Add SoundData:getSampleCount() function

Adds SoundData:getSampleCount(), calculates how many samples there are
in this particular SoundData. resolves #578

--HG--
branch : sounddata-samplecount

src/modules/sound/SoundData.cpp

@@ -147,6 +147,11 @@ int SoundData::getSampleRate() const
 	return sampleRate;
 }
 
+int SoundData::getSampleCount() const
+{
+	return (size/channels)/(bits/8);
+}
+
 int SoundData::getDuration() const
 {
 	return size/(channels*sampleRate*bits/8);

src/modules/sound/SoundData.h

@@ -48,6 +48,7 @@ public:
 	virtual int getChannels() const;
 	virtual int getBits() const;
 	virtual int getSampleRate() const;
+	virtual int getSampleCount() const;
 
 	virtual int getDuration() const;
 

src/modules/sound/wrap_SoundData.cpp

@@ -53,6 +53,13 @@ int w_SoundData_getSampleRate(lua_State *L)
 	return 1;
 }
 
+int w_SoundData_getSampleCount(lua_State *L)
+{
+	SoundData *t = luax_checksounddata(L, 1);
+	lua_pushinteger(L, t->getSampleCount());
+	return 1;
+}
+
 int w_SoundData_getDuration(lua_State *L)
 {
 	SoundData *t = luax_checksounddata(L, 1);
@@ -87,6 +94,7 @@ static const luaL_Reg functions[] =
 	{ "getChannels", w_SoundData_getChannels },
 	{ "getBits", w_SoundData_getBits },
 	{ "getSampleRate", w_SoundData_getSampleRate },
+	{ "getSampleCount", w_SoundData_getSampleCount },
 	{ "getDuration", w_SoundData_getDuration },
 	{ "setSample", w_SoundData_setSample },
 	{ "getSample", w_SoundData_getSample },

src/modules/sound/wrap_SoundData.h

@@ -36,6 +36,7 @@ int w_getSize(lua_State *L);
 int w_getChannels(lua_State *L);
 int w_getBits(lua_State *L);
 int w_getSampleRate(lua_State *L);
+int w_getSampleCount(lua_State *L);
 int w_getDuration(lua_State *L);
 int w_setSample(lua_State *L);
 int w_getSample(lua_State *L);