TKDIB.C

/******************************Module*Header*******************************\ 
* Module Name: dib.c
*
* (Brief description)
*
* Created: 21-Feb-1994 23:12:58
* Author: Gilman Wong [gilmanw]
*
* Copyright (c) 1994 Microsoft Corporation
*
* (General description of its use)
*
* Dependencies:
*
* (#defines)
* (#includes)
*
\**************************************************************************/

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "tk.h"

#define static

#define BFT_BITMAP 0x4d42 // 'BM' -- indicates structure is BITMAPFILEHEADER

// struct BITMAPFILEHEADER {
// WORD bfType
// DWORD bfSize
// WORD bfReserved1
// WORD bfReserved2
// DWORD bfOffBits
// }
#define OFFSET_bfType 0
#define OFFSET_bfSize 2
#define OFFSET_bfReserved1 6
#define OFFSET_bfReserved2 8
#define OFFSET_bfOffBits 10
#define SIZEOF_BITMAPFILEHEADER 14

// Read a WORD-aligned DWORD. Needed because BITMAPFILEHEADER has
// WORD-alignment.
#define READDWORD(pv) ( (DWORD)((PWORD)(pv))[0] \
| ((DWORD)((PWORD)(pv))[1] << 16) ) \

// Computes the number of BYTES needed to contain n number of bits.
#define BITS2BYTES(n) ( ((n) + 7) >> 3 )

/****************************************************************************
* *
* FUNCTION : DibNumColors(VOID FAR * pv) *
* *
* PURPOSE : Determines the number of colors in the DIB by looking at *
* the BitCount filed in the info block. *
* *
* RETURNS : The number of colors in the DIB. *
* *
* Stolen from SDK ShowDIB example. *
****************************************************************************/

WORD DibNumColors(VOID FAR * pv)
{
WORD bits;
BITMAPINFOHEADER UNALIGNED *lpbi;
BITMAPCOREHEADER UNALIGNED *lpbc;

lpbi = ((LPBITMAPINFOHEADER)pv);
lpbc = ((LPBITMAPCOREHEADER)pv);

/* With the BITMAPINFO format headers, the size of the palette
* is in biClrUsed, whereas in the BITMAPCORE - style headers, it
* is dependent on the bits per pixel ( = 2 raised to the power of
* bits/pixel).
*
* Because of the way we use this call, BITMAPINFOHEADER may be out
* of alignment if it follows a BITMAPFILEHEADER. So use the macro
* to safely access DWORD fields.
*/
if (READDWORD(&lpbi->biSize) != sizeof(BITMAPCOREHEADER)){
if (READDWORD(&lpbi->biClrUsed) != 0)
{
return (WORD) READDWORD(&lpbi->biClrUsed);
}
bits = lpbi->biBitCount;
}
else
bits = lpbc->bcBitCount;

switch (bits){
case 1:
return 2;
case 4:
return 16;
case 8:
return 256;
default:
/* A 24 bitcount DIB has no color table */
return 0;
}
}

/******************************Public*Routine******************************\
* tkDIBImageLoad
*
* ANSI version stub. Only here for orthogonality with tkRGBImageLoad.
*
* History:
* 22-Feb-1994 -by- Gilman Wong [gilmanw]
* Wrote it.
\**************************************************************************/

TK_RGBImageRec *tkDIBImageLoadAW(char *fileName, BOOL bUnicode);

TK_RGBImageRec *tkDIBImageLoad(char *fileName)
{
return tkDIBImageLoadAW(fileName, FALSE);
}

/******************************Public*Routine******************************\
* tkDIBImageLoadAW
*
* Loads a DIB file (specified as either an ANSI or Unicode filename,
* depending on the bUnicode flag) and converts it into a TK image format.
*
* The technique used is based on CreateDIBSection and SetDIBits.
* CreateDIBSection is used to create a DIB with a format easily converted
* into the TK image format (packed 24BPP RGB). The only conversion
* required is swapping R and B in each RGB triplet (see history below)
* The resulting bitmap is selected into a memory DC.
*
* The DIB file is mapped into memory and SetDIBits called to initialize
* the memory DC bitmap. It is during this step that GDI converts the
* arbitrary DIB file format to RGB format.
*
* Finally, the RGB data in the DIB section is read out and repacked
* as 24BPP 'BGR'.
*
* Returns:
* Pointer to TK_RGBImageRec. If an error occurs, a diagnostic error
* message is put into the error stream and tkQuit() is called,
* terminating the app.
*
* History:
* - 22-Feb-1994 -by- Gilman Wong [gilmanw]
* Wrote it.
*
* - 01-May-1995 : [marcfo]
* Don't quit if can't open DIB file - return NULL.
*
* - 27-Jul-1995 : [marcfo]
* Changed CreateDIBSection to create an RGB mapping, so this would work
* on win95. Swapping of R and B required, to generate BGR (R=low byte)
* for GL. If the GL 'BGR' (R=high byte) extension becomes part of api
* in OpenGL 2.0, then we can avoid swap and do a memcpy to grab the bits.
*
\**************************************************************************/

