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creates an extruded pentagon VBO with indexing and VAO
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void CreatePentagon() { | |
float step = 2.0*M_PI/5, t=0; | |
Vertex Vertices[7+7+12]; | |
// pentagon[0] = vec3(0); | |
// bottom | |
vec4 color(1,0,0,1); | |
Vertices[0].normal = vec3(0,-1,0); | |
Vertices[0].color = color; | |
for (int i=1; i<7; i++, t-=step) { | |
Vertices[i].pos = vec3(cosf(t),0,sinf(t)); | |
Vertices[i].color = color; | |
Vertices[i].normal = vec3(0,-1,0); | |
} | |
color = vec4(0,1,0,1); | |
// top | |
for (int i=7; i<14; i++) { | |
Vertices[i].pos = Vertices[(7+(7-i))%7].pos + vec3(0,1,0); | |
Vertices[i].color = color; | |
Vertices[i].normal = vec3(0,1,0); | |
} | |
color = vec4(0,0,1,1); | |
// walls | |
for (int i=14; i<26; i+=2, t+=step) { | |
Vertices[i+1].pos = vec3(cosf(t), 0, sinf(t)); | |
Vertices[i+1].color = color; | |
Vertices[i+1].normal = Vertices[i].pos; | |
Vertices[i].pos = vec3(cosf(t), 1, sinf(t)); | |
Vertices[i].color = color; | |
Vertices[i].normal = Vertices[i].pos; // yes, cause it must be normalized | |
} | |
// convert to this silly orientation, you can remove this (just for the assignment) | |
for (int i=0; i<26; i++) { | |
float t = Vertices[i].pos.y; | |
Vertices[i].pos.y = Vertices[i].pos.z; | |
Vertices[i].pos.z = t; | |
t = Vertices[i].normal.y; | |
Vertices[i].normal.y = Vertices[i].normal.x; | |
Vertices[i].normal.x = t; | |
} | |
GLushort Indices[] = { | |
0,1,2, | |
0,2,3, | |
0,3,4, | |
0,4,5, | |
0,5,6, // bottom done | |
7,8,9, | |
7,9,10, | |
7,10,11, | |
7,11,12, | |
7,12,13, // top done | |
14,15,16, // walls start | |
15,17,16, | |
16,17,18, | |
17,19,18, | |
18,19,20, | |
19,21,20, | |
20,21,22, | |
21,23,22, | |
22,23,24, | |
23,25,24, | |
25,0,1 | |
}; | |
// Create Vertex Array Object | |
genVAO(1, &VaoId[VAO_PENT]); | |
bindVAO(VaoId[VAO_PENT]); | |
// Create Buffer for vertex data | |
glGenBuffers(1, &BufferId[BUF_PENT_VERTS]); | |
glBindBuffer(GL_ARRAY_BUFFER, BufferId[BUF_PENT_VERTS]); | |
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW); | |
// Assign vertex attributes | |
glVertexAttribPointer(rootNode.shader.in_Position, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0); | |
glVertexAttribPointer(rootNode.shader.in_Color, 4, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)myOffset(Vertex,color)); | |
if (rootNode.shader.in_Normal != -1) { | |
glVertexAttribPointer(rootNode.shader.in_Normal, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)myOffset(Vertex,normal)); | |
glEnableVertexAttribArray(rootNode.shader.in_Normal); | |
} | |
glEnableVertexAttribArray(rootNode.shader.in_Position); | |
glEnableVertexAttribArray(rootNode.shader.in_Color); | |
// Vreate Buffer for indics | |
glGenBuffers(1, &BufferId[BUF_PENT_IDX]); | |
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, BufferId[BUF_PENT_IDX]); | |
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW); | |
GLenum ErrorCheckValue = glGetError(); | |
if (ErrorCheckValue != GL_NO_ERROR) { | |
fprintf(stderr,"ERROR: Could not create a VBO (%d): %s \n", __LINE__, gluErrorString(ErrorCheckValue)); | |
exit(-1); | |
} | |
bindVAO(0); | |
} |
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