dmlib: tools/lib64gfx.c comparison

Cleanup the RLE decoder.

author	Matti Hamalainen <ccr@tnsp.org>
date	Fri, 11 May 2018 02:26:09 +0300
parents	7729fefe8e57
children	d883b4c1cf48

comparison

equal deleted inserted replaced

-:7729fefe8e57
+:f0232684857a
 const Uint8 rleMarker, const Uint8 rleMask1, const Uint8 rleMask2, const int rleType)
 {
 int res;
 if ((res = dmGrowBufAlloc(dst, BUF_SIZE_INITIAL, BUF_SIZE_GROW)) != DMERR_OK)
-{
-dmError(res,
-"Could not allocate RLE decoding buffer.\n");
 goto err;
-}
 // Perform RLE decode
 while (src < srcEnd)
 {
-Uint8 c = *src++;
+Uint8 data = *src++;
-int cnt = 1;
+int count = 1;
 switch (rleType)
 {
 case DM_RLE_MARKER:
-if (c == rleMarker)
+// A simple marker byte RLE variant: [Marker] [count] [data]
+if (data == rleMarker)
 {
 if (srcEnd - src < 2)
 {
 res = DMERR_INVALID_DATA;
 goto err;
 }
-cnt = *src++;
+count = *src++;
-c = *src++;
+data = *src++;
 }
 break;
 case DM_RLE_MASK:
-if ((c & rleMask1) == rleMarker)
+// Mask marker RLE: usually high bit(s) of byte mark RLE sequence
+// and the lower bits contain the count: [Mask + count] [data]
+if ((data & rleMask1) == rleMarker)
 {
 if (srcEnd - src < 1)
 {
 res = DMERR_INVALID_DATA;
 goto err;
 }
-// XXX TODO actually we probably want another mask here
+count = data & rleMask2;
-cnt = c & rleMask2;
+data = *src++;
-c = *src++;
 }
 break;
 }
-while (cnt--)
+while (count--)
 {
-if (!dmGrowBufPutU8(dst, c))
+if (!dmGrowBufPutU8(dst, data))
 {
 res = DMERR_MALLOC;
 goto err;
 }
 }
 }
-// Reallocate the memory
-if ((res = dmGrowBufResize(dst)) != DMERR_OK)
-goto err;
 res = DMERR_OK;
 err:
 return res;

Mercurial > hg > dmlib