pivot.h

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/*
 Copyright (C) 2001-2006, William Joseph.
 All Rights Reserved.

 This file is part of GtkRadiant.

 GtkRadiant is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 GtkRadiant is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with GtkRadiant; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined(INCLUDED_PIVOT_H)
#define INCLUDED_PIVOT_H

#include "math/matrix.h"

inline void billboard_viewplaneOriented (Matrix4& rotation, const Matrix4& world2screen)
{
    rotation = g_matrix4_identity;
    Vector3 x(world2screen.x().getVector3().getNormalised());
    Vector3 y(world2screen.y().getVector3().getNormalised());
    Vector3 z(world2screen.z().getVector3().getNormalised());
    rotation.y().getVector3() = Vector3(x.y(), y.y(), z.y());
    rotation.z().getVector3() = -Vector3(x.z(), y.z(), z.z());
    rotation.x().getVector3() = rotation.y().getVector3().crossProduct(rotation.z().getVector3()).getNormalised();
    rotation.y().getVector3() = rotation.z().getVector3().crossProduct(rotation.x().getVector3());

}

inline void billboard_viewpointOriented (Matrix4& rotation, const Matrix4& world2screen)
{
    Matrix4 screen2world(matrix4_full_inverse(world2screen));

    rotation = g_matrix4_identity;
    rotation.y().getVector3() = screen2world.y().getVector3().getNormalised();
    rotation.z().getVector3() = -screen2world.z().getVector3().getNormalised();
    rotation.x().getVector3() = rotation.y().getVector3().crossProduct(rotation.z().getVector3()).getNormalised();
    rotation.y().getVector3() = rotation.z().getVector3().crossProduct(rotation.x().getVector3());
}

inline void ConstructObject2Screen (Matrix4& object2screen, const Matrix4& object2world, const Matrix4& world2view,
        const Matrix4& view2device, const Matrix4& device2screen)
{
    object2screen = device2screen;
    matrix4_multiply_by_matrix4(object2screen, view2device);
    matrix4_multiply_by_matrix4(object2screen, world2view);
    matrix4_multiply_by_matrix4(object2screen, object2world);
}

inline void ConstructObject2Device (Matrix4& object2screen, const Matrix4& object2world, const Matrix4& world2view,
        const Matrix4& view2device)
{
    object2screen = view2device;
    matrix4_multiply_by_matrix4(object2screen, world2view);
    matrix4_multiply_by_matrix4(object2screen, object2world);
}

inline void ConstructDevice2Object (Matrix4& device2object, const Matrix4& object2world, const Matrix4& world2view,
        const Matrix4& view2device)
{
    ConstructObject2Device(device2object, object2world, world2view, view2device);
    matrix4_full_invert(device2object);
}

inline void pivot_scale (Matrix4& scale, const Matrix4& pivot2screen)
{
    Matrix4 pre_scale(g_matrix4_identity);
    pre_scale[0] = static_cast<float> (pivot2screen.x().getVector3().getLength());
    pre_scale[5] = static_cast<float> (pivot2screen.y().getVector3().getLength());
    pre_scale[10] = static_cast<float> (pivot2screen.z().getVector3().getLength());

    scale = pivot2screen;
    matrix4_multiply_by_matrix4(scale, pre_scale);
    matrix4_full_invert(scale);
    matrix4_multiply_by_matrix4(scale, pivot2screen);
}

// scale by (inverse) W
inline void pivot_perspective (Matrix4& scale, const Matrix4& pivot2screen)
{
    scale = g_matrix4_identity;
    scale[0] = scale[5] = scale[10] = pivot2screen[15];
}

inline void ConstructDevice2Manip (Matrix4& device2manip, const Matrix4& object2world, const Matrix4& world2view,
        const Matrix4& view2device, const Matrix4& device2screen)
{
    Matrix4 pivot2screen;
    ConstructObject2Screen(pivot2screen, object2world, world2view, view2device, device2screen);

    ConstructObject2Device(device2manip, object2world, world2view, view2device);

