import { mat4, vec2 } from 'gl-matrix'; import Shaders from './Shaders'; export default class Renderer { private readonly gl: WebGLRenderingContext; private readonly shaders: Shaders; private readonly center: vec2 = vec2.create(); private readonly translation: vec2 = vec2.create(); private readonly viewport: mat4 = mat4.create(); constructor(private readonly canvas: HTMLCanvasElement) { this.gl = this.mkContext(); this.shaders = new Shaders(this.gl); this.gl.clearColor(0.0, 0.0, 0.0, 1.0); this.gl.enable(this.gl.BLEND); this.gl.blendFunc(this.gl.ONE, this.gl.ONE_MINUS_SRC_ALPHA); this.gl.pixelStorei(this.gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, 1); this.setSize(); } public createBuffer(): WebGLBuffer { const ret = this.gl.createBuffer(); if (!ret) throw new Error('unable to create buffer'); return ret; } public getContext(): WebGLRenderingContext { return this.gl; } public getVertexPosLoc(): number { return this.shaders.vertexPosLoc; } public getTextureCoordLoc(): number { return this.shaders.textureCoordLoc; } public getSamplerLoc(): WebGLUniformLocation { return this.shaders.samplerLoc; } public setCenter(v: vec2|number[]) { vec2.copy(this.center, v); } public setTranslation(v: vec2|number[]) { vec2.sub(this.translation, v, this.center); this.gl.uniform2fv(this.shaders.translateLoc, this.translation); } public clear(): void { this.gl.clear(this.gl.COLOR_BUFFER_BIT); this.setTranslation([0, 0]); } private mkContext(): WebGLRenderingContext { const gl = ( this.canvas.getContext('webgl') || this.canvas.getContext('experimental-webgl') ); if (!gl) throw new Error('unable to initialize WebGL context'); return gl; } private setSize(): void { const w = this.canvas.width; const h = this.canvas.height; this.gl.viewport(0, 0, w, h); this.clear(); mat4.identity(this.viewport); mat4.scale(this.viewport, this.viewport, [2 * 64 / w, -2 * 64 / h, 1.0]); this.gl.uniformMatrix4fv(this.shaders.viewportLoc, false, this.viewport); } }