cocos_lib/cocos/primitive/Sphere.cpp

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3.7 KiB

/****************************************************************************
Copyright (c) 2021-2023 Xiamen Yaji Software Co., Ltd.
http://www.cocos.com
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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****************************************************************************/
#include "primitive/Sphere.h"
namespace cc {
IGeometry sphere(float radius, const ccstd::optional<ISphereOptions> &opts) {
const uint32_t segments = opts.has_value() ? opts->segments : 32;
// lat === latitude
// lon === longitude
ccstd::vector<float> positions;
ccstd::vector<float> normals;
ccstd::vector<float> uvs;
ccstd::vector<uint32_t> indices;
const Vec3 minPos(-radius, -radius, -radius);
const Vec3 maxPos(radius, radius, radius);
const float boundingRadius = radius;
for (uint32_t lat = 0; lat <= segments; lat++) {
const float theta = static_cast<float>(lat) * math::PI / static_cast<float>(segments);
const float sinTheta = sin(theta);
const float cosTheta = -cos(theta);
for (uint32_t lon = 0; lon <= segments; ++lon) {
const float phi = static_cast<float>(lon) * 2.F * math::PI / static_cast<float>(segments) - math::PI / 2.F;
const float sinPhi = sin(phi);
const float cosPhi = cos(phi);
const float x = sinPhi * sinTheta;
const float y = cosTheta;
const float z = cosPhi * sinTheta;
const float u = static_cast<float>(lon) / static_cast<float>(segments);
const float v = static_cast<float>(lat) / static_cast<float>(segments);
positions.emplace_back(x * radius);
positions.emplace_back(y * radius);
positions.emplace_back(z * radius);
normals.emplace_back(x);
normals.emplace_back(y);
normals.emplace_back(z);
uvs.emplace_back(u);
uvs.emplace_back(v);
if ((lat < segments) && (lon < segments)) {
const uint32_t seg1 = segments + 1;
const uint32_t a = seg1 * lat + lon;
const uint32_t b = seg1 * (lat + 1) + lon;
const uint32_t c = seg1 * (lat + 1) + lon + 1;
const uint32_t d = seg1 * lat + lon + 1;
indices.emplace_back(a);
indices.emplace_back(d);
indices.emplace_back(b);
indices.emplace_back(d);
indices.emplace_back(c);
indices.emplace_back(b);
}
}
}
IGeometry info;
info.positions = positions;
info.normals = normals;
info.uvs = uvs;
info.boundingRadius = boundingRadius;
info.minPos = minPos;
info.maxPos = maxPos;
info.indices = indices;
return info;
}
} // namespace cc