Cube* Cube::Create()
{
static const Scalar Normals[] = {
0, 0, +1.0f, // A+Z
0, -1.0f, 0, // A-Y
-1.0f, 0, 0, // A-X
0, 0, +1.0f, // B+Z
0, -1.0f, 0, // B-Y
+1.0f, 0, 0, // B+X
0, 0, +1.0f, // C+Z
0, +1.0f, 0, // C+Y
+1.0f, 0, 0, // C+X
0, 0, +1.0f, // D+Z
0, +1.0f, 0, // D+Y
-1.0f, 0, 0, // D-X
0, 0, -1.0f, // E-Z
0, -1.0f, 0, // E-Y
-1.0f, 0, 0, // E-X
0, 0, -1.0f, // F-Z
0, -1.0f, 0, // F-Y
+1.0f, 0, 0, // F+X
0, 0, -1.0f, // G-Z
0, +1.0f, 0, // G+Y
+1.0f, 0, 0, // G+X
0, 0, -1.0f, // H-Z
0, +1.0f, 0, // H+Y
-1.0f, 0, 0 // H-X
};
static const int Indices[] = {
0, 9, 6, // +Z
0, 3, 6,
15, 18, 21, // -Z
15, 12, 21,
14, 23, 11, // +Y
14, 2, 11,
5, 8, 20, // -Y
5, 17, 20,
10, 22, 19, // +X
10, 7, 19,
1, 13, 16, // -X
1, 4, 16
};
static const Scalar TexCoords[] = {
0.995f, 0.005f, // A+Z
0.005f, 0.995f, // A-Y
0.995f, 0.005f, // A-X
0.005f, 0.005f, // B+Z
0.995f, 0.995f, // B-Y
0.005f, 0.005f, // B+X
0.005f, 0.995f, // C+Z
0.995f, 0.005f, // C+Y
0.005f, 0.995f, // C+X
0.995f, 0.995f, // D+Z
0.005f, 0.005f, // D+Y
0.995f, 0.995f, // D-X
0.005f, 0.005f, // E-Z
0.005f, 0.005f, // E-Y
0.005f, 0.005f, // E-X
0.995f, 0.005f, // F-Z
0.995f, 0.005f, // F-Y
0.995f, 0.005f, // F+X
0.995f, 0.995f, // G-Z
0.995f, 0.995f, // G+Y
0.995f, 0.995f, // G+X
0.005f, 0.995f, // H-Z
0.005f, 0.995f, // H+Y
0.005f, 0.995f // H-X
};
static const Scalar Positions[] = {
-0.5f, -0.5f, +0.5f,
-0.5f, -0.5f, +0.5f,
-0.5f, -0.5f, +0.5f,
+0.5f, -0.5f, +0.5f,
+0.5f, -0.5f, +0.5f,
+0.5f, -0.5f, +0.5f,
+0.5f, +0.5f, +0.5f,
+0.5f, +0.5f, +0.5f,
+0.5f, +0.5f, +0.5f,
-0.5f, +0.5f, +0.5f,
-0.5f, +0.5f, +0.5f,
-0.5f, +0.5f, +0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
+0.5f, -0.5f, -0.5f,
+0.5f, -0.5f, -0.5f,
+0.5f, -0.5f, -0.5f,
+0.5f, +0.5f, -0.5f,
+0.5f, +0.5f, -0.5f,
+0.5f, +0.5f, -0.5f,
-0.5f, +0.5f, -0.5f,
-0.5f, +0.5f, -0.5f,
-0.5f, +0.5f, -0.5f
};
Cube* C = new Cube;
if(C->CreateBuffers() != BGE_SUCCESS) {
delete C;
return NULL;
}
C->SetPositionData(24, Positions);
C->SetNormalData(24, Normals);
C->SetTexCoordData(24, TexCoords);
C->SetIndexData(36, Indices);
C->Unbind();
return C;
}
Cube* Cube::Create(Scalar Length, Scalar Width, Scalar Height)
{
Cube* C = new Cube;
if(C->CreateBuffers() != BGE_SUCCESS) {
delete C;
return NULL;
}
/* So following changes affect our cube's VAO */
C->BindVAO();
/* *
* A cube has 6 faces, each composed of two triangles.
