Vap/web/vap/gl-util.js

/*
 * Tencent is pleased to support the open source community by making vap available.
 *
 * Copyright (C) 2020 THL A29 Limited, a Tencent company.  All rights reserved.
 *
 * Licensed under the MIT License (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * http://opensource.org/licenses/MIT
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
export function createShader(gl, type, source) {
    const shader = gl.createShader(type)
    gl.shaderSource(shader, source)
    gl.compileShader(shader)
    // if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
    //     console.error(gl.getShaderInfoLog(shader))
    // }
    return shader
}

export function createProgram(gl, vertexShader, fragmentShader) {
    const program = gl.createProgram()
    gl.attachShader(program, vertexShader)
    gl.attachShader(program, fragmentShader)
    gl.linkProgram(program)
    // if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
    //     console.error(gl.getProgramInfoLog(program))
    // }
    gl.useProgram(program)
    return program
}

export function createTexture(gl, index, imgData) {
    const texture = gl.createTexture()
    const textrueIndex = gl.TEXTURE0 + index
    gl.activeTexture(textrueIndex)
    gl.bindTexture(gl.TEXTURE_2D, texture)
    // gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true)
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
    if (imgData) {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, imgData)
    }
    return texture
}

export function cleanWebGL(gl, shaders, program, textures, buffers) {
    try {
        gl.clear(gl.COLOR_BUFFER_BIT)
        textures.forEach(t => {
            gl.deleteTexture(t)
        })
        buffers.forEach(b => {
            gl.deleteBuffer(b)
        })
        shaders.forEach(shader => {
            gl.detachShader(program, shader)
            gl.deleteShader(shader)
        })
        gl.clear(gl.COLOR_BUFFER_BIT)
        gl.deleteProgram(program)
    } catch (e) {}
}