ref: 9eaba52cafcac7c2f3bfc72d7be1f15893196be1
dir: /DoConfig/fltk/src/Fl_BMP_Image.cxx/
//
// "$Id$"
//
// Fl_BMP_Image routines.
//
// Copyright 1997-2010 by Easy Software Products.
// Image support by Matthias Melcher, Copyright 2000-2009.
//
// 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
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
// Contents:
//
// Fl_BMP_Image::Fl_BMP_Image() - Load a BMP image file.
//
//
// Include necessary header files...
//
#include <FL/Fl_BMP_Image.H>
#include <FL/fl_utf8.h>
#include <FL/Fl.H>
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
//
// BMP definitions...
//
#ifndef BI_RGB
# define BI_RGB 0 // No compression - straight BGR data
# define BI_RLE8 1 // 8-bit run-length compression
# define BI_RLE4 2 // 4-bit run-length compression
# define BI_BITFIELDS 3 // RGB bitmap with RGB masks
#endif // !BI_RGB
//
// Local functions...
//
static int read_long(FILE *fp);
static unsigned short read_word(FILE *fp);
static unsigned int read_dword(FILE *fp);
/**
The 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.
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.
*/
Fl_BMP_Image::Fl_BMP_Image(const char *bmp) // I - File to read
: Fl_RGB_Image(0,0,0) {
FILE *fp; // File pointer
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
// Open the file...
if ((fp = fl_fopen(bmp, "rb")) == NULL) {
ld(ERR_FILE_ACCESS);
return;
}
// Get the header...
byte = (uchar)getc(fp); // Check "BM" sync chars
bit = (uchar)getc(fp);
if (byte != 'B' || bit != 'M') {
fclose(fp);
ld(ERR_FORMAT);
return;
}
read_dword(fp); // Skip size
read_word(fp); // Skip reserved stuff
read_word(fp);
offbits = (long)read_dword(fp);// Read offset to image data
// Then the bitmap information...
info_size = read_dword(fp);
// printf("offbits = %ld, info_size = %d\n", offbits, info_size);
havemask = 0;
row_order = -1;
use_5_6_5 = 0;
if (info_size < 40) {
// Old Windows/OS2 BMP header...
w(read_word(fp));
h(read_word(fp));
read_word(fp);
depth = read_word(fp);
compression = BI_RGB;
colors_used = 0;
repcount = info_size - 12;
} else {
// New BMP header...
w(read_long(fp));
// If the height is negative, the row order is flipped
temp = read_long(fp);
if (temp < 0) row_order = 1;
h(abs(temp));
read_word(fp);
depth = read_word(fp);
compression = read_dword(fp);
dataSize = read_dword(fp);
read_long(fp);
read_long(fp);
colors_used = read_dword(fp);
read_dword(fp);
repcount = info_size - 40;
if (!compression && depth>=8 && w()>32/depth) {
int Bpp = depth/8;
int maskSize = (((w()*Bpp+3)&~3)*h()) + (((((w()+7)/8)+3)&~3)*h());
if (maskSize==2*dataSize) {
havemask = 1;
h(h()/2);
bDepth = 4;
}
}
}
// printf("w() = %d, h() = %d, depth = %d, compression = %d, colors_used = %d, repcount = %d\n",
// w(), h(), depth, compression, colors_used, repcount);
// Skip remaining header bytes...
while (repcount > 0) {
getc(fp);
repcount --;
}
// Check header data...
if (!w() || !h() || !depth) {
fclose(fp);
w(0); h(0); d(0); ld(ERR_FORMAT);
return;
}
// Get colormap...
if (colors_used == 0 && depth <= 8)
colors_used = 1 << depth;
for (repcount = 0; repcount < colors_used; repcount ++) {
// Read BGR color...
if (fread(colormap[repcount], 1, 3, fp)==0) { /* ignore */ }
// Skip pad byte for new BMP files...
if (info_size > 12) getc(fp);
}
// Read first dword of colormap. It tells us if 5:5:5 or 5:6:5 for 16 bit
if (depth == 16)
use_5_6_5 = (read_dword(fp) == 0xf800);
// Set byte depth for RGBA images
if (depth == 32)
bDepth=4;
// Setup image and buffers...
d(bDepth);
if (offbits) fseek(fp, offbits, SEEK_SET);
if (((size_t)w()) * h() * d() > max_size() ) {
Fl::warning("BMP file \"%s\" is too large!\n", bmp);
fclose(fp);
w(0); h(0); d(0); ld(ERR_FORMAT);
return;
}
array = new uchar[w() * h() * d()];
alloc_array = 1;
// Read the image data...
color = 0;
repcount = 0;
align = 0;
byte = 0;
temp = 0;
if (row_order < 0) {
start_y = h() - 1;
end_y = -1;
} else {
start_y = 0;
end_y = h();
}
for (y = start_y; y != end_y; y += row_order) {
ptr = (uchar *)array + y * w() * d();
switch (depth)
{
case 1 : // Bitmap
for (x = w(), bit = 128; x > 0; x --) {
if (bit == 128) byte = (uchar)getc(fp);
if (byte & bit) {
*ptr++ = colormap[1][2];
*ptr++ = colormap[1][1];
*ptr++ = colormap[1][0];
} else {
*ptr++ = colormap[0][2];
*ptr++ = colormap[0][1];
*ptr++ = colormap[0][0];
}
if (bit > 1)
bit >>= 1;
else
bit = 128;
}
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 7) / 8; temp & 3; temp ++) {
getc(fp);
}
break;
case 4 : // 16-color
for (x = w(), bit = 0xf0; x > 0; x --) {
// Get a new repcount as needed...
if (repcount == 0) {
if (compression != BI_RLE4) {
repcount = 2;
color = -1;
} else {
while (align > 0) {
align --;
getc(fp);
}
if ((repcount = getc(fp)) == 0) {
if ((repcount = getc(fp)) == 0) {
// End of line...
x ++;
continue;
} else if (repcount == 1) {
// End of image...
break;
} else if (repcount == 2) {
// Delta...
repcount = getc(fp) * getc(fp) * w();
color = 0;
} else {
// Absolute...
color = -1;
align = ((4 - (repcount & 3)) / 2) & 1;
}
} else {
color = getc(fp);
}
}
}
// Get a new color as needed...
repcount --;
// Extract the next pixel...
if (bit == 0xf0) {
// Get the next color byte as needed...
if (color < 0) temp = getc(fp);
else temp = color;
// Copy the color value...
