Cylinder.h

// author: http://www.songho.ca/opengl/gl_cylinder.html

#pragma once
#include <vector>
class Cylinder
{
public:
    // ctor/dtor
    Cylinder(float baseRadius = 1.0f, float topRadius = 1.0f, float height = 1.0f,
        int sectorCount = 36, int stackCount = 1, bool smooth = true);
    ~Cylinder() {}

    // getters/setters
    float getBaseRadius() const { return baseRadius; }
    float getTopRadius() const { return topRadius; }
    float getHeight() const { return height; }
    int getSectorCount() const { return sectorCount; }
    int getStackCount() const { return stackCount; }
    void set(float baseRadius, float topRadius, float height,
        int sectorCount, int stackCount, bool smooth = true);
    void setBaseRadius(float radius);
    void setTopRadius(float radius);
    void setHeight(float radius);
    void setSectorCount(int sectorCount);
    void setStackCount(int stackCount);
    void setSmooth(bool smooth);

    // for vertex data
    unsigned int getVertexCount() const { return (unsigned int)vertices.size() / 3; }
    unsigned int getNormalCount() const { return (unsigned int)normals.size() / 3; }
    unsigned int getTexCoordCount() const { return (unsigned int)texCoords.size() / 2; }
    unsigned int getIndexCount() const { return (unsigned int)indices.size(); }
    unsigned int getLineIndexCount() const { return (unsigned int)lineIndices.size(); }
    unsigned int getTriangleCount() const { return getIndexCount() / 3; }
    unsigned int getVertexSize() const { return (unsigned int)vertices.size() * sizeof(float); }
    unsigned int getNormalSize() const { return (unsigned int)normals.size() * sizeof(float); }
    unsigned int getTexCoordSize() const { return (unsigned int)texCoords.size() * sizeof(float); }
    unsigned int getIndexSize() const { return (unsigned int)indices.size() * sizeof(unsigned int); }
    unsigned int getLineIndexSize() const { return (unsigned int)lineIndices.size() * sizeof(unsigned int); }
    const float* getVertices() const { return vertices.data(); }
    const float* getNormals() const { return normals.data(); }
    const float* getTexCoords() const { return texCoords.data(); }
    const unsigned int* getIndices() const { return indices.data(); }
    const unsigned int* getLineIndices() const { return lineIndices.data(); }

    // for interleaved vertices: V/N/T
    unsigned int getInterleavedVertexCount() const { return getVertexCount(); }    // # of vertices
    unsigned int getInterleavedVertexSize() const { return (unsigned int)interleavedVertices.size() * sizeof(unsigned int); }    // # of bytes
    int getInterleavedStride() const { return interleavedStride; }   // should be 32 bytes
    const float* getInterleavedVertices() const { return &interleavedVertices[0]; }

    // for indices of base/top/side parts
    unsigned int getBaseIndexCount() const { return ((unsigned int)indices.size() - baseIndex) / 2; }
    unsigned int getTopIndexCount() const { return ((unsigned int)indices.size() - baseIndex) / 2; }
    unsigned int getSideIndexCount() const { return baseIndex; }
    unsigned int getBaseStartIndex() const { return baseIndex; }
    unsigned int getTopStartIndex() const { return topIndex; }
    unsigned int getSideStartIndex() const { return 0; }   // side starts from the begining

    void draw() const;          // draw all


protected:

private:
    // member functions
    void clearArrays();
    void buildVerticesSmooth();
    void buildInterleavedVertices();
    void buildUnitCircleVertices();
    void addVertex(float x, float y, float z);
    void addNormal(float x, float y, float z);
    void addTexCoord(float s, float t);
    void addIndices(unsigned int i1, unsigned int i2, unsigned int i3);
    std::vector<float> getSideNormals();
    std::vector<float> computeFaceNormal(float x1, float y1, float z1,
        float x2, float y2, float z2,
        float x3, float y3, float z3);

    // memeber vars
    float baseRadius;
    float topRadius;
    float height;
    int sectorCount;                        // # of slices
    int stackCount;                         // # of stacks
    unsigned int baseIndex;                 // starting index of base
    unsigned int topIndex;                  // starting index of top
    bool smooth;
    std::vector<float> unitCircleVertices;
    std::vector<float> vertices;
    std::vector<float> normals;
    std::vector<float> texCoords;
    std::vector<unsigned int> indices;
    std::vector<unsigned int> lineIndices;

    // interleaved
    std::vector<float> interleavedVertices;
    int interleavedStride;                  // # of bytes to hop to the next vertex (should be 32 bytes)

};