1 files changed, 153 insertions, 0 deletions
diff --git a/DevIL/src-IL/src/il_rle.cpp b/DevIL/src-IL/src/il_rle.cpp
new file mode 100644
index 00000000..5644f8e3
--- /dev/null
+++ b/DevIL/src-IL/src/il_rle.cpp
@@ -0,0 +1,153 @@
+//-----------------------------------------------------------------------------
+// Description: Functions for run-length encoding
+//-----------------------------------------------------------------------------
+
+// RLE code from TrueVision's TGA sample code available as Tgautils.zip at
+//	ftp://ftp.truevision.com/pub/TGA.File.Format.Spec/PC.Version
+
+#define IL_RLE_C
+
+#include "il_internal.h"
+#include "il_rle.h"
+
+ILboolean ilRleCompressLine(ILubyte *p, ILuint n, ILubyte bpp,
+			ILubyte *q, ILuint *DestWidth, ILenum CompressMode) {
+	
+	ILint		DiffCount;		// pixel count until two identical
+	ILint		SameCount;		// number of identical adjacent pixels
+	ILint		RLEBufSize = 0; // count of number of bytes encoded
+	ILint		MaxRun;
+	const ILint bmp_pad_to_even = 1 - ((ILint)q - *DestWidth) % 2;
+
+	switch( CompressMode ) {
+		case IL_TGACOMP:
+			MaxRun = TGA_MAX_RUN;
+			break;
+		case IL_SGICOMP:
+			MaxRun = SGI_MAX_RUN;
+			break;
+		case IL_BMPCOMP:
+			MaxRun = BMP_MAX_RUN;
+			break;
+		default:
+			ilSetError(IL_INVALID_PARAM);
+			return IL_FALSE;
+	}
+
+	while( n > 0 ) {	
+		// Analyze pixels
+		DiffCount = CountDiffPixels(p, bpp, (ILint)n > MaxRun ? MaxRun : n);
+		SameCount = CountSamePixels(p, bpp, (ILint)n > MaxRun ? MaxRun : n);
+
+		if( CompressMode == IL_BMPCOMP ) {
+			ILint remaining_data = n - DiffCount - SameCount;
+			if( remaining_data < 3  ) { // check if the run has gone near the end
+				// no absolute run can be done
+				// complete the line adding 0x01 + pixel, for each pixel
+				while( remaining_data > 0 ) {
+					*q++ = 0x01;
+					*q++ = *p++;
+					remaining_data--;
+				}
+				DiffCount = 0;
+				SameCount = 0;
+				n = 0;
+			}
+		}
+
+		if( DiffCount > 0 ) { // create a raw packet (bmp absolute run)
+			switch(CompressMode) {
+				case IL_TGACOMP:
+					*q++ = (ILbyte)(DiffCount - 1);
+					break;
+				case IL_BMPCOMP:
+					*q++ = 0x00; RLEBufSize++;
+					*q++ = (ILbyte)DiffCount;
+					break;
+				case IL_SGICOMP:
+					*q++ = (ILbyte)(DiffCount | 0x80);
+					break;
+			}
+			n -= DiffCount;
+			RLEBufSize += (DiffCount * bpp) + 1;
+
+			while( DiffCount > 0 ) {
+				switch(bpp) {
+					case 4:	*q++ = *p++;
+					case 3: *q++ = *p++;
+					case 2: *q++ = *p++;
+					case 1: *q++ = *p++;
+				}
+				DiffCount--;
+			}
+		
+			if( CompressMode == IL_BMPCOMP ) {
+				if( (size_t)q % 2 == bmp_pad_to_even ) {
+					*q++ = 0x00; // insert padding
+				}
+			}
+		}
+
+		if( SameCount > 1 ) { // create a RLE packet
+			switch(CompressMode) {
+				case IL_TGACOMP:
+					*q++ = (ILbyte)((SameCount - 1) | 0x80);
+					break;
+				case IL_SGICOMP:
+				case IL_BMPCOMP:
+					*q++ = (ILbyte)(SameCount);
+					break;
+			}
+			n -= SameCount;
+			RLEBufSize += bpp + 1;
+			p += (SameCount - 1) * bpp;
+			*q++ = *p++;
+			switch(bpp) {
+				case 4:	*q++ = *p++;
+				case 3: *q++ = *p++;
+				case 2: *q++ = *p++;
+				case 1: *q++ = *p++;
+			}
+		}
+	}
+
+	// write line termination code
+	switch(CompressMode) {
+		case IL_SGICOMP:
+			++RLEBufSize;
+			*q++ = 0;
+			break;
+		case IL_BMPCOMP: 
+			*q++ = 0x00; RLEBufSize++;
+			*q++ = 0x00; RLEBufSize++;
+			break;
+	}
+	*DestWidth = RLEBufSize;
+	
+	return IL_TRUE;
+}
+
+
+// Compresses an entire image using run-length encoding
+ILuint ilRleCompress(ILubyte *Data, ILuint Width, ILuint Height, ILuint Depth, ILubyte Bpp,
+		ILubyte *Dest, ILenum CompressMode, ILuint *ScanTable) {
+	ILuint DestW = 0, i, j, LineLen, Bps = Width * Bpp, SizeOfPlane = Width * Height * Bpp;
+
+	if( ScanTable )
+		imemclear(ScanTable,Depth*Height*sizeof(ILuint));
+	for( j = 0; j < Depth; j++ ) {
+		for( i = 0; i < Height; i++ ) {
+			if( ScanTable )
+				*ScanTable++ = DestW;
+			ilRleCompressLine(Data + j * SizeOfPlane + i * Bps, Width, Bpp, Dest + DestW, &LineLen, CompressMode);
+			DestW += LineLen;
+		}
+	}
+	
+	if( CompressMode == IL_BMPCOMP ) { // add end of image
+		*(Data+DestW) = 0x00; DestW++;
+		*(Data+DestW) = 0x01; DestW++;
+	}
+
+	return DestW;
+}