import { mat4 } from 'gl-matrix';
import { ClipSpaceNearZ } from '@antv/g-device-api';
/**
 * Convert a projection matrix {@param m} between differing clip spaces.
 *
 * There are two kinds of clip-space conventions in active use in graphics APIs, differing in the
 * range of the Z axis: OpenGL (and thus GL ES and WebGL) use a Z range of [-1, 1] which matches
 * the X and Y axis ranges. Direct3D, Vulkan, Metal, and WebGPU all use a Z range of [0, 1], which
 * differs from the X and Y axis ranges, but makes sense from the perspective of a camera: a camera
 * can see to the left and right of it, above and below it, but only in front and not behind it.
 *
 * The [0, 1] convention for Z range also has better characteristics for "reversed depth". Since
 * floating point numbers have higher precision around 0 than around 1. We then get to choose where
 * to put the extra precise bits: close to the near plane, or close to the far plane.
 *
 * With OpenGL's [-1, 1] convention, both -1 and 1 have similar amounts of precision, so we don't
 * get to make the same choice, and our higher precision around 0 is stuck in the middle of the
 * scene, which doesn't particularly help.
 *
 * The gl-matrix library has two different kinds of entry points: {@method mat4.perpsective} will
 * generate a matrix with a [-1, 1] clip space, corresponding to {@see ClipSpaceNearZ.NegativeOne},
 * but {@method mat4.perspectiveZO} will generate a matrix with a [0, 1] clip space, corresponding
 * to {@see ClipSpaceNearZ.Zero}.
 *
 * This function does nothing if {@param dst} and {@param src} are the same.
 */
export declare function projectionMatrixConvertClipSpaceNearZ(m: mat4, dst: ClipSpaceNearZ, src: ClipSpaceNearZ): void;
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