Scene3D

import java.util.ArrayList;
import android.opengl.Matrix;

public class Scene3D {
    public ArrayList<Material3D> materials;
    public ArrayList<Object3D> objects;
    public ArrayList<Light3D> lights;
    public ArrayList<Animation> animations;
    public float[] background;
    public float[] ambient;

    public Material3D FindMaterial(String name)
    {
        if (materials == null || name == null) return null;
        int i, n = materials.size();
        for (i = 0; i < n; i++) {
            Material3D mat = materials.get(i);
            if (mat.name.equals(name))
                return mat;
        }
        return null;
    }

    public Object3D FindObject(String name)
    {
        if (objects == null || name == null) return null;
        int i, n = objects.size();
        for (i = 0; i < n; i++) {
            Object3D obj = objects.get(i);
            if (obj.name.equals(name))
                return obj;
        }
        return null;
    }

    public Light3D FindLight(String name)
    {
        if (lights == null || name == null) return null;
        int i, n = lights.size();
        for (i = 0; i < n; i++) {
            Light3D light = lights.get(i);
            if (light.name.equals(name))
                return light;
        }
        return null;
    }

    public Animation FindAnimation(int id)
    {
        if (animations == null || id == 0xffff) return null;
        int i, n = animations.size();
        for (i = 0; i < n; i++) {
            Animation anim = animations.get(i);
            if (anim.id == id)
                return anim;
        }
        return null;
    }

    private void lerp3(float[] out, float[] from, float[] to, float t)
    {
        for (int i = 0; i < 3; i++)
            out[i] = from[i] + (to[i] - from[i]) * t;
    }

    private AnimKey findVec(AnimKey[] keys, float time)
    {
        AnimKey key = keys[keys.length - 1];

        // We'll use either first, or last, or interpolated key
        for (int j = 0; j < keys.length; j++) {
            if (keys[j].time >= time) {
                if (j > 0) {
                    float local = (time - keys[j - 1].time) /
                        (keys[j].time - keys[j - 1].time);
                    key = new AnimKey();
                    key.time = time;
                    key.data = new float[3];
                    lerp3(key.data, keys[j - 1].data, keys[j].data, local);
                }
                else
                    key = keys[j];
                break;
            }
        }

        return key;
    }

    private void applyRot(float[] result, float[] data, float t)
    {
        if (Math.abs(data[3]) > 1.0e-7 && Math.hypot(Math.hypot(data[0], data[1]), data[2]) > 1.0e-7)
            Matrix.rotateM(result, 0, (float) (data[3] * t * 180 / Math.PI), data[0], data[1], data[2]);
    }

    public void Compute(float time)
    {
        int i, n = animations.size();
        for (i = 0; i < n; i++) {
            Animation anim = animations.get(i);
            Object3D obj = anim.object;
            float[] result = new float[16];

            Matrix.setIdentityM(result, 0);

            if (anim.position != null && anim.position.length > 0) {
                AnimKey key = findVec(anim.position, time);
                float[] pos = key.data;
                Matrix.translateM(result, 0, pos[0], pos[1], pos[2]);
            }

            if (anim.rotation != null && anim.rotation.length > 0) {
                // All rotations that are prior to the target time should be applied sequentially
                for (int j = anim.rotation.length - 1; j > 0; j--) {
                    if (time >= anim.rotation[j].time) // rotation in the past, apply as is
                        applyRot(result, anim.rotation[j].data, 1);
                    else if (time > anim.rotation[j - 1].time) {
                        // rotation between key frames, apply part of it
                        float local = (time - anim.rotation[j - 1].time) /
                                (anim.rotation[j].time - anim.rotation[j - 1].time);
                        applyRot(result, anim.rotation[j].data, local);
                    }
                    // otherwise, it's a rotation in the future, skip it
                }

                // Always apply the first rotation
                applyRot(result, anim.rotation[0].data, 1);
            }

            if (anim.scaling != null && anim.scaling.length > 0) {
                AnimKey key = findVec(anim.scaling, time);
                float[] scale = key.data;
                Matrix.scaleM(result, 0, scale[0], scale[1], scale[2]);
            }

            if (anim.parent != null)
                Matrix.multiplyMM(anim.result, 0, anim.parent.result, 0, result, 0);
            else
                Matrix.translateM(anim.result, 0, result, 0, 0, 0, 0);

            if (obj != null && obj.trMatrix != null) {
                float[] pivot = new float[16];
                Matrix.setIdentityM(pivot, 0);
                Matrix.translateM(pivot, 0, -anim.pivot[0], -anim.pivot[1], -anim.pivot[2]);
                Matrix.multiplyMM(result, 0, pivot, 0, obj.trMatrix, 0);
            }
            else {
                Matrix.setIdentityM(result, 0);
                Matrix.translateM(result, 0, -anim.pivot[0], -anim.pivot[1], -anim.pivot[2]);
            }
            Matrix.multiplyMM(anim.world, 0, anim.result, 0, result, 0);
        }
    }
}

class Object3D {
    public String name;
    public int vertCount;
    public int indCount;
    public ArrayList<FaceMat> faceMats;
    public int glVertices;
    public int glIndices;
    public float[] vertexBuffer;
    public float[] trMatrix;
}

class FaceMat {
    public Material3D material;
    public int[] indexBuffer;
    public int indCount;
    public int bufOffset;
}

class Light3D {
    public String name;
    public float[] pos;
    public float[] color;
    public float[] dir;
    public float theta, phi;
}

class Material3D {
    public String name;
    public float[] ambient;
    public float[] diffuse;
    public float[] specular;
    public String texture;
    public float shininess;
    public float shinStren;
    public float transparency;
    public float selfIllum;
    public int type;
}

class Animation {
    public int id;
    public String name;
    public Object3D object;
    public Light3D light;
    public Animation parent;
    public float[] pivot;

    public AnimKey[] position;
    public AnimKey[] rotation;
    public AnimKey[] scaling;

    public float[] result;
    public float[] world;
}

class AnimKey {
    public float time;
    public float[] data;
}