@icanvas/components/webgl/libs/texture.js

这是icanvas的界面组件包

import GAME from '@icanvas/core';
export default class Texture extends GAME.Component {
	texture = null;

	verticesBuffer = null;
	offsetVertices = 0;
	offsetUvs = 0;
	offsetTotal = 0;

	indexesBuffer = null;
	constructor(Key) {
		super();
		this.setTexture(Key);
	}
	setTexture(Key) {
		let gl = GAME.Render.Context;
		let BaseTexture = GAME.Res.Image.Get(Key);
		
		this.width = BaseTexture.width;
		this.height = BaseTexture.height;
		this.texture = BaseTexture.texture;

		let array = new Float32Array(Math.max(BaseTexture.vertices.length, BaseTexture.uvs.length) * 2);
		for (let i = 0, l = (array.length / 4) | 0; i < l; i++) {
			array[i * 4] = BaseTexture.vertices[i * 2];
			array[i * 4 + 1] = BaseTexture.vertices[i * 2 + 1];
			array[i * 4 + 2] = BaseTexture.uvs[i * 2];
			array[i * 4 + 3] = BaseTexture.uvs[i * 2 + 1];
		}
		this.verticesBuffer = gl.GetBuffer(array, gl.ARRAY_BUFFER);
		this.offsetVertices = Float32Array.BYTES_PER_ELEMENT * 2;
		this.offsetUvs = Float32Array.BYTES_PER_ELEMENT * 2;
		this.offsetTotal = this.offsetVertices + this.offsetUvs;

		this.indexesBuffer = gl.GetBuffer(BaseTexture.indexes.Uint16Array, gl.ELEMENT_ARRAY_BUFFER);
	}
	size = new GAME.Math.Vector2();
	get width() {
		return this.size.x;
	}
	set width(width) {
		this.size.x = width;
	}
	get height() {
		return this.size.y;
	}
	set height(height) {
		this.size.y = height;
	}
	anchorCenter(x = true, y = true) {
		if (x) this.anchor.x = this.size.x / 2;
		if (y) this.anchor.y = this.size.y / 2;
		return this;
	}
	setSize(x, y) {
		this.size.set(x, y);
		return this;
	}
	update(gl) {
		gl.bindBuffer(gl.ARRAY_BUFFER, this.verticesBuffer);
		gl.vertexAttribPointer(gl.Program.a_Position.id, 2, gl.FLOAT, false, this.offsetTotal, 0);
		gl.vertexAttribPointer(gl.Program.a_TexCoord.id, 2, gl.FLOAT, false, this.offsetTotal, this.offsetVertices);

		gl.bindTexture(gl.TEXTURE_2D, this.texture);
		gl.uniform1i(gl.Program.u_Sampler.id, 0);

		gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.indexesBuffer);
		gl.drawElements(gl.TRIANGLE_STRIP, this.indexesBuffer.buffer.length, gl.UNSIGNED_SHORT, 0);
	}
}