private static Vector2 RenderToTexture2D(string path, Shape shape, float pixelsPerUnit = 100)
{
// reset the shape's rotation
Quaternion oldRotation = shape.transform.rotation;
shape.transform.rotation = Quaternion.identity;
// get the bounds of our shape and all its children
Bounds bounds = shape.GetShapeBounds();
Vector2 size = shape.GetShapePixelSize(pixelsPerUnit: pixelsPerUnit);
int w = (int)size.x;
int h = (int)size.y;
// get all the shapes in draw order
List <Shape> shapes = shape.GetShapesInDrawOrder();
// if the shape is a UI component, we need to set up the canvas in a way
// that the camera can point to the image only without the UI
// components moving around based on the camera
Canvas canvas = shape.GetComponentInParent <Canvas>();
int oldCanvasLayer = -1;
RenderMode oldRenderMode = 0;
List <GraphicState> modifiedGraphics = null;
if (canvas)
{
oldCanvasLayer = canvas.gameObject.layer;
canvas.gameObject.layer = 31;
oldRenderMode = canvas.renderMode;
canvas.renderMode = RenderMode.WorldSpace;
// without a way to selectively show just the shape we want, this is
// the only way I can think of to do it. even this won't work if the
// user has a UI component not found by this function.
modifiedGraphics = DisableUIGraphics(canvas);
}
// make a new render texture
RenderTexture rt = new RenderTexture(w, h, 32, RenderTextureFormat.ARGB32);
rt.filterMode = FilterMode.Point;
rt.autoGenerateMips = false;
rt.Create();
// set up the camera to point exactly at the object's bounds and set its
// culling layer to show only layer 31
// note that if the user has anything on layer 31 then it will also
// show up in the png, but in that event they can just move it away
Camera cam = new GameObject().AddComponent <Camera>();
cam.backgroundColor = new Color(1, 1, 1, 0);
cam.clearFlags = CameraClearFlags.SolidColor;
cam.transform.position = bounds.center;
cam.transform.position -= new Vector3(0, 0, 10);
cam.orthographic = true;
cam.orthographicSize = bounds.extents.y;
cam.aspect = bounds.size.x / bounds.size.y;
cam.targetTexture = rt;
cam.cullingMask = 1 << 31;
// make the render texture active so calls to Texture2D.ReadPixels() will
// read from it
RenderTexture oldRT = RenderTexture.active;
RenderTexture.active = rt;
// draw each shape with blending turned off, and layer them on top of each
// other with blending between shapes but not between a shape and the
// camera's background color, which is what would happen if we just let the
// camera render all of them - the camera's background color affects the
// color of semi-transparent pixels even if the background color has an
// alpha value of 0. this is because the shader's blending is trying to
// alias against the background color, but in the png we don't want that.
// there's no shader option I'm aware of that would be able to blend between
// shapes but not between a shape and the background color, so that's why
// we have to do it manually.
Texture2D dstTex = null;
foreach (Shape s in shapes)
{
if (canvas)
{
Graphic g = s.GetComponent <Graphic>();
g.enabled = true;
if (s.GetComponent <Mask>() != null)
{
foreach (GraphicState gs in modifiedGraphics)
{
if (gs.graphic == g && gs.showMaskGraphic)
{
s.GetComponent <Mask>().showMaskGraphic = true;
}
}
}
}
if (dstTex == null)
{
dstTex = s.DrawToTexture2D(cam, w, h);
}
else
{
Texture2D srcTex = s.DrawToTexture2D(cam, w, h);
BlendTextures(dstTex, srcTex);
DestroyImmediate(srcTex);
}
if (canvas)
{
if (s.GetComponent <Mask>() == null)
{
s.GetComponent <Graphic>().enabled = false;
}
else
{
s.GetComponent <Mask>().showMaskGraphic = false;
}
}
}
// put the old render texture back
RenderTexture.active = oldRT;
// grab the sprite's pivot point based on the top object's location
// relative to its children
Vector2 pivot = shape.GetPivot();
// restore the shape's rotation
shape.transform.rotation = oldRotation;
// restore the canvas
if (canvas)
{
canvas.gameObject.layer = oldCanvasLayer;
canvas.renderMode = oldRenderMode;
foreach (GraphicState gs in modifiedGraphics)
{
gs.graphic.enabled = true;
if (gs.hasMask)
{
gs.graphic.GetComponent <Mask>().showMaskGraphic = gs.showMaskGraphic;
}
}
}
// save the png
byte[] bytes = dstTex.EncodeToPNG();
System.IO.File.WriteAllBytes(path, bytes);
// clean up
DestroyImmediate(dstTex);
DestroyImmediate(cam.gameObject);
DestroyImmediate(rt);
return(pivot);
}
