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 Copyright (c) 2021-2023 Xiamen Yaji Software Co., Ltd.

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 of this software and associated documentation files (the "Software"), to deal
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 of the Software, and to permit persons to whom the Software is furnished to do so,
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 all copies or substantial portions of the Software.

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#include "primitive/Plane.h"
namespace cc {

IGeometry plane(ccstd::optional<IPlaneOptions> options) {
    if (!options.has_value()) {
        options = IPlaneOptions();
    }
    const float width = options->width;
    const float length = options->length;
    const uint32_t uSegments = options->widthSegments;
    const uint32_t vSegments = options->lengthSegments;

    const float hw = width * 0.5F;
    const float hl = length * 0.5F;

    ccstd::vector<float> positions;
    ccstd::vector<float> uvs;
    ccstd::vector<uint32_t> indices;
    const Vec3 minPos(-hw, 0, -hl);
    const Vec3 maxPos(hw, 0, hl);
    const float boundingRadius = sqrt(width * width + length * length);

    Vec3 c00(-hw, 0, hl);
    Vec3 c10(hw, 0, hl);
    Vec3 c01(-hw, 0, -hl);

    for (uint32_t y = 0; y <= vSegments; ++y) {
        for (uint32_t x = 0; x <= uSegments; ++x) {
            const float u = static_cast<float>(x) / static_cast<float>(uSegments);
            const float v = static_cast<float>(y) / static_cast<float>(vSegments);

            Vec3 temp1 = c00.lerp(c10, u);
            Vec3 temp2 = c00.lerp(c01, v);
            temp2.subtract(c00);
            temp1.add(temp2);

            positions.emplace_back(temp1.x);
            positions.emplace_back(temp1.y);
            positions.emplace_back(temp1.z);
            if (options->includeUV) {
                uvs.emplace_back(u);
                uvs.emplace_back(v);
            }

            if ((x < uSegments) && (y < vSegments)) {
                const uint32_t uSeg1 = uSegments + 1;
                const uint32_t a = x + y * uSeg1;
                const uint32_t b = x + (y + 1) * uSeg1;
                const uint32_t c = (x + 1) + (y + 1) * uSeg1;
                const uint32_t d = (x + 1) + y * uSeg1;

                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 result;
    result.positions = positions;
    result.boundingRadius = boundingRadius;
    result.minPos = minPos;
    result.maxPos = maxPos;
    result.indices = indices;

    if (options->includeNormal) {
        const uint32_t nVertex = (vSegments + 1) * (uSegments + 1);
        ccstd::vector<float> normals(3 * nVertex);
        for (uint32_t i = 0; i < nVertex; ++i) {
            normals[i * 3 + 0] = 0;
            normals[i * 3 + 1] = 1;
            normals[i * 3 + 2] = 0;
        }
        result.normals = normals;
    }
    if (options->includeUV) {
        result.uvs = uvs;
    }
    return result;
}

} // namespace cc