskSize==2*dataSize) {
int maskSize = (((width*Bpp+3)&~3)*height) + (((((width+7)/8)+3)&~3)*height);
if (maskSize == 2*dataSize) {
havemask = 1;
h(h()/2);
height = height/2;
bDepth = 4;
}
}
}
CHECK_ERROR
// printf("w() = %d, h() = %d, depth = %d, compression = %d, colors_used = %d, repcount = %d\n",
// w(), h(), depth, compression, colors_used, repcount);
// printf("width =%4d, height =%4d, depth = %2d, compression = %d, colors_used = %3d, repcount = %2d, row_order = %2d\n",
// width, height, depth, compression, colors_used, repcount, row_order);
// Skip remaining header bytes...
while (repcount > 0) {
rdr.read_byte();
repcount --;
}
if (repcount > 0)
rdr.skip(repcount);
CHECK_ERROR
// Check header data...
if (!w() || !h() || !depth) {
w(0); h(0); d(0); ld(ERR_FORMAT);
if (!width || !height || !depth) {
ld(ERR_FORMAT);
return;
}
@@ -206,15 +242,16 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
if (colors_used == 0 && depth <= 8)
colors_used = 1 << depth;
for (repcount = 0; repcount < colors_used; repcount ++) {
for (int i = 0; i < colors_used; i++) {
// Read BGR color...
colormap[repcount][0] = rdr.read_byte();
colormap[repcount][1] = rdr.read_byte();
colormap[repcount][2] = rdr.read_byte();
colormap[i][0] = rdr.read_byte();
colormap[i][1] = rdr.read_byte();
colormap[i][2] = rdr.read_byte();
// Skip pad byte for new BMP files...
if (info_size > 12) rdr.read_byte();
}
CHECK_ERROR
// Read first dword of colormap. It tells us if 5:5:5 or 5:6:5 for 16 bit
if (depth == 16)
@@ -222,18 +259,18 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
// Set byte depth for RGBA images
if (depth == 32)
bDepth=4;
bDepth = 4;
// Setup image and buffers...
d(bDepth);
if (offbits) rdr.seek(offbits);
CHECK_ERROR
if (((size_t)w()) * h() * d() > max_size() ) {
if (((size_t)width) * height * bDepth > max_size() ) {
Fl::warning("BMP file \"%s\" is too large!\n", rdr.name());
w(0); h(0); d(0); ld(ERR_FORMAT);
ld(ERR_FORMAT);
return;
}
array = new uchar[w() * h() * d()];
array = new uchar[width * height * bDepth];
alloc_array = 1;
// Read the image data...
@@ -244,20 +281,20 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
temp = 0;
if (row_order < 0) {
start_y = h() - 1;
start_y = height - 1;
end_y = -1;
} else {
start_y = 0;
end_y = h();
end_y = height;
}
for (y = start_y; y != end_y; y += row_order) {
ptr = (uchar *)array + y * w() * d();
ptr = (uchar *)array + y * width * bDepth;
switch (depth)
{
case 1 : // Bitmap
for (x = w(), bit = 128; x > 0; x --) {
for (x = width, bit = 128; x > 0; x --) {
if (bit == 128) byte = rdr.read_byte();
if (byte & bit) {
@@ -277,13 +314,13 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
}
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 7) / 8; temp & 3; temp ++) {
for (temp = (width + 7) / 8; temp & 3; temp ++) {
rdr.read_byte();
}
break;
case 4 : // 16-color
for (x = w(), bit = 0xf0; x > 0; x --) {
for (x = width, bit = 0xf0; x > 0; x --) {
// Get a new repcount as needed...
if (repcount == 0) {
if (compression != BI_RLE4) {
@@ -305,7 +342,7 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
break;
} else if (repcount == 2) {
// Delta...
repcount = rdr.read_byte() * rdr.read_byte() * w();
repcount = rdr.read_byte() * rdr.read_byte() * width;
color = 0;
} else {
// Absolute...