*ptr++ = colormap[(temp >> 4) & 15][2];
*ptr++ = colormap[(temp >> 4) & 15][1];
*ptr++ = colormap[(temp >> 4) & 15][0];
bit = 0x0f;
} else {
bit = 0xf0;
// Copy the color value...
*ptr++ = colormap[temp & 15][2];
*ptr++ = colormap[temp & 15][1];
*ptr++ = colormap[temp & 15][0];
}
}
if (!compression) {
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 1) / 2; temp & 3; temp ++) {
getc(fp);
}
}
break;
case 8 : // 256-color
for (x = w(); x > 0; x --) {
// Get a new repcount as needed...
if (compression != BI_RLE8) {
repcount = 1;
color = -1;
}
if (repcount == 0) {
while (align > 0) {
align --;
getc(fp);
}
if ((repcount = getc(fp)) == 0) {
if ((repcount = getc(fp)) == 0) {
// End of line...
x ++;
continue;
} else if (repcount == 1) {
// End of image...
break;
} else if (repcount == 2) {
// Delta...
repcount = getc(fp) * getc(fp) * w();
color = 0;
} else {
// Absolute...
color = -1;
align = (2 - (repcount & 1)) & 1;
}
} else {
color = getc(fp);
}
}
// Get a new color as needed...
if (color < 0) temp = getc(fp);
else temp = color;
repcount --;
// Copy the color value...
*ptr++ = colormap[temp][2];
*ptr++ = colormap[temp][1];
*ptr++ = colormap[temp][0];
if (havemask) ptr++;
}
if (!compression) {
// Read remaining bytes to align to 32 bits...
for (temp = w(); temp & 3; temp ++) {
getc(fp);
}
}
break;
case 16 : // 16-bit 5:5:5 or 5:6:5 RGB
for (x = w(); x > 0; x --, ptr += bDepth) {
uchar b = getc(fp), a = getc(fp) ;
if (use_5_6_5) {
ptr[2] = (uchar)(( b << 3 ) & 0xf8);
ptr[1] = (uchar)(((a << 5) & 0xe0) | ((b >> 3) & 0x1c));
ptr[0] = (uchar)(a & 0xf8);
} else {
ptr[2] = (uchar)((b << 3) & 0xf8);
ptr[1] = (uchar)(((a << 6) & 0xc0) | ((b >> 2) & 0x38));
ptr[0] = (uchar)((a<<1) & 0xf8);
}
}
// Read remaining bytes to align to 32 bits...
for (temp = w() * 2; temp & 3; temp ++) {
getc(fp);
}
break;
case 24 : // 24-bit RGB
for (x = w(); x > 0; x --, ptr += bDepth) {
ptr[2] = (uchar)getc(fp);
ptr[1] = (uchar)getc(fp);
ptr[0] = (uchar)getc(fp);
}
// Read remaining bytes to align to 32 bits...
for (temp = w() * 3; temp & 3; temp ++) {
getc(fp);
}
break;
case 32 : // 32-bit RGBA
for (x = w(); x > 0; x --, ptr += bDepth) {
ptr[2] = (uchar)getc(fp);
ptr[1] = (uchar)getc(fp);
ptr[0] = (uchar)getc(fp);
ptr[3] = (uchar)getc(fp);
}
break;
}
}
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) {
if (bit == 128) byte = (uchar)getc(fp);
if (byte & bit)
*ptr = 0;
else
*ptr = 255;
if (bit > 1)
bit >>= 1;
else
bit = 128;
}
// Read remaining bytes to align to 32 bits...
for (temp = (w() + 7) / 8; temp & 3; temp ++)
getc(fp);
}
}
// Close the file and return...
fclose(fp);
}
//
// 'read_word()' - Read a 16-bit unsigned integer.
//
static unsigned short // O - 16-bit unsigned integer
read_word(FILE *fp) { // I - File to read from
unsigned char b0, b1; // Bytes from file
b0 = (uchar)getc(fp);
b1 = (uchar)getc(fp);
return ((b1 << 8) | b0);
}
//
// 'read_dword()' - Read a 32-bit unsigned integer.
//
static unsigned int // O - 32-bit unsigned integer
read_dword(FILE *fp) { // I - File to read from
unsigned char b0, b1, b2, b3; // Bytes from file
b0 = (uchar)getc(fp);
b1 = (uchar)getc(fp);
b2 = (uchar)getc(fp);
b3 = (uchar)getc(fp);
return ((((((b3 << 8) | b2) << 8) | b1) << 8) | b0);
}
//
// 'read_long()' - Read a 32-bit signed integer.
//
static int // O - 32-bit signed integer
read_long(FILE *fp) { // I - File to read from
unsigned char b0, b1, b2, b3; // Bytes from file
b0 = (uchar)getc(fp);
b1 = (uchar)getc(fp);
b2 = (uchar)getc(fp);
b3 = (uchar)getc(fp);
return ((int)(((((b3 << 8) | b2) << 8) | b1) << 8) | b0);
}
//
// End of "$Id$".
//