playcanvas
Version:
PlayCanvas WebGL game engine
94 lines (76 loc) • 3.13 kB
JavaScript
var gsplatCompressedDataVS = /* glsl */ `
uniform highp usampler2D packedTexture;
uniform highp sampler2D chunkTexture;
// work values
vec4 chunkDataA; // x: min_x, y: min_y, z: min_z, w: max_x
vec4 chunkDataB; // x: max_y, y: max_z, z: scale_min_x, w: scale_min_y
vec4 chunkDataC; // x: scale_min_z, y: scale_max_x, z: scale_max_y, w: scale_max_z
vec4 chunkDataD; // x: min_r, y: min_g, z: min_b, w: max_r
vec4 chunkDataE; // x: max_g, y: max_b, z: unused, w: unused
uvec4 packedData; // x: position bits, y: rotation bits, z: scale bits, w: color bits
vec3 unpack111011(uint bits) {
return vec3(
float(bits >> 21u) / 2047.0,
float((bits >> 11u) & 0x3ffu) / 1023.0,
float(bits & 0x7ffu) / 2047.0
);
}
vec4 unpack8888(uint bits) {
return vec4(
float(bits >> 24u) / 255.0,
float((bits >> 16u) & 0xffu) / 255.0,
float((bits >> 8u) & 0xffu) / 255.0,
float(bits & 0xffu) / 255.0
);
}
const float norm = 1.0 / (sqrt(2.0) * 0.5);
vec4 unpackRotation(uint bits) {
float a = (float((bits >> 20u) & 0x3ffu) / 1023.0 - 0.5) * norm;
float b = (float((bits >> 10u) & 0x3ffu) / 1023.0 - 0.5) * norm;
float c = (float(bits & 0x3ffu) / 1023.0 - 0.5) * norm;
float m = sqrt(1.0 - (a * a + b * b + c * c));
uint mode = bits >> 30u;
if (mode == 0u) return vec4(m, a, b, c);
if (mode == 1u) return vec4(a, m, b, c);
if (mode == 2u) return vec4(a, b, m, c);
return vec4(a, b, c, m);
}
// read center
vec3 readCenter(SplatSource source) {
uint w = uint(textureSize(chunkTexture, 0).x) / 5u;
uint chunkId = source.id / 256u;
ivec2 chunkUV = ivec2((chunkId % w) * 5u, chunkId / w);
// read chunk and packed compressed data
chunkDataA = texelFetch(chunkTexture, chunkUV, 0);
chunkDataB = texelFetch(chunkTexture, chunkUV + ivec2(1, 0), 0);
chunkDataC = texelFetch(chunkTexture, chunkUV + ivec2(2, 0), 0);
chunkDataD = texelFetch(chunkTexture, chunkUV + ivec2(3, 0), 0);
chunkDataE = texelFetch(chunkTexture, chunkUV + ivec2(4, 0), 0);
packedData = texelFetch(packedTexture, source.uv, 0);
return mix(chunkDataA.xyz, vec3(chunkDataA.w, chunkDataB.xy), unpack111011(packedData.x));
}
vec4 readColor(in SplatSource source) {
vec4 r = unpack8888(packedData.w);
return vec4(mix(chunkDataD.xyz, vec3(chunkDataD.w, chunkDataE.xy), r.rgb), r.w);
}
vec4 getRotation() {
return unpackRotation(packedData.y);
}
vec3 getScale() {
return exp(mix(vec3(chunkDataB.zw, chunkDataC.x), chunkDataC.yzw, unpack111011(packedData.z)));
}
// given a rotation matrix and scale vector, compute 3d covariance A and B
void readCovariance(in SplatSource source, out vec3 covA, out vec3 covB) {
mat3 rot = quatToMat3(getRotation());
vec3 scale = getScale();
// M = S * R
mat3 M = transpose(mat3(
scale.x * rot[0],
scale.y * rot[1],
scale.z * rot[2]
));
covA = vec3(dot(M[0], M[0]), dot(M[0], M[1]), dot(M[0], M[2]));
covB = vec3(dot(M[1], M[1]), dot(M[1], M[2]), dot(M[2], M[2]));
}
`;
export { gsplatCompressedDataVS as default };