    Matrix4 scale;
    pivot_scale(scale, pivot2screen);
    matrix4_multiply_by_matrix4(device2manip, scale);
    pivot_perspective(scale, pivot2screen);
    matrix4_multiply_by_matrix4(device2manip, scale);

    matrix4_full_invert(device2manip);
}

inline void Pivot2World_worldSpace (Matrix4& manip2world, const Matrix4& pivot2world, const Matrix4& modelview,
        const Matrix4& projection, const Matrix4& viewport)
{
    manip2world = pivot2world;

    Matrix4 pivot2screen;
    ConstructObject2Screen(pivot2screen, pivot2world, modelview, projection, viewport);

    Matrix4 scale;
    pivot_scale(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);
    pivot_perspective(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);
}

inline void Pivot2World_viewpointSpace (Matrix4& manip2world, Vector3& axis, const Matrix4& pivot2world,
        const Matrix4& modelview, const Matrix4& projection, const Matrix4& viewport)
{
    manip2world = pivot2world;

    Matrix4 pivot2screen;
    ConstructObject2Screen(pivot2screen, pivot2world, modelview, projection, viewport);

    Matrix4 scale;
    pivot_scale(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);

    billboard_viewpointOriented(scale, pivot2screen);
    axis = scale.z().getVector3();
    matrix4_multiply_by_matrix4(manip2world, scale);

    pivot_perspective(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);
}

inline void Pivot2World_viewplaneSpace (Matrix4& manip2world, const Matrix4& pivot2world, const Matrix4& modelview,
        const Matrix4& projection, const Matrix4& viewport)
{
    manip2world = pivot2world;

    Matrix4 pivot2screen;
    ConstructObject2Screen(pivot2screen, pivot2world, modelview, projection, viewport);

    Matrix4 scale;
    pivot_scale(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);

    billboard_viewplaneOriented(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);

    pivot_perspective(scale, pivot2screen);
    matrix4_multiply_by_matrix4(manip2world, scale);
}

#include "renderable.h"
#include "cullable.h"
#include "render.h"

const Colour4b g_colour_x(255, 0, 0, 255);
const Colour4b g_colour_y(0, 255, 0, 255);
const Colour4b g_colour_z(0, 0, 255, 255);

class Shader;

class RenderablePivot: public OpenGLRenderable
{
        VertexBuffer<PointVertex> m_vertices;
    public:
        mutable Matrix4 m_localToWorld;
        typedef Static<Shader*> StaticShader;
        static Shader* getShader ()
        {
            return StaticShader::instance();
        }

        RenderablePivot ()
        {
            m_vertices.reserve(6);

            m_vertices.push_back(PointVertex(Vertex3f(0, 0, 0), g_colour_x));
            m_vertices.push_back(PointVertex(Vertex3f(16, 0, 0), g_colour_x));

            m_vertices.push_back(PointVertex(Vertex3f(0, 0, 0), g_colour_y));
            m_vertices.push_back(PointVertex(Vertex3f(0, 16, 0), g_colour_y));

            m_vertices.push_back(PointVertex(Vertex3f(0, 0, 0), g_colour_z));
            m_vertices.push_back(PointVertex(Vertex3f(0, 0, 16), g_colour_z));
        }

        void render (RenderStateFlags state) const
        {
            if (m_vertices.size() == 0)
                return;
            if (m_vertices.data() == 0)
                return;
            glVertexPointer(3, GL_FLOAT, sizeof(PointVertex), &m_vertices.data()->vertex);
            glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(PointVertex), &m_vertices.data()->colour);
            glDrawArrays(GL_LINES, 0, m_vertices.size());
        }

        void render (Renderer& renderer, const VolumeTest& volume, const Matrix4& localToWorld) const
        {
            renderer.PushState();

            Pivot2World_worldSpace(m_localToWorld, localToWorld, volume.GetModelview(), volume.GetProjection(),
                    volume.GetViewport());

            renderer.Highlight(Renderer::ePrimitive, false);
            renderer.SetState(getShader(), Renderer::eWireframeOnly);
            renderer.SetState(getShader(), Renderer::eFullMaterials);
            renderer.addRenderable(*this, m_localToWorld);

            renderer.PopState();
        }
};

#endif