TK_RGBImageRec *tkDIBImageLoadAW(char *fileName, BOOL bUnicode)
{
TK_RGBImageRec *final = (TK_RGBImageRec *) NULL; // Ptr to TK image struct
// to return. Non-NULL
// only for success.

WORD wNumColors; // Number of colors in color table
BITMAPFILEHEADER *pbmf; // Ptr to file header
BITMAPINFOHEADER UNALIGNED *pbmihFile;
BITMAPCOREHEADER UNALIGNED *pbmchFile; // Ptr to file's core header (if it exists)
PVOID pvBitsFile; // Ptr to bitmap bits in file
PBYTE pjBitsRGB; // Ptr to 24BPP RGB image in DIB section
PBYTE pjTKBits = (PBYTE) NULL; // Ptr to final TK image bits
PBYTE pjSrc; // Ptr to image file used for conversion
PBYTE pjDst; // Ptr to TK image used for conversion

// These need to be cleaned up when we exit:
HANDLE hFile = INVALID_HANDLE_VALUE; // File handle
HANDLE hMap = (HANDLE) NULL; // Mapping object handle
PVOID pvFile = (PVOID) NULL; // Ptr to mapped file
HDC hdcMem = (HDC) NULL; // 24BPP mem DC
HBITMAP hbmRGB = (HBITMAP) NULL; // 24BPP RGB bitmap
BITMAPINFO *pbmiSource = (BITMAPINFO *) NULL; // Ptr to source BITMAPINFO
BITMAPINFO *pbmiRGB = (BITMAPINFO *) NULL; // Ptr to file's BITMAPINFO

int i, j;
int padBytes;

// Map the DIB file into memory.

hFile = bUnicode ?
CreateFileW((LPWSTR) fileName, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, 0, 0) :
CreateFileA((LPSTR) fileName, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, 0, 0);

if (hFile == INVALID_HANDLE_VALUE)
goto tkDIBLoadImage_cleanup;

hMap = CreateFileMappingA(hFile, NULL, PAGE_READONLY, 0, 0, NULL);
if (!hMap)
goto tkDIBLoadImage_cleanup;

pvFile = MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, 0);
if (!pvFile)
goto tkDIBLoadImage_cleanup;

// Check the file header. If the BFT_BITMAP magic number is there,
// then the file format is a BITMAPFILEHEADER followed immediately
// by either a BITMAPINFOHEADER or a BITMAPCOREHEADER. The bitmap
// bits, in this case, are located at the offset bfOffBits from the
// BITMAPFILEHEADER.
//
// Otherwise, this may be a raw BITMAPINFOHEADER or BITMAPCOREHEADER
// followed immediately with the color table and the bitmap bits.

pbmf = (BITMAPFILEHEADER *) pvFile;

if ( pbmf->bfType == BFT_BITMAP )
{
pbmihFile = (BITMAPINFOHEADER *) ((PBYTE) pbmf + SIZEOF_BITMAPFILEHEADER);

// BITMAPFILEHEADER is WORD aligned, so use safe macro to read DWORD
// bfOffBits field.

pvBitsFile = (PVOID *) ((PBYTE) pbmf
+ READDWORD((PBYTE) pbmf + OFFSET_bfOffBits));
}
else
{
pbmihFile = (BITMAPINFOHEADER *) pvFile;

// Determination of where the bitmaps bits are needs to wait until we
// know for sure whether we have a BITMAPINFOHEADER or a BITMAPCOREHEADER.
}

// Determine the number of colors in the DIB palette. This is non-zero
// only for 8BPP or less.

wNumColors = DibNumColors(pbmihFile);

// Create a BITMAPINFO (with color table) for the DIB file. Because the
// file may not have one (BITMAPCORE case) and potential alignment problems,
// we will create a new one in memory we allocate.
//
// We distinguish between BITMAPINFO and BITMAPCORE cases based upon
// BITMAPINFOHEADER.biSize.

