playcanvas/build/playcanvas/src/scene/shader-lib/glsl/chunks/gsplat/frag/gsplatWorkBufferGeometry.d.ts

Open-source WebGL/WebGPU 3D engine for the web

declare const _default: "\n#ifdef GSPLAT_WORKBUFFER_GEOMETRY\n\n    // world-space transform data previously written to the work buffer (see gsplatWriteVS)\n    uniform highp usampler2D uWorkBufferTransformA;\n    uniform highp usampler2D uWorkBufferTransformB;\n\n    // inverse of matrix_model, to convert stored world-space data back to local space\n    uniform mat4 matrix_model_inverse;\n\n    // world-space camera position\n    uniform vec3 uCameraPosition;\n\n    ivec2 wbCoord;\n    uvec4 wbTransformA;\n\n    // cache transformA at the destination pixel; must be called before any getters\n    void initWorkBufferGeometry(ivec2 coord) {\n        wbCoord = coord;\n        wbTransformA = texelFetch(uWorkBufferTransformA, coord, 0);\n    }\n\n    vec3 workBufferWorldCenter() {\n        return vec3(uintBitsToFloat(wbTransformA.x), uintBitsToFloat(wbTransformA.y), uintBitsToFloat(wbTransformA.z));\n    }\n\n    // world-space rotation (x,y,z,w), decoded to match the work buffer write encoding\n    vec4 workBufferWorldRotation() {\n        #ifdef GSPLAT_WORKBUFFER_COMPACT\n            // half-angle projected quaternion, 11+11+10 bits (see containerCompactWrite)\n            uint data = texelFetch(uWorkBufferTransformB, wbCoord, 0).x;\n            vec3 p = vec3(\n                float(data & 0x7FFu) / 2047.0 * 2.0 - 1.0,\n                float((data >> 11u) & 0x7FFu) / 2047.0 * 2.0 - 1.0,\n                float((data >> 22u) & 0x3FFu) / 1023.0 * 2.0 - 1.0\n            );\n            float d = dot(p, p);\n            return vec4(sqrt(max(0.0, 2.0 - d)) * p, 1.0 - d);\n        #else\n            // rotation.xy in transformA.w, rotation.z in transformB.x (see containerPackedWrite)\n            vec2 rotXY = unpackHalf2x16(wbTransformA.w);\n            vec3 r = vec3(rotXY, unpackHalf2x16(texelFetch(uWorkBufferTransformB, wbCoord, 0).x).x);\n            return vec4(r, sqrt(max(0.0, 1.0 - dot(r, r))));\n        #endif\n    }\n\n    vec3 workBufferWorldScale() {\n        #ifdef GSPLAT_WORKBUFFER_COMPACT\n            // log-encoded scale, 3x8 bits: 0 = true zero, 1-255 maps to e^-12..e^9 (see containerCompactWrite)\n            uint data = wbTransformA.w;\n            float sx = float(data & 0xFFu);\n            float sy = float((data >> 8u) & 0xFFu);\n            float sz = float((data >> 16u) & 0xFFu);\n            const float logRange = 21.0 / 255.0;\n            const float logMin = -12.0;\n            return vec3(\n                sx == 0.0 ? 0.0 : exp(sx * logRange + logMin),\n                sy == 0.0 ? 0.0 : exp(sy * logRange + logMin),\n                sz == 0.0 ? 0.0 : exp(sz * logRange + logMin)\n            );\n        #else\n            uvec2 b = texelFetch(uWorkBufferTransformB, wbCoord, 0).xy;\n            return vec3(unpackHalf2x16(b.x).y, unpackHalf2x16(b.y));\n        #endif\n    }\n\n    // rotate vector by the inverse of unit quaternion q (x,y,z,w)\n    vec3 quatRotateInv(vec4 q, vec3 v) {\n        vec3 t = -q.xyz;\n        return v + 2.0 * cross(t, cross(t, v) + q.w * v);\n    }\n\n    // Source-format-compatible getters for user modifier code: local-space values reconstructed\n    // from the stored world-space data (quantized by the work buffer format, so rotation and\n    // scale are approximate).\n    vec3 getCenter() {\n        return (matrix_model_inverse * vec4(workBufferWorldCenter(), 1.0)).xyz;\n    }\n\n    // returns (w,x,y,z) to match the source format getRotation convention\n    vec4 getRotation() {\n        vec4 worldRotation = workBufferWorldRotation();\n        vec4 localRotation = quatMul(vec4(-model_rotation.xyz, model_rotation.w), worldRotation);\n        return localRotation.wxyz;\n    }\n\n    vec3 getScale() {\n        return workBufferWorldScale() / model_scale;\n    }\n\n#endif\n";
export default _default;