Renderables.h

#pragma once

#include "math/AABB.h"
#include "render/RenderableGeometry.h"
#include "render/RenderableBox.h"
#include "render.h"

namespace selection
{

class RenderableCornerPoints :
    public render::RenderableGeometry
{
private:
    const std::vector<AABB>& _aabbs;
    bool _needsUpdate;
    Vector4 _colour;

public:
    RenderableCornerPoints(const std::vector<AABB>& aabbs) :
        _aabbs(aabbs),
        _needsUpdate(true),
        _colour(1, 1, 1, 1)
    {}

    void setColour(const Colour4b& colour)
    {
        _colour.x() = colour.r / 255.0;
        _colour.y() = colour.g / 255.0;
        _colour.z() = colour.b / 255.0;
        _colour.w() = colour.a / 255.0;
    }

    void queueUpdate()
    {
        _needsUpdate = true;
    }

protected:
    void updateGeometry() override
    {
        if (!_needsUpdate) return;

        _needsUpdate = false;

        std::vector<MeshVertex> vertices;
        std::vector<unsigned int> indices;

        // 8 vertices per box
        vertices.reserve(_aabbs.size() * 8);
        indices.reserve(_aabbs.size() * 8);

        unsigned int index = 0;

        for (const auto& aabb : _aabbs)
        {
            // Calculate the corner vertices of this bounding box
            Vector3 max(aabb.origin + aabb.extents);
            Vector3 min(aabb.origin - aabb.extents);

            auto boxVertices = render::detail::getWireframeBoxVertices(min, max, _colour);
            
            for (const auto& vertex : boxVertices)
            {
                vertices.emplace_back(std::move(vertex));
                indices.push_back(index++);
            }
        }

        RenderableGeometry::updateGeometry(render::GeometryType::Points, vertices, indices);
    }
};

namespace detail
{

inline void generateQuad(std::vector<MeshVertex>& vertices, std::vector<unsigned int>& indices, 
    double size, const Vector4& colour)
{
    unsigned int indexOffset = static_cast<unsigned int>(vertices.size());

    vertices.push_back(MeshVertex({ -size,  size, 0 }, { 0,0,0 }, { 0,0 }, colour));
    vertices.push_back(MeshVertex({  size,  size, 0 }, { 0,0,0 }, { 0,0 }, colour));
    vertices.push_back(MeshVertex({  size, -size, 0 }, { 0,0,0 }, { 0,0 }, colour));
    vertices.push_back(MeshVertex({ -size, -size, 0 }, { 0,0,0 }, { 0,0 }, colour));

    indices.push_back(indexOffset + 0);
    indices.push_back(indexOffset + 1);
    indices.push_back(indexOffset + 1);
    indices.push_back(indexOffset + 2);
    indices.push_back(indexOffset + 2);
    indices.push_back(indexOffset + 3);
    indices.push_back(indexOffset + 3);
    indices.push_back(indexOffset + 0);
}

inline Vector4 toVector4(const Colour4b& colour)
{
    return
    {
        colour.r / 255.0,
        colour.g / 255.0,
        colour.b / 255.0,
        colour.a / 255.0,
    };
}

}

// Renders a fixed size point array as line strip
class RenderableLineStrip :
    public render::RenderableGeometry
{
protected:
    const Matrix4& _localToWorld;
    bool _needsUpdate;
    Vector4 _colour;

    std::vector<Vertex3f> _rawPoints;

public:
    void queueUpdate()
    {
        _needsUpdate = true;
    }

    void setColour(const Colour4b& colour)
    {
        _colour = detail::toVector4(colour);
        queueUpdate();
    }

    const std::vector<Vertex3f>& getRawPoints() const
    {
        return _rawPoints;
    }

protected:
    RenderableLineStrip(std::size_t numPoints, const Matrix4& localToWorld) :
        _localToWorld(localToWorld),
        _needsUpdate(true),
        _rawPoints(numPoints)
    {}

    void updateGeometry() override
    {
        if (!_needsUpdate) return;

        _needsUpdate = false;

        std::vector<MeshVertex> vertices;
        std::vector<unsigned int> indices;

        unsigned int index = 0;

        for (const auto& vertex : _rawPoints)
        {
            vertices.push_back(MeshVertex(_localToWorld * vertex, { 0,0,0 }, { 0,0 }, _colour));

            if (index > 0)
            {
                indices.push_back(index - 1);
                indices.push_back(index);
            }