pbmiSource = (BITMAPINFO *)
LocalAlloc(LMEM_FIXED, sizeof(BITMAPINFO)
+ wNumColors * sizeof(RGBQUAD));
if (!pbmiSource)
{
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

// Note: need to use safe READDWORD macro because pbmihFile may
// have only WORD alignment if it follows a BITMAPFILEHEADER.

switch (READDWORD(&pbmihFile->biSize))
{
case sizeof(BITMAPINFOHEADER):

// Convert WORD-aligned BITMAPINFOHEADER to aligned BITMAPINFO.

pbmiSource->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmiSource->bmiHeader.biWidth = READDWORD(&pbmihFile->biWidth);
pbmiSource->bmiHeader.biHeight = READDWORD(&pbmihFile->biHeight);
pbmiSource->bmiHeader.biPlanes = pbmihFile->biPlanes;
pbmiSource->bmiHeader.biBitCount = pbmihFile->biBitCount;
pbmiSource->bmiHeader.biCompression =
READDWORD(&pbmihFile->biCompression);
pbmiSource->bmiHeader.biSizeImage =
READDWORD(&pbmihFile->biSizeImage);
pbmiSource->bmiHeader.biXPelsPerMeter =
READDWORD(&pbmihFile->biXPelsPerMeter);
pbmiSource->bmiHeader.biYPelsPerMeter =
READDWORD(&pbmihFile->biYPelsPerMeter);
pbmiSource->bmiHeader.biClrUsed =
READDWORD(&pbmihFile->biClrUsed);
pbmiSource->bmiHeader.biClrImportant =
READDWORD(&pbmihFile->biClrImportant);

// Copy color table. It immediately follows the BITMAPINFOHEADER.

memcpy((PVOID) &pbmiSource->bmiColors[0], (PVOID) (pbmihFile + 1),
wNumColors * sizeof(RGBQUAD));

// If we haven't already determined the position of the image bits,
// we may now assume that they immediately follow the color table.

if (!pvBitsFile)
pvBitsFile = (PVOID) ((PBYTE) (pbmihFile + 1)
+ wNumColors * sizeof(RGBQUAD));
break;

case sizeof(BITMAPCOREHEADER):
pbmchFile = (BITMAPCOREHEADER *) pbmihFile;

// Convert BITMAPCOREHEADER to BITMAPINFOHEADER.

pbmiSource->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmiSource->bmiHeader.biWidth = (DWORD) pbmchFile->bcWidth;
pbmiSource->bmiHeader.biHeight = (DWORD) pbmchFile->bcHeight;
pbmiSource->bmiHeader.biPlanes = pbmchFile->bcPlanes;
pbmiSource->bmiHeader.biBitCount = pbmchFile->bcBitCount;
pbmiSource->bmiHeader.biCompression = BI_RGB;
pbmiSource->bmiHeader.biSizeImage = 0;
pbmiSource->bmiHeader.biXPelsPerMeter = 0;
pbmiSource->bmiHeader.biYPelsPerMeter = 0;
pbmiSource->bmiHeader.biClrUsed = wNumColors;
pbmiSource->bmiHeader.biClrImportant = wNumColors;

// Convert RGBTRIPLE color table into RGBQUAD color table.

{
RGBQUAD *rgb4 = pbmiSource->bmiColors;
RGBTRIPLE *rgb3 = (RGBTRIPLE *) (pbmchFile + 1);

for (i = 0; i < wNumColors; i++)
{
rgb4->rgbRed = rgb3->rgbtRed ;
rgb4->rgbGreen = rgb3->rgbtGreen;
rgb4->rgbBlue = rgb3->rgbtBlue ;
rgb4->rgbReserved = 0;

rgb4++;
rgb3++;
}
}

// If we haven't already determined the position of the image bits,
// we may now assume that they immediately follow the color table.

if (!pvBitsFile)
pvBitsFile = (PVOID) ((PBYTE) (pbmihFile + 1)
+ wNumColors * sizeof(RGBTRIPLE));
break;

default:
MESSAGEBOX(GetFocus(), "Unknown DIB file format.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

// Fill in default values (for fields that can have defaults).

if (pbmiSource->bmiHeader.biSizeImage == 0)
pbmiSource->bmiHeader.biSizeImage =
BITS2BYTES( (DWORD) pbmiSource->bmiHeader.biWidth *
pbmiSource->bmiHeader.biBitCount ) *
pbmiSource->bmiHeader.biHeight;
if (pbmiSource->bmiHeader.biClrUsed == 0)
pbmiSource->bmiHeader.biClrUsed = wNumColors;

