1 //
2 // Copyright 2014 The ANGLE Project Authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
5 //
6 // geometry_utils:
7 // Helper library for generating certain sets of geometry.
8 //
9
10 #include "geometry_utils.h"
11
12 #define _USE_MATH_DEFINES
13 #include <math.h>
14
15 using namespace angle;
16
SphereGeometry()17 SphereGeometry::SphereGeometry() {}
18
~SphereGeometry()19 SphereGeometry::~SphereGeometry() {}
20
CubeGeometry()21 CubeGeometry::CubeGeometry() {}
22
~CubeGeometry()23 CubeGeometry::~CubeGeometry() {}
24
CreateSphereGeometry(size_t sliceCount,float radius,SphereGeometry * result)25 void CreateSphereGeometry(size_t sliceCount, float radius, SphereGeometry *result)
26 {
27 size_t parellelCount = sliceCount / 2;
28 size_t vertexCount = (parellelCount + 1) * (sliceCount + 1);
29 size_t indexCount = parellelCount * sliceCount * 6;
30 float angleStep = static_cast<float>(2.0f * M_PI) / sliceCount;
31
32 result->positions.resize(vertexCount);
33 result->normals.resize(vertexCount);
34 for (size_t i = 0; i < parellelCount + 1; i++)
35 {
36 for (size_t j = 0; j < sliceCount + 1; j++)
37 {
38 Vector3 direction(sinf(angleStep * i) * sinf(angleStep * j), cosf(angleStep * i),
39 sinf(angleStep * i) * cosf(angleStep * j));
40
41 size_t vertexIdx = i * (sliceCount + 1) + j;
42 result->positions[vertexIdx] = direction * radius;
43 result->normals[vertexIdx] = direction;
44 }
45 }
46
47 result->indices.clear();
48 result->indices.reserve(indexCount);
49 for (size_t i = 0; i < parellelCount; i++)
50 {
51 for (size_t j = 0; j < sliceCount; j++)
52 {
53 result->indices.push_back(static_cast<unsigned short>(i * (sliceCount + 1) + j));
54 result->indices.push_back(static_cast<unsigned short>((i + 1) * (sliceCount + 1) + j));
55 result->indices.push_back(
56 static_cast<unsigned short>((i + 1) * (sliceCount + 1) + (j + 1)));
57
58 result->indices.push_back(static_cast<unsigned short>(i * (sliceCount + 1) + j));
59 result->indices.push_back(
60 static_cast<unsigned short>((i + 1) * (sliceCount + 1) + (j + 1)));
61 result->indices.push_back(static_cast<unsigned short>(i * (sliceCount + 1) + (j + 1)));
62 }
63 }
64 }
65
GenerateCubeGeometry(float radius,CubeGeometry * result)66 void GenerateCubeGeometry(float radius, CubeGeometry *result)
67 {
68 result->positions.resize(24);
69 result->positions[0] = Vector3(-radius, -radius, -radius);
70 result->positions[1] = Vector3(-radius, -radius, radius);
71 result->positions[2] = Vector3(radius, -radius, radius);
72 result->positions[3] = Vector3(radius, -radius, -radius);
73 result->positions[4] = Vector3(-radius, radius, -radius);
74 result->positions[5] = Vector3(-radius, radius, radius);
75 result->positions[6] = Vector3(radius, radius, radius);
76 result->positions[7] = Vector3(radius, radius, -radius);
77 result->positions[8] = Vector3(-radius, -radius, -radius);
78 result->positions[9] = Vector3(-radius, radius, -radius);
79 result->positions[10] = Vector3(radius, radius, -radius);
80 result->positions[11] = Vector3(radius, -radius, -radius);
81 result->positions[12] = Vector3(-radius, -radius, radius);
82 result->positions[13] = Vector3(-radius, radius, radius);
83 result->positions[14] = Vector3(radius, radius, radius);
84 result->positions[15] = Vector3(radius, -radius, radius);
85 result->positions[16] = Vector3(-radius, -radius, -radius);
86 result->positions[17] = Vector3(-radius, -radius, radius);
87 result->positions[18] = Vector3(-radius, radius, radius);
88 result->positions[19] = Vector3(-radius, radius, -radius);
89 result->positions[20] = Vector3(radius, -radius, -radius);
90 result->positions[21] = Vector3(radius, -radius, radius);
91 result->positions[22] = Vector3(radius, radius, radius);
