R6.6 is the Xorg base-lineXORG-MAINXORG-STABLE

1 files changed, 207 insertions, 0 deletions

diff --git a/src/image/epackbits.c b/src/image/epackbits.c
new file mode 100644
index 0000000..1ceed56
--- /dev/null
+++ b/src/image/epackbits.c
@@ -0,0 +1,207 @@
+/* $Xorg: epackbits.c,v 1.4 2000/08/17 19:46:41 cpqbld Exp $ */
+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992 Sam Leffler
+ * Copyright (c) 1991, 1992 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and 
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the names of
+ * Sam Leffler and Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Sam Leffler and Silicon Graphics.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
+ * 
+ * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
+ * OF THIS SOFTWARE.
+ */
+
+#include <X11/Xfuncproto.h>
+#include "lbximage.h"
+
+/*
+ * -------------------------------------------------------------------------
+ *              PackBits encoding for 8 bit color images
+ * -------------------------------------------------------------------------
+ */
+
+#define PutByte(byte,bufptr,bytesLeft) \
+{ \
+    if (*bytesLeft < 1) {\
+         *outbuf = outptr; \
+         return (0); \
+    } \
+    *bufptr++ = byte; \
+    (*bytesLeft)--; \
+}
+    
+
+static int
+EncodePackBits (inbuf, numPixels, outbuf, bytesLeft)
+
+char *inbuf;
+int numPixels;
+char **outbuf;
+int *bytesLeft;
+
+{
+    register int pixelsLeft = numPixels;
+    register char *outptr = *outbuf;
+    register char *lastliteral;
+    register int n, b;
+    enum { BASE, LITERAL, RUN, LITERAL_RUN } state;
+
+    state = BASE;
+    lastliteral = 0;
+
+    while (pixelsLeft > 0)
+    {
+	/*
+	 * Find the longest string of identical bytes.
+	 */
+
+	b = *inbuf++, pixelsLeft--, n = 1;
+	for (; pixelsLeft > 0 && b == *inbuf; pixelsLeft--, inbuf++)
+	    n++;
+
+    again:
+
+	switch (state)
+	{
+	case BASE:		/* initial state, set run/literal */
+	    if (n > 1)
+	    {
+		state = RUN;
+
+		if (n > 128)
+		{
+		    PutByte (-127, outptr, bytesLeft);
+		    PutByte (b, outptr, bytesLeft);
+		    n -= 128;
+		    goto again;
+		}
+
+		PutByte (-(n-1), outptr, bytesLeft);
+		PutByte (b, outptr, bytesLeft);
+	    }
+	    else
+	    {
+		lastliteral = outptr;
+		PutByte (0, outptr, bytesLeft);
+		PutByte (b, outptr, bytesLeft);
+		state = LITERAL;
+	    }
+
+	    break;
+
+	case LITERAL:		/* last object was literal string */
+	    if (n > 1)
+	    {
+		state = LITERAL_RUN;
+
+		if (n > 128)
+		{
+		    PutByte (-127, outptr, bytesLeft);
+		    PutByte (b, outptr, bytesLeft);
+		    n -= 128;
+		    goto again;
+		}
+
+		    PutByte (-(n-1), outptr, bytesLeft); /* encode run */
+		    PutByte (b, outptr, bytesLeft);
+	    }
+	    else
+	    {			/* extend literal */
+		if (++(*lastliteral) == 127)
+		    state = BASE;
+		PutByte (b, outptr, bytesLeft);
+	    }
+
+	    break;
+
+	case RUN:		/* last object was run */
+	    if (n > 1)
+	    {
+		if (n > 128)
+		{
+		    PutByte (-127, outptr, bytesLeft);
+		    PutByte (b, outptr, bytesLeft);
+		    n -= 128;
+		    goto again;
+		}
+		PutByte (-(n-1), outptr, bytesLeft);
+		PutByte (b, outptr, bytesLeft);
+	    }
+	    else
+	    {
+		lastliteral = outptr;
+		PutByte (0, outptr, bytesLeft);
+		PutByte (b, outptr, bytesLeft);
+		state = LITERAL;
+	    }
+
+	    break;
+
+	case LITERAL_RUN:	/* literal followed by a run */
+	    /*
+	     * Check to see if previous run should
+	     * be converted to a literal, in which
+	     * case we convert literal-run-literal
+	     * to a single literal.
+	     */
+
+	    if (n == 1 && outptr[-2] == (char)-1 && *lastliteral < 126)
+	    {
+		state = (((*lastliteral) += 2) == 127 ? BASE : LITERAL);
+		outptr[-2] = outptr[-1];	/* replicate */
+	    }
+	    else
+		state = RUN;
+	    goto again;
+	}
+    }
+
+    *outbuf = outptr;
+
+    return (1);
+}
+
+
+int
+LbxImageEncodePackBits (inbuf, outbuf, outbufSize, format, depth,
+    num_scan_lines, scan_line_size, bytesCompressed)
+
+char *inbuf;
+char *outbuf;
+int outbufSize;
+int format;
+int depth;
+int num_scan_lines;
+int scan_line_size;
+int *bytesCompressed;
+
+{
+    char *outbuf_start = outbuf;
+    int padded_scan_line_size = (scan_line_size % 4) ?
+	scan_line_size + (4 - scan_line_size % 4) : scan_line_size;
+    int bytesLeft = outbufSize;
+
+    while (num_scan_lines > 0)
+    {
+	if (!EncodePackBits (inbuf, scan_line_size, &outbuf, &bytesLeft))
+	    return (LBX_IMAGE_COMPRESS_NOT_WORTH_IT);
+
+	inbuf += padded_scan_line_size;
+	num_scan_lines--;
+    }
+
+    *bytesCompressed = outbuf - outbuf_start;
+    return (LBX_IMAGE_COMPRESS_SUCCESS);
+}