////  GeometryCache.cpp//  interface////  Created by Andrzej Kapolka on 6/21/13.//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved. #include <cmath> #include "GeometryCache.h"#include "world.h" GeometryCache::~GeometryCache() {    foreach (const VerticesIndices& vbo, _hemisphereVBOs) {        glDeleteBuffers(1, &vbo.first);        glDeleteBuffers(1, &vbo.second);    }} void GeometryCache::renderHemisphere(int slices, int stacks) {    VerticesIndices& vbo = _hemisphereVBOs[SlicesStacks(slices, stacks)];    int vertices = slices * (stacks - 1) + 1;    int indices = slices * 2 * 3 * (stacks - 2) + slices * 3;    if (vbo.first == 0) {            GLfloat* vertexData = new GLfloat[vertices * 3];        GLfloat* vertex = vertexData;        for (int i = 0; i < stacks - 1; i++) {            float phi = PIf * 0.5f * i / (stacks - 1);            float z = sinf(phi), radius = cosf(phi);                        for (int j = 0; j < slices; j++) {                float theta = PIf * 2.0f * j / slices;                 *(vertex++) = sinf(theta) * radius;                *(vertex++) = cosf(theta) * radius;                *(vertex++) = z;            }        }        *(vertex++) = 0.0f;        *(vertex++) = 0.0f;        *(vertex++) = 1.0f;                glGenBuffers(1, &vbo.first);        glBindBuffer(GL_ARRAY_BUFFER, vbo.first);        const int BYTES_PER_VERTEX = 3 * sizeof(GLfloat);        glBufferData(GL_ARRAY_BUFFER, vertices * BYTES_PER_VERTEX, vertexData, GL_STATIC_DRAW);        delete[] vertexData;                GLushort* indexData = new GLushort[indices];        GLushort* index = indexData;        for (int i = 0; i < stacks - 2; i++) {            GLushort bottom = i * slices;            GLushort top = bottom + slices;            for (int j = 0; j < slices; j++) {                int next = (j + 1) % slices;                                *(index++) = bottom + j;                *(index++) = top + next;                *(index++) = top + j;                                *(index++) = bottom + j;                *(index++) = bottom + next;                *(index++) = top + next;            }        }        GLushort bottom = (stacks - 2) * slices;        GLushort top = bottom + slices;        for (int i = 0; i < slices; i++) {                *(index++) = bottom + i;            *(index++) = bottom + (i + 1) % slices;            *(index++) = top;        }                glGenBuffers(1, &vbo.second);        glBindBuffer(GL_ARRAY_BUFFER, vbo.second);        const int BYTES_PER_INDEX = sizeof(GLushort);        glBufferData(GL_ARRAY_BUFFER, indices * BYTES_PER_INDEX, indexData, GL_STATIC_DRAW);        delete[] indexData;        } else {        glBindBuffer(GL_ARRAY_BUFFER, vbo.first);        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbo.second);    }    glEnableClientState(GL_VERTEX_ARRAY);    glEnableClientState(GL_NORMAL_ARRAY);     glVertexPointer(3, GL_FLOAT, 0, 0);    glNormalPointer(GL_FLOAT, 0, 0);            glDrawRangeElementsEXT(GL_TRIANGLES, 0, vertices - 1, indices, GL_UNSIGNED_SHORT, 0);            glDisableClientState(GL_VERTEX_ARRAY);    glDisableClientState(GL_NORMAL_ARRAY);        glBindBuffer(GL_ARRAY_BUFFER, 0);    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);}