@itwin/core-frontend
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iTwin.js frontend components
30 lines • 1.6 kB
JavaScript
;
/*---------------------------------------------------------------------------------------------
* Copyright (c) Bentley Systems, Incorporated. All rights reserved.
* See LICENSE.md in the project root for license terms and full copyright notice.
*--------------------------------------------------------------------------------------------*/
/** @packageDocumentation
* @module WebGL
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.addLogDepth = addLogDepth;
const core_bentley_1 = require("@itwin/core-bentley");
const System_1 = require("../System");
const Common_1 = require("./Common");
// Based on http://tulrich.com/geekstuff/log_depth_buffer.txt
// Previously attempted to adjust z in vertex shader along the lines of https://outerra.blogspot.com/2013/07/logarithmic-depth-buffer-optimizations.html
// - but interpolation along triangles intersecting the near plane was far too wonky.
const finalizeDepth = "return 0.0 == u_logZ.x ? -v_eyeSpace.z / u_logZ.y : log(-v_eyeSpace.z * u_logZ.x) / u_logZ.y;";
/** @internal */
function addLogDepth(builder) {
(0, core_bentley_1.assert)(System_1.System.instance.supportsLogZBuffer);
(0, Common_1.addEyeSpace)(builder);
const frag = builder.frag;
frag.addUniform("u_logZ", 3 /* VariableType.Vec2 */, (prog) => {
prog.addProgramUniform("u_logZ", (uniform, params) => {
uniform.setUniform2fv(params.target.uniforms.frustum.logZ);
});
});
frag.set(20 /* FragmentShaderComponent.FinalizeDepth */, finalizeDepth);
}
//# sourceMappingURL=LogarithmicDepthBuffer.js.map