@@ -343,17 +380,18 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
}
}
CHECK_ERROR
if (!compression) {
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 1) / 2; temp & 3; temp ++) {
for (temp = (width + 1) / 2; temp & 3; temp ++) {
rdr.read_byte();
}
}
break;
case 8 : // 256-color
for (x = w(); x > 0; x --) {
for (x = width; x > 0; x --) {
// Get a new repcount as needed...
if (compression != BI_RLE8) {
repcount = 1;
@@ -365,6 +403,7 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
align --;
rdr.read_byte();
}
CHECK_ERROR
if ((repcount = rdr.read_byte()) == 0) {
if ((repcount = rdr.read_byte()) == 0) {
@@ -376,7 +415,7 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
break;
} else if (repcount == 2) {
// Delta...
repcount = rdr.read_byte() * rdr.read_byte() * w();
repcount = rdr.read_byte() * rdr.read_byte() * width;
color = 0;
} else {
// Absolute...
@@ -387,6 +426,7 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
color = rdr.read_byte();
}
}
CHECK_ERROR
// Get a new color as needed...
if (color < 0) temp = rdr.read_byte();
@@ -403,14 +443,14 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
if (!compression) {
// Read remaining bytes to align to 32 bits...
for (temp = w(); temp & 3; temp ++) {
for (temp = width; temp & 3; temp ++) {
rdr.read_byte();
}
}
break;
case 16 : // 16-bit 5:5:5 or 5:6:5 RGB
for (x = w(); x > 0; x --, ptr += bDepth) {
for (x = width; x > 0; x --, ptr += bDepth) {
uchar b = rdr.read_byte(), a = rdr.read_byte() ;
if (use_5_6_5) {
ptr[2] = (uchar)(( b << 3 ) & 0xf8);
@@ -424,26 +464,26 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
}
// Read remaining bytes to align to 32 bits...
for (temp = w() * 2; temp & 3; temp ++) {
for (temp = width * 2; temp & 3; temp ++) {
rdr.read_byte();
}
break;
case 24 : // 24-bit RGB
for (x = w(); x > 0; x --, ptr += bDepth) {
for (x = width; x > 0; x --, ptr += bDepth) {
ptr[2] = rdr.read_byte();
ptr[1] = rdr.read_byte();
ptr[0] = rdr.read_byte();
}
// Read remaining bytes to align to 32 bits...
for (temp = w() * 3; temp & 3; temp ++) {
for (temp = width * 3; temp & 3; temp ++) {
rdr.read_byte();
}
break;
case 32 : // 32-bit RGBA
for (x = w(); x > 0; x --, ptr += bDepth) {
for (x = width; x > 0; x --, ptr += bDepth) {
ptr[2] = rdr.read_byte();
ptr[1] = rdr.read_byte();
ptr[0] = rdr.read_byte();
@@ -451,12 +491,13 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
}
break;
}
CHECK_ERROR
}
if (havemask) {
for (y = h() - 1; y >= 0; y --) {
ptr = (uchar *)array + y * w() * d() + 3;
for (x = w(), bit = 128; x > 0; x --, ptr+=bDepth) {
for (y = height - 1; y >= 0; y --) {
ptr = (uchar *)array + y * width * bDepth + 3;
for (x = width, bit = 128; x > 0; x --, ptr += bDepth) {
if (bit == 128) byte = rdr.read_byte();
if (byte & bit)
*ptr = 0;
@@ -468,9 +509,19 @@ void Fl_BMP_Image::load_bmp_(Fl_Image_Reader &rdr)
bit = 128;
}
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 7) / 8; temp & 3; temp ++)
for (temp = (width + 7) / 8; temp & 3; temp ++)
rdr.read_byte();
}
}
CHECK_ERROR
// Success: set image attributes and return
// File is closed when returning...
}
w(width);
h(height);
d(bDepth);
ld(0);
} // load_bmp_()