Smooth lines now draw the entire line in 1 OpenGL draw call, rather than 2.

src/modules/graphics/opengl/Polyline.h

@@ -46,12 +46,14 @@ class Polyline
 {
 public:
 	Polyline(GLenum mode = GL_TRIANGLE_STRIP, bool quadindices = false)
-		: vertices(NULL)
-		, overdraw(NULL)
+		: vertices(nullptr)
+		, overdraw(nullptr)
 		, vertex_count(0)
 		, overdraw_vertex_count(0)
 		, draw_mode(mode)
 		, use_quad_indices(quadindices)
+		, vertex_start(0)
+		, overdraw_vertex_start(0)
 	{}
 	virtual ~Polyline();
 
@@ -70,6 +72,7 @@ public:
 	void draw();
 
 protected:
+	virtual void calc_overdraw_vertex_count(bool is_looping);
 	virtual void render_overdraw(const std::vector<Vector> &normals, float pixel_size, bool is_looping);
 	virtual void fill_color_array(Color *colors);
 
@@ -94,6 +97,8 @@ protected:
 	size_t overdraw_vertex_count;
 	GLenum draw_mode;
 	bool use_quad_indices;
+	size_t vertex_start;
+	size_t overdraw_vertex_start;
 
 }; // Polyline
 
@@ -112,13 +117,13 @@ public:
 	void render(const float *vertices, size_t count, float halfwidth, float pixel_size, bool draw_overdraw)
 	{
 		Polyline::render(vertices, count, 2 * count - 4, halfwidth, pixel_size, draw_overdraw);
-		// discard the first and last two vertices. (these are redundant)
-		for (size_t i = 0; i < vertex_count - 2; ++i)
-			this->vertices[i] = this->vertices[i+2];
+		// discard the first two vertices. (these are redundant)
+		vertex_start = 2;
 		vertex_count -= 2;
 	}
 
 protected:
+	virtual void calc_overdraw_vertex_count(bool is_looping);
 	virtual void render_overdraw(const std::vector<Vector> &normals, float pixel_size, bool is_looping);
 	virtual void fill_color_array(Color *colors);
 	virtual void renderEdge(std::vector<Vector> &anchors, std::vector<Vector> &normals,