            ++index;
        }

        RenderableGeometry::updateGeometry(render::GeometryType::Lines, vertices, indices);
    }
};

template<typename RemapPolicy>
class RenderableSemiCircle :
    public RenderableLineStrip
{
public:
    RenderableSemiCircle(std::size_t segments, double radius, const Matrix4& localToWorld) :
        RenderableLineStrip((segments << 2) + 1, localToWorld)
    {
        draw_semicircle<RemapPolicy>(segments, radius, _rawPoints);
    }
};

template<typename RemapPolicy>
class RenderableCircle :
    public RenderableLineStrip
{
public:
    RenderableCircle(std::size_t segments, double radius, const Matrix4& localToWorld) :
        RenderableLineStrip(segments << 3, localToWorld)
    {
        draw_circle<RemapPolicy>(segments, radius, _rawPoints);
    }
};

class RenderableArrowLine :
    public RenderableLineStrip
{
public:
    RenderableArrowLine(const Vector3& direction, const Matrix4& localToWorld) :
        RenderableLineStrip(2, localToWorld)
    {
        _rawPoints[0] = Vector3(0, 0, 0);
        _rawPoints[1] = direction;
    }
};

class RenderableQuad :
    public RenderableLineStrip
{
public:
    RenderableQuad(double edgeLength, const Matrix4& localToWorld) :
        RenderableLineStrip(5, localToWorld)
    {
        _rawPoints[0] = Vector3(edgeLength, edgeLength, 0);
        _rawPoints[1] = Vector3(edgeLength, -edgeLength, 0);
        _rawPoints[2] = Vector3(-edgeLength, -edgeLength, 0);
        _rawPoints[3] = Vector3(-edgeLength, edgeLength, 0);
        _rawPoints[4] = _rawPoints[0];
    }
};

// Renders a few flat-shaded triangles as arrow head, offset by a given amount
class RenderableArrowHead :
    public render::RenderableGeometry
{
protected:
    Vector3 _offset;
    const Vector3& _screenAxis;
    double _width;
    double _height;
    const Matrix4& _localToWorld;
    bool _needsUpdate;
    Vector4 _colour;

    std::vector<Vertex3f> _rawPoints;

public:
    RenderableArrowHead(const Vector3& offset, const Vector3& screenAxis, double width, double height, const Matrix4& localToWorld) :
        _offset(offset),
        _screenAxis(screenAxis),
        _width(width),
        _height(height),
        _localToWorld(localToWorld),
        _needsUpdate(true),
        _rawPoints(3)
    {}

    void queueUpdate()
    {
        _needsUpdate = true;
    }

    void setColour(const Colour4b& colour)
    {
        _colour = detail::toVector4(colour);
        queueUpdate();
    }

    const std::vector<Vertex3f>& getRawPoints() const
    {
        return _rawPoints;
    }

protected:
    void updateGeometry() override
    {
        if (!_needsUpdate) return;

        _needsUpdate = false;

        std::vector<MeshVertex> vertices;
        std::vector<unsigned int> indices;

        auto direction = _offset.getNormalised();
        auto sideWays = _offset.cross(_screenAxis).getNormalised();

        _rawPoints[0] = _offset; // tip
        _rawPoints[1] = _offset - direction * _height + sideWays * _width;
        _rawPoints[2] = _offset - direction * _height - sideWays * _width;

        unsigned int index = 0;

        for (const auto& vertex : _rawPoints)
        {
            vertices.push_back(MeshVertex(_localToWorld * vertex, _screenAxis, { 0,0 }, _colour));
            indices.push_back(index++);
        }

        RenderableGeometry::updateGeometry(render::GeometryType::Triangles, vertices, indices);
    }
};

class RenderablePoint :
    public render::RenderableGeometry
{
protected:
    const Vertex3f& _point;
    const Matrix4& _localToWorld;
    bool _needsUpdate;
    Vector4 _colour;

public:
    RenderablePoint(const Vertex3f& point, const Matrix4& localToWorld) :
        _point(point),
        _localToWorld(localToWorld),
        _needsUpdate(true)
    {}

    void queueUpdate()
    {
        _needsUpdate = true;
    }

    void setColour(const Colour4b& colour)
    {
        _colour = detail::toVector4(colour);
        queueUpdate();
    }

protected:
    void updateGeometry() override
    {
        if (!_needsUpdate) return;

        _needsUpdate = false;

        std::vector<MeshVertex> vertices;
        std::vector<unsigned int> indices;

        vertices.push_back(MeshVertex(_localToWorld * _point, { 0,0,0 }, { 0,0 }, _colour));
        indices.push_back(0);

        RenderableGeometry::updateGeometry(render::GeometryType::Points, vertices, indices);
    }
};

}