7a14aadb28
* Add missing method to query the type of a light * IcoSphere now generates front facing triangles * Add a fairly generic sphere object to use in samples it provides an ico sphere with normal, and reuses the same vertex/index buffer for each new instance. Each instance can have its own material, size and position. currently it’s not possible to change the # of subdivisions. * FilamentApp now provides a “default” pbr material this makes it easier to create renderables for testing. * clean-up lightbulb and add spheres for each light lightbulb now has less hardcoded things and it spawns a small sphere for each light.
84 lines
3.1 KiB
C++
84 lines
3.1 KiB
C++
/*
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* Copyright (C) 2018 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "IcoSphere.h"
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#include <array>
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static constexpr float X = .525731112119133606f;
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static constexpr float Z = .850650808352039932f;
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static constexpr float N = 0.f;
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const IcoSphere::VertexList IcoSphere::sVertices = {
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{ -X, N, Z }, { X, N, Z }, { -X, N, -Z }, { X, N, -Z },
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{ N, Z, X }, { N, Z, -X }, { N, -Z, X }, { N, -Z, -X },
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{ Z, X, N }, { -Z, X, N }, { Z, -X, N }, { -Z, -X, N }
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};
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const IcoSphere::TriangleList IcoSphere::sTriangles = {
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{ 1, 4, 0 }, { 4, 9, 0 }, { 4, 5, 9 }, { 8, 5, 4 }, { 1, 8, 4 },
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{ 1, 10, 8 }, { 10, 3, 8 }, { 8, 3, 5 }, { 3, 2, 5 }, { 3, 7, 2 },
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{ 3, 10, 7 }, { 10, 6, 7 }, { 6, 11, 7 }, { 6, 0, 11 }, { 6, 1, 0 },
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{ 10, 1, 6 }, { 11, 0, 9 }, { 2, 11, 9 }, { 5, 2, 9 }, { 11, 2, 7 }
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};
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IcoSphere::IcoSphere(size_t subdivisions) {
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mMesh = std::move(make_icosphere(subdivisions));
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}
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IcoSphere::Index IcoSphere::vertex_for_edge(
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Lookup& lookup, VertexList& vertices, Index first, Index second) {
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Lookup::key_type key(first, second);
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if (key.first > key.second) {
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std::swap(key.first, key.second);
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}
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auto inserted = lookup.insert({ key, vertices.size() });
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if (inserted.second) {
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auto edge0 = vertices[first];
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auto edge1 = vertices[second];
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auto point = normalize(edge0 + edge1);
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vertices.push_back(point);
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}
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return inserted.first->second;
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}
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IcoSphere::TriangleList IcoSphere::subdivide(VertexList& vertices, TriangleList const& triangles) {
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Lookup lookup;
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TriangleList result;
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for (Triangle const& each : triangles) {
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std::array<Index, 3> mid;
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mid[0] = vertex_for_edge(lookup, vertices, each.vertex[0], each.vertex[1]);
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mid[1] = vertex_for_edge(lookup, vertices, each.vertex[1], each.vertex[2]);
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mid[2] = vertex_for_edge(lookup, vertices, each.vertex[2], each.vertex[0]);
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result.push_back({ each.vertex[0], mid[0], mid[2] });
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result.push_back({ each.vertex[1], mid[1], mid[0] });
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result.push_back({ each.vertex[2], mid[2], mid[1] });
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result.push_back({ mid[0], mid[1], mid[2] });
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}
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return result;
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}
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IcoSphere::IndexedMesh IcoSphere::make_icosphere(int subdivisions) {
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VertexList vertices = sVertices;
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TriangleList triangles = sTriangles;
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for (int i = 0; i < subdivisions; ++i) {
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triangles = subdivide(vertices, triangles);
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}
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return { vertices, triangles };
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}
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