package engine.math;

import engine.utils.BufferUtils;

import java.nio.FloatBuffer;

public class Matrix4f {

    public static final int SIZE = 4 * 4;
    public float[] elements = new float[4 * 4];

    public Matrix4f(){

    }

    public static Matrix4f identity(){
        Matrix4f result = new Matrix4f();
        for (int i = 0; i < SIZE; i++){
            result.elements[i] = 0.0f;
        }
        result.elements[0 + 0 * 4] = 1.0f;
        result.elements[1 + 1 * 4] = 1.0f;
        result.elements[2 + 2 * 4] = 1.0f;
        result.elements[3 + 3 * 4] = 1.0f;
        return result;
    }

    public static Matrix4f orthographic(float left, float right, float bottom, float top, float near, float far){
        Matrix4f result = identity();

        result.elements[0 + 0 * 4] = 2.0f / (right - left);
        result.elements[1 + 1 * 4] = 2.0f / (top - bottom);
        result.elements[2 + 2 * 4] = 2.0f / (near - far);

        result.elements[0 + 3 * 4] = (left + right) / (left - right);
        result.elements[1 + 3 * 4] = (bottom + top) / (bottom - top);
        result.elements[2 + 3 * 4] = (far + near) / (far - near);

        return result;
    }

    public static Matrix4f translate(Vector3f vector){
        Matrix4f result= identity();
        result.elements[0 + 3*4] = vector.x;
        result.elements[1 + 3*4] = vector.y;
        result.elements[2 + 3*4] = vector.z;

        return result;
    }

    public static Matrix4f scale(Vector3f vector){
        Matrix4f result= identity();
        result.elements[0 + 0*4] = vector.x;
        result.elements[1 + 1*4] = vector.y;
        result.elements[2 + 2*4] = vector.z;

        return result;
    }

    public static Matrix4f rotateX(float angle){
        Matrix4f result = identity();
        float r = (float) Math.toRadians(angle);
        float cos = (float) Math.cos(r);
        float sin = (float) Math.sin(r);

        result.elements[1 + 1 * 4] = cos;
        result.elements[2 + 1 * 4] = -sin;

        result.elements[1 + 2 * 4] = sin;
        result.elements[2 + 2 * 4] = cos;

        return result;
    }

    public static Matrix4f rotateY(float angle){
        Matrix4f result = identity();
        float r = (float) Math.toRadians(angle);
        float cos = (float) Math.cos(r);
        float sin = (float) Math.sin(r);

        result.elements[0 + 0 * 4] = cos;
        result.elements[2 + 0 * 4] = sin;

        result.elements[0 + 2 * 4] = -sin;
        result.elements[2 + 2 * 4] = cos;

        return result;
    }

    public static Matrix4f rotateZ(float angle){
        Matrix4f result = identity();
        float r = (float) Math.toRadians(angle);
        float cos = (float) Math.cos(r);
        float sin = (float) Math.sin(r);

        result.elements[0 + 0 * 4] = cos;
        result.elements[1 + 0 * 4] = -sin;

        result.elements[0 + 1 * 4] = sin;
        result.elements[1 + 1 * 4] = cos;

        return result;
    }

    public Matrix4f multiply(Matrix4f matrix){
        Matrix4f result = new Matrix4f();
        for (int y = 0; y< 4; y++){
            for (int x = 0; x< 4; x++){
                float sum = 0.0f;
                for (int e = 0; e< 4; e++){
                    sum += this.elements[x + e * 4] * matrix.elements[e + y * 4];
                }
                result.elements[x + y * 4] = sum;
            }
        }
        return result;
    }

    public FloatBuffer toFloatBuffer() {
        return BufferUtils.createFloatBuffer(elements);
    }

}