import { mat4, vec3, quat, mat3 } from "gl-matrix";

export class Camera {
    pos: vec3;

    yaw: number;
    pitch: number;
    roll: number;

    #proj: mat4;

    fovY: number;
    aspect: number;
    far: number;
    near: number;
    constructor(pos: vec3) {
        this.pos = pos;
        this.#proj = mat4.create();
        this.yaw = 0;
        this.pitch = 0;
        this.roll = 0;
        console.log("forward" , this.forward);
        console.log("up" , this.up);
    }
    rotateRight(rad: number) {
        this.yaw += rad;
        if(this.yaw >= Math.PI * 2 ){
            this.yaw -= Math.PI * 2;
        }
    }
    rotateUp(rad: number) {
        this.pitch += rad;
        this.pitch = Math.min(this.pitch, Math.PI * 89/ 180);
        this.pitch = Math.max(this.pitch, - Math.PI * 89 / 180);
    }
    rotateClockwise(rad: number) {
        this.roll += rad;
    }
    get viewMatrix(): mat4 {
        const eye = vec3.create();
        const lookAt = mat4.create();
        vec3.add(eye, this.pos, this.forward);
        return mat4.lookAt(lookAt, this.pos, eye, this.up);
    }
    /**
     * update projection matrix
     */
    UpdateProjectionMat() {
        mat4.perspective(this.#proj, this.fovY, this.aspect, this.near, this.far);
    }
    get projectionMatrix(): mat4 {
        return this.#proj;
    }
    get forward(): vec3 {
        const sinYaw = -Math.sin(this.yaw);
        const cosYaw = Math.cos(this.yaw);
        const ret = vec3.fromValues(sinYaw * Math.cos(this.pitch), -Math.sin(this.pitch), cosYaw * Math.cos(this.pitch));
        vec3.normalize(ret,ret);
        return ret;
    }
    get up(): vec3 {
        const right = vec3.cross(vec3.create(),this.forward,[0,1,0]);
        vec3.normalize(right,right);
        const ret = vec3.cross(vec3.create(),right,this.forward);
        vec3.normalize(ret,ret);
        /*const a = Math.sin(this.yaw);
        const b = Math.cos(this.yaw);
        const u = vec3.fromValues(b * Math.sin(this.pitch), Math.cos(this.pitch), a * Math.sin(this.pitch));
        const v = vec3.create();
        vec3.cross(v, u, this.forward);
        const ret = vec3.create();
        const tmp1 = vec3.create();
        const tmp2 = vec3.create();
        vec3.add(ret, vec3.scale(tmp1, u, Math.cos(this.roll)), vec3.scale(tmp2, v, -Math.sin(this.roll)));*/
        return ret;
    }
    get right(): vec3 {
        const ret = vec3.create();
        vec3.cross(ret, this.forward, this.up);
        return ret;
    }
};