Mesh screen ratio as static

Author: clementlandrin

h3d/scene/Mesh.hx

@@ -89,23 +89,7 @@ class Mesh extends Object {
 			return;
 		}
 
-		var absPos = getAbsPos();
-		var worldCenter = absPos.getPosition();
-		var worldScale = absPos.getScale();
-		var worldRadius = bounds.dimension() * hxd.Math.max( worldScale.x, hxd.Math.max(worldScale.y, worldScale.z) ) / 2.0;
-
-		var cameraRight = ctx.camera.getRight();
-		var cameraUp = ctx.camera.getUp();
-		var cameraTopLeft = (cameraUp - cameraRight).normalized();
-		var worldTopLeft = worldCenter + cameraTopLeft * worldRadius;
-		var worldBottomRight = worldCenter - cameraTopLeft * worldRadius;
-
-		var screenTopLeft = ctx.camera.projectInline( worldTopLeft.x, worldTopLeft.y, worldTopLeft.z, 1.0, 1.0, false );
-		var screenBottomRight = ctx.camera.projectInline( worldBottomRight.x, worldBottomRight.y, worldBottomRight.z, 1.0, 1.0, false );
-
-		var screenArea = hxd.Math.max( screenBottomRight.x - screenTopLeft.x, screenBottomRight.y - screenTopLeft.y );
-
-		curScreenRatio = screenArea * screenArea;
+		curScreenRatio = screenRatio(getAbsPos(), bounds, ctx.camera);
 
 		if ( inheritLod )
 			ctx.forcedScreenRatio = curScreenRatio;
@@ -148,4 +132,22 @@ class Mesh extends Object {
 		return this.primitive = prim;
 	}
 
+	public static function screenRatio(absPos : h3d.Matrix, bounds : h3d.col.Bounds, camera : h3d.Camera) {
+		var worldCenter = absPos.getPosition();
+		var worldScale = absPos.getScale();
+		var worldRadius = bounds.dimension() * hxd.Math.max( worldScale.x, hxd.Math.max(worldScale.y, worldScale.z) ) / 2.0;
+
+		var cameraRight = camera.getRight();
+		var cameraUp = camera.getUp();
+		var cameraTopLeft = (cameraUp - cameraRight).normalized();
+		var worldTopLeft = worldCenter + cameraTopLeft * worldRadius;
+		var worldBottomRight = worldCenter - cameraTopLeft * worldRadius;
+
+		var screenTopLeft = camera.projectInline( worldTopLeft.x, worldTopLeft.y, worldTopLeft.z, 1.0, 1.0, false );
+		var screenBottomRight = camera.projectInline( worldBottomRight.x, worldBottomRight.y, worldBottomRight.z, 1.0, 1.0, false );
+
+		var screenArea = hxd.Math.max( screenBottomRight.x - screenTopLeft.x, screenBottomRight.y - screenTopLeft.y );
+
+		return screenArea * screenArea;
+	}
 }