diff --git a/engine/include/GearSrc/Log.h b/engine/include/GearSrc/Log.h
index ab2e505..6ed098b 100644
--- a/engine/include/GearSrc/Log.h
+++ b/engine/include/GearSrc/Log.h
@@ -15,7 +15,7 @@ enum GSLogLevel {
 	GSLogDebug
 };
 
-GSDECL void GSLog(int level, const char* fmt, ...);
+GSDECL void GSLog(GSEngine engine, int level, const char* fmt, ...);
 
 #ifdef __cplusplus
 }
diff --git a/engine/include/GearSrc/Math.h b/engine/include/GearSrc/Math.h
index 65c7b9a..3c7d834 100644
--- a/engine/include/GearSrc/Math.h
+++ b/engine/include/GearSrc/Math.h
@@ -11,6 +11,7 @@ extern "C" {
 #define GSMathPi 3.14159265358979323846
 
 GSDECL void	GSMathCross3(GSVector3 r, GSVector3 v0, GSVector3 v1);
+GSDECL GSNumber GSMathInner3(GSVector3 v0, GSVector3 v1);
 GSDECL void	GSMathNormalize3(GSVector3 vec);
 GSDECL void	GSMathSubtract3(GSVector3 r, GSVector3 v0, GSVector3 v1);
 GSDECL void	GSMathAdd3(GSVector3 r, GSVector3 v0, GSVector3 v1);
diff --git a/engine/include/GearSrc/TypeDefs.h b/engine/include/GearSrc/TypeDefs.h
index 072e3e8..f7ea5f1 100644
--- a/engine/include/GearSrc/TypeDefs.h
+++ b/engine/include/GearSrc/TypeDefs.h
@@ -202,6 +202,8 @@ struct _GSFile {
 };
 
 struct _GSResource {
+	GSEngine engine;
+
 	GSFile file;
 };
 #endif
diff --git a/engine/src/client.c b/engine/src/client.c
index 7955b00..a1fd595 100644
--- a/engine/src/client.c
+++ b/engine/src/client.c
@@ -68,7 +68,7 @@ GSClient GSClientCreate(GSEngine engine) {
 		}
 	}
 
-	GSLog(GSLogInfo, "Created client");
+	GSLog(engine, GSLogInfo, "Created client");
 
 	return client;
 }
@@ -79,9 +79,9 @@ void GSClientDestroy(GSClient client) {
 
 	GSGLDestroy(client->gl);
 
-	free(client);
+	GSLog(client->engine, GSLogInfo, "Destroyed client");
 
-	GSLog(GSLogInfo, "Destroyed client");
+	free(client);
 }
 
 static void scene(GSClient client) {
diff --git a/engine/src/core.c b/engine/src/core.c
index 6138657..7cc1718 100644
--- a/engine/src/core.c
+++ b/engine/src/core.c
@@ -14,7 +14,7 @@ void GSInit(void) {
 
 	GSVersionGet(&version);
 
-	GSLog(GSLogInfo, "GearSrc Engine %s", version.string);
+	GSLog(NULL, GSLogInfo, "GearSrc Engine %s", version.string);
 }
 
 GSBool GSEngineRegisterResource(GSEngine engine, const char* name, const char* path) {
@@ -22,7 +22,7 @@ GSBool GSEngineRegisterResource(GSEngine engine, const char* name, const char* p
 	if((resource = GSResourceOpen(engine, path)) != NULL) {
 		shput(engine->resource, name, resource);
 
-		GSLog(GSLogInfo, "Registered resource %s as %s", path, name);
+		GSLog(engine, GSLogInfo, "Registered resource %s as %s", path, name);
 
 		return GSTrue;
 	}
@@ -36,7 +36,7 @@ void GSEngineUnregisterResource(GSEngine engine, const char* name) {
 	if(ind != -1) {
 		GSResourceClose(engine->resource[ind].value);
 
-		GSLog(GSLogInfo, "Unregistered resource %s", name);
+		GSLog(engine, GSLogInfo, "Unregistered resource %s", name);
 
 		shdel(engine->resource, name);
 	}
@@ -65,7 +65,7 @@ GSEngine GSEngineCreate(GSEngineParam* param) {
 	GSEngineRegisterResource(engine, "game", "game.gsp");
 
 	if(engine != NULL && param->client && (engine->client = GSClientCreate(engine)) == NULL) {
-		GSLog(GSLogError, "Failed to create client");
+		GSLog(engine, GSLogError, "Failed to create client");
 
 		GSEngineDestroy(engine);
 
@@ -73,7 +73,7 @@ GSEngine GSEngineCreate(GSEngineParam* param) {
 	}
 
 	if(engine != NULL && param->server && (engine->server = GSServerCreate(engine)) == NULL) {
-		GSLog(GSLogError, "Failed to create server");
+		GSLog(engine, GSLogError, "Failed to create server");
 
