import { main } from "./lib/platform.js";
import { Shader } from "./lib/shader.js";
import { BasicPlane } from "./lib/basic-plane.js";

main((gl, core) => {
  const shader = new Shader(gl, core)
    .attach(
      gl.VERTEX_SHADER,
      `
      attribute vec4 aVertexPosition;
      attribute vec2 aTextureCoord;
      
      uniform mat4 uModelViewMatrix;
      uniform mat4 uProjectionMatrix;

      varying highp vec2 vTextureCoord;
      
      void main() {
        gl_Position = uProjectionMatrix * uModelViewMatrix * aVertexPosition;
        vTextureCoord = aTextureCoord;
      }
    `
    )
    .attach(
      gl.FRAGMENT_SHADER,
      `
      uniform lowp float uTime;
      uniform lowp float uSinTime;
      uniform lowp float uCosTime;

      varying highp vec2 vTextureCoord;

      void main() {
        lowp float slowedSinTime = sin(uTime*0.001)*0.5+0.5;
        lowp float slowedCosTime = cos(uTime*0.005)*0.5+0.5;
        
        gl_FragColor = vec4(vTextureCoord.x * 0.5 - slowedSinTime, vTextureCoord.y, vTextureCoord.y * 0.5 + slowedSinTime, 1.0);
        gl_FragColor = clamp(gl_FragColor, 0.0, 1.0);
      }
    `
    )
    .link();

  const plane = new BasicPlane(gl, core);
  plane.attachShader(shader);

  const render = () => {
    core.clear();
    plane.draw2D();

    if (gl.getError() !== gl.NO_ERROR) {
      throw new Error("WebGL error");
    }

    requestAnimationFrame(render);
  };

  requestAnimationFrame(render);
});