package com.sforzando.graphics3d;

public class GraphicsRenderer {
    public static Image render (List<DynamicModel> objects, List<StaticModel> models, GraphicsRenderingContext ctx) {
        List<StaticModel.Face> faces = List.<StaticModel.Face>of();
        for (StaticModel m : models)
            for (StaticModel.Face f : m.getFaces())
                faces.add(f);
        for (DynamicModel m : objects)
            for (StaticModel.Face f : m.getCurrentPose().getFaces())
                faces.add(f);
        Map<StaticModel.Face, PointMatrix> visibleMatrices = Map.<StaticModel.Face, PointMatrix>of();
        Point3D cameraPos = ctx.getCamera().getPosition();
        Plane cameraPlane = ctx.getCamera().getVector().calculatePerpendicularPlane();
        for (StaticModel.Face f : faces) {
            VertexMatrix vm = f.getVertices();
            PointMatrix pm = new PointMatrix(f.generatePointMatrix().getFirstVertex());
            for (Vertex v : vm.getVertices()) {
                Point3D vPos = v.getPosition();
                double dist = vPos.calculateDistanceTo(cameraPlane);
                BoundedPlane fovAtDist = BoundedPlane.centered(cameraPos, angleTransform(ctx.getFOV()) * dist);
                Point2D newVPos = fovAtDist.coerce(vPos);
                pm.addPoint(newVPos);
            }
            boolean isOutOfBounds = true;
            for (Point2D p : pm.getPoints()) {
                if (!p.isBeyondBounds()) {
                    isOutOfBounds = false;
                    break;
                }
            }
            if (!isOutOfBounds) visibleMatrices.put(f, pm);
        }
        DirectColorModel out = DirectColorModel(32, 0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF);
        WritableRaster image = new WritableRaster(out.createCompatibleSampleModel(ctx.getWidth(), ctx.getHeight()), new Point(0, 0));
        for (StaticModel.Face f : visibleMatrices.keySet()) {
            Texture texture = f.getTexture();
            Raster r = transformTexture(texture, visibleMatrices.get(f));
            AlphaComposite.SrcAtop.createContext(texture.asImage().getColorModel(), out, null).compose(image, r, image);
        }
        return new BufferedImage(out, image, true, new Hashtable<String, Object>());
    }

    public static double angleTransform (int fov) {
        double radians = (fov / 180) * Math.PI;
        return Math.pow(Math.pow(1 - Math.abs(Math.cos(radians)), 2), Math.pow(Math.sin(radians), 2), 1 / 2);
    }

    public static Raster transformTexture (Texture t, PointMatrix m) {
        PointMatrix tM = t.generatePointMatrix();
        t.translate(m.getPointPos(m.getPoint()).getX() - tM.getPointPos(tM.getPoint()).getX(), m.getPointPos(m.getPoint()).getY() - tM.getPointPos(tM.getPoint()).getY());
        if (m.getPoint(m.getFirstPoint() + 1) != tM.getPoint(tM.getFirstPoint() + 1) {
            t.redefineOrigin(tM.getFirstPoint());
}