1 files changed, 185 insertions, 0 deletions
diff --git a/DevIL/src-IL/src/il_bits.cpp b/DevIL/src-IL/src/il_bits.cpp
new file mode 100644
index 00000000..4e3ba7f4
--- /dev/null
+++ b/DevIL/src-IL/src/il_bits.cpp
@@ -0,0 +1,185 @@
+//-----------------------------------------------------------------------------
+//
+// ImageLib Sources
+// Copyright (C) 2000-2008 by Denton Woods
+// Last modified: 08/14/2004
+//
+// Filename: src-IL/src/il_bits.c
+//
+// Description: Implements a file class that reads/writes bits directly.
+//
+//-----------------------------------------------------------------------------
+
+
+#include "il_internal.h"
+#include "il_bits.h"
+
+
+// Opens a BITFILE just like fopen opens a FILE.
+/*BITFILE *bopen(const char *FileName, const char *Mode)
+{
+	BITFILE *ToReturn = NULL;
+
+	if (FileName != NULL) {
+		ToReturn = (BITFILE*)ialloc(sizeof(BITFILE));
+		if (ToReturn != NULL) {
+			iopenr((char*)FileName);
+			ToReturn->File = iGetFile();
+			ToReturn->BitPos = 0;
+			ToReturn->ByteBitOff = 8;
+			ToReturn->Buff = 0;
+		}
+	}
+
+	return ToReturn;
+}*/
+
+
+// Converts a FILE to a BITFILE.
+BITFILE *bfile(ILHANDLE File)
+{
+	BITFILE *ToReturn = NULL;
+
+	if (File != NULL) {
+		ToReturn = (BITFILE*)ialloc(sizeof(BITFILE));
+		if (ToReturn != NULL) {
+			ToReturn->File = File;
+			ToReturn->BitPos = itell() << 3;
+			ToReturn->ByteBitOff = 8;
+			ToReturn->Buff = 0;
+		}
+	}
+
+	return ToReturn;
+}
+
+
+// Closes an open BITFILE and frees memory for it.
+ILint bclose(BITFILE *BitFile)
+{
+	if (BitFile == NULL || BitFile->File == NULL)
+		return IL_EOF;
+
+	// Removed 01-26-2008.  The file will get closed later by
+	//  the calling function.
+	//icloser(BitFile->File);
+	ifree(BitFile);
+
+	return 0;
+}
+
+
+// Returns the current bit position of a BITFILE.
+ILint btell(BITFILE *BitFile)
+{
+	return BitFile->BitPos;
+}
+
+
+// Seeks in a BITFILE just like fseek for FILE.
+ILint bseek(BITFILE *BitFile, ILuint Offset, ILuint Mode)
+{
+	ILint KeepPos, Len;
+
+	if (BitFile == NULL || BitFile->File == NULL)
+		return 1;
+
+	switch (Mode)
+	{
+		case IL_SEEK_SET:
+			if (!iseek(Offset >> 3, Mode)) {
+				BitFile->BitPos = Offset;
+				BitFile->ByteBitOff = BitFile->BitPos % 8;
+			}
+			break;
+		case IL_SEEK_CUR:
+			if (!iseek(Offset >> 3, Mode)) {
+				BitFile->BitPos += Offset;
+				BitFile->ByteBitOff = BitFile->BitPos % 8;
+			}
+			break;
+		case IL_SEEK_END:
+			KeepPos = itell();
+			iseek(0, IL_SEEK_END);
+			Len = itell();
+			iseek(0, IL_SEEK_SET);
+
+			if (!iseek(Offset >> 3, Mode)) {
+				BitFile->BitPos = (Len << 3) + Offset;
+				BitFile->ByteBitOff = BitFile->BitPos % 8;
+			}
+
+			break;
+
+		default:
+			return 1;
+	}
+
+	return 0;
+}
+
+
+// hehe, "bread".  It reads data into Buffer from the BITFILE, just like fread for FILE.
+ILint bread(void *Buffer, ILuint Size, ILuint Number, BITFILE *BitFile)
+{
+	// Note that this function is somewhat useless: In binary image
+	// formats, there are some pad bits after each scanline. This
+	// function does not take that into account, so you must use bseek to
+	// skip the calculated value of bits.
+
+	ILuint	BuffPos = 0, Count = Size * Number;
+
+	while (BuffPos < Count) {
+		if (BitFile->ByteBitOff < 0 || BitFile->ByteBitOff > 7) {
+			BitFile->ByteBitOff = 7;
+			if (iread(&BitFile->Buff, 1, 1) != 1)  // Reached eof or error...
+				return BuffPos;
+		}
+
+		*((ILubyte*)(Buffer) + BuffPos) = (ILubyte)!!(BitFile->Buff & (1 << BitFile->ByteBitOff));
+
+		BuffPos++;
+		BitFile->ByteBitOff--;
+	}
+
+	return BuffPos;
+}
+
+
+// Reads bits and puts the first bit in the file as the highest in the return value.
+ILuint breadVal(ILuint NumBits, BITFILE *BitFile)
+{
+	ILuint	BuffPos = 0;
+	ILuint	Buffer = 0;
+
+	// Only returning up to 32 bits at one time
+	if (NumBits > 32) {
+		ilSetError(IL_INTERNAL_ERROR);
+		return 0;
+	}
+
+	while (BuffPos < NumBits) {
+		Buffer <<= 1;
+		if (BitFile->ByteBitOff < 0 || BitFile->ByteBitOff > 7) {
+			BitFile->ByteBitOff = 7;
+			if (iread(&BitFile->Buff, 1, 1) != 1)  // Reached eof or error...
+				return BuffPos;
+		}
+
+		Buffer = Buffer + (ILubyte)!!(BitFile->Buff & (1 << BitFile->ByteBitOff));
+
+		BuffPos++;
+		BitFile->ByteBitOff--;
+	}
+
+	return BuffPos;
+}
+
+
+// Not implemented yet.
+/*ILint bwrite(void *Buffer, ILuint Size, ILuint Number, BITFILE *BitFile)
+{
+
+
+	return 0;
+}*/