| 1 | const fragTemplate = [
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| 2 | "precision mediump float;",
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| 3 | "void main(void){",
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| 4 | "float test = 0.1;",
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| 5 | "%forloop%",
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| 6 | "gl_FragColor = vec4(0.0);",
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| 7 | "}"
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| 8 | ].join("\n");
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| 9 | function generateIfTestSrc(maxIfs) {
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| 10 | let src = "";
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| 11 | for (let i = 0; i < maxIfs; ++i) {
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| 12 | if (i > 0) {
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| 13 | src += "\nelse ";
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| 14 | }
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| 15 | if (i < maxIfs - 1) {
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| 16 | src += `if(test == ${i}.0){}`;
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| 17 | }
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| 18 | }
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| 19 | return src;
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| 20 | }
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| 21 | function checkMaxIfStatementsInShader(maxIfs, gl) {
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| 22 | if (maxIfs === 0) {
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| 23 | throw new Error("Invalid value of `0` passed to `checkMaxIfStatementsInShader`");
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| 24 | }
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| 25 | const shader = gl.createShader(gl.FRAGMENT_SHADER);
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| 26 | while (true) {
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| 27 | const fragmentSrc = fragTemplate.replace(/%forloop%/gi, generateIfTestSrc(maxIfs));
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| 28 | gl.shaderSource(shader, fragmentSrc);
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| 29 | gl.compileShader(shader);
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| 30 | if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
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| 31 | maxIfs = maxIfs / 2 | 0;
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| 32 | } else {
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| 33 | break;
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| 34 | }
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| 35 | }
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| 36 | return maxIfs;
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| 37 | }
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| 38 |
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| 39 | export { checkMaxIfStatementsInShader };
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| 40 |
|