add length

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.25)
 include(FetchContent)
 
-set(BLT_GRAPHICS_VERSION 2.0.1)
+set(BLT_GRAPHICS_VERSION 2.0.2)
 set(BLT_GRAPHICS_TEST_VERSION 0.0.1)
 
 project(BLT_WITH_GRAPHICS VERSION ${BLT_GRAPHICS_VERSION})

include/blt/gfx/renderer/batch_2d_renderer.h

@@ -102,12 +102,13 @@ namespace blt::gfx
 			return *this;
 		}
 
+		[[nodiscard]] f32 length() const;
+
 		std::vector<line2d_t> lines;
 	};
 
 	struct curve2d_t
 	{
-	public:
 		curve2d_t(vec2 p0, vec2 p1, vec2 p2);
 		curve2d_t(vec2 p0, vec2 p1, vec2 p2, vec2 p3);
 
@@ -117,6 +118,10 @@ namespace blt::gfx
 
 		[[nodiscard]] curve2d_mesh_data_t to_mesh(i32 segments, f32 thickness = 1.0) const;
 
+		[[nodiscard]] f32 length(i32 segments) const;
+
+		[[nodiscard]] f32 length_fast() const;
+
 		vec2 m_p0, m_p1, m_p2, m_p3;
 	};
 

src/blt/gfx/renderer/batch_2d_renderer.cpp

@@ -116,6 +116,14 @@ namespace blt::gfx
 		return vertices;
 	}
 
+	f32 curve2d_mesh_data_t::length() const
+	{
+		f32 length = 0;
+		for (const auto& line : lines)
+			length += (line.p2 - line.p1).magnitude();
+		return length;
+	}
+
 	curve2d_t::curve2d_t(const vec2 p0, const vec2 p1, const vec2 p2): m_p0(p0), m_p1(p1), m_p2(p1), m_p3(p2)
 	{}
 
@@ -157,6 +165,31 @@ namespace blt::gfx
 		return mesh_data;
 	}
 
+	f32 curve2d_t::length(const i32 segments) const
+	{
+		f32 length = 0;
+		float t = 0;
+		const float diff = 1.0f / static_cast<float>(segments);
+
+		for (i32 i = 0; i < segments; ++i)
+		{
+			auto begin = get_point(t);
+			t += diff;
+			auto end = get_point(t);
+
+			length += (end - begin).magnitude();
+		}
+		return length;
+	}
+
+	f32 curve2d_t::length_fast() const
+	{
+		const auto d1 = (m_p1 - m_p0).magnitude();
+		const auto d2 = (m_p2 - m_p1).magnitude();
+		const auto d3 = (m_p3 - m_p2).magnitude();
+		return d1 + d2 + d3;
+	}
+
 	void batch_renderer_2d::create()
 	{
 		{