 		GSEngineDestroy(engine);
 
@@ -81,7 +81,7 @@ GSEngine GSEngineCreate(GSEngineParam* param) {
 	}
 
 	if(engine == NULL) {
-		GSLog(GSLogError, "Failed to create engine");
+		GSLog(engine, GSLogError, "Failed to create engine");
 	}
 
 	return engine;
@@ -121,8 +121,8 @@ void GSEngineLoop(GSEngine engine) {
 	long	 wait	       = 1000 / tps;
 
 	if(engine->param->sleep == NULL || engine->param->get_tick == NULL) {
-		GSLog(GSLogWarn, "sleep and/or get_tick parameter are missing!");
-		GSLog(GSLogWarn, "This will result game to be crazy fast!!!");
+		GSLog(engine, GSLogWarn, "sleep and/or get_tick parameter are missing!");
+		GSLog(engine, GSLogWarn, "This will result game to be crazy fast!!!");
 	} else {
 		t = engine->param->get_tick();
 
diff --git a/engine/src/file.c b/engine/src/file.c
index 2282f7d..a3c33ed 100644
--- a/engine/src/file.c
+++ b/engine/src/file.c
@@ -20,7 +20,7 @@ GSFile GSFileOpen(GSEngine engine, const char* path) {
 		file->size = ftell(file->fp);
 		fseek(file->fp, 0, SEEK_SET);
 
-		GSLog(GSLogInfo, "Opened %s", path);
+		GSLog(engine, GSLogInfo, "Opened %s", path);
 
 		return file;
 	}
@@ -37,7 +37,7 @@ GSFile GSFileOpen(GSEngine engine, const char* path) {
 				if((file->data = GSResourceGet(engine->resource[i].value, nam, &file->size)) != NULL) {
 					free(s);
 
-					GSLog(GSLogInfo, "Opened %s", path);
+					GSLog(engine, GSLogInfo, "Opened %s", path);
 					return file;
 				}
 				break;
@@ -46,7 +46,7 @@ GSFile GSFileOpen(GSEngine engine, const char* path) {
 	}
 	free(s);
 
-	GSLog(GSLogError, "Could not open %s", path);
+	GSLog(engine, GSLogError, "Could not open %s", path);
 	GSFileClose(file);
 	return NULL;
 }
diff --git a/engine/src/gl_shader.c b/engine/src/gl_shader.c
index b7a0783..594c3b0 100644
--- a/engine/src/gl_shader.c
+++ b/engine/src/gl_shader.c
@@ -3,7 +3,7 @@
 #include <GearSrc/File.h>
 #include <GearSrc/Log.h>
 
-static void err(const char* path, GLuint shader) {
+static void err(GSEngine engine, const char* path, GLuint shader) {
 	GLint len, ret;
 	char* e;
 
@@ -14,7 +14,7 @@ static void err(const char* path, GLuint shader) {
 
 	glGetShaderInfoLog(shader, len, &ret, e);
 
-	GSLog(GSLogError, "%s: %s\n", path, e);
+	GSLog(engine, GSLogError, "%s: %s\n", path, e);
 
 	free(e);
 }
@@ -66,7 +66,7 @@ GSBool GSGLShaderPrepare(GSGL gl, GLuint* shader, const char* vs, const char* fs
 	glCompileShader(vsi);
 	glGetShaderiv(vsi, GL_COMPILE_STATUS, &st);
 	if(!st) {
-		err(vs, vsi);
+		err(gl->engine, vs, vsi);
 
 		glDeleteShader(vsi);
 		glDeleteShader(fsi);
@@ -78,7 +78,7 @@ GSBool GSGLShaderPrepare(GSGL gl, GLuint* shader, const char* vs, const char* fs
 	glCompileShader(fsi);
 	glGetShaderiv(fsi, GL_COMPILE_STATUS, &st);
 	if(!st) {
-		err(fs, fsi);
+		err(gl->engine, fs, fsi);
 
 		glDeleteShader(vsi);
 		glDeleteShader(fsi);
diff --git a/engine/src/log.c b/engine/src/log.c
index 8e9fab4..a90d7fd 100644
--- a/engine/src/log.c
+++ b/engine/src/log.c
@@ -1,6 +1,6 @@
 #include <GearSrc/Log.h>
 
-void GSLog(int level, const char* fmt, ...) {
+void GSLog(GSEngine engine, int level, const char* fmt, ...) {
 	va_list va;
 	FILE*	out = stdout;
 
diff --git a/engine/src/math.c b/engine/src/math.c
index dcc606e..a26b894 100644
--- a/engine/src/math.c
+++ b/engine/src/math.c
@@ -6,6 +6,15 @@ void GSMathCross3(GSVector3 r, GSVector3 v0, GSVector3 v1) {
 	r[2] = v0[0] * v1[1] - v0[1] * v1[0];
 }
 