// Create memory DC.

hdcMem = CreateCompatibleDC(NULL);
if (!hdcMem) {
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

// Create a 24BPP RGB DIB section and select it into the memory DC.

pbmiRGB = (BITMAPINFO *)
LocalAlloc(LMEM_FIXED|LMEM_ZEROINIT, sizeof(BITMAPINFO) );
if (!pbmiRGB)
{
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

pbmiRGB->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmiRGB->bmiHeader.biWidth = pbmiSource->bmiHeader.biWidth;
pbmiRGB->bmiHeader.biHeight = pbmiSource->bmiHeader.biHeight;
pbmiRGB->bmiHeader.biPlanes = 1;
pbmiRGB->bmiHeader.biBitCount = 24;
pbmiRGB->bmiHeader.biCompression = BI_RGB;
pbmiRGB->bmiHeader.biSizeImage = pbmiRGB->bmiHeader.biWidth
* abs(pbmiRGB->bmiHeader.biHeight) * 3;

hbmRGB = CreateDIBSection(hdcMem, pbmiRGB, DIB_RGB_COLORS,
(PVOID *) &pjBitsRGB, NULL, 0);

if (!hbmRGB)
{
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

if (!SelectObject(hdcMem, hbmRGB))
{
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

// Slam the DIB file image into the memory DC. GDI will do the work of
// translating whatever format the DIB file has into RGB format.

if (!SetDIBits(hdcMem, hbmRGB, 0, pbmiSource->bmiHeader.biHeight,
pvBitsFile, pbmiSource, DIB_RGB_COLORS))
{
MESSAGEBOX(GetFocus(), "Image file conversion error.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}
GdiFlush(); // make sure that SetDIBits executes

// Convert to TK image format (packed RGB format).
// Allocate with malloc to be consistent with tkRGBImageLoad (i.e., app
// can deallocate with free()).

pjTKBits = (PBYTE) malloc(pbmiRGB->bmiHeader.biSizeImage);
if (!pjTKBits)
{
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}

pjSrc = pjBitsRGB;
pjDst = pjTKBits;
// src lines end on LONG boundary - so need to skip over any padding bytes
padBytes = pbmiSource->bmiHeader.biWidth % sizeof(LONG);
for (i = 0; i < pbmiSource->bmiHeader.biHeight; i++)
{
for (j = 0; j < pbmiSource->bmiHeader.biWidth; j++)
{
// swap R and B
*pjDst++ = pjSrc[2];
*pjDst++ = pjSrc[1];
*pjDst++ = pjSrc[0];
pjSrc += 3;
}
pjSrc += padBytes;
}

// Allocate and initialize the TK_RGBImageRec.
// Allocate with malloc to be consistent with tkRGBImageLoad (i.e., app
// can deallocate with free()).

final = (TK_RGBImageRec *)malloc(sizeof(TK_RGBImageRec));
if (final == NULL) {
MESSAGEBOX(GetFocus(), "Out of memory.", "Error", MB_OK);
goto tkDIBLoadImage_cleanup;
}
// If we get to here, we have suceeded!
final->sizeX = pbmiSource->bmiHeader.biWidth;
final->sizeY = pbmiSource->bmiHeader.biHeight;
final->data = pjTKBits;

// Cleanup objects.

tkDIBLoadImage_cleanup:
{
if (hdcMem)
DeleteDC(hdcMem);

if (hbmRGB)
DeleteObject(hbmRGB);

if (pbmiRGB)
LocalFree(pbmiRGB);

if (pbmiSource)
LocalFree(pbmiSource);

if (pvFile)
UnmapViewOfFile(pvFile);

if (hMap)
CloseHandle(hMap);

if (hFile != INVALID_HANDLE_VALUE)
CloseHandle(hFile);
}

// Check for error.

if (!final)
{
if (pjTKBits)
free(pjTKBits);

if ( (hFile == INVALID_HANDLE_VALUE) || !hMap || !pvFile )
{
CHAR ach[256];

bUnicode ? wsprintf(ach, "Failed to open DIB file %ws.\n", fileName) :
wsprintf(ach, "Failed to open DIB file %s.\n", fileName);

MESSAGEBOX(GetFocus(), ach, "Error", MB_OK);
}
}

return final;
}