/// <reference path="./glsl.d.ts" />
import vert_src from "./vertex.vert";
import frag_src from "./fragment.frag";

import {createProgramFromSource, ProgramError, ShaderError} from "./gl_util";
import { Camera } from "./camera";
import * as G from "./glWrapper";
import { Drawable, RenderState } from "./drawable";
import { Model } from "./model";
import { mat4 } from "gl-matrix";


export class Drawer3D implements Drawable{
    gl : WebGL2RenderingContext;
    program: G.GLProgram;
    camera : Camera;
    model: Model | undefined;
    constructor(gl: WebGL2RenderingContext){
        this.gl = gl;
        this.camera = new Camera([-20,1,-10]);
        this.camera.far = 1000;
        this.camera.near = 0.1;
        this.camera.fovY = Math.PI * 90 / 180;
        this.camera.aspect = 1;
        this.model = undefined;
        try{
            this.program = new G.GLProgram(createProgramFromSource(gl,vert_src,frag_src));
            const attr = this.program.getActiveAttributes(gl);
            console.log(attr);
        }
        catch(e){
            if(e instanceof ShaderError){
                console.log(e.info);
            }
            throw e;
        }
    }
    async init(){
        const gl = this.gl;
        const url = new URL("../assets/models/teapot/teapot.obj",import.meta.url);
        this.model = await Model.loadFromOBJ(gl,url.href);
        console.log("loading model complete");
        this.model.ready(gl,this.program);
    }
    draw(gl: WebGL2RenderingContext,state:RenderState): void {
        if(this.model !== undefined){
            this.camera.aspect = gl.canvas.width/gl.canvas.height;
            this.camera.UpdateProjectionMat();
            this.program.use(gl);

            this.program.setUniformMat4f(gl,"viewMat",this.camera.viewMatrix);
            this.program.setUniformMat4f(gl,"projectionMat",this.camera.projectionMatrix);
            this.program.setUniformMat4f(gl,"modelMat",mat4.fromTranslation(mat4.create(),[0,0,0]));
            
            this.model.draw(gl);
        }
    }
}