* We only need 8 vertices (3 components for each vertex, 24 buffer size)
* The indices buffer will create our triangles
* */
C->NumFaces = 6;
C->NumVertices = 4 * 6; /* 4 vertices per face */
C->NumIndices = 36; /* 2 triangles per face, 3 vertices per triangle */
Scalar* Vertices = new Scalar[72];
Scalar* Normals = new Scalar[72];
Scalar* TexCoords = new Scalar[48];
unsigned int* Indices = new unsigned int[36];
/* *
* H__________G
* /| /|
* D/_|_______C/ | +Y HEIGHT
* | | | | | MODEL COORDINATE
* | | | | |
* | |E______|__|F |_____ +X WIDTH
* | / | / /
* |/_________|/ /
* A B +Z LENGTH
*
* Each of A through H corresponds to 3 separate vertices.
* They are separate so normals can be constant across each
* of the cube's faces.
*
* e.g. A corresponds to vertices A+Z, A-Y and A-X
*
* Texcoords
* Z and X faces: When the face normal is pointing towards you and
* the Y axis pointing up, texcoords are as follows
* BL 0, 0 BR 1, 0
* TL 0, 1 TR 1, 1
*
* e.g. +Z face:
* A 0, 0
* B 1, 0
* D 0, 1
* C 1, 1
*
* Y faces:
* +Y:
* D 0, 0
* C 1, 0
* H 0, 1
* G 1, 1
*
* -Y:
* E 0, 0
* F 1, 0
* A 0, 1
* B 1, 1
* */
/* *
* Convenience. Dimensions are full edge measurements and the cube is
* formed around the origin (0, 0, 0) anyways
* */
Width /= 2;
Length /= 2;
Height /= 2;
memset((void*)Normals, 0, sizeof(Normals[0]) * 72);
memset((void*)TexCoords, 0, sizeof(TexCoords[0]) * 48);
/* +Z */
Indices[0] = 0;
Indices[1] = 9;
Indices[2] = 6;
Indices[3] = 0;
Indices[4] = 3;
Indices[5] = 6;
/* -Z */
Indices[6] = 15;
Indices[7] = 18;
Indices[8] = 21;
Indices[9] = 15;
Indices[10] = 12;
Indices[11] = 21;
/* -X */
Indices[12] = 14;
Indices[13] = 23;
Indices[14] = 11;
Indices[15] = 14;
Indices[16] = 2;
Indices[17] = 11;
/* +X */
Indices[18] = 5;
Indices[19] = 8;
Indices[20] = 20;
Indices[21] = 5;
Indices[22] = 17;
Indices[23] = 20;
/* +Y */
Indices[24] = 10;
Indices[25] = 22;
Indices[26] = 19;
Indices[27] = 10;
Indices[28] = 7;
Indices[29] = 19;
/* -Y */
Indices[30] = 1;
Indices[31] = 13;
Indices[32] = 16;
Indices[33] = 1;
Indices[34] = 4;
Indices[35] = 16;
/* A+Z */
Vertices[0] = -Width;
Vertices[1] = -Height;
Vertices[2] = +Length;
Normals[2] = +1.0f;
/* A-Y */
Vertices[3] = -Width;
Vertices[4] = -Height;
Vertices[5] = +Length;
Normals[4] = -1.0f;
TexCoords[3] = 1;
/* A-X */
Vertices[6] = -Width;
Vertices[7] = -Height;
Vertices[8] = +Length;
Normals[6] = -1.0f;
TexCoords[4] = 1;
/* B+Z */
Vertices[9] = +Width;
Vertices[10] = -Height;
Vertices[11] = +Length;
Normals[11] = +1.0f;
TexCoords[6] = 1;
/* B-Y */
Vertices[12] = +Width;
Vertices[13] = -Height;
Vertices[14] = +Length;
Normals[13] = -1.0f;
TexCoords[8] = 1;
TexCoords[9] = 1;
/* B+X */
Vertices[15] = +Width;
Vertices[16] = -Height;
Vertices[17] = +Length;
Normals[15] = + 1.0f;
/* C+Z */
Vertices[18] = +Width;
Vertices[19] = +Height;
Vertices[20] = +Length;
Normals[20] = +1.0f;
