- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
- 92
- 93
- 94
- 95
- 96
- 97
- 98
- 99
- 100
- 101
- 102
- 103
- 104
- 105
- 106
- 107
- 108
- 109
- 110
- 111
- 112
- 113
- 114
- 115
- 116
- 117
- 118
- 119
- 120
- 121
- 122
- 123
- 124
- 125
- 126
- 127
- 128
- 129
- 130
- 131
- 132
- 133
- 134
- 135
- 136
- 137
- 138
- 139
- 140
- 141
- 142
- 143
- 144
- 145
- 146
- 147
- 148
- 149
- 150
- 151
- 152
- 153
- 154
- 155
- 156
- 157
- 158
- 159
import * as event from "./../../system/event.js";
import { extractUniforms } from "./utils/uniforms.js";
import { extractAttributes } from "./utils/attributes.js";
import { compileProgram } from "./utils/program.js";
import { setPrecision, getMaxShaderPrecision } from "./utils/precision.js";
import { minify } from "./utils/string.js";
/**
* @classdesc
* a base GL Shader object
*/
export default class GLShader {
/**
* @param {WebGLRenderingContext} gl - the current WebGL rendering context
* @param {string} vertex - a string containing the GLSL source code to set
* @param {string} fragment - a string containing the GLSL source code to set
* @param {string} [precision=auto detected] - float precision ('lowp', 'mediump' or 'highp').
* @see https://developer.mozilla.org/en-US/docs/Games/Techniques/3D_on_the_web/GLSL_Shaders
* @example
* // create a basic shader
* let myShader = new me.GLShader(
* // WebGL rendering context
* gl,
* // vertex shader
* [
* "void main() {",
* " gl_Position = doMathToMakeClipspaceCoordinates;",
* "}"
* ].join("\n"),
* // fragment shader
* [
* "void main() {",
* " gl_FragColor = doMathToMakeAColor;",
* "}"
* ].join("\n")
* )
* // use the shader
* myShader.bind();
*/
constructor(gl, vertex, fragment, precision) {
/**
* the active gl rendering context
* @type {WebGLRenderingContext}
*/
this.gl = gl;
/**
* the vertex shader source code
* @type {string}
*/
this.vertex = setPrecision(minify(vertex), precision || getMaxShaderPrecision(this.gl));
/**
* the fragment shader source code
* @type {string}
*/
this.fragment = setPrecision(minify(fragment), precision || getMaxShaderPrecision(this.gl));
/**
* the location attributes of the shader
* @type {GLint[]}
*/
this.attributes = extractAttributes(this.gl, this);
/**
* a reference to the shader program (once compiled)
* @type {WebGLProgram}
*/
this.program = compileProgram(this.gl, this.vertex, this.fragment, this.attributes);
/**
* the uniforms of the shader
* @type {object}
*/
this.uniforms = extractUniforms(this.gl, this);
// destroy the shader on context lost (will be recreated on context restore)
event.on(event.ONCONTEXT_LOST, this.destroy, this);
}
/**
* Installs this shader program as part of current rendering state
*/
bind() {
this.gl.useProgram(this.program);
}
/**
* returns the location of an attribute variable in this shader program
* @param {string} name - the name of the attribute variable whose location to get.
* @returns {GLint} number indicating the location of the variable name if found. Returns -1 otherwise
*/
getAttribLocation(name) {
let attr = this.attributes[name];
if (typeof attr !== "undefined") {
return attr;
} else {
return -1;
}
}
/**
* Set the uniform to the given value
* @param {string} name - the uniform name
* @param {object|Float32Array} value - the value to assign to that uniform
* @example
* myShader.setUniform("uProjectionMatrix", this.projectionMatrix);
*/
setUniform(name, value) {
let uniforms = this.uniforms;
if (typeof uniforms[name] !== "undefined") {
if (typeof value === "object" && typeof value.toArray === "function") {
uniforms[name] = value.toArray();
} else {
uniforms[name] = value;
}
} else {
throw new Error("undefined (" + name + ") uniform for shader " + this);
}
}
/**
* activate the given vertex attribute for this shader
* @param {WebGLRenderingContext} gl - the current WebGL rendering context
* @param {object[]} attributes - an array of vertex attributes
* @param {number} vertexByteSize - the size of a single vertex in bytes
*/
setVertexAttributes(gl, attributes, vertexByteSize) {
// set the vertex attributes
for (let index = 0; index < attributes.length; ++index) {
let element = attributes[index];
let location = this.getAttribLocation(element.name);
if (location !== -1) {
gl.enableVertexAttribArray(location);
gl.vertexAttribPointer(location, element.size, element.type, element.normalized, vertexByteSize, element.offset);
} else {
gl.disableVertexAttribArray(index);
}
}
}
/**
* destroy this shader objects resources (program, attributes, uniforms)
*/
destroy() {
this.uniforms = null;
this.attributes = null;
this.gl.deleteProgram(this.program);
this.vertex = null;
this.fragment = null;
}
}