Fixes lines not drawing if one point is outside the camera

src/engine/EngineContext.cpp

@@ -505,7 +505,7 @@ namespace fgl::engine
 
 		model->syncBuffers( command_buffer );
 
-		constexpr int val { 16 };
+		constexpr int val { 1 };
 
 		constexpr float x_offset { -( static_cast< float >( val ) * 30.0f ) / 2.0f };
 		constexpr float y_offset { -( static_cast< float >( val ) * 20.0f ) / 2.0f };

src/engine/debug/drawers.cpp

@@ -133,28 +133,33 @@ namespace fgl::engine::debug
 		inline void
 			drawLine( const LineSegment< CoordinateSpace::World > line, const glm::vec3 color, const float thickness )
 		{
-			const Coordinate< CoordinateSpace::Screen > start_screen { toScreenSpace( line.getPosition() ) };
-			const Coordinate< CoordinateSpace::Screen > end_screen { toScreenSpace( line.getEnd() ) };
+			Coordinate< CoordinateSpace::Screen > start_screen { toScreenSpace( line.getPosition() ) };
+			Coordinate< CoordinateSpace::Screen > end_screen { toScreenSpace( line.getEnd() ) };
 
-			if ( !inView( start_screen.vec() ) && !inView( end_screen.vec() ) ) return;
+			if ( isBehind( start_screen.vec() ) && isBehind( end_screen.vec() ) ) return;
 
+			const auto frustum { getDebugDrawingCamera().getFrustumBounds() };
+
+			if ( !frustum.intersects( line ) ) return;
+
+			//Check if either point is behind the camera
 			if ( isBehind( start_screen.vec() ) )
 			{
-				const auto frustum { getDebugDrawingCamera().getFrustumBounds() };
 				const auto new_line { line.flip() };
 
 				const auto new_point { frustum.intersection( new_line ) };
+
+				start_screen = toScreenSpace( new_point );
 			}
 			else if ( isBehind( end_screen.vec() ) )
-			{}
-			else
 			{
-				ImGui::GetBackgroundDrawList()->AddLine(
-					glmToImgui( start_screen ),
-					glmToImgui( end_screen ),
-					ImColor( color.x, color.y, color.z ),
-					thickness );
+				const auto new_point { frustum.intersection( line ) };
+
+				end_screen = toScreenSpace( new_point );
 			}
+
+			ImGui::GetBackgroundDrawList()->AddLine(
+				glmToImgui( start_screen ), glmToImgui( end_screen ), ImColor( color.x, color.y, color.z ), thickness );
 		}
 
 		void drawLine(

src/engine/primitives/Frustum.cpp

@@ -325,16 +325,24 @@ namespace fgl::engine
 		CoordinateSpace::World >::intersection( const Line< CoordinateSpace::World >& line ) const
 	{
 		Coordinate< CoordinateSpace::World > coordinate { line.getEnd() };
+		const float max_dist { signedDistance( line.getDirection(), coordinate, line.getPosition() ) };
 
 		//Test each. Whatever the line enters exists first is the point to return
 		auto testPlane = [ & ]( const Plane< CoordinateSpace::World >& plane )
 		{
-			const auto old_distance { signedDistance( line.getDirection(), coordinate, line.getPosition() ) };
+			const float old_distance { signedDistance( line.getDirection(), coordinate, line.getPosition() ) };
 			const auto intersection { line.intersection( plane ) };
+
+			if ( std::isnan( intersection.x ) || std::isnan( intersection.y ) || std::isnan( intersection.z ) ) return;
+
 			const auto intersection_distance {
 				signedDistance( line.getDirection(), intersection, line.getPosition() )
 			};
-			if ( old_distance < intersection_distance ) coordinate = intersection;
+
+			if ( intersection_distance < 0.0f ) return;
+			if ( intersection_distance > max_dist ) return;
+
+			if ( old_distance > intersection_distance ) coordinate = intersection;
 		};
 
 		testPlane( this->right );
@@ -344,6 +352,10 @@ namespace fgl::engine
 		testPlane( this->top );
 		testPlane( this->bottom );
 
+		const auto distance { signedDistance( line.getDirection(), coordinate, line.getPosition() ) };
+
+		assert( distance > 0.0f );
+
 		return coordinate;
 	}
 

src/engine/primitives/lines/LineSegment.hpp

@@ -47,6 +47,9 @@ namespace fgl::engine
 			return plane.isForward( start ) != plane.isForward( end );
 		}
 
+		template < typename T >
+		bool intersets( const T t ) const;
+
 		template < typename T >
 			requires is_plane< T >
 		Coordinate< CType > FGL_FLATTEN intersection( const T plane ) const

src/engine/primitives/points/Coordinate.hpp

@@ -85,4 +85,10 @@ namespace fgl::engine
 
 	static_assert( sizeof( glm::vec3 ) == sizeof( ModelCoordinate ) );
 
-} // namespace fgl::engine
+	template < fgl::engine::CoordinateSpace CType >
+	::std::ostream& operator<<( ::std::ostream& os, const fgl::engine::Coordinate< CType > coordinate )
+	{
+		return os << "(" << coordinate.x << ", " << coordinate.y << ", " << coordinate.z << ")";
+	}
+
+} // namespace fgl::engine