Initial import of the CDE 2.1.30 sources from the Open Group.

cde/lib/DtHelp/il/ilcompress.c

@@ -0,0 +1,114 @@
+/* $XConsortium: ilcompress.c /main/3 1995/10/23 15:42:52 rswiston $ */
+/**---------------------------------------------------------------------
+***	
+***    (c)Copyright 1991 Hewlett-Packard Co.
+***    
+***                             RESTRICTED RIGHTS LEGEND
+***    Use, duplication, or disclosure by the U.S. Government is subject to
+***    restrictions as set forth in sub-paragraph (c)(1)(ii) of the Rights in
+***    Technical Data and Computer Software clause in DFARS 252.227-7013.
+***                             Hewlett-Packard Company
+***                             3000 Hanover Street
+***                             Palo Alto, CA 94304 U.S.A.
+***    Rights for non-DOD U.S. Government Departments and Agencies are as set
+***    forth in FAR 52.227-19(c)(1,2).
+***
+***-------------------------------------------------------------------*/
+
+#include "ilint.h"
+#include "ilpipelem.h"
+#include "ilcompress.h"
+#include "ilcodec.h"
+#include "ilerrors.h"
+
+
+    /*  --------------------------- ilCompress ----------------------------------- */
+    /*  Public function; see spec.
+        Forces pipe data to be compressed with the given "compression", in constant
+        strips. If "dstStripHeight" is zero (0), then any stripHeight is allowable,
+        but if compression is done, it is done with the default strip height.
+    */
+ilBool ilCompress (
+    ilPipe              pipe,
+    unsigned int        compression,
+    ilPtr               pCompData,
+    long                dstStripHeight,
+    unsigned long       mustBeZero
+    )
+{
+    unsigned int        state;
+    ilPipeInfo          info;                              
+    ilImageDes          des;
+    ilImageFormat       format;
+    ilSrcElementData    srcData;
+    ilBool              correct;
+     
+
+    if (ilGetPipeInfo (pipe, FALSE, &info, &des, &format) != IL_PIPE_FORMING)
+        if (!pipe->context->error)
+            return ilDeclarePipeInvalid (pipe, IL_ERROR_PIPE_STATE);
+
+    if (mustBeZero != 0)
+        return ilDeclarePipeInvalid(pipe, IL_ERROR_PAR_NOT_ZERO);
+
+        /*  Force requested strip height to image height if greater. */
+    if (dstStripHeight > info.height)
+        dstStripHeight = info.height;
+
+        /*  Check current pipe image and force decompression if wrong compression, or 
+            inconstant strip height, or not requested (non-zero) strip height.
+        */
+    if ((des.compression != compression)
+     || (dstStripHeight && (info.stripHeight != dstStripHeight))
+     || !info.constantStrip)
+        ilGetPipeInfo (pipe, TRUE, &info, &des, &format);       /* decompress */
+
+        /*  Specify the input (and therefore the output) strip height: if dstStripHeight
+            is zero, take default, otherwise requested, always  constant strips.
+        */
+    if (dstStripHeight <= 0)
+        dstStripHeight = ilRecommendedStripHeight (&des, &format, info.width, info.height);
+    srcData.consumerImage = (ilObject)NULL;
+    srcData.minBufferHeight = 0;
+    srcData.stripHeight = dstStripHeight;
+    srcData.constantStrip = TRUE;
+ 
+        /*  Pipe image is now correct compression or is uncompressed.  For compression
+            types which have no variants, exit if already requested compression; for
+            types with variant, call compression-specific code to check variant.
+        */
+    switch (compression) {
+
+      case IL_UNCOMPRESSED:                     /* image now uncompressed; skip */
+        break;
+
+      case IL_G3:                               /* check G3 variants */
+        return _ilCompressG3 (pipe, &info, &des, &format, &srcData, pCompData);
+        break;
+
+      case IL_JPEG:                             /* check JPEG variants */
+        return _ilCompressJPEG (pipe, &info, &des, &format, &srcData, pCompData);
+        break;
+
+      case IL_G4:                               /* check G4 variants */
+        return _ilCompressG4 (pipe, &info, &des, &format, &srcData, pCompData);
+        break;
+
+      case IL_LZW:
+        if (des.compression != IL_LZW)
+            return _ilCompressLZW (pipe, &info, &des, &format, &srcData);
+        break;
+
+      case IL_PACKBITS:   
+        if (des.compression != IL_PACKBITS)
+            return _ilCompressPackbits (pipe, &info, &des, &format, &srcData);
+        break;
+
+      default:
+        return ilDeclarePipeInvalid (pipe, IL_ERROR_COMPRESSION);
+    }
+
+        /*  No (re)compression needed; exit with success */
+    pipe->context->error = IL_OK;
+    return TRUE;
+}