Camera.cpp

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#include <tdme/engine/Camera.h>
 
#include <tdme/tdme.h>
#include <tdme/engine/subsystems/renderer/Renderer.h>
#include <tdme/engine/Frustum.h>
#include <tdme/math/Math.h>
#include <tdme/math/Matrix4x4.h>
#include <tdme/math/Vector3.h>
#include <tdme/utilities/Console.h>
 
using tdme::engine::subsystems::renderer::Renderer;
using tdme::engine::Camera;
using tdme::engine::Frustum;
using tdme::math::Math;
using tdme::math::Matrix4x4;
using tdme::math::Vector3;
using tdme::utilities::Console;
 
Camera::Camera(Renderer* renderer)
{
    this->renderer = renderer;
    width = 0;
    height = 0;
    fovX = 45.0f;
    zNear = 0.1f;
    zFar = 150.0f;
    cameraMode = CAMERAMODE_LOOKAT;
    frustumMode = FRUSTUMMODE_PERSPECTIVE;
    orthographicFrustumScale = 1.0f;
    upVector.set(0.0f, 1.0f, 0.0f);
    forwardVector.set(0.0f, 0.0f, 1.0f);
    sideVector.set(1.0f, 0.0f, 0.0f);
    lookFrom.set(0.0f, 50.0f, 400.0f);
    lookAt.set(0.0f, 50.0f, 0.0f);
    frustum = new Frustum(renderer);
}
 
Camera::~Camera() {
    delete frustum;
}
 
Vector3 Camera::defaultUp(0.0f, 1.0f, 0.0f);
 
Vector3 Camera::computeUpVector(const Vector3& lookFrom, const Vector3& lookAt)
{
    Vector3 tmpForward;
    Vector3 tmpUpVector;
    tmpForward.set(lookAt).sub(lookFrom).normalize();
    if (Math::abs(tmpForward.getX()) < Math::EPSILON && Math::abs(tmpForward.getZ()) < Math::EPSILON) {
        tmpUpVector.set(0.0f, 0.0f, tmpForward.getY()).normalize();
        return tmpUpVector;
    }
    auto tmpSide = Vector3::computeCrossProduct(tmpForward, defaultUp).normalize();
    tmpUpVector = Vector3::computeCrossProduct(tmpSide, tmpForward).normalize();
    return tmpUpVector;
}
 
Matrix4x4& Camera::computeProjectionMatrix()
{
    // see: see http://www.songho.ca/opengl/gl_transform.html
    switch(frustumMode) {
        case FRUSTUMMODE_ORTHOGRAPHIC:
            {
                auto leftPlane = (-width / 2.0f) * orthographicFrustumScale;
                auto rightPlane = (width / 2.0f) * orthographicFrustumScale;
                auto topPlane = (height / 2.0f) * orthographicFrustumScale;
                auto bottomPlane = (-height / 2.0f) * orthographicFrustumScale;
                auto nearPlane = zNear;
                auto farPlane = zFar;
                return projectionMatrix.set(
                    2.0f / (rightPlane - leftPlane),
                    0.0f,
                    0.0f,
                    0.0f,
                    0.0f,
                    2.0f / (topPlane - bottomPlane),
                    0.0f,
                    0.0f,
                    0.0f,
                    0.0f,
                    -2.0f / (farPlane - nearPlane),
                    0.0f,
                    -(rightPlane + leftPlane) / (rightPlane - leftPlane),
                    -(topPlane + bottomPlane) / (topPlane - bottomPlane),
                    -(farPlane + nearPlane) / (farPlane - nearPlane),
                    1.0f
                );
            }
        default:
            {
                // see: https://github.com/g-truc/glm
                auto aspect = static_cast<float>(this->height) / static_cast<float>(this->width);
                auto rad = fovX * 3.1415927f / 180.0f;
                auto _height = Math::cos(0.5f * rad) / Math::sin(0.5 * rad);
                auto _width = _height * aspect;
                return projectionMatrix.set(
                    _width,
                    0.0f,
                    0.0f,
                    0.0f,
                    0.0f,
                    _height,
                    0.0f,
                    0.0f,
                    0.0f,
                    0.0f,
                    -(zFar + zNear) / (zFar - zNear),
                    -1.0f,
                    0.0f,
                    0.0f,
                    -(2.0f * zFar * zNear) / (zFar - zNear),
                    1.0f
                );
            }
    }
}
 
Matrix4x4& Camera::computeModelViewMatrix()
{
    Vector3 tmpUp = upVector;
    if (cameraMode == CAMERAMODE_LOOKAT) {
        forwardVector.set(lookAt).sub(lookFrom).normalize();
        sideVector = Vector3::computeCrossProduct(forwardVector, upVector).normalize();
        tmpUp = Vector3::computeCrossProduct(sideVector, forwardVector);
    }
    modelViewMatrix.
        identity().
        translate(
            lookFrom.clone().scale(-1.0f)
        ).
        multiply(
            Matrix4x4(
                sideVector[0],
                tmpUp[0],
                -forwardVector[0],
                0.0f,
                sideVector[1],
                tmpUp[1],
                -forwardVector[1],
                0.0f,
                sideVector[2],
                tmpUp[2],
                -forwardVector[2],
                0.0f,
                0.0f,
                0.0f,
                0.0f,
                1.0f
            )
        );
    return modelViewMatrix;
}
 
void Camera::update(int contextIdx, int32_t width, int32_t height)
{
    auto reshaped = false;
    auto _width = width;
    auto _height = height;
    if (this->width != _width || this->height != _height) {
        reshaped = true;
        if (_height <= 0)
            _height = 1;
 
        this->width = _width;
        this->height = _height;
        renderer->getViewportMatrix().set(
            _width / 2.0f,
            0.0f,
            0.0f,
            0.0f,
            0.0f,
            _height / 2.0f,
            0.0f,
            0.0f,
            0.0f,
            0.0f,
            1.0f,
            0.0f,
            0 + (_width / 2.0f),
            0 + (_height / 2.0f),
            0.0f,
            1.0f
        );
    }
 
    // setup projection and model view matrices and such
    renderer->getCameraPosition().set(lookFrom);
    renderer->getProjectionMatrix().set(computeProjectionMatrix());
    renderer->onUpdateProjectionMatrix(contextIdx);
    renderer->getModelViewMatrix().set(computeModelViewMatrix());
    renderer->onUpdateModelViewMatrix(contextIdx);
    renderer->getCameraMatrix().set(renderer->getModelViewMatrix());
    renderer->onUpdateCameraMatrix(contextIdx);
 
    //
    mvpInvertedMatrix.set(modelViewMatrix).multiply(projectionMatrix).invert();
    mvpMatrix.set(modelViewMatrix).multiply(projectionMatrix);
 
    // viewport
    renderer->setViewPort(width, height);
    renderer->updateViewPort();
}