+GSNumber GSMathInner3(GSVector3 v0, GSVector3 v1) {
+	GSNumber r = 0;
+	int	 i;
+
+	for(i = 0; i < 3; i++) r += v0[i] * v1[i];
+
+	return r;
+}
+
 void GSMathNormalize3(GSVector3 vec) {
 	GSNumber l = 0;
 	int	 i;
diff --git a/engine/src/model.c b/engine/src/model.c
index 2037981..624b1a2 100644
--- a/engine/src/model.c
+++ b/engine/src/model.c
@@ -270,7 +270,7 @@ GSModel GSModelOpen(GSEngine engine, const char* path) {
 
 	GSEngineUnregisterResource(engine, "model-ws");
 
-	GSLog(GSLogInfo, "Opened model %s, %d vertexes, %d faces", path, arrlen(model->vertex), arrlen(model->face));
+	GSLog(engine, GSLogInfo, "Opened model %s, %d vertexes, %d faces", path, arrlen(model->vertex), arrlen(model->face));
 
 	/* TODO: check for animation */
 	if(gl != NULL) {
diff --git a/engine/src/resource.c b/engine/src/resource.c
index dbaa1d3..ec6d4a6 100644
--- a/engine/src/resource.c
+++ b/engine/src/resource.c
@@ -39,6 +39,8 @@ GSResource GSResourceOpen(GSEngine engine, const char* path) {
 
 	memset(resource, 0, sizeof(*resource));
 
+	resource->engine = engine;
+
 	if((resource->file = GSFileOpen(engine, path)) == NULL) {
 		GSResourceClose(resource);
 		return NULL;
@@ -50,7 +52,7 @@ GSResource GSResourceOpen(GSEngine engine, const char* path) {
 	}
 
 	if(memcmp(sig, res_sig, 4) != 0) {
-		GSLog(GSLogError, "%s: Resource has wrong signature", path);
+		GSLog(engine, GSLogError, "%s: Resource has wrong signature", path);
 		GSResourceClose(resource);
 		return NULL;
 	}
@@ -58,7 +60,7 @@ GSResource GSResourceOpen(GSEngine engine, const char* path) {
 	return resource;
 }
 
-int find_entry(GSFile f, const char* name, int max, GSU32* totsz, GSU32* actsz, GSU32* cmpsz, GSU32* seekpos) {
+int find_entry(GSEngine engine, GSFile f, const char* name, int max, GSU32* totsz, GSU32* actsz, GSU32* cmpsz, GSU32* seekpos) {
 	GSU32 crc = GSEndianSwapU32BE(GSCRC32((void*)name, strlen(name)));
 	int   i;
 
@@ -101,7 +103,7 @@ int find_entry(GSFile f, const char* name, int max, GSU32* totsz, GSU32* actsz,
 			if(totsz != NULL) *totsz = tsz;
 
 			if(crc == t && strcmp(fn, name) == 0) {
-				GSLog(GSLogDebug, "Directory %s/ found", fn);
+				GSLog(engine, GSLogDebug, "Directory %s/ found", fn);
 				free(fn);
 				return n;
 			}
@@ -128,7 +130,7 @@ int find_entry(GSFile f, const char* name, int max, GSU32* totsz, GSU32* actsz,
 			*seekpos = GSEndianSwapU32BE(*seekpos);
 
 			if(crc == t && strcmp(fn, name) == 0) {
-				GSLog(GSLogDebug, "File %s found", fn);
+				GSLog(engine, GSLogDebug, "File %s found", fn);
 				free(fn);
 				return -2;
 			}
@@ -158,7 +160,7 @@ void* GSResourceGet(GSResource resource, const char* name, unsigned int* size) {
 
 		if(s != NULL) s[0] = 0;
 
-		m = find_entry(resource->file, f, m, strlen(f) == 0 ? &totsz : NULL, &actsz, &cmpsz, &seekpos);
+		m = find_entry(resource->engine, resource->file, f, m, strlen(f) == 0 ? &totsz : NULL, &actsz, &cmpsz, &seekpos);
 		if(m == -1) break;
 		if(m == -2) {
 			unsigned char* cmp = malloc(cmpsz);
diff --git a/engine/src/server.c b/engine/src/server.c
index e69ead1..96d1a2d 100644
--- a/engine/src/server.c
+++ b/engine/src/server.c
@@ -9,15 +9,15 @@ GSServer GSServerCreate(GSEngine engine) {
 
 	server->engine = engine;
 
-	GSLog(GSLogInfo, "Created server");
+	GSLog(engine, GSLogInfo, "Created server");
 
 	return server;
 }
 
 void GSServerDestroy(GSServer server) {
-	free(server);
+	GSLog(server->engine, GSLogInfo, "Destroyed server");
 
-	GSLog(GSLogInfo, "Destroyed server");
+	free(server);
 }
 
 void GSServerStep(GSServer server) {