56 lines
1.6 KiB
JavaScript
56 lines
1.6 KiB
JavaScript
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//
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// initShaders.js
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//
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async function readFile(file) {
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let result_base64 = await new Promise((resolve) => {
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var xhr = new XMLHttpRequest();
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xhr.addEventListener("load", (data) => resolve(data.target.response));
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xhr.open("GET", file);
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xhr.send();
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});
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return result_base64;
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}
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async function initShaders( gl, vertexShaderFilename, fragmentShaderFilename )
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{
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const compileShader = ( gl, gl_shaderType, shaderSource ) => {
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// Create the shader
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shader = gl.createShader( gl_shaderType );
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// Set the shader source code
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gl.shaderSource( shader, shaderSource );
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// Compile the shader to make it readable for the GPU
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gl.compileShader( shader );
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var success = gl.getShaderParameter(shader, gl.COMPILE_STATUS);
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if (!success) {
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// Something went wrong during compilation; get the error
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throw "could not compile shader:" + gl.getShaderInfoLog(shader);
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}
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else {
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return shader;
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}
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}
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/*
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* Setup shader program
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*/
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vShaderSource = await readFile(vertexShaderFilename);
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fShaderSource = await readFile(fragmentShaderFilename);
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vertexShader = compileShader( gl, gl.VERTEX_SHADER, vShaderSource );
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fragmentShader = compileShader( gl, gl.FRAGMENT_SHADER, fShaderSource );
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// Build the program
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const program = gl.createProgram();
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// Attach shaders to it
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gl.attachShader( program, vertexShader );
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gl.attachShader( program, fragmentShader );
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gl.linkProgram( program );
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return program;
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}
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