TexCoords[12] = 1;
TexCoords[13] = 1;
/* C+Y */
Vertices[21] = +Width;
Vertices[22] = +Height;
Vertices[23] = +Length;
Normals[22] = + 1.0f;
TexCoords[14] = 1;
/* C+X */
Vertices[24] = +Width;
Vertices[25] = +Height;
Vertices[26] = +Length;
Normals[24] = +1.0f;
TexCoords[17] = 1;
/* D+Z */
Vertices[27] = -Width;
Vertices[28] = +Height;
Vertices[29] = +Length;
Normals[29] = +1.0f;
TexCoords[19] = 1;
/* D+Y */
Vertices[30] = -Width;
Vertices[31] = +Height;
Vertices[32] = +Length;
Normals[31] = +1.0f;
/* D-X */
Vertices[33] = -Width;
Vertices[34] = +Height;
Vertices[35] = +Length;
Normals[33] = -1.0f;
TexCoords[22] = 1;
TexCoords[23] = 1;
/* E-Z */
Vertices[36] = -Width;
Vertices[37] = -Height;
Vertices[38] = -Length;
Normals[38] = -1.0f;
TexCoords[24] = 1;
/* E-Y */
Vertices[39] = -Width;
Vertices[40] = -Height;
Vertices[41] = -Length;
Normals[40] = -1.0f;
/* E-X */
Vertices[42] = -Width;
Vertices[43] = -Height;
Vertices[44] = -Length;
Normals[42] = -1.0f;
/* F-Z */
Vertices[45] = +Width;
Vertices[46] = -Height;
Vertices[47] = -Length;
Normals[47] = -1.0f;
/* F-Y */
Vertices[48] = +Width;
Vertices[49] = -Height;
Vertices[50] = -Length;
Normals[49] = -1.0f;
TexCoords[32] = 1;
/* F+X */
Vertices[51] = +Width;
Vertices[52] = -Height;
Vertices[53] = -Length;
Normals[51] = +1.0f;
TexCoords[34] = 1;
/* G-Z */
Vertices[54] = +Width;
Vertices[55] = +Height;
Vertices[56] = -Length;
Normals[56] = -1.0f;
TexCoords[37] = 1;
/* G+Y */
Vertices[57] = +Width;
Vertices[58] = +Height;
Vertices[59] = -Length;
Normals[58] = +1.0f;
TexCoords[38] = 1;
TexCoords[39] = 1;
/* G+X */
Vertices[60] = +Width;
Vertices[61] = +Height;
Vertices[62] = -Length;
Normals[60] = +1.0f;
TexCoords[40] = 1;
TexCoords[41] = 1;
/* H-Z */
Vertices[63] = -Width;
Vertices[64] = +Height;
Vertices[65] = -Length;
Normals[65] = -1.0f;
TexCoords[42] = 1;
TexCoords[43] = 1;
/* H+Y */
Vertices[66] = -Width;
Vertices[67] = +Height;
Vertices[68] = -Length;
Normals[67] = +1.0f;
TexCoords[45] = 1;
/* H-X */
Vertices[69] = -Width;
Vertices[70] = +Height;
Vertices[71] = -Length;
Normals[69] = -1.0f;
TexCoords[47] = 1;
glBindBuffer(GL_ARRAY_BUFFER, C->MeshBuffers[MESH_BUFFER_POSITIONS]);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices[0]) * 72, Vertices,
GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, C->MeshBuffers[MESH_BUFFER_NORMALS]);
glBufferData(GL_ARRAY_BUFFER, sizeof(Normals[0]) * 72, Normals,
GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, C->MeshBuffers[MESH_BUFFER_TEXCOORDS]);
glBufferData(GL_ARRAY_BUFFER, sizeof(TexCoords[0]) * 48, TexCoords,
GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, C->MeshBuffers[MESH_BUFFER_INDICES]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices[0]) * 36,
Indices, GL_STATIC_DRAW);
C->Unbind();
delete[] Vertices;
delete[] Normals;
delete[] Indices;
delete[] TexCoords;
return C;
}