92 result->positions[23] = Vector3(radius, radius, -radius);
93
94 result->normals.resize(24);
95 result->normals[0] = Vector3(0.0f, -1.0f, 0.0f);
96 result->normals[1] = Vector3(0.0f, -1.0f, 0.0f);
97 result->normals[2] = Vector3(0.0f, -1.0f, 0.0f);
98 result->normals[3] = Vector3(0.0f, -1.0f, 0.0f);
99 result->normals[4] = Vector3(0.0f, 1.0f, 0.0f);
100 result->normals[5] = Vector3(0.0f, 1.0f, 0.0f);
101 result->normals[6] = Vector3(0.0f, 1.0f, 0.0f);
102 result->normals[7] = Vector3(0.0f, 1.0f, 0.0f);
103 result->normals[8] = Vector3(0.0f, 0.0f, -1.0f);
104 result->normals[9] = Vector3(0.0f, 0.0f, -1.0f);
105 result->normals[10] = Vector3(0.0f, 0.0f, -1.0f);
106 result->normals[11] = Vector3(0.0f, 0.0f, -1.0f);
107 result->normals[12] = Vector3(0.0f, 0.0f, 1.0f);
108 result->normals[13] = Vector3(0.0f, 0.0f, 1.0f);
109 result->normals[14] = Vector3(0.0f, 0.0f, 1.0f);
110 result->normals[15] = Vector3(0.0f, 0.0f, 1.0f);
111 result->normals[16] = Vector3(-1.0f, 0.0f, 0.0f);
112 result->normals[17] = Vector3(-1.0f, 0.0f, 0.0f);
113 result->normals[18] = Vector3(-1.0f, 0.0f, 0.0f);
114 result->normals[19] = Vector3(-1.0f, 0.0f, 0.0f);
115 result->normals[20] = Vector3(1.0f, 0.0f, 0.0f);
116 result->normals[21] = Vector3(1.0f, 0.0f, 0.0f);
117 result->normals[22] = Vector3(1.0f, 0.0f, 0.0f);
118 result->normals[23] = Vector3(1.0f, 0.0f, 0.0f);
119
120 result->texcoords.resize(24);
121 result->texcoords[0] = Vector2(0.0f, 0.0f);
122 result->texcoords[1] = Vector2(0.0f, 1.0f);
123 result->texcoords[2] = Vector2(1.0f, 1.0f);
124 result->texcoords[3] = Vector2(1.0f, 0.0f);
125 result->texcoords[4] = Vector2(1.0f, 0.0f);
126 result->texcoords[5] = Vector2(1.0f, 1.0f);
127 result->texcoords[6] = Vector2(0.0f, 1.0f);
128 result->texcoords[7] = Vector2(0.0f, 0.0f);
129 result->texcoords[8] = Vector2(0.0f, 0.0f);
130 result->texcoords[9] = Vector2(0.0f, 1.0f);
131 result->texcoords[10] = Vector2(1.0f, 1.0f);
132 result->texcoords[11] = Vector2(1.0f, 0.0f);
133 result->texcoords[12] = Vector2(0.0f, 0.0f);
134 result->texcoords[13] = Vector2(0.0f, 1.0f);
135 result->texcoords[14] = Vector2(1.0f, 1.0f);
136 result->texcoords[15] = Vector2(1.0f, 0.0f);
137 result->texcoords[16] = Vector2(0.0f, 0.0f);
138 result->texcoords[17] = Vector2(0.0f, 1.0f);
139 result->texcoords[18] = Vector2(1.0f, 1.0f);
140 result->texcoords[19] = Vector2(1.0f, 0.0f);
141 result->texcoords[20] = Vector2(0.0f, 0.0f);
142 result->texcoords[21] = Vector2(0.0f, 1.0f);
143 result->texcoords[22] = Vector2(1.0f, 1.0f);
144 result->texcoords[23] = Vector2(1.0f, 0.0f);
145
146 result->indices.resize(36);
147 result->indices[0] = 0;
148 result->indices[1] = 2;
149 result->indices[2] = 1;
150 result->indices[3] = 0;
151 result->indices[4] = 3;
152 result->indices[5] = 2;
153 result->indices[6] = 4;
154 result->indices[7] = 5;
155 result->indices[8] = 6;
156 result->indices[9] = 4;
157 result->indices[10] = 6;
158 result->indices[11] = 7;
159 result->indices[12] = 8;
160 result->indices[13] = 9;
161 result->indices[14] = 10;
162 result->indices[15] = 8;
163 result->indices[16] = 10;
164 result->indices[17] = 11;
165 result->indices[18] = 12;
166 result->indices[19] = 15;
167 result->indices[20] = 14;
168 result->indices[21] = 12;
169 result->indices[22] = 14;
170 result->indices[23] = 13;
171 result->indices[24] = 16;
172 result->indices[25] = 17;
173 result->indices[26] = 18;
174 result->indices[27] = 16;
175 result->indices[28] = 18;
176 result->indices[29] = 19;
177 result->indices[30] = 20;
178 result->indices[31] = 23;
179 result->indices[32] = 22;
180 result->indices[33] = 20;
181 result->indices[34] = 22;
182 result->indices[35] = 21;
183 }
184