added some comments, cleanup

svn-id: r4950

4 files changed, 47 insertions, 28 deletions

diff --git a/common/util.cpp b/common/util.cpp
index 86711866c9..cea9d3a8f0 100644
--- a/common/util.cpp
+++ b/common/util.cpp
@@ -21,9 +21,15 @@
 #include "stdafx.h"
 #include "util.h"
 
+//
 // 8-bit alpha blending routines
-int BlendCache[256][256];
+//
+static int BlendCache[256][256];
 
+//
+// Find the entry in the given palette which matches the color defined by
+// the tripel (r,b,g) most closely.
+//
 int RGBMatch(byte *palette, int r, int g, int b)
 {
 	int i, bestidx = 0, besterr = 0xFFFFFF;
@@ -45,6 +51,9 @@ int RGBMatch(byte *palette, int r, int g, int b)
 	return bestidx;
 }
 
+//
+// Blend two 8 bit colors into a third, all colors being defined by palette indices.
+//
 int Blend(int src, int dst, byte *palette)
 {
 	int r, g, b;
@@ -70,6 +79,9 @@ int Blend(int src, int dst, byte *palette)
 	return (BlendCache[dst][src] = RGBMatch(palette, r , g , b ));
 }
 
+//
+// Reset the blending cache
+//
 void ClearBlendCache(byte *palette, int weight)
 {
 	for (int i = 0; i < 256; i++)
@@ -80,9 +92,9 @@ void ClearBlendCache(byte *palette, int weight)
 }
 
 
-/*
- * Print hexdump of the data passed in, 8 bytes a row
- */
+//
+// Print hexdump of the data passed in, 8 bytes a row
+//
 void hexdump(const byte * data, int len)
 {
 	int i;
@@ -121,7 +133,12 @@ void hexdump(const byte * data, int len)
 	printf("|\n");
 }
 
-// Resource string length, supports special chars starting with FF
+//
+// Given a pointer to a Scumm resource, this function returns the length
+// of the (string) data in that resource. To do so it understands certain
+// special chars starting with FF. The reason for this function is that
+// sometimes resource data will contain 0 bytes, thus we can't just use strlen.
+//
 int resStrLen(const char *src)
 {
 	int num = 0;
diff --git a/scumm/actor.cpp b/scumm/actor.cpp
index 9790993403..6fad8ae9c1 100644
--- a/scumm/actor.cpp
+++ b/scumm/actor.cpp
@@ -258,7 +258,7 @@ int Actor::updateActorDirection(bool is_walking)
 	dir = remapDirection(newDirection, is_walking);
 	shouldInterpolate = (dir & 1024);
 	to = toSimpleDir(dirType, dir & 1023);
-	num = numSimpleDirDirections(dirType);
+	num = dirType ? 8 : 4;
 
 	if (shouldInterpolate) {
 		// Turn left or right, depending on which is shorter.
diff --git a/scumm/scumm.h b/scumm/scumm.h
index 4fa6b212c8..c547a8067d 100644
--- a/scumm/scumm.h
+++ b/scumm/scumm.h
@@ -1384,7 +1384,6 @@ int oldDirToNewDir(int dir);
 int normalizeAngle(int angle);
 int fromSimpleDir(int dirtype, int dir);
 int toSimpleDir(int dirtype, int dir);
-int numSimpleDirDirections(int dirType);
 
 
 #endif
diff --git a/scumm/scummvm.cpp b/scumm/scummvm.cpp
index 1aac72a417..499e9bab27 100644
--- a/scumm/scummvm.cpp
+++ b/scumm/scummvm.cpp
@@ -1143,15 +1143,9 @@ void Scumm::destroy()
 	free(_classData);
 }
 
-const int new_dir_table[4] = {
-	270,
-	90,
-	180,
-	0,
-};
-
-const int16 many_direction_tab[16] = {71, 109, 251, 289, -1, -1, -1, -1, 22, 72, 107, 157, 202, 252, 287, 337};
-
+//
+// Convert an old style direction to a new style one (angle),
+//
 int newDirToOldDir(int dir)
 {
 	if (dir >= 71 && dir <= 109)
@@ -1163,21 +1157,24 @@ int newDirToOldDir(int dir)
 	return 3;
 }
 
+//
+// Convert an new style (angle) direction to an old style one.
+//
 int oldDirToNewDir(int dir)
 {
+	const int new_dir_table[4] = { 270, 90, 180, 0 };
 	return new_dir_table[dir];
 }
 
-
-int numSimpleDirDirections(int dirType)
-{
-	return dirType ? 8 : 4;
-}
-
-
-/* Convert an angle to a simple direction */
+//
+// Convert an angle to a simple direction.
+//
 int toSimpleDir(int dirType, int dir)
 {
+	const int16 many_direction_tab[16] = {
+		71, 109, 251, 289,  -1,  -1,  -1,  -1,
+		22,  72, 107, 157, 202, 252, 287, 337
+	};
 	int num = dirType ? 8 : 4;
 	const int16 *dirtab = &many_direction_tab[dirType * 8];
 	for (int i = 1; i < num; i++, dirtab++) {
@@ -1188,16 +1185,22 @@ int toSimpleDir(int dirType, int dir)
 
 }
 
-/* Convert a simple direction to an angle */
+//
+// Convert a simple direction to an angle
+//
 int fromSimpleDir(int dirType, int dir)
 {
-	if (!dirType)
-		return dir * 90;
-	else
+	if (dirType)
 		return dir * 45;
+	else
+		return dir * 90;
 }
 
 
+//
+// Normalize the given angle - that means, ensure it is positive, and
+// change it to the closest multiple of 45 degree by abusing toSimpleDir.
+//
 int normalizeAngle(int angle)
 {
 	int temp;