[master] e0d630e - Add error checking and improve constructor of Fl_BMP_Image
"Albrecht Schlosser"
Sep 27, 2021
commit e0d630ed72f354916efec1e620adf6f276b40564
Author: Albrecht Schlosser <albrechts.fltk@online.de>
AuthorDate: Mon Sep 27 19:21:21 2021 +0200
Commit: Albrecht Schlosser <albrechts.fltk@online.de>
CommitDate: Mon Sep 27 19:26:04 2021 +0200
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
FL/Fl_BMP_Image.H | 12 +--
src/Fl_BMP_Image.cxx | 249 +++++++++++++++++++++++++++++++--------------------
2 files changed, 156 insertions(+), 105 deletions(-)
diff --git FL/Fl_BMP_Image.H FL/Fl_BMP_Image.H
index c779d65..63dd301 100644
--- FL/Fl_BMP_Image.H
+++ FL/Fl_BMP_Image.H
@@ -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);
};
diff --git src/Fl_BMP_Image.cxx src/Fl_BMP_Image.cxx
index 8fb4cdd..8b326ed 100644
--- src/Fl_BMP_Image.cxx
+++ src/Fl_BMP_Image.cxx
@@ -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.
+ \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.
+
+ The destructor frees all memory and server resources that are used by
+ the image.
+
+ 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.
+
+ If \p length is not used
+ - it defaults to -1 (unlimited size)
+ - buffer overruns will not be checked.
- 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.
+ \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.
+ 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. This code will not check for buffer overruns.
+ \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
+ \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
-
- // Reader is already open at this point.
+ 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
+
+ // 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_()
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