Move some functions from gl_draw to half_edge

find_center() and get_normalized_scale_factor()
are not really related to drawing in it's own, but are
operation related to the HE_* structures

src/gl_draw.c

@@ -61,74 +61,8 @@ static void draw_obj(uint32_t xrot, uint32_t yrot, uint32_t zrot);
 static void draw_Planet_1(void);
 static void draw_Planet_2(void);
 static void gl_destroy(void);
-static HE_vert *find_center(HE_obj const * const obj);
-static float get_normalized_scale_factor(HE_obj const * const obj);
 
 
-/**
- * Calculates the factor that can be used to scaled down the object
- * to the size of 1.
- *
- * @param obj the object we want to scale
- * @return the corresponding scale factor
- */
-static float get_normalized_scale_factor(HE_obj const * const obj)
-{
-	float max = obj->vertices[0].x +
-		obj->vertices[0].y + obj->vertices[0].z;
-	float min = obj->vertices[0].x +
-		obj->vertices[0].y + obj->vertices[0].z;
-
-	uint32_t i;
-
-	for (i = 0; i < obj->vc; i++) {
-		if ((obj->vertices[i].x +
-				obj->vertices[i].y +
-				obj->vertices[i].z) > max)
-			max = obj->vertices[i].x +
-				obj->vertices[i].y +
-				obj->vertices[i].z;
-		else if ((obj->vertices[i].x +
-				obj->vertices[i].y +
-				obj->vertices[i].z) < min)
-			min = obj->vertices[i].x +
-				obj->vertices[i].y +
-				obj->vertices[i].z;
-	}
-
-	return 1 / (max - min);
-}
-
-/**
- * Find the center of an object and store the coordinates
- * in a HE_vert struct.
- *
- * @param obj the object we want to find the center of
- * @return newly allocated HE_vert with empty edge member
- * and coordinates which represent the middle of the object
- */
-static HE_vert *find_center(HE_obj const * const obj)
-{
-	float x = 0,
-		  y = 0,
-		  z = 0;
-	uint32_t i;
-	HE_vert *newvert = malloc(sizeof(HE_vert));
-
-	for (i = 0; i < obj->vc; i++) {
-		x += obj->vertices[i].x;
-		y += obj->vertices[i].y;
-		z += obj->vertices[i].z;
-	}
-
-	newvert->x = x / i;
-	newvert->y = y / i;
-	newvert->z = z / i;
-	newvert->edge = NULL;
-
-	return newvert;
-}
-
 /**
  * Call glVertex3f on all of the vertices of the object,
  * in appropriate order.

src/half_edge.c

@@ -45,6 +45,70 @@ HE_edge **get_all_emanating_edges(HE_vert *vertice)
 	return NULL;
 }
 
+/**
+ * Find the center of an object and store the coordinates
+ * in a HE_vert struct.
+ *
+ * @param obj the object we want to find the center of
+ * @return newly allocated HE_vert with empty edge member
+ * and coordinates which represent the middle of the object
+ */
+HE_vert *find_center(HE_obj const * const obj)
+{
+	float x = 0,
+		  y = 0,
+		  z = 0;
+	uint32_t i;
+	HE_vert *newvert = malloc(sizeof(HE_vert));
+
+	for (i = 0; i < obj->vc; i++) {
+		x += obj->vertices[i].x;
+		y += obj->vertices[i].y;
+		z += obj->vertices[i].z;
+	}
+
+	newvert->x = x / i;
+	newvert->y = y / i;
+	newvert->z = z / i;
+	newvert->edge = NULL;
+
+	return newvert;
+}
+
+/**
+ * Calculates the factor that can be used to scaled down the object
+ * to the size of 1.
+ *
+ * @param obj the object we want to scale
+ * @return the corresponding scale factor
+ */
+float get_normalized_scale_factor(HE_obj const * const obj)
+{
+	float max = obj->vertices[0].x +
+		obj->vertices[0].y + obj->vertices[0].z;
+	float min = obj->vertices[0].x +
+		obj->vertices[0].y + obj->vertices[0].z;
+
+	uint32_t i;
+
+	for (i = 0; i < obj->vc; i++) {
+		if ((obj->vertices[i].x +
+				obj->vertices[i].y +
+				obj->vertices[i].z) > max)
+			max = obj->vertices[i].x +
+				obj->vertices[i].y +
+				obj->vertices[i].z;
+		else if ((obj->vertices[i].x +
+				obj->vertices[i].y +
+				obj->vertices[i].z) < min)
+			min = obj->vertices[i].x +
+				obj->vertices[i].y +
+				obj->vertices[i].z;
+	}
+
+	return 1 / (max - min);
+}
+
 /**
  * Parse an .obj string and return a HE_obj
  * that represents the whole object.

src/half_edge.h

@@ -124,6 +124,8 @@ struct HE_obj {
 
 
 HE_edge **get_all_emanating_edges(HE_vert *vertice);
+HE_vert *find_center(HE_obj const * const obj);
+float get_normalized_scale_factor(HE_obj const * const obj);
 HE_obj *parse_obj